v0.26.3: bump version

Add an optional 16-byte AACS Volume ID to the Mapfile, persisted as a
'# freemkv-vid: <32-hex>' header comment so it survives to deferred-mux
and resume without touching the ISO payload. ddrescue treats the line
as a comment, so the pos/size/status data parser is unaffected.

- Mapfile gains set_vid/vid accessors; save() emits the comment in the
  header block, load() parses it back (malformed/absent -> None, never
  errors the load). Load->save round-trip preserves it (patch pass).
- Thread vid through CopyOptions and SweepOptions; sweep persists it
  when creating/opening the mapfile.
- Unit test: round-trips the VID, asserts the saved comment, and
  confirms data ranges parse identically with and without the comment.

.gitignore

@@ -4,3 +4,7 @@ Cargo.lock
 *.swo
 .DS_Store
 .cargo/
+.claude/worktrees/
+
+# session scratch — never track (may contain RE breadcrumbs)
+scratch/

CHANGELOG.md

@@ -1,5 +1,396 @@
 # Changelog
 
+## 0.26.1 (2026-05-22)
+
+### Added
+
+- **AACS resolver path 5 — KEYDB unit-keys direct fallback.** When a
+  KEYDB entry for the disc has no VUK field but does have pre-decrypted
+  unit keys, the resolver now consumes those unit keys directly instead
+  of treating the entry as unusable. Covers ~4,572 entries in the
+  public keydb (≈2.5% of the database, heavily skewed toward MKBv76+
+  UHD discs that DVDFab/FindVUK can no longer extract VUKs for).
+  Surfaces as `KeySource::KeyDbUnitKeys`; `AacsState::vuk` and
+  `ResolvedKeys::vuk` are `None` on this path because no VUK exists to
+  return. Partial CPS-unit coverage is rejected so a disc is never
+  half-decrypted.
+
+### Changed
+
+- **AACS resolver path order reordered root-to-leaf.** Paths now run in
+  derivation-strength order: device-key (1) → processing-key (2) →
+  KEYDB-derived from MK+VID (3) → KEYDB VUK direct (4) → KEYDB unit
+  keys direct (5). Previous order was leaf-first (KEYDB hash lookup,
+  then derivation). Resolution runs once per disc, so the few extra
+  milliseconds of MKB walking when a KEYDB VUK would have answered are
+  invisible against the rip itself; the new order matches the AACS
+  derivation hierarchy. `KeySource` enum variants are reordered to
+  match.
+- **`AacsState::vuk` type is now `Option<[u8; 16]>`** (was `[u8; 16]`).
+  Required by path 5, which has no VUK. Public-API break.
+- **`ResolvedKeys::vuk` type is now `Option<[u8; 16]>`** (was
+  `[u8; 16]`). Same rationale.
+
+## 0.25.14 (2026-05-21)
+
+### Changed
+
+- `Drive::is_libredrive_active()` renamed to `Drive::is_raw_read_active()`.
+  Same semantics; old name removed. Mirrored on the internal
+  `PlatformDriver::is_libredrive_active()` trait method (now
+  `is_raw_read_active()`).
+- `Error::AacsLibredriveUnsupported` renamed to
+  `Error::AacsRawReadUnsupported`; the underlying numeric code (E7016)
+  is unchanged. The `E_AACS_LIBREDRIVE_UNSUPPORTED` constant is
+  renamed to `E_AACS_RAW_READ_UNSUPPORTED`.
+
+No behavioural change — purely a rename pass.
+
+## 0.25.13 (2026-05-21)
+
+### Added
+
+- **`DrmScheme` top-level dispatcher.** New `drm` module with a
+  `DrmScheme` enum (`Css`, `Aacs10`, `Aacs20`, `Aacs21`) and a
+  `detect` + `load` pair that uniformly handles all four content
+  protection schemes. Replaces the inlined dispatch in
+  `disc::encrypt::resolve_encryption` and the scattered CSS routing
+  in `disc::mod`. Both CSS call sites now route through the same
+  entry point.
+- **AACS 2.1 Media Key Variant framework.** New `aacs::variants`
+  module implementing the Media Key Variant derivation chain
+  (`Kp + C → Kmp → ⊕KCD → Kpnew → Km → VUK`), Variant-scheme MKB
+  record parsing (record types `0x82` / `0x83`), bit-0x02 SoftKCD
+  and bit-0x04 online-challenge detection with dedicated error
+  variants. Wired into `DrmScheme::Aacs21` but the dispatcher arm
+  is commented out pending validation against a Variant-scheme
+  disc. Per-manufacturer Key Correction Data must be supplied by
+  the integrator; `KEY_CORRECTION_DATA_PLACEHOLDER` is the empty
+  placeholder slot.
+- **`AacsVersion` enum.** Replaces the `aacs2: bool` field on
+  `ContentCertificate`, `UnitKeyFile`, and `ResolvedKeys`.
+  `parse_unit_key_ro` and `parse_content_cert` now take/emit the
+  enum. `resolve_keys` is split into `resolve_keys_v1`,
+  `resolve_keys_v2`, and `resolve_keys_v21` (the last not reachable
+  from the dispatcher today).
+
+### Fixed
+
+- **Libredrive raw-read VID shortcut deleted.** v0.25.11 introduced a
+  `do_handshake` branch that, on libredrive-active drives, skipped the
+  AACS cert handshake and issued `READ_DISC_STRUCTURE` format 0x80
+  with AGID=0 directly. The hypothesis was that unlocked
+  drives would serve VID without auth. Empirical test (BU40N
+  + UHD disc, 2026-05-21) showed the drive returns
+  `0x05 / 0x6F / 0x02` (`ILLEGAL_REQUEST / Copy protection key
+  exchange failure: KEY NOT ESTABLISHED`) to that CDB regardless of
+  drive-unlock state. The AACS spec requires a successful
+  `REPORT_KEY` / `SEND_KEY` exchange to establish an AGID before
+  format 0x80 returns VID; that requirement is enforced by the drive
+  itself and isn't bypassed by libredrive firmware. The shortcut
+  fired for every libredrive-active drive, so v0.25.11 / v0.25.12
+  MOVIE scans were stuck at E7017 instead of progressing to the
+  real wall (no DK walks MKB v77).
+- `Disc::do_handshake` now always routes through `do_handshake_cert`.
+  `Drive::is_libredrive_active()` and the Mt1959 MMkv+LbDr marker
+  detection are kept as informational signals (logged in the
+  `handshake_entry` warn line) but no longer steer the auth path.
+- `read_volume_id_libredrive` deleted (~50 LOC).
+
+The corollary: AACS resolution on HRL-burned drives + UHD discs now
+fails honestly. Either cert auth succeeds (drive unlock may or
+may not bypass the HRL — that's the new empirical question) and we
+hit the actual DK wall (E7018 "No DK that walks this MKB" for v77+
+UHD without a v77+ DK in keydb), or cert auth fails and we surface
+E7015. Both are real verdicts; E7017's previous spurious dispatch
+is gone.
+
+## 0.25.12 (2026-05-21)
+
+No libfreemkv source changes — unified sync bump for autorip's
+`aacs_failure_message` two-line wording rewrite. See the autorip
+v0.25.12 release for details.
+
+## 0.25.11 (2026-05-21)
+
+### Added
+
+- **Libredrive raw-read VID path.** When the Mt1959 unlock response
+  confirms both the active-mode (`MMkv`) and mode-ID (`LbDr`) markers,
+  `Drive::is_libredrive_active()` returns true and `do_handshake`
+  skips the AACS cert dance entirely — VID is retrieved via
+  `READ_DISC_STRUCTURE` format 0x80 with AGID=0, and bus encryption
+  is already off. This is what unblocks UHD ripping on drives whose
+  leaked host cert is on the AACS HRL.
+- New `Error` variants for finer-grained AACS failure reporting:
+  `AacsHostCertRejected` (E7015), `AacsLibredriveUnsupported`
+  (E7016), `AacsVidUnavailable` (E7017), `AacsMkUnavailable`
+  (E7018), `AacsVukNotInKeydb` (E7019). Lets CLIs/UIs render which
+  piece of the AACS chain failed instead of always saying "no keys."
+
+### Fixed
+
+- `validate_processing_key` now matches libaacs `_validate_pk`
+  exactly: XORs `uv` into `mk[12..16]` (was omitted), AES-decrypts
+  `mk_dv` and checks the `01 23 45 67 89 AB CD EF` magic (was
+  AES-encrypt + 12-zero check). Pre-fix, every non-zero-uv
+  processing key was rejected — i.e. essentially every real disc.
+- `mkb_find_cvalues` now prefers record type `0x07` (AACS 2.x) and
+  falls back to `0x05` (AACS 1.0), so the walker handles both
+  generations without an out-of-band version flag.
+- `resolve_keys` short-circuits paths 2/3/4 when VID is the zero
+  sentinel — saves cycles and emits an honest "VID unavailable" log
+  instead of the misleading "all paths failed."
+- AES-CMAC VID verification gains NIST SP 800-38B KAT + round-trip
+  + mutation + all-zero-rejection tests.
+
+### Removed
+
+- **Built-in AACS keys** (added in 0.25.9). `src/aacs/builtin_keys.rs`
+  deleted; `KeyDb::with_builtins`, `KeyDb::load_or_builtins`,
+  `KeyDb::merge_from`, and internal dedup helpers gone. The
+  compiled-in shortcut was a slim convenience that didn't move the
+  hard problem (no v77+ DKs) and added a maintenance surface.
+- **Operator plugin slot** at `~/.config/freemkv/local_keys.cfg`
+  (added in 0.25.9). `local_plugin_path` and `KeyDb::merge_local_plugin`
+  removed. Single source: the main `keydb.cfg`.
+- `KeyDb::load` reverts to the pre-0.25.9 form — read the file or
+  return I/O error; no layering, no fallback.
+- `Disc::scan` reverts to surfacing `KeydbLoad { path: "<no keydb
+  in search paths>" }` for an encrypted disc with no keydb — same
+  sentinel autorip's message switch already handles.
+
+CSS player keys in `src/css/auth.rs` remain compiled in; they're
+1999-era public inputs separate from the AACS pipeline and were
+never part of the 0.25.9 additions.
+
+## 0.25.9 (2026-05-20)
+
+### Fixed
+
+- **MKB record-type identification.** `mkb_find_mk_dv` and `mkb_version`
+  had their record-type constants swapped. The Verify Media Key record
+  is Type 0x81 (AACS 1.0) or Type 0x86 (AACS 2.0/2.1), not 0x10. The
+  Type-and-Version record is Type 0x10, not 0x81. PK and DK derivation
+  paths therefore failed silently on every disc, masking how often the
+  fallback paths could have succeeded. Fixed; mk_dv extracted at
+  offset 4 of the verify record, MKB version read at offset 8 of the
+  Type 0x10 record body. Tests added for both forms.
+
+### Added
+
+- **Built-in AACS keys.** Four device keys (covering MKB v01-v82+) and
+  three processing keys (covering v63-v68) are now compiled into
+  `libfreemkv` directly. DVDs and Blu-rays (AACS 1.0) decrypt with
+  zero external files. Combined with the existing 31 CSS player keys
+  in `css/auth.rs`, the library is self-sufficient for all DVD and
+  AACS 1.0 content.
+- **Operator plugin slot.** `~/.config/freemkv/local_keys.cfg` is
+  loaded automatically (same format as `keydb.cfg`) and layered
+  additively on top of the built-ins and the main keydb.cfg. For
+  operators who derive their own keys, this is the additive surface
+  to drop them into — main keydb.cfg from upstream auto-update stays
+  separate and overwritable.
+- `KeyDb::with_builtins()`, `KeyDb::load_or_builtins()`,
+  `KeyDb::empty()` constructors.
+
+### Changed
+
+- `Disc::scan` no longer errors when keydb.cfg is absent. With
+  built-ins covering DVD/BD, missing keydb is treated as "no UHD
+  keys available" — the AACS 2.0 / UHD code path surfaces a
+  specific error only when the disc actually needs keys that
+  aren't in built-ins, main keydb, or local plugin.
+
+## 0.25.8 (2026-05-20)
+
+### Changed
+
+- Synchronized to autorip 0.25.8. No libfreemkv code changes —
+  unified versioning bump only. autorip 0.25.7 image was DOA
+  (missing +x on the binary); see autorip changelog.
+
+## 0.25.7 (2026-05-20)
+
+### Fixed — BU40N firmware wedge on KEYDB-miss discs
+
+`disc::encrypt::do_handshake` used to fire up to 16 AACS authenticate
+attempts back-to-back with no pause between them. Each attempt is
+5-10 SCSI REPORT_KEY/SEND_KEY exchanges. On a disc whose host cert
+isn't in our KEYDB (or one the drive rejects), that's 80-160 SCSI
+commands hammered at the drive in a few hundred milliseconds — and
+the BU40N (plus most consumer optical drives) responds by entering
+a fast-fail firmware wedge state where every subsequent CDB returns
+`ILLEGAL_REQUEST/INVALID_FIELD_IN_CDB` (sense 0x05/0x24) until the
+drive is physically power-cycled.
+
+Live wedge event 2026-05-20 during a UHD disc scan
+(KEYDB miss) confirmed the diagnosis and motivated this fix.
+
+Defence-in-depth:
+- `MAX_CERT_ATTEMPTS` capped at 3 (was 16). If three different
+  host certs all fail, more won't help — the drive doesn't have a
+  match.
+- 1-second sleep between attempts. Gives the drive's firmware time
+  to recover internal state between auth challenges.
+- Bail immediately on any sense code with sense_key = 0x05
+  (`ILLEGAL_REQUEST`). The drive isn't merely rejecting our cert
+  — it's saying "I won't talk to you anymore" — so trying more
+  certs would deepen the wedge.
+
+## 0.25.6 (2026-05-20)
+
+### Changed
+
+- Synchronized to autorip 0.25.6 release. No behavioural changes.
+
+## 0.25.5 (2026-05-20)
+
+### Changed
+
+- Synchronized to autorip 0.25.5 release. No behavioural changes.
+
+## 0.25.4 (2026-05-20)
+
+### Changed
+
+- Synchronized to autorip 0.25.4 release. No behavioural changes
+  in the library — the v0.25.4 release ships the autorip-side
+  in-container NFS mount option.
+
+## 0.25.3 (2026-05-19)
+
+### Changed
+
+- Synchronized to autorip 0.25.3 release. No behavioural changes
+  in the library — the v0.25.3 release ships the autorip-side
+  parallel mux pipeline.
+
+## 0.25.2 (2026-05-19)
+
+### Fixed
+
+- **DTS-HD codec ID** — `MkvTrack::audio` now emits `A_DTS/MA` for
+  DTS-HD MA and `A_DTS/HR` for DTS-HD HR instead of mislabelling
+  both as plain `A_DTS`. Strict players (Plex transcoder, some
+  hardware decoders, AV receivers) reject lossless DTS-HD MA
+  payload when the track advertises `A_DTS` because the ID
+  implies the 1.5 Mbps core-only bitstream.
+- **PGS subtitle BlockDuration** — the PGS parser is now stateful:
+  it pairs each display PCS with the following empty/clear PCS to
+  compute a duration, and the MKV muxer emits a `BlockGroup` +
+  `BlockDuration` for subtitles that carry one. Without this the
+  last bitmap lingered on screen until the next display set
+  replaced it (or until end of file).
+
+### Changed
+
+- `codec::Frame` gains `duration_ns: Option<u64>` (set by parsers
+  that can compute one; currently only PGS).
+- `pes::PesFrame` gains `duration_ns: Option<u64>` (in-memory only;
+  not part of the on-wire serialization).
+- `MkvMuxer::write_frame` now takes a final `duration_ns: Option<u64>`
+  parameter. When `Some`, the frame is emitted as a `BlockGroup`
+  with `BlockDuration` instead of a `SimpleBlock`.
+
+## 0.25.1 (2026-05-19)
+
+### New — autorip event_fn plumbing
+
+- `PrefetchedSectorSource::new_with_events(reader, extents, batch,
+  halt, event_fn)` — same producer-thread pipeline as `new()`, plus
+  an optional callback fired from the producer with `BytesRead`
+  events after every successful batch. Lets the autorip multipass
+  + resume mux paths drive their progress UI from the highway
+  without polling the consumer side.
+- `build_iso_pipeline` gains an `event_fn` parameter so callers can
+  wire the same callback through one ctor.
+
+### Changed
+
+- `pes::Stream` trait: new default `errors() -> u64` method
+  (default returns 0). Lets `Box<dyn Stream>` callers query the
+  skip-on-error counter without downcasting. `DiscStream` overrides
+  to surface its existing `errors` field.
+
+### Removed (breaking)
+
+- `DiscStream::new_pipeline` and `DiscStream::read_pipeline`
+  deleted. All file-backed mux now uses `build_iso_pipeline` →
+  `PipelinedPesStream`. `DiscStream` is now the single-threaded
+  inline reader used by autorip's live-drive single-pass path only.
+- `DiscStream::demux_thread` and `demux_rx` fields removed.
+- `M2tsStream::open` deleted; `Mode::Read` variant removed.
+  `m2ts://` URLs go through the internal `build_m2ts_pipeline`
+  helper in `mux/resolve.rs` → `PipelinedPesStream`. `M2tsStream`
+  is a write-only sink now.
+
+## 0.25.0 (2026-05-19)
+
+### New — the freemkv mux throughput "highway"
+
+Three-stage pipelined PES read path. Read+decrypt runs on a
+producer thread, M2TS demux runs on a second thread, codec parse
+runs on the caller's thread. Communication between stages is via
+bounded `crossbeam_channel` with a recycled buffer pool — no
+allocations or memcpys in the steady-state hot loop.
+
+**Throughput on the test bed (a UHD disc, 62 GiB ISO →
+`null://`, single-thread caller):**
+
+|                                       |   MB/s |
+| ------------------------------------- | -----: |
+| 0.23.2 baseline                       |     60 |
+| + memchr SIMD HEVC start-code scan    |     69 |
+| + ts.feed no-copy boundary            |     72 |
+| + `PrefetchedSectorSource` (producer) |    124 |
+| + `DemuxThread` (3-stage pipeline)    |    135 |
+| + zero-copy recycled buffer pool      |    148 |
+| + 16 KiB initial PesAssembler buffer  |    162 |
+| + mimalloc allocator in freemkv CLI   |  200+  |
+| **+ warm cache**                      | **660** |
+
+The new public API:
+
+- `libfreemkv::PrefetchedSectorSource` — wraps any `SectorSource`,
+  spawns a producer thread, exposes recycled-buffer channels.
+- `libfreemkv::io::byte_prefetcher::BytePrefetcher` —
+  `std::io::Read` analogue for byte-stream sources (m2ts files,
+  sockets, stdin).
+- `libfreemkv::mux::demux_thread::DemuxThread` — the M2TS demux
+  worker; `spawn_zero_copy` takes either prefetcher's channels.
+- `libfreemkv::PipelinedPesStream` — the read-side `Stream` impl
+  that runs codec parse on the caller thread.
+- `libfreemkv::build_iso_pipeline(reader, title, keys, batch,
+  format, halt)` — the canonical ctor that wires all three stages
+  for an ISO file source.
+
+### Changed (breaking)
+
+- `IsoSectorReader` (the naive duplicate of `FileSectorSource`)
+  deleted. `FileSectorSource` is the sole file-backed sector
+  source; it carries the SEQUENTIAL fadvise hint, the periodic
+  DONTNEED page-cache eviction, and (new) the per-read
+  `readahead()` async-prefetch syscall.
+- `mux::input("iso://...", &opts)` now returns a
+  `PipelinedPesStream`. Function signature
+  `input(&str, &InputOptions) -> io::Result<Box<dyn Stream>>` is
+  unchanged; callers that treated the return value as
+  `Box<dyn Stream>` keep working.
+
+### Other
+
+- `FileSectorSource` exposes per-OS `prefetch()` hooks
+  (`readahead(2)` on Linux, `fcntl(F_RDADVISE)` on macOS, no-op on
+  Windows + other).
+- AACS decrypt thread-pool: env var renamed from
+  `FREEMKV_DECRYPT_THREADS` to `FREEMKV_THREADS`; default raised
+  to `cores.clamp(1, 64)`.
+- `PesAssembler` initial buffer capacity 256 KiB → 16 KiB (avoids
+  the 64-page first-touch fault tax on every PES boundary).
+- HEVC / H.264 `find_start_code` swapped onto
+  `memchr::memmem::find` (SIMD).
+
 ## 0.18.4 (2026-05-09)
 
 ### Build / CI hardening — no library code changes
@@ -94,8 +485,7 @@ in-tree consumers (autorip, the `freemkv` CLI) drove their own multipass
 loops in 0.18 rounds 1-3; 0.18.1 lands the cleanup with the deprecated names
 still alive for one minor-version window.
 
-The 0.18 design notes are in
-`(internal)/memory/0_18_redesign.md` (private) — this entry sticks to
+The 0.18 design notes are kept privately — this entry sticks to
 what changed at the public surface.
 
 #### Flat verbs
@@ -375,7 +765,7 @@ recovery.
   `READ_RECOVERY_TIMEOUT_MS = 60_000` (the v0.17.3 baseline; the kernel-
   auto-retry pattern is now provided by the `/dev/sr0` fallback above).
 
-### Empirical results (Dune Part Two UHD, BU40N direct SATA)
+### Empirical results (a UHD disc, BU40N direct SATA)
 
 - Pass 1: **94.6 MB recovered** (28% of formerly-bad data, 33 sr0 fallback
   saves), **11 s of main-title content** restored. Patch completed all 47
@@ -503,7 +893,7 @@ bridges (notably the Initio INIC-1618L) that crash on MEDIUM ERROR retries.
 - Patch instrumentation: counters for reads_ok/err, writes_ok/err, finished/unreadable.
 - `as_encoded_bytes()` replaces `as_bytes()` for portable OsStr handling.
 - Removed inline retry/reset from Drive::read — orchestration layer handles recovery.
-- Removed all `(internal)` references from public code.
+- Removed all internal references from public code.
 
 ## 0.13.26 (2026-04-27)
 
@@ -531,7 +921,7 @@ warnings` red on Linux CI that the Mac toolchain doesn't catch.
 
 ### Pre-commit gate uses CI's exact toolchain
 
-`(internal)/scripts/precommit.sh` (new) runs `cargo +1.86 fmt
+A new pre-commit script runs `cargo +1.86 fmt
 --check`, `cargo +1.86 clippy -- -D warnings`, and `cargo +1.86 test
 --tests` across all 5 freemkv crates. Mirrors each repo's
 `.github/workflows/ci.yml` step-for-step. Use it as a pre-commit hook
@@ -573,7 +963,7 @@ Through the entire 0.13.x line, every CHECK CONDITION reply from the
 drive (the standard way SCSI reports a sector failure) was being
 collapsed into a synthetic `status=0xFF, sense_key=0` "transport
 wedge" sentinel and the real sense data was thrown away. Live tracing
-on the BU40N reading Dune 2 on 2026-04-27 confirmed it: the drive was
+on the BU40N reading a UHD disc on 2026-04-27 confirmed it: the drive was
 returning `host_status=0, driver_status=8, status=2, exec_elapsed_ms=1416`
 on every bad sector — a clean CHECK CONDITION carrying full sense
 data — and the library was misclassifying it as a wedge and bailing.
@@ -645,7 +1035,7 @@ recovered or marked Unreadable. Calibration data
 
 ### Replace bisect-on-fail with hysteresis state machine (Block ↔ Single)
 
-Live test on Dune 2 v0.13.21 showed bisect-on-fail recovered every
+Live test on a UHD disc v0.13.21 showed bisect-on-fail recovered every
 recoverable sector, but spent ~30 sec per damaged 60-block (paying a
 ~5 sec kernel timeout at every bisection level). Each level descended
 log₂(60) ≈ 6 times on the failing branch.
@@ -674,7 +1064,7 @@ Per-block cost on a 60-sector damaged block with 1 bad sector:
 
 Plus inside a damaged cluster spanning many 60-blocks, hysteresis
 pays the bpt=batch fail cost ONCE on entry; bisection paid it every
-60 sectors. For Dune 2's ~1248-sector boundary cluster that's ~21
+60 sectors. For the ~1248-sector boundary cluster that's ~21
 fewer 5-sec waits = ~100 sec saved.
 
 Telemetry: new `phase=mode_change` trace event with `from`, `to`,
@@ -692,8 +1082,7 @@ synthetic BU40N-pattern reader; same 100% recovery expectation.
 ### Fix: Disc::copy bisect-on-fail (replaces skip-forward)
 
 Empirical live-hardware testing on the LG BU40N (see
-`(internal)/docs/audits/2026-04-26-test-plan-audit.md` and the
-TEST_PLAN.md run log) revealed that the drive often **fails
+the internal test-plan audit and run log) revealed that the drive often **fails
 multi-sector READ commands** in damaged regions but **succeeds when
 asked one sector at a time**. The old skip-forward strategy responded
 to multi-sector failures by jumping up to 1 % of the disc forward,
@@ -705,7 +1094,7 @@ half, retry each half, recurse down to single-sector reads. Sectors
 the drive can read individually are recovered in Pass 1; only sectors
 that fail at bpt=1 are marked NonTrimmed for the patch passes.
 
-Empirical results on Dune 2 UHD on the BU40N:
+Empirical results on a UHD disc on the BU40N:
 - Old algorithm: 25 GB read in Pass 1, then ~6 GB skip-forwarded;
   retry passes failed to recover most of the skipped zone.
 - New algorithm: ~99 % of disc recovered in Pass 1; only the truly
@@ -747,7 +1136,7 @@ LUN/BUS/HOST reset. `READ_RECOVERY_TIMEOUT_MS` (60 s) unchanged.
 `ioctl(fd, SG_IO, &hdr)`. The old pattern abandoned slow-but-alive
 commands faster than the drive could drain its internal queue,
 deepening the BU40N wedge. Per the audit at
-`(internal)/docs/audits/2026-04-26-scsi-architecture-research.md`,
+internal SCSI-architecture research,
 no reference project (MakeMKV / sg_dd / ddrescue) does what we did —
 all use sync blocking SG_IO with 8-60 s timeouts and let the kernel's
 mid-layer (`scsi_eh.rst`) run ABORT TASK / LUN RESET / BUS RESET /
@@ -874,7 +1263,7 @@ clean reads (Finished sectors) and freezes during skip-forward bad zones,
 which made every previous version's UI look hung at the bad-zone boundary.
 This was the v0.13.9 stall-guard origin bug.
 
-Live trace from v0.13.14: Pass 1 hit a Dune 2 bad zone at 24 GB and
+Live trace from v0.13.14: Pass 1 hit a bad zone at 24 GB and
 appeared "stuck" for 14 minutes per autorip's UI (`bytes_good = 23.97 GB`
 unchanged). Disc trace events showed `pos` actually advanced from 25.8 GB
 to 70 GB during that window — Pass 1 was 83 % through the disc, marking
@@ -922,7 +1311,7 @@ trace events were silently dropped by the default `libfreemkv=warn` rule.
 
 ### Telemetry: instrument the rip pipeline for in-flight diagnosis
 
-v0.13.12 shipped Fix 1+2+4 + cross-platform parity but a live test on Dune 2
+v0.13.12 shipped Fix 1+2+4 + cross-platform parity but a live test
 showed Pass 1 sat for 14 minutes with `bytes_good=0` while the inner loop
 appeared to iterate (the throttled `on_progress` log fired every 78s). The
 async fd_recovery design at §7 said each `execute()` call should bound at
@@ -966,7 +1355,7 @@ The v0.13.9 stall guard at `disc/mod.rs` exited Pass 1 early when
 `bytes_good` was flat for `stall_secs` (default 120s). This violated the
 ddrescue model: Pass 1 must sweep end-to-end, marking failed reads
 NonTrimmed for Pass 2 retry. The guard caused Pass 1 to bail at 30% on
-Dune 2 with 56 GB still NonTried, leaving Pass 2 nothing useful to do.
+a UHD disc with 56 GB still NonTried, leaving Pass 2 nothing useful to do.
 
 - Deleted the stall-guard state vars and the `if cur_good != ...
   break 'outer;` block.
@@ -1021,7 +1410,7 @@ same observable recovery contract as Linux:
 
 `PatchResult` now reports `blocks_attempted`, `blocks_read_ok`,
 `blocks_read_failed`. Pass 2's "100 minutes recovered 0 bytes" mystery
-(Dune 2) becomes diagnosable from these counters: distinguish "drive
+(a UHD disc) becomes diagnosable from these counters: distinguish "drive
 returned Ok but write/record dropped data" from "every read was Err for
 the entire range" without instrumenting from outside the lib.
 
@@ -1050,7 +1439,7 @@ against the spawned close()). The intent was to escape the 60-s
 blocking reopen.
 
 The cost was too high: a single transient poll timeout permanently
-killed the transport. Live test on Dune 2 (post-replug):
+killed the transport. Live test on a UHD disc (post-replug):
 - Pass 1 ran for **45 ms** then returned with 0 GB good and 80 GB
   pending.
 - The first SCSI READ timed out, fd went to -1, every subsequent
@@ -1083,7 +1472,7 @@ Sync bump for the autorip-side fix in 0.13.10 (Pass 1 batch reporting).
 ### Fix: Disc::copy silent stall + SgIoTransport reopen-after-timeout serialization
 
 Two correlated fixes for a hang observed live on the LG BU40N during a
-v0.13.8 rip of Dune: Part Two. At ~30 % progress through Pass 1
+v0.13.8 rip of a UHD disc. At ~30 % progress through Pass 1
 (disc → ISO), `bytes_good` froze for 10+ minutes with `errs=0`,
 no error surfaced, drive not wedged.
 
@@ -1970,10 +2359,9 @@ Rip recovery rewritten. The old binary-search-per-bad-sector model paid the full
 - **Kernel transfer limit detection**: auto-detect `max_hw_sectors_kb` via sysfs, resolve sg→block device. Previously hardcoded to 510 sectors (1MB) which exceeded the 120KB kernel limit, causing all reads to error and fall back to 6KB reads at 4.8 MB/s. Now auto-tunes to 48 sectors (96KB) or whatever the device supports.
 - **Result: 12.5 MB/s sustained, 23 MB/s peak** (was 4.8 MB/s)
 
-### LibreDrive — full init pipeline
+### Drive init pipeline
 
-- **All 10 ARM handlers translated**: unlock, firmware upload (A: WRITE_BUFFER, B: MODE SELECT), calibrate (256 zones), register reads, status, probe, set_read_speed, keepalive, timing
-- **Cold boot firmware upload**: WRITE_BUFFER 1888B (A variant) or MODE SELECT 2496B (B variant) proven on hardware
+- **Full drive init pipeline**: unlock, calibrate (256 zones), register reads, status, probe, set_read_speed, keepalive, timing
 - **Speed calibration**: 256+ disc surface probes, 64-entry speed table, triple SET_CD_SPEED
 - **Platform trait locked down**: `pub(crate)`, 3 methods only (init, set_read_speed, is_ready)
 - **Init guard**: prevents double-init, signature mismatch aborts early
@@ -1988,7 +2376,7 @@ Rip recovery rewritten. The old binary-search-per-bad-sector model paid the full
 ### Profiles
 
 - **206 profiles with full per-drive data**: ld_microcode (base64), all CDBs, speed tables, signatures
-- **Automated pipeline**: `sdf_unpack --profiles` → profiles.json (no manual merging)
+- **Automated pipeline**: profile import → profiles.json (no manual merging)
 
 ## 0.4.0 (2026-04-07)
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libfreemkv"
-version = "0.23.2"
+version = "0.26.3"
 edition = "2024"
 rust-version = "1.86"
 license = "AGPL-3.0-only"
@@ -31,9 +31,19 @@ tracing = "0.1"
 # Bounded MPSC channel with kernel-wakeup send_timeout. Used by `io::pipeline`
 # so the halt-aware send/finish loops can BLOCK on consumer drain instead of
 # polling — the 50 ms poll cadence of the previous mpsc-based impl capped mux
-# throughput at ~1 MB/s (see (internal)/memory/
-# feedback_send_with_halt_poll_throttle.md, 0.21.7).
+# throughput at ~1 MB/s (0.21.7).
 crossbeam-channel = "0.5"
+# Persistent work-stealing thread pool for parallel AACS unit
+# decryption. Per-call std::thread::scope spawned fresh OS threads
+# and that overhead dominated for typical batch sizes (60 units).
+# rayon's global pool initialises once on first use.
+rayon = "1"
+# SIMD-accelerated bytestring search. Drives the HEVC/H.264 start-code
+# scan in `mux::codec::h264::find_start_code` — naive byte-by-byte
+# walk is ~500 MB/s single-thread on x86_64; memchr's vectorised
+# `memmem::find` for the 3-byte `00 00 01` needle hits ~5 GB/s on
+# AVX2-capable hosts.
+memchr = "2"
 
 [target.'cfg(target_os = "linux")'.dependencies]
 libc = "0.2"

Makefile

@@ -1,6 +1,5 @@
 # libfreemkv — local dev helper.
-# Mirrors the cross-crate scripts in (internal)/scripts/test-all.sh
-# but scoped to this single crate.
+# Mirrors the workspace-wide CI checks but scoped to this single crate.
 
 .PHONY: test build check ci clean
 

README.md

@@ -6,6 +6,8 @@
 
 Rust library for 4K UHD / Blu-ray / DVD optical drives. Drive access, disc scanning, stream labels, AACS decryption, CSS decryption, KEYDB updates, and content reading in one crate. Bundled drive profiles — no external files needed.
 
+Built-in keys cover DVDs and Blu-rays (AACS 1.0). For UHD (AACS 2.0 / 2.1) discs, an optional `keydb.cfg` supplies disc-specific volume unique keys.
+
 **12+ MB/s** sustained read speeds on BD. Full init: unlock, firmware upload, speed calibration — all from pure Rust.
 
 Multi-lingual by design — the library outputs structured data and numeric error codes, never English text. Build any UI or localization on top.
@@ -18,7 +20,7 @@ Part of the [freemkv](https://github.com/freemkv) project.
 
 ```toml
 [dependencies]
-libfreemkv = "0.18"
+libfreemkv = "0.25"
 ```
 
 ## Quick Start
@@ -56,8 +58,7 @@ output.finish()?;
 For damaged discs the library exposes two flat verbs — `Disc::sweep` for the
 forward Pass 1 and `Disc::patch` for retrying bad ranges. The library never
 loops; the multipass policy is the caller's job. See
-[`docs/rip-recovery.md`](docs/rip-recovery.md) and the design notes in
-`(internal)/memory/0_18_redesign.md`.
+[`docs/rip-recovery.md`](docs/rip-recovery.md).
 
 ```rust
 use libfreemkv::{SweepOptions, PatchOptions};
@@ -122,7 +123,11 @@ loop {
 
 Streams implement `FrameSource` (read) and/or `FrameSink` (write); direction is type-checked. `input()` / `output()` resolve URL strings to PES stream instances. All URLs use the `scheme://path` format — bare paths are rejected.
 
-AACS decryption requires a KEYDB.cfg file. If available at `~/.config/aacs/KEYDB.cfg` or passed via `ScanOptions`, the library handles everything — handshake, key derivation, and per-sector decryption — without the application needing to know anything about encryption.
+### Keys
+
+DVDs (CSS) decrypt out of the box — the 1999-era public player keys are compiled into the library.
+
+Blu-rays and UHD (AACS) require a `keydb.cfg` at `~/.config/freemkv/keydb.cfg` (or passed via `ScanOptions`). The file holds all DKs, PKs, host certs, and per-disc VUKs. No AACS key material is compiled into the binary.
 
 ## Architecture
 

docs/api-design.md

@@ -85,10 +85,10 @@ All URLs require a `scheme://path` format. Bare paths are rejected.
 // PES pipeline (frame-level) — input() returns Box<dyn FrameSource>,
 // output() returns Box<dyn FrameSink>.
 let input = libfreemkv::input("disc:///dev/sg4", &opts)?;    // DiscStream
-let input = libfreemkv::input("iso://Dune.iso", &opts)?;     // IsoStream
-let output = libfreemkv::output("mkv://Dune.mkv", &title)?;  // MkvOutputStream
-let output = libfreemkv::output("m2ts://Dune.m2ts", &title)?; // M2tsOutputStream
-let output = libfreemkv::output("network://10.0.0.1:9000", &title)?; // NetworkOutputStream
+let input = libfreemkv::input("iso://Movie.iso", &opts)?;     // IsoStream
+let output = libfreemkv::output("mkv://Movie.mkv", &title)?;  // MkvOutputStream
+let output = libfreemkv::output("m2ts://Movie.m2ts", &title)?; // M2tsOutputStream
+let output = libfreemkv::output("network://192.0.2.10:9000", &title)?; // NetworkOutputStream
 let output = libfreemkv::output("null://", &title)?;          // NullOutputStream
 ```
 

src/aacs/handshake.rs

@@ -1235,8 +1235,8 @@ mod tests {
     }
 
     #[test]
-    fn test_aes_cmac() {
-        // Basic CMAC test — at minimum verify it produces consistent output
+    fn test_aes_cmac_deterministic() {
+        // Same (data, key) must always produce the same MAC.
         let key = [
             0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf,
             0x4f, 0x3c,
@@ -1248,6 +1248,93 @@ mod tests {
         assert_ne!(mac1, [0u8; 16]); // shouldn't be all zeros
     }
 
+    #[test]
+    fn test_aes_cmac_nist_kat_full_block() {
+        // NIST SP 800-38B Appendix D.1, Example 2 (Mlen = 128):
+        //   K = 2b7e1516 28aed2a6 abf71588 09cf4f3c
+        //   M = 6bc1bee2 2e409f96 e93d7e11 7393172a
+        //   T = 070a16b4 6b4d4144 f79bdd9d d04a287c
+        let key = [
+            0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf,
+            0x4f, 0x3c,
+        ];
+        let data = [
+            0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93,
+            0x17, 0x2a,
+        ];
+        let expected = [
+            0x07, 0x0a, 0x16, 0xb4, 0x6b, 0x4d, 0x41, 0x44, 0xf7, 0x9b, 0xdd, 0x9d, 0xd0, 0x4a,
+            0x28, 0x7c,
+        ];
+        let mac = aes_cmac_16(&data, &key);
+        assert_eq!(mac, expected, "AES-CMAC-128 must match NIST SP 800-38B KAT");
+    }
+
+    #[test]
+    fn test_vid_mac_verify_roundtrip() {
+        // Simulate the drive-side: pick a (bus_key, vid), compute the MAC, and
+        // verify the host-side check accepts it. Then mutate VID and MAC each
+        // in turn and verify both mutations cause a mismatch (the path that
+        // would yield Error::AacsVidMac in read_volume_id).
+        let bus_key = [
+            0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54,
+            0x32, 0x10,
+        ];
+        let vid = [
+            0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe, 0xba, 0xbe, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66,
+            0x77, 0x88,
+        ];
+
+        // Drive returns vid + mac where mac == AES-CMAC-128(bus_key, vid).
+        let drive_mac = aes_cmac_16(&vid, &bus_key);
+        let calc_mac = aes_cmac_16(&vid, &bus_key);
+        assert_eq!(calc_mac, drive_mac, "honest drive: MACs must match");
+
+        // Mutate the MAC: a malicious drive that swapped VID but returned its
+        // original MAC would produce a mismatch here.
+        let mut bad_mac = drive_mac;
+        bad_mac[0] ^= 0x01;
+        assert_ne!(calc_mac, bad_mac, "mutated MAC must be rejected");
+
+        // Mutate the VID: even one bit of VID drift produces a wildly different
+        // CMAC (this is what catches a substituted VID with a stale MAC).
+        let mut bad_vid = vid;
+        bad_vid[15] ^= 0x01;
+        let calc_for_bad_vid = aes_cmac_16(&bad_vid, &bus_key);
+        assert_ne!(
+            calc_for_bad_vid, drive_mac,
+            "MAC over mutated VID must not match original MAC"
+        );
+
+        // Wrong bus key (e.g. handshake replayed against the wrong session)
+        // also produces a different MAC over the same VID.
+        let mut wrong_key = bus_key;
+        wrong_key[0] ^= 0xff;
+        let calc_with_wrong_key = aes_cmac_16(&vid, &wrong_key);
+        assert_ne!(
+            calc_with_wrong_key, drive_mac,
+            "MAC under wrong bus key must not match"
+        );
+    }
+
+    #[test]
+    fn test_vid_mac_all_zero_mac_rejected() {
+        // Defensive: a buggy or hostile drive that returns all-zero MAC must
+        // be rejected (the real MAC over any non-trivial VID is nearly never
+        // 0...0). This guards against a class of "drive returned garbage"
+        // failures masquerading as success.
+        let bus_key = [
+            0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf,
+            0x4f, 0x3c,
+        ];
+        let vid = [
+            0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93,
+            0x17, 0x2a,
+        ];
+        let calc_mac = aes_cmac_16(&vid, &bus_key);
+        assert_ne!(calc_mac, [0u8; 16], "real CMAC must not be all zeros");
+    }
+
     #[test]
     fn test_verify_host_cert_from_keydb() {
         // Verify the host cert from our KEYDB

src/aacs/keydb.rs

@@ -89,6 +89,17 @@ pub(crate) fn parse_hex20(s: &str) -> Option<[u8; 20]> {
 }
 
 impl KeyDb {
+    /// Construct an empty KeyDb. Used by unit tests; production code
+    /// reaches a populated KeyDb via [`KeyDb::load`] or [`KeyDb::parse`].
+    pub fn empty() -> Self {
+        KeyDb {
+            device_keys: Vec::new(),
+            processing_keys: Vec::new(),
+            host_certs: Vec::new(),
+            disc_entries: HashMap::new(),
+        }
+    }
+
     /// Parse a KEYDB.cfg file from a string.
     pub fn parse(data: &str) -> Self {
         let mut db = KeyDb {
@@ -106,10 +117,19 @@ impl KeyDb {
                 continue;
             }
 
-            // Device Key
+            // Device Key.
+            // Two shapes are accepted:
+            //   1. Positioned DK: `| DK | DEVICE_KEY 0x... | DEVICE_NODE 0x... | KEY_UV 0x... | KEY_U_MASK_SHIFT 0x...`
+            //      → loaded into `device_keys` (deterministic tree walk via `calc_pk_from_dk`).
+            //   2. Orphan DK: `| DK | DEVICE_KEY 0x...` with no position fields.
+            //      → loaded into `processing_keys` (brute walker / terminal validation).
+            // Per AACS spec a "PK" IS a DK at terminal position, so both row types
+            // are DKs in the unified model; only the metadata differs.
             if line.starts_with("| DK") {
                 if let Some(dk) = Self::parse_device_key(line) {
                     db.device_keys.push(dk);
+                } else if let Some(key) = Self::parse_orphan_dk(line) {
+                    db.processing_keys.push(key);
                 }
                 continue;
             }
@@ -152,7 +172,7 @@ impl KeyDb {
         db
     }
 
-    /// Load KEYDB.cfg from a file path.
+    /// Load a KEYDB.cfg from disk.
     pub fn load(path: &std::path::Path) -> std::io::Result<Self> {
         let data = std::fs::read_to_string(path)?;
         Ok(Self::parse(&data))
@@ -184,8 +204,46 @@ impl KeyDb {
             .or_else(|| self.disc_entries.get(&hash))
     }
 
-    // ── Parsers ─────────────────────────────────────────────────────────────
+    /// Iterate every disc entry. Used by Path 3 (scan for matching VID).
+    pub fn iter_disc_entries(&self) -> impl Iterator<Item = &DiscEntry> {
+        self.disc_entries.values()
+    }
+}
 
+// ── KeyProvider impl ──────────────────────────────────────────────────────────
+//
+// Lets `KeyDb` plug into `resolve_keys` via the trait. Cloning happens in the
+// bulk methods because the trait returns owned `Vec`s (so HTTP-backed providers
+// don't need to retain state across calls).
+
+impl super::provider::KeyProvider for KeyDb {
+    fn device_keys(&self) -> Vec<DeviceKey> {
+        self.device_keys.clone()
+    }
+    fn processing_keys(&self) -> Vec<[u8; 16]> {
+        self.processing_keys.clone()
+    }
+    fn host_certs(&self) -> Vec<HostCert> {
+        self.host_certs.clone()
+    }
+    fn lookup_disc_by_hash(&self, disc_hash: &[u8; 20]) -> Option<DiscEntry> {
+        let mut hex = String::with_capacity(42);
+        hex.push_str("0x");
+        for b in disc_hash {
+            hex.push_str(&format!("{b:02X}"));
+        }
+        self.find_disc(&hex).cloned()
+    }
+    fn lookup_disc_by_vid(&self, volume_id: &[u8; 16]) -> Option<DiscEntry> {
+        self.iter_disc_entries()
+            .find(|e| matches!(e.disc_id, Some(id) if &id == volume_id))
+            .cloned()
+    }
+}
+
+// ── Private parsers (re-open the inherent impl) ─────────────────────────────
+
+impl KeyDb {
     fn parse_device_key(line: &str) -> Option<DeviceKey> {
         // | DK | DEVICE_KEY 0x... | DEVICE_NODE 0x... | KEY_UV 0x... | KEY_U_MASK_SHIFT 0x...
         let key_str = line.split("DEVICE_KEY").nth(1)?.split('|').next()?.trim();
@@ -218,6 +276,30 @@ impl KeyDb {
         None
     }
 
+    /// Parse an orphan DK row: a `| DK |` line carrying only the
+    /// `DEVICE_KEY` field (no position metadata). The key is then
+    /// treated like a terminal/unpositioned label by the resolver
+    /// (Path 2's brute walker). Returns `None` if the line carries
+    /// any position field — those are positioned DKs and parsed by
+    /// [`Self::parse_device_key`] instead.
+    fn parse_orphan_dk(line: &str) -> Option<[u8; 16]> {
+        if line.contains("DEVICE_NODE")
+            || line.contains("KEY_UV")
+            || line.contains("KEY_U_MASK_SHIFT")
+        {
+            return None;
+        }
+        let key_str = line
+            .split("DEVICE_KEY")
+            .nth(1)?
+            .split('|')
+            .next()?
+            .split(';')
+            .next()?
+            .trim();
+        parse_hex16(key_str)
+    }
+
     fn parse_host_cert(line: &str) -> Option<HostCert> {
         // | HC | HOST_PRIV_KEY 0x... | HOST_CERT 0x...
         let priv_str = line
@@ -366,9 +448,9 @@ mod tests {
 
     #[test]
     fn test_parse_disc_entry() {
-        let line = r#"***REMOVED*** = DUNE_PART_TWO (Dune: Part Two) | D | 2024-04-02 | M | ***REMOVED*** | I | ***REMOVED*** | V | ***REMOVED*** | U | 1-***REMOVED*** ; MKBv77"#;
+        let line = r#"0x000102030405060708090A0B0C0D0E0F10111213 = SAMPLE_FILM (Sample Film) | D | 2024-01-01 | M | 0x000102030405060708090A0B0C0D0E0F | I | 0x101112131415161718191A1B1C1D1E1F | V | 0x202122232425262728292A2B2C2D2E2F | U | 1-0x303132333435363738393A3B3C3D3E3F ; MKBv77"#;
         let entry = KeyDb::parse_disc_entry(line).unwrap();
-        assert_eq!(entry.title, "Dune: Part Two");
+        assert_eq!(entry.title, "Sample Film");
         assert!(entry.media_key.is_some());
         assert!(entry.vuk.is_some());
         assert_eq!(entry.unit_keys.len(), 1);
@@ -377,17 +459,58 @@ mod tests {
 
     #[test]
     fn test_parse_device_key() {
-        let line = "| DK | DEVICE_KEY ***REMOVED*** | DEVICE_NODE 0x0800 | KEY_UV 0x00000400 | KEY_U_MASK_SHIFT 0x17 ; MKBv01-MKBv48";
+        let line = "| DK | DEVICE_KEY 0x000102030405060708090A0B0C0D0E0F | DEVICE_NODE 0x0800 | KEY_UV 0x00000400 | KEY_U_MASK_SHIFT 0x17 ; MKBv01-MKBv48";
         let dk = KeyDb::parse_device_key(line).unwrap();
         assert_eq!(dk.node, 0x0800);
         assert_eq!(dk.u_mask_shift, 0x17);
     }
 
+    #[test]
+    fn test_orphan_dk_row_loads_into_processing_keys() {
+        // `| DK |` row without position fields = an orphan DK. Per the
+        // unified model the resolver treats it like a terminal/PK
+        // candidate: it lands in `processing_keys` and the brute walker
+        // handles it.
+        let cfg = r#"
+| DK | DEVICE_KEY 0xDEADBEEF0001020304050607080900AA ; orphan, no position fields
+| DK | DEVICE_KEY 0x000102030405060708090A0B0C0D0E0F | DEVICE_NODE 0x0800 | KEY_UV 0x00000400 | KEY_U_MASK_SHIFT 0x17 ; positioned MKBv01-MKBv48
+| PK | 0xCAFEBABE0001020304050607080900BB ; legacy PK row still works
+"#;
+        let db = KeyDb::parse(cfg);
+        assert_eq!(
+            db.device_keys.len(),
+            1,
+            "positioned DK row should land in device_keys"
+        );
+        // Orphan DK + legacy PK row both end up in processing_keys.
+        assert_eq!(
+            db.processing_keys.len(),
+            2,
+            "orphan DK row + legacy PK row both belong in processing_keys"
+        );
+        assert_eq!(db.processing_keys[0][..4], [0xDE, 0xAD, 0xBE, 0xEF]);
+        assert_eq!(db.processing_keys[1][..4], [0xCA, 0xFE, 0xBA, 0xBE]);
+    }
+
+    #[test]
+    fn test_parse_orphan_dk_rejects_lines_with_position_fields() {
+        // The parser must NOT pick up a positioned DK row as an orphan
+        // (that would double-count). parse_orphan_dk explicitly checks.
+        let positioned = "| DK | DEVICE_KEY 0x000102030405060708090A0B0C0D0E0F | DEVICE_NODE 0x0800 | KEY_UV 0x00000400 | KEY_U_MASK_SHIFT 0x17";
+        assert!(
+            KeyDb::parse_orphan_dk(positioned).is_none(),
+            "positioned DK must not match orphan parser"
+        );
+        let orphan = "| DK | DEVICE_KEY 0xDEADBEEF0001020304050607080900AA";
+        let key = KeyDb::parse_orphan_dk(orphan).expect("orphan should parse");
+        assert_eq!(key[..4], [0xDE, 0xAD, 0xBE, 0xEF]);
+    }
+
     #[test]
     fn test_parse_host_cert() {
-        let line = "| HC | HOST_PRIV_KEY ***REMOVED*** | HOST_CERT ***REMOVED*** ; Revoked";
+        let line = "| HC | HOST_PRIV_KEY 0xDEADBEEF000102030405060708090A0B0C0D0E0F | HOST_CERT 0x000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F303132333435363738393A3B3C3D3E3F404142434445464748494A4B4C4D4E4F505152535455565758595A5B ; Revoked";
         let hc = KeyDb::parse_host_cert(line).unwrap();
-        assert_eq!(hc.private_key[0], 0x90);
+        assert_eq!(hc.private_key[0], 0xDE);
         assert_eq!(hc.certificate.len(), 92);
     }
 
@@ -405,15 +528,15 @@ mod tests {
         assert!(!db.host_certs.is_empty());
         assert!(db.disc_entries.len() > 170000);
 
-        // Look up Dune: Part Two
-        let dune = db
+        // Look up any disc entry carrying a full key set.
+        let entry = db
             .disc_entries
             .values()
-            .find(|e| e.title.contains("Dune: Part Two") && e.vuk.is_some())
-            .expect("Dune: Part Two not found");
-        assert!(dune.media_key.is_some());
-        assert!(dune.vuk.is_some());
-        assert!(!dune.unit_keys.is_empty());
+            .find(|e| e.vuk.is_some() && e.media_key.is_some() && !e.unit_keys.is_empty())
+            .expect("no disc entry with a full key set");
+        assert!(entry.media_key.is_some());
+        assert!(entry.vuk.is_some());
+        assert!(!entry.unit_keys.is_empty());
 
         eprintln!(
             "Parsed {} disc entries, {} DK, {} PK",

src/aacs/mod.rs

@@ -17,6 +17,8 @@ pub mod decrypt;
 pub mod handshake;
 pub mod keydb;
 pub mod keys;
+pub mod provider;
+pub mod variants;
 
 // Explicit re-exports — only items needed by external consumers and sibling crate modules.
 // AES primitives (aes_ecb_encrypt, aes_ecb_decrypt, aes_cbc_decrypt) are pub(crate) in decrypt.rs.
@@ -25,8 +27,16 @@ pub use decrypt::{
     is_unit_encrypted,
 };
 pub use keydb::{DeviceKey, DiscEntry, HostCert, KeyDb};
+pub use keys::probe;
 pub use keys::{
-    ContentCert, ResolvedKeys, UnitKeyFile, decrypt_unit_key, derive_media_key_from_dk,
-    derive_media_key_from_pk, derive_vuk, disc_hash, disc_hash_hex, mkb_version,
-    parse_content_cert, parse_unit_key_ro, read_mkb_from_drive, resolve_keys,
+    AacsVersion, ContentCert, ResolveContext, ResolvedKeys, UnitKeyFile, decrypt_unit_key,
+    derive_media_key_from_dk, derive_media_key_from_pk, derive_vuk, disc_hash, disc_hash_hex,
+    mkb_version, parse_content_cert, parse_unit_key_ro, read_mkb_from_drive, resolve_keys_v1,
+    resolve_keys_v2, resolve_keys_v21,
+};
+pub use provider::KeyProvider;
+pub use variants::{
+    KEY_CORRECTION_DATA_PLACEHOLDER, MediaKeyVariantError, MkbRecord, ProcessingKeyMatch,
+    derive_media_key_variant, is_variant_mkb, variant_data_record, variant_key_data, variant_nonce,
+    walk_mkb, walk_processing_key,
 };

src/aacs/provider.rs

@@ -0,0 +1,105 @@
+//! Key source abstraction for the AACS resolve chain.
+//!
+//! libfreemkv keeps all crypto (AES-G primitives, SD-tree walking,
+//! validation, MK/VUK/TK derivation) but accepts key material from
+//! arbitrary backends via [`KeyProvider`].
+//!
+//! Methods come in two flavors:
+//!
+//! - **Bulk material** ([`device_keys`], [`processing_keys`],
+//!   [`host_certs`]) — the resolver unions results across all
+//!   providers and tries each candidate.
+//! - **Disc-keyed lookup** ([`lookup_disc_by_hash`],
+//!   [`lookup_disc_by_vid`]) — the resolver short-circuits on the
+//!   first hit, so providers are queried in array order with
+//!   fastest/closest first.
+//!
+//! Default impls return empty / `None` so backends only override
+//! the methods they actually support — an HTTP keyserver might
+//! implement only `lookup_disc_by_hash`, while a local file might
+//! implement all five.
+//!
+//! Calls may block (disk I/O, network round-trips). The resolver
+//! invokes each method at most a handful of times per scan; for
+//! per-disc memoization, implementations should cache internally.
+//!
+//! [`device_keys`]: KeyProvider::device_keys
+//! [`processing_keys`]: KeyProvider::processing_keys
+//! [`host_certs`]: KeyProvider::host_certs
+//! [`lookup_disc_by_hash`]: KeyProvider::lookup_disc_by_hash
+//! [`lookup_disc_by_vid`]: KeyProvider::lookup_disc_by_vid
+
+use super::keydb::{DeviceKey, DiscEntry, HostCert};
+
+/// Source of AACS key material.
+///
+/// Implementors return raw material only — the resolver in
+/// `aacs::keys` owns all the crypto (DK→PK walking, PK validation,
+/// MK→VUK→TK derivation). See module docs for method semantics.
+pub trait KeyProvider: Send + Sync {
+    /// Device keys (top-of-tree, walked by the resolver).
+    fn device_keys(&self) -> Vec<DeviceKey> {
+        Vec::new()
+    }
+
+    /// Processing keys — terminal PKs or walk-input PKs. The
+    /// resolver tries each as a terminal first (cheap validate).
+    fn processing_keys(&self) -> Vec<[u8; 16]> {
+        Vec::new()
+    }
+
+    /// AACS host certificates (with their private keys) for drive
+    /// authentication. Multiple in case some are revoked.
+    fn host_certs(&self) -> Vec<HostCert> {
+        Vec::new()
+    }
+
+    /// Direct per-disc lookup by SHA-1 of `Unit_Key_RO.inf`. Returns
+    /// `Some(entry)` if this provider has pre-computed material for
+    /// the disc (paths 4 and 5). Short-circuits the resolver.
+    fn lookup_disc_by_hash(&self, _disc_hash: &[u8; 20]) -> Option<DiscEntry> {
+        None
+    }
+
+    /// Lookup by Volume ID (path 3 — pre-computed MK + matching
+    /// VID). Short-circuits the resolver on hit.
+    fn lookup_disc_by_vid(&self, _volume_id: &[u8; 16]) -> Option<DiscEntry> {
+        None
+    }
+}
+
+/// Resolver-side helpers that aggregate across a provider array.
+///
+/// The resolver consumes `&[&dyn KeyProvider]` directly; these
+/// helpers wrap the union-vs-short-circuit policy per method.
+pub(crate) struct Providers<'a>(pub &'a [&'a dyn KeyProvider]);
+
+impl Providers<'_> {
+    /// Union — gather DKs from every provider.
+    pub fn device_keys(&self) -> Vec<DeviceKey> {
+        self.0.iter().flat_map(|p| p.device_keys()).collect()
+    }
+
+    /// Union — gather PKs from every provider.
+    pub fn processing_keys(&self) -> Vec<[u8; 16]> {
+        self.0.iter().flat_map(|p| p.processing_keys()).collect()
+    }
+
+    /// Union — gather host certs from every provider. Not yet wired into
+    /// the SCSI handshake (which still reads `KeyDb.host_certs` directly);
+    /// kept here so a provider-aware handshake refactor is a drop-in.
+    #[allow(dead_code)]
+    pub fn host_certs(&self) -> Vec<HostCert> {
+        self.0.iter().flat_map(|p| p.host_certs()).collect()
+    }
+
+    /// Short-circuit — query providers in array order, first hit wins.
+    pub fn lookup_disc_by_hash(&self, disc_hash: &[u8; 20]) -> Option<DiscEntry> {
+        self.0.iter().find_map(|p| p.lookup_disc_by_hash(disc_hash))
+    }
+
+    /// Short-circuit — query providers in array order, first hit wins.
+    pub fn lookup_disc_by_vid(&self, volume_id: &[u8; 16]) -> Option<DiscEntry> {
+        self.0.iter().find_map(|p| p.lookup_disc_by_vid(volume_id))
+    }
+}

src/aacs/variants.rs

@@ -0,0 +1,679 @@
+//! AACS Media Key Variant chain.
+//!
+//! On AACS 2.1 the Media Key derivation gains a second stage on top of
+//! the classical subset-difference walk. The classical walk yields a
+//! Media Key Precursor (Kmp) rather than the final Media Key; the
+//! Precursor combines with disc-supplied Variant Key Data (VKD) and an
+//! integrator-supplied Key Correction Data (KCD) constant to produce
+//! the Media Key.
+//!
+//! This module is wiring only — `resolve_keys` is not aware of it. The
+//! entry point is [`derive_media_key_variant`]. The Variant scheme is
+//! detected via the new MKB record types `0x82` (Encrypted Media Key
+//! Variant Data + Variant Key Data) and `0x83` (Variant Number). When
+//! a disc carries neither, callers should fall back to the classical
+//! single-stage derivation in [`super::keys`].
+//!
+//! The chain follows the published spec:
+//!
+//! ```text
+//! Kmp     = AES-128D(Kp, C) XOR uv
+//! Kpnew   = Kmp XOR KCD
+//! Kvn     = AES-G(Kp, Nonce) & 0xFFFF   (low 16 bits, BE)
+//! VKD_idx = Kvn XOR VARIANTS[uv]
+//! VKD     = vkd_table[VKD_idx * 16 .. +16]
+//! Km      = AES-128D(Kpnew, VKD) XOR uv
+//! ```
+//!
+//! Two condition bits on `Kmp[15]` route off the hardcoded-KCD path
+//! (Soft Correction and Online Challenge). The chain refuses to run in
+//! either case — callers must handle those modes out of band.
+
+use super::decrypt::aes_ecb_decrypt;
+use super::keydb::DeviceKey;
+
+// ── Public constants ──────────────────────────────────────────────────────
+
+/// Placeholder Key Correction Data. Sixteen zero bytes.
+///
+/// Integrators MUST supply a non-placeholder KCD via the `kcd` argument
+/// to [`derive_media_key_variant`]; the chain refuses to operate when
+/// the supplied KCD compares equal to this placeholder.
+pub const KEY_CORRECTION_DATA_PLACEHOLDER: [u8; 16] = [0u8; 16];
+
+// ── MKB record walking ────────────────────────────────────────────────────
+
+/// A single MKB record produced by [`walk_mkb`].
+#[derive(Debug, Clone)]
+pub struct MkbRecord {
+    /// Byte offset of the record within the MKB.
+    pub offset: usize,
+    /// Record type byte.
+    pub rec_type: u8,
+    /// Record length in bytes (includes the 4-byte header).
+    pub rec_len: usize,
+    /// Record body (the bytes after the 4-byte header).
+    pub body: Vec<u8>,
+}
+
+/// Walk an MKB into a flat list of records.
+///
+/// MKB record framing per AACS: 1 byte type, 3 bytes BE length
+/// INCLUDING the 4-byte header, followed by payload. The walker stops
+/// at the first `(type=0, len=0)` end marker or at end of buffer.
+pub fn walk_mkb(mkb: &[u8]) -> Vec<MkbRecord> {
+    let mut out = Vec::new();
+    let mut pos = 0;
+    while pos + 4 <= mkb.len() {
+        let rec_type = mkb[pos];
+        let rec_len = ((mkb[pos + 1] as usize) << 16)
+            | ((mkb[pos + 2] as usize) << 8)
+            | (mkb[pos + 3] as usize);
+        if rec_type == 0 && rec_len == 0 {
+            break;
+        }
+        if rec_len < 4 || pos + rec_len > mkb.len() {
+            break;
+        }
+        let body = mkb[pos + 4..pos + rec_len].to_vec();
+        out.push(MkbRecord {
+            offset: pos,
+            rec_type,
+            rec_len,
+            body,
+        });
+        pos += rec_len;
+    }
+    out
+}
+
+/// True iff `records` contains at least one Media Key Variant record
+/// (type `0x82` or `0x83`).
+pub fn is_variant_mkb(records: &[MkbRecord]) -> bool {
+    records.iter().any(|r| matches!(r.rec_type, 0x82 | 0x83))
+}
+
+/// Body of the Encrypted Media Key Variant Data record (type `0x82`).
+pub fn variant_data_record(records: &[MkbRecord]) -> Option<&[u8]> {
+    records
+        .iter()
+        .find(|r| r.rec_type == 0x82)
+        .map(|r| r.body.as_slice())
+}
+
+/// 16-byte Nonce from the Variant Number record (type `0x83`). Returns
+/// the first 16 bytes of the body.
+pub fn variant_nonce(records: &[MkbRecord]) -> Option<[u8; 16]> {
+    let r = records.iter().find(|r| r.rec_type == 0x83)?;
+    if r.body.len() < 16 {
+        return None;
+    }
+    let mut out = [0u8; 16];
+    out.copy_from_slice(&r.body[..16]);
+    Some(out)
+}
+
+/// Body of the Variant Key Data record. Returns the first `0x82` body
+/// that is a non-empty multiple of 16 bytes.
+pub fn variant_key_data(records: &[MkbRecord]) -> Option<&[u8]> {
+    records
+        .iter()
+        .find(|r| r.rec_type == 0x82 && !r.body.is_empty() && r.body.len() % 16 == 0)
+        .map(|r| r.body.as_slice())
+}
+
+// ── AES-G ────────────────────────────────────────────────────────────────
+
+/// AES-G(x1, x2) = AES-128D(x1, x2) XOR x2.
+///
+/// The Media Key Variant chain uses AES-G to derive both the variant
+/// number (`Kvn = AES-G(Kp, Nonce)`) and the Volume Unique Key
+/// (`Kvu = AES-G(Km, VID)`). See [`super::keys::derive_vuk`] for the
+/// classical VUK form — the math is identical, this exposes it as a
+/// neutral primitive for the variant chain.
+fn aes_g(x1: &[u8; 16], x2: &[u8; 16]) -> [u8; 16] {
+    let mut out = aes_ecb_decrypt(x1, x2);
+    for i in 0..16 {
+        out[i] ^= x2[i];
+    }
+    out
+}
+
+// ── Subset-difference walk that exposes (Kp, uv) ──────────────────────────
+
+/// AES-G3 seed register initial value.
+const AESG3_SEED: [u8; 16] = [
+    0x7B, 0x10, 0x3C, 0x5D, 0xCB, 0x08, 0xC4, 0xE5, 0x1A, 0x27, 0xB0, 0x17, 0x99, 0x05, 0x3B, 0xD9,
+];
+
+/// AES-G3 single step: AES-G against the seed register at offset `inc`.
+fn aesg3_step(key: &[u8; 16], inc: u8) -> [u8; 16] {
+    let mut seed = AESG3_SEED;
+    seed[15] = seed[15].wrapping_add(inc);
+    aes_g(key, &seed)
+}
+
+fn calc_v_mask(uv: u32) -> u32 {
+    let mut v_mask: u32 = 0xFFFF_FFFF;
+    while (uv & !v_mask) == 0 && v_mask != 0 {
+        v_mask <<= 1;
+    }
+    v_mask
+}
+
+fn calc_pk_from_dk(dk: &[u8; 16], uv: u32, v_mask: u32, dev_key_v_mask: u32) -> [u8; 16] {
+    let mut left_child = aesg3_step(dk, 0);
+    let mut pk = aesg3_step(dk, 1);
+    let mut right_child = aesg3_step(dk, 2);
+    let mut current_v_mask = dev_key_v_mask;
+
+    while current_v_mask != v_mask {
+        let mut bit_pos: i32 = -1;
+        for i in (0..32).rev() {
+            if (current_v_mask & (1u32 << i)) == 0 {
+                bit_pos = i;
+                break;
+            }
+        }
+
+        let curr_key = if bit_pos < 0 || (uv & (1u32 << bit_pos as u32)) == 0 {
+            left_child
+        } else {
+            right_child
+        };
+
+        left_child = aesg3_step(&curr_key, 0);
+        pk = aesg3_step(&curr_key, 1);
+        right_child = aesg3_step(&curr_key, 2);
+
+        current_v_mask = ((current_v_mask as i32) >> 1) as u32;
+    }
+
+    pk
+}
+
+/// Outcome of a subset-difference walk against an MKB. Carries the
+/// processing key and the matching `uv` slot — both needed as inputs
+/// to the variant chain.
+#[derive(Debug, Clone, Copy)]
+pub struct ProcessingKeyMatch {
+    /// Processing Key.
+    pub kp: [u8; 16],
+    /// Subset-difference node number that matched.
+    pub uv: u32,
+    /// 16-byte cvalue that the matched uv selected.
+    pub cvalue: [u8; 16],
+    /// Index of the matching cvalue within the cvalues record.
+    pub cvalue_index: usize,
+}
+
+fn mkb_find_body(records: &[MkbRecord], rec_type: u8) -> Option<&[u8]> {
+    records
+        .iter()
+        .find(|r| r.rec_type == rec_type && !r.body.is_empty())
+        .map(|r| r.body.as_slice())
+}
+
+fn mkb_find_mk_dv(records: &[MkbRecord]) -> Option<[u8; 16]> {
+    let r = records
+        .iter()
+        .find(|r| (r.rec_type == 0x81 || r.rec_type == 0x86) && r.body.len() >= 16)?;
+    let mut out = [0u8; 16];
+    out.copy_from_slice(&r.body[..16]);
+    Some(out)
+}
+
+/// Walk an MKB and return the first `(Kp, uv, cvalue)` that
+/// `device_keys` covers. Returns `None` if no DK walks any uv.
+pub fn walk_processing_key(
+    records: &[MkbRecord],
+    device_keys: &[DeviceKey],
+) -> Option<ProcessingKeyMatch> {
+    let mk_dv = mkb_find_mk_dv(records)?;
+    let uvs = mkb_find_body(records, 0x04)?;
+    let cvalues = mkb_find_body(records, 0x07).or_else(|| mkb_find_body(records, 0x05))?;
+
+    let num_uvs = uvs
+        .chunks(5)
+        .take_while(|c| c.len() == 5 && (c[0] & 0xC0) == 0)
+        .count();
+
+    for dk in device_keys {
+        let device_number = dk.node as u32;
+
+        for uvs_idx in 0..num_uvs {
+            let p_uv = &uvs[1 + 5 * uvs_idx..];
+            let u_mask_shift = uvs[5 * uvs_idx];
+
+            if u_mask_shift & 0xC0 != 0 {
+                break;
+            }
+
+            let uv = u32::from_be_bytes([p_uv[0], p_uv[1], p_uv[2], p_uv[3]]);
+            if uv == 0 {
+                continue;
+            }
+
+            let u_mask: u32 = 0xFFFF_FFFFu32.wrapping_shl(u_mask_shift as u32);
+            let v_mask = calc_v_mask(uv);
+
+            if ((device_number & u_mask) == (uv & u_mask))
+                && ((device_number & v_mask) != (uv & v_mask))
+            {
+                let dev_key_v_mask = calc_v_mask(dk.uv);
+                let dev_key_u_mask: u32 = 0xFFFF_FFFFu32.wrapping_shl(dk.u_mask_shift as u32);
+
+                if u_mask == dev_key_u_mask && (uv & dev_key_v_mask) == (dk.uv & dev_key_v_mask) {
+                    let pk = calc_pk_from_dk(&dk.key, uv, v_mask, dev_key_v_mask);
+
+                    if uvs_idx >= cvalues.len() / 16 {
+                        continue;
+                    }
+                    let mut cv = [0u8; 16];
+                    cv.copy_from_slice(&cvalues[uvs_idx * 16..(uvs_idx + 1) * 16]);
+
+                    // Validate: AES-D(Kp, cv), XOR uv into low 4 bytes,
+                    // then AES-D(.., mk_dv) must reveal the verify magic.
+                    let mut km_candidate = aes_ecb_decrypt(&pk, &cv);
+                    let uv_bytes = uv.to_be_bytes();
+                    for i in 0..4 {
+                        km_candidate[12 + i] ^= uv_bytes[i];
+                    }
+                    let dec_vd = aes_ecb_decrypt(&km_candidate, &mk_dv);
+                    const VERIFY_MAGIC: [u8; 8] = [0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF];
+                    // On a classical (non-variant) MKB this magic must
+                    // match. On a variant MKB it won't — `km_candidate`
+                    // is really Kmp and the magic check is moot. We
+                    // still gate the walk on cvalue indexing being
+                    // sane; the chain itself enforces the variant
+                    // semantics downstream.
+                    let classical_ok = dec_vd[..8] == VERIFY_MAGIC;
+                    let variant_present = is_variant_mkb(records);
+                    if !(classical_ok || variant_present) {
+                        continue;
+                    }
+
+                    return Some(ProcessingKeyMatch {
+                        kp: pk,
+                        uv,
+                        cvalue: cv,
+                        cvalue_index: uvs_idx,
+                    });
+                }
+            }
+        }
+    }
+    None
+}
+
+// ── Error reporting ───────────────────────────────────────────────────────
+
+/// Outcome of [`derive_media_key_variant`] when the chain cannot
+/// produce a Media Key. Every variant is a classification only — no
+/// strings, no Display impl beyond the error code.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum MediaKeyVariantError {
+    /// MKB carries no Variant records. Caller should fall back to the
+    /// classical single-stage derivation.
+    NotVariantMkb,
+    /// MKB is missing a required record (mk_dv, subset-difference,
+    /// cvalues, variant data, or variant nonce).
+    MkbIncomplete,
+    /// `device_keys` did not cover any uv slot in this MKB.
+    ProcessingKeyUnavailable,
+    /// `Kmp[15]` carries bit `0x02`: the soft-correction path applies
+    /// for this Precursor. Out of scope for the hardcoded-KCD chain.
+    SoftCorrectionRequired,
+    /// `Kmp[15]` carries bit `0x04`: the online-challenge path applies
+    /// for this Precursor. Out of scope for the hardcoded-KCD chain.
+    OnlineChallengeRequired,
+    /// Supplied KCD equals [`KEY_CORRECTION_DATA_PLACEHOLDER`]. The
+    /// derivation refuses to run with the all-zero placeholder.
+    KcdNotProvided,
+    /// `VARIANTS[uv]` lookup for the matched uv is not implemented.
+    VariantsTableUnavailable,
+    /// VKD index resolved out of the supplied `vkd_table`.
+    VkdIndexOutOfRange,
+}
+
+impl std::fmt::Display for MediaKeyVariantError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let code: u16 = match self {
+            MediaKeyVariantError::NotVariantMkb => 7100,
+            MediaKeyVariantError::MkbIncomplete => 7101,
+            MediaKeyVariantError::ProcessingKeyUnavailable => 7102,
+            MediaKeyVariantError::SoftCorrectionRequired => 7103,
+            MediaKeyVariantError::OnlineChallengeRequired => 7104,
+            MediaKeyVariantError::KcdNotProvided => 7105,
+            MediaKeyVariantError::VariantsTableUnavailable => 7106,
+            MediaKeyVariantError::VkdIndexOutOfRange => 7107,
+        };
+        write!(f, "E{code}")
+    }
+}
+
+impl std::error::Error for MediaKeyVariantError {}
+
+// ── Chain ─────────────────────────────────────────────────────────────────
+
+/// Look up `VARIANTS[uv]` for the matched uv. The byte layout of the
+/// per-uv slot in the Variant Number record is undocumented and is
+/// disc-specific; this helper returns `None` until a Variant disc is
+/// available to fix the layout against.
+fn variants_for_uv(_records: &[MkbRecord], _uv_index: usize) -> Option<u16> {
+    None
+}
+
+/// Run the Media Key Variant chain on an MKB.
+///
+/// Inputs:
+///
+/// - `mkb_records`  : MKB pre-walked via [`walk_mkb`].
+/// - `device_keys`  : pool of device keys; the chain runs against the
+///   first uv slot any DK covers.
+/// - `kcd`          : integrator-supplied Key Correction Data. Must not
+///   equal [`KEY_CORRECTION_DATA_PLACEHOLDER`].
+/// - `vid`          : 16-byte Volume ID for the disc. Used to derive
+///   the final VUK alongside the Media Key.
+///
+/// Returns `(Km, Kvu)` on success.
+pub fn derive_media_key_variant(
+    mkb_records: &[MkbRecord],
+    device_keys: &[DeviceKey],
+    kcd: &[u8; 16],
+    vid: &[u8; 16],
+) -> Result<([u8; 16], [u8; 16]), MediaKeyVariantError> {
+    if !is_variant_mkb(mkb_records) {
+        return Err(MediaKeyVariantError::NotVariantMkb);
+    }
+
+    let pkm = walk_processing_key(mkb_records, device_keys)
+        .ok_or(MediaKeyVariantError::ProcessingKeyUnavailable)?;
+
+    let nonce = variant_nonce(mkb_records).ok_or(MediaKeyVariantError::MkbIncomplete)?;
+    let vkd_table = variant_key_data(mkb_records).ok_or(MediaKeyVariantError::MkbIncomplete)?;
+    let c_value = variant_data_record(mkb_records).ok_or(MediaKeyVariantError::MkbIncomplete)?;
+    if c_value.len() < 16 {
+        return Err(MediaKeyVariantError::MkbIncomplete);
+    }
+    let mut c_block = [0u8; 16];
+    c_block.copy_from_slice(&c_value[..16]);
+
+    // Step: Kmp = AES-128D(Kp, C) XOR uv  (uv into low 4 bytes).
+    let mut kmp = aes_ecb_decrypt(&pkm.kp, &c_block);
+    let uv_bytes = pkm.uv.to_be_bytes();
+    for i in 0..4 {
+        kmp[12 + i] ^= uv_bytes[i];
+    }
+
+    // Condition bits on Kmp[15] route off the hardcoded-KCD path.
+    if kmp[15] & 0b0000_0010 != 0 {
+        return Err(MediaKeyVariantError::SoftCorrectionRequired);
+    }
+    if kmp[15] & 0b0000_0100 != 0 {
+        return Err(MediaKeyVariantError::OnlineChallengeRequired);
+    }
+    if kcd == &KEY_CORRECTION_DATA_PLACEHOLDER {
+        return Err(MediaKeyVariantError::KcdNotProvided);
+    }
+
+    // Step: Kpnew = Kmp XOR KCD.
+    let mut kpnew = [0u8; 16];
+    for i in 0..16 {
+        kpnew[i] = kmp[i] ^ kcd[i];
+    }
+
+    // Step: Kvn = AES-G(Kp, Nonce) & 0xFFFF  (low 16 bits, BE).
+    let kvn_block = aes_g(&pkm.kp, &nonce);
+    let kvn = u16::from_be_bytes([kvn_block[14], kvn_block[15]]);
+
+    // Step: VKD_idx = Kvn XOR VARIANTS[uv].
+    let v_for_uv = variants_for_uv(mkb_records, pkm.cvalue_index)
+        .ok_or(MediaKeyVariantError::VariantsTableUnavailable)?;
+    let vkd_idx = kvn ^ v_for_uv;
+
+    // Step: VKD = vkd_table[VKD_idx * 16 .. +16].
+    let off = (vkd_idx as usize) * 16;
+    if off + 16 > vkd_table.len() {
+        return Err(MediaKeyVariantError::VkdIndexOutOfRange);
+    }
+    let mut vkd = [0u8; 16];
+    vkd.copy_from_slice(&vkd_table[off..off + 16]);
+
+    // Step: Km = AES-128D(Kpnew, VKD) XOR uv.
+    let mut km = aes_ecb_decrypt(&kpnew, &vkd);
+    for i in 0..4 {
+        km[12 + i] ^= uv_bytes[i];
+    }
+
+    // Step: Kvu = AES-G(Km, VID).
+    let kvu = aes_g(&km, vid);
+
+    Ok((km, kvu))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // ── Helpers ──
+
+    fn synthetic_mkb_classical() -> Vec<u8> {
+        // Minimal MKB: type/version record + cvalues + mk_dv. No variant
+        // records.
+        let mut mkb = vec![
+            0x10, 0x00, 0x00, 0x0C, 0x48, 0x14, 0x10, 0x03, 0x00, 0x00, 0x00, 0x4D,
+        ];
+        mkb.extend_from_slice(&[0x07, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&[0xAB; 16]);
+        mkb.extend_from_slice(&[0x86, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&[0xCD; 16]);
+        mkb
+    }
+
+    fn synthetic_mkb_with_variant() -> Vec<u8> {
+        let mut mkb = synthetic_mkb_classical();
+        // 0x82 — 16-byte body (Variant data / VKD slot).
+        mkb.extend_from_slice(&[0x82, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&[0xEE; 16]);
+        // 0x83 — 16-byte body (Variant Nonce).
+        mkb.extend_from_slice(&[0x83, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&[0x55; 16]);
+        mkb
+    }
+
+    // ── Walker / record detection ──
+
+    #[test]
+    fn walker_parses_synthetic_mkb() {
+        let mkb = synthetic_mkb_classical();
+        let recs = walk_mkb(&mkb);
+        assert_eq!(recs.len(), 3);
+        assert_eq!(recs[0].rec_type, 0x10);
+        assert_eq!(recs[1].rec_type, 0x07);
+        assert_eq!(recs[2].rec_type, 0x86);
+    }
+
+    #[test]
+    fn variant_detection_negative_on_classical() {
+        let recs = walk_mkb(&synthetic_mkb_classical());
+        assert!(!is_variant_mkb(&recs));
+        assert!(variant_nonce(&recs).is_none());
+        assert!(variant_key_data(&recs).is_none());
+        assert!(variant_data_record(&recs).is_none());
+    }
+
+    #[test]
+    fn variant_detection_positive_on_variant() {
+        let recs = walk_mkb(&synthetic_mkb_with_variant());
+        assert!(is_variant_mkb(&recs));
+        assert_eq!(variant_nonce(&recs), Some([0x55; 16]));
+        assert_eq!(variant_key_data(&recs), Some(&[0xEE; 16][..]));
+        assert_eq!(variant_data_record(&recs), Some(&[0xEE; 16][..]));
+    }
+
+    // ── Chain entry-point classification ──
+
+    #[test]
+    fn chain_rejects_non_variant_mkb() {
+        let recs = walk_mkb(&synthetic_mkb_classical());
+        let err = derive_media_key_variant(&recs, &[], &[0xAA; 16], &[0u8; 16])
+            .expect_err("classical MKB must be rejected");
+        assert_eq!(err, MediaKeyVariantError::NotVariantMkb);
+    }
+
+    #[test]
+    fn chain_rejects_placeholder_kcd() {
+        // To reach the KCD check we need a complete variant MKB AND a
+        // DK that walks it. We construct both via the synthetic
+        // fixture below.
+        let (recs, dk, _kp, _expected_kmp) = synthetic_variant_setup(/*kmp15*/ 0x00);
+        let err =
+            derive_media_key_variant(&recs, &[dk], &KEY_CORRECTION_DATA_PLACEHOLDER, &[0u8; 16])
+                .expect_err("placeholder KCD must be rejected");
+        assert_eq!(err, MediaKeyVariantError::KcdNotProvided);
+    }
+
+    #[test]
+    fn chain_detects_soft_correction_bit() {
+        let (recs, dk, _, _) = synthetic_variant_setup(/*kmp15*/ 0x02);
+        let err = derive_media_key_variant(&recs, &[dk], &[0xAA; 16], &[0u8; 16])
+            .expect_err("bit 0x02 must surface SoftCorrectionRequired");
+        assert_eq!(err, MediaKeyVariantError::SoftCorrectionRequired);
+    }
+
+    #[test]
+    fn chain_detects_online_challenge_bit() {
+        let (recs, dk, _, _) = synthetic_variant_setup(/*kmp15*/ 0x04);
+        let err = derive_media_key_variant(&recs, &[dk], &[0xAA; 16], &[0u8; 16])
+            .expect_err("bit 0x04 must surface OnlineChallengeRequired");
+        assert_eq!(err, MediaKeyVariantError::OnlineChallengeRequired);
+    }
+
+    #[test]
+    fn chain_surfaces_variants_table_gap_on_clean_kmp() {
+        // With both condition bits clear and a non-placeholder KCD, the
+        // chain advances to the per-uv VARIANTS[uv] lookup, which is
+        // not yet wired. That returns VariantsTableUnavailable —
+        // proving the bit checks and KCD check all passed.
+        let (recs, dk, _, _) = synthetic_variant_setup(/*kmp15*/ 0x00);
+        let err = derive_media_key_variant(&recs, &[dk], &[0xAA; 16], &[0u8; 16])
+            .expect_err("expected VariantsTableUnavailable at the per-uv lookup");
+        assert_eq!(err, MediaKeyVariantError::VariantsTableUnavailable);
+    }
+
+    #[test]
+    fn error_display_is_code_only() {
+        // No English in Display — every variant emits "E7xxx" and
+        // nothing else.
+        let cases = [
+            MediaKeyVariantError::NotVariantMkb,
+            MediaKeyVariantError::MkbIncomplete,
+            MediaKeyVariantError::ProcessingKeyUnavailable,
+            MediaKeyVariantError::SoftCorrectionRequired,
+            MediaKeyVariantError::OnlineChallengeRequired,
+            MediaKeyVariantError::KcdNotProvided,
+            MediaKeyVariantError::VariantsTableUnavailable,
+            MediaKeyVariantError::VkdIndexOutOfRange,
+        ];
+        for e in cases {
+            let s = e.to_string();
+            assert!(
+                s.starts_with('E') && s.len() == 5,
+                "error display must be E#### only, got {s:?}"
+            );
+            assert!(
+                s.chars().skip(1).all(|c| c.is_ascii_digit()),
+                "error display must be E + digits, got {s:?}"
+            );
+        }
+    }
+
+    // ── Fixture construction ──
+
+    /// Build a synthetic variant MKB plus a DK that walks the single
+    /// subset-difference slot it carries. `kmp15` is the value of the
+    /// low byte of `Kmp[15]` that the chain will land on — pick `0x02`
+    /// to exercise the SoftCorrection bit, `0x04` to exercise
+    /// OnlineChallenge, `0x00` otherwise.
+    ///
+    /// The fixture pins:
+    /// - MKB subset-difference: `u_mask_shift=3, uv=2`. With these
+    ///   masks the discriminator bit (u_mask=1, v_mask=0) is bit 2.
+    /// - one DK at `node=4, uv=2, u_mask_shift=3`. node 4 has bit 2 set
+    ///   (differs from uv=2 on bit 2 → disagrees on v_mask) while
+    ///   agreeing with uv on bits 3+ (the u_mask=1 region). dk.uv ==
+    ///   MKB.uv and dk.u_mask_shift == MKB.u_mask_shift make
+    ///   `dev_key_v_mask == v_mask`, so `calc_pk_from_dk` loops zero
+    ///   times — Kp = aesg3_step(dk, 1).
+    /// - one cvalue in record 0x07 chosen so AES-D(Kp, C) ⊕ uv produces a
+    ///   Kmp whose byte-15 is exactly `kmp15`.
+    /// - record 0x82 with a 16-byte body (acts as both Variant Data
+    ///   and Variant Key Data; satisfies the parser heuristics).
+    /// - record 0x83 with a 16-byte Nonce.
+    ///
+    /// Returns (records, dk, planted_kp, planted_kmp).
+    fn synthetic_variant_setup(kmp15: u8) -> (Vec<MkbRecord>, DeviceKey, [u8; 16], [u8; 16]) {
+        use crate::aacs::decrypt::aes_ecb_encrypt;
+
+        // Build header.
+        let mut mkb = vec![
+            0x10, 0x00, 0x00, 0x0C, 0x48, 0x14, 0x10, 0x03, 0x00, 0x00, 0x00, 0x4D,
+        ];
+
+        // Subset-difference (0x04): u_mask_shift=3, uv=00 00 00 02.
+        mkb.extend_from_slice(&[0x04, 0x00, 0x00, 0x09]);
+        mkb.extend_from_slice(&[0x03, 0x00, 0x00, 0x00, 0x02]);
+
+        // Pick a known DK; with dk.uv == MKB.uv (==2) and
+        // dk.u_mask_shift == MKB.u_mask_shift (==1), dev_key_v_mask
+        // equals the MKB's v_mask and the calc_pk_from_dk loop is a
+        // no-op — Kp = aesg3_step(dk, 1).
+        let dk_bytes: [u8; 16] = [
+            0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE,
+            0xFF, 0x00,
+        ];
+        let kp = aesg3_step(&dk_bytes, 1);
+
+        // Plant Kmp with chosen byte-15, then compute C such that
+        // AES-D(Kp, C) ⊕ uv == Kmp. uv=2 → low-4 bytes XOR is 00 00 00 02.
+        let mut kmp = [0x42u8; 16];
+        kmp[15] = kmp15;
+        let mut aes_d_result = kmp;
+        aes_d_result[15] ^= 0x02;
+        let c_block = aes_ecb_encrypt(&kp, &aes_d_result);
+
+        // cvalues record (0x07): one 16-byte cvalue. The walker
+        // indexes it for the magic-check step; on a variant MKB the
+        // magic check fails but `variant_present` is true so the
+        // walker still returns the match. Content is don't-care.
+        mkb.extend_from_slice(&[0x07, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&[0xAB; 16]);
+
+        // Verify Media Key (0x86): body content is don't-care.
+        mkb.extend_from_slice(&[0x86, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&[0xCD; 16]);
+
+        // 0x82 record: holds C (Encrypted Media Key Variant Data) AND
+        // doubles as the VKD table (single 16-byte entry → VKDidx must
+        // resolve to 0 for `chain_surfaces_variants_table_gap` test —
+        // but the test never reaches the VKD lookup since the
+        // VARIANTS[uv] helper is not yet wired).
+        mkb.extend_from_slice(&[0x82, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&c_block);
+
+        // 0x83 record: 16-byte Nonce.
+        mkb.extend_from_slice(&[0x83, 0x00, 0x00, 0x14]);
+        mkb.extend_from_slice(&[0x77; 16]);
+
+        let recs = walk_mkb(&mkb);
+
+        let dk = DeviceKey {
+            key: dk_bytes,
+            node: 4,
+            uv: 2,
+            u_mask_shift: 3,
+        };
+        (recs, dk, kp, kmp)
+    }
+}

src/css/auth.rs

@@ -4,13 +4,14 @@
 //!   1. Bus authentication (challenge-response) → bus key
 //!   2. Read disc key block (READ DVD STRUCTURE) → XOR with bus key → decrypt with player keys → disc key
 //!   3. Read title key (REPORT KEY format 0x04) → XOR with bus key → decrypt with disc key → title key
-//!
-//! Based on libdvdcss (VideoLAN) and Stevenson 1999 analysis.
 
 use crate::drive::Drive;
 use crate::error::{Error, Result};
 
-// ── Player keys (from libdvdcss, Stevenson's PlayerKey cracker) ───────────
+// ── Built-in public DVD CSS player keys ────────────────────────────────────
+//
+// These 31 5-byte player keys are long-public CSS inputs. With them
+// compiled in, DVD ripping works with no external key file required.
 
 const PLAYER_KEYS: [[u8; 5]; 31] = [
     [0x01, 0xaf, 0xe3, 0x12, 0x80],

src/css/mod.rs

@@ -16,6 +16,7 @@ pub mod lfsr;
 pub(crate) mod tables;
 
 use crate::disc::Extent;
+use crate::drive::Drive;
 use crate::sector::SectorSource;
 
 /// CSS decryption state for a DVD title.
@@ -25,6 +26,50 @@ pub struct CssState {
     pub title_key: [u8; 5],
 }
 
+/// Inputs for CSS key acquisition.
+///
+/// The acquisition path depends on which inputs the caller supplies:
+///
+/// - With `drive` + `auth_lba` set, [`resolve`] runs the full SCSI bus
+///   auth + title-key path (live BU40N / DVD drive).
+/// - With `reader` + `extents` set, [`resolve`] falls back to the
+///   crack path (Stevenson known-plaintext attack on encrypted PES
+///   headers; works on disc images and on drives whose CSS auth path
+///   is unavailable).
+///
+/// `live_drive` always wins when both modes are populated.
+pub struct CssContext<'a> {
+    /// Live SCSI drive — when present, [`resolve`] tries the auth path.
+    pub drive: Option<&'a mut Drive>,
+    /// LBA of a known-scrambled sector for the auth path's title-key
+    /// query. Required when `drive` is set.
+    pub auth_lba: Option<u32>,
+    /// Sector source for the crack path.
+    pub reader: Option<&'a mut dyn SectorSource>,
+    /// Extents to scan for the crack path. Required when `reader` is
+    /// set.
+    pub extents: Option<&'a [Extent]>,
+}
+
+/// Acquire a CSS title key using whichever inputs the context provides.
+///
+/// Order of attempts:
+///   1. SCSI auth path (when `drive` and `auth_lba` are set).
+///   2. Crack path (when `reader` and `extents` are set).
+///
+/// Returns `None` if neither path is configured or both fail.
+pub fn resolve(ctx: &mut CssContext<'_>) -> Option<CssState> {
+    if let (Some(drive), Some(lba)) = (ctx.drive.as_deref_mut(), ctx.auth_lba) {
+        if let Ok(title_key) = auth::authenticate_and_read_title_key(drive, lba) {
+            return Some(CssState { title_key });
+        }
+    }
+    if let (Some(reader), Some(extents)) = (ctx.reader.as_deref_mut(), ctx.extents) {
+        return crack_key(reader, extents);
+    }
+    None
+}
+
 /// Crack the CSS title key by reading encrypted sectors and applying
 /// a known-plaintext attack on MPEG-2 headers.
 ///

src/decrypt.rs

@@ -3,9 +3,131 @@
 //! Decrypts sectors in-place using resolved keys from disc scanning.
 //! Handles AACS 1.0, AACS 2.0, and CSS transparently.
 //! The caller never sees encrypted data unless explicitly bypassed.
+//!
+//! ## Parallel AACS decrypt
+//!
+//! Each AACS aligned unit (6144 bytes) is decrypted INDEPENDENTLY of
+//! every other unit — per-unit key derivation from the unit_key plus
+//! the unit's own first-16-byte header. There is no cross-unit
+//! dependency, so a buffer of N units can be decrypted on N threads
+//! in parallel via a persistent rayon thread pool.
+//!
+//! Small buffers (< [`PARALLEL_MIN_UNITS`] units) fall through to the
+//! serial path to avoid pool dispatch overhead beating the per-unit
+//! AES work.
+//!
+//! ## Thread-count configuration — three layers
+//!
+//! Resolution order (highest wins):
+//! 1. The most recent [`set_decrypt_threads`] call with `n > 0`.
+//!    Calling this *replaces* the live thread pool — useful for a
+//!    settings-page slider in a long-running daemon.
+//! 2. `FREEMKV_THREADS` env var, if set and `> 0`. Single knob
+//!    covering decrypt today, intended to also drive any future
+//!    input-side / output-side worker pools.
+//! 3. Default: all available cores. Algorithm optimisation comes
+//!    first — we measure single-thread performance to find serial
+//!    bottlenecks before throwing parallelism at it — but once a
+//!    pool is engaged we use the whole box. Hard cap at
+//!    [`MAX_THREADS`] (rayon stack memory).
 
 use crate::aacs;
 use crate::css;
+use rayon::prelude::*;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::{Arc, RwLock};
+
+/// Minimum units in a buffer before we pay the pool-dispatch cost of
+/// fanning out. Below this, serial is faster.
+const PARALLEL_MIN_UNITS: usize = 8;
+
+/// Hard upper bound on configurable thread count. Anything larger is
+/// almost certainly a misconfiguration; rayon would happily allocate
+/// thousands of worker stacks otherwise.
+pub const MAX_THREADS: usize = 64;
+
+/// Process-wide decrypt thread count override. `0` means "use env
+/// var, else default" — see [`decrypt_threads`] for the resolution
+/// order.
+static DECRYPT_THREADS: AtomicUsize = AtomicUsize::new(0);
+
+/// Current rayon pool. `RwLock<Option<Arc<...>>>` so that
+/// [`set_decrypt_threads`] can swap the pool out without leaking the
+/// old one and without blocking ongoing decrypt work (in-flight calls
+/// hold an `Arc` clone via [`decrypt_pool`] and finish on the old
+/// pool; new calls pick up the new pool).
+static DECRYPT_POOL: RwLock<Option<Arc<rayon::ThreadPool>>> = RwLock::new(None);
+
+/// Configure how many threads to use for AACS unit decryption. A value
+/// of `0` resets to the env / default resolution. `1` forces serial.
+/// `N > 1` builds a new rayon pool of size N and atomically replaces
+/// the live pool.
+///
+/// Thread-safe. Live decrypt calls keep their previously-acquired
+/// pool reference for the rest of the call — no mid-call pool
+/// switch. Subsequent calls see the new pool.
+///
+/// Pool construction is ~ms-scale; safe to call from a settings POST
+/// handler.
+pub fn set_decrypt_threads(n: usize) {
+    let clamped = n.min(MAX_THREADS);
+    DECRYPT_THREADS.store(clamped, Ordering::Relaxed);
+    // Drop the existing pool. Next decrypt_pool() call rebuilds with
+    // the new resolved thread count.
+    if let Ok(mut guard) = DECRYPT_POOL.write() {
+        *guard = None;
+    }
+}
+
+/// Get (or lazily build) the active rayon thread pool. Returns an
+/// `Arc` so in-flight work survives a concurrent
+/// [`set_decrypt_threads`] swap.
+fn decrypt_pool() -> Arc<rayon::ThreadPool> {
+    // Fast path: pool already built.
+    if let Ok(guard) = DECRYPT_POOL.read() {
+        if let Some(pool) = guard.as_ref() {
+            return Arc::clone(pool);
+        }
+    }
+    // Slow path: build a new one under the write lock. Double-check
+    // after acquiring in case another caller built it first.
+    let mut guard = DECRYPT_POOL.write().expect("DECRYPT_POOL RwLock poisoned");
+    if let Some(pool) = guard.as_ref() {
+        return Arc::clone(pool);
+    }
+    let n = decrypt_threads();
+    let pool = Arc::new(
+        rayon::ThreadPoolBuilder::new()
+            .num_threads(n)
+            .thread_name(|i| format!("freemkv-decrypt-{i}"))
+            .build()
+            .expect("rayon decrypt pool build failed"),
+    );
+    *guard = Some(Arc::clone(&pool));
+    pool
+}
+
+/// Current effective decrypt thread count. Resolution order:
+/// 1. Most recent [`set_decrypt_threads`] value (if > 0)
+/// 2. `FREEMKV_THREADS` env var (if set and > 0)
+/// 3. Default: all available cores, capped at [`MAX_THREADS`].
+pub fn decrypt_threads() -> usize {
+    let explicit = DECRYPT_THREADS.load(Ordering::Relaxed);
+    if explicit > 0 {
+        return explicit;
+    }
+    let env = std::env::var("FREEMKV_THREADS")
+        .ok()
+        .and_then(|v| v.parse::<usize>().ok())
+        .unwrap_or(0);
+    if env > 0 {
+        return env.min(MAX_THREADS);
+    }
+    let cores = std::thread::available_parallelism()
+        .map(|n| n.get())
+        .unwrap_or(2);
+    cores.clamp(1, MAX_THREADS)
+}
 
 /// Resolved decryption state from disc scanning.
 /// Passed to `decrypt_sectors()` — the caller doesn't need to know
@@ -57,29 +179,44 @@ pub fn decrypt_sectors(
                     return Err(crate::error::Error::DecryptFailed);
                 }
             };
-            let rdk = read_data_key.as_ref();
+            let rdk: Option<[u8; 16]> = *read_data_key;
             let unit_len = aacs::ALIGNED_UNIT_LEN;
+            let nthreads = decrypt_threads();
+            let chunks: Vec<&mut [u8]> = buf.chunks_mut(unit_len).collect();
+            let nunits = chunks.len();
 
-            for chunk in buf.chunks_mut(unit_len) {
+            // Per-unit decrypt closure. The is_unit_encrypted check is
+            // a byte-0 heuristic; on a misfire we snapshot+restore via
+            // the original bytes so non-m2ts (e.g. MPLS/CLPI nav files)
+            // survive. See test `nav_file_unit_survives_decrypt_attempt`.
+            let decrypt_one = |chunk: &mut [u8]| {
                 if chunk.len() == unit_len && aacs::is_unit_encrypted(chunk) {
-                    // `is_unit_encrypted` is a byte-0 heuristic: it fires on any
-                    // unit whose first byte has the top 2 bits set, which is
-                    // correct for m2ts source packets (where those bits are the
-                    // copy-control marker) but false-positives on any other binary
-                    // data with similarly-shaped first bytes — notably MPLS/CLPI
-                    // navigation files that begin with ASCII magic ('M', 'H'…)
-                    // and survive sweep mixed in with encrypted m2ts payloads.
-                    // `decrypt_unit_full` self-checks via TS-sync verification and
-                    // returns false on a misfire, but it has already mutated the
-                    // chunk by then. Snapshot and restore on verification failure
-                    // — same pattern `decrypt_unit_try_keys` uses for multi-key
-                    // discs. Real m2ts units verify and stay decrypted; nav-file
-                    // sectors get scrambled briefly and then put back as-was.
                     let original: Vec<u8> = chunk.to_vec();
-                    if !aacs::decrypt_unit_full(chunk, &uk, rdk) {
+                    if !aacs::decrypt_unit_full(chunk, &uk, rdk.as_ref()) {
                         chunk.copy_from_slice(&original);
                     }
                 }
+            };
+
+            if nthreads <= 1 || nunits < PARALLEL_MIN_UNITS {
+                // Serial path: avoids thread-pool overhead for tiny
+                // buffers; also the only path when caller pinned
+                // single-threaded via FREEMKV_THREADS=1.
+                for chunk in chunks {
+                    decrypt_one(chunk);
+                }
+            } else {
+                // Parallel path via rayon's persistent global pool.
+                // The pool is built once on first use (lazy_static-style)
+                // and reused across every decrypt_sectors call — no
+                // per-call OS thread spawn, no thread-creation latency
+                // amortised per batch. Each unit decrypts independently
+                // (own key derivation), so par_iter is sound.
+                decrypt_pool().install(|| {
+                    chunks.into_par_iter().for_each(|chunk| {
+                        decrypt_one(chunk);
+                    });
+                });
             }
         }
         DecryptKeys::Css { title_key } => {

src/disc/encrypt.rs

@@ -14,19 +14,173 @@ pub(super) struct HandshakeResult {
 }
 
 impl Disc {
-    /// SCSI handshake result — volume ID and bus keys from ECDH authentication.
-    /// Only available when scanning from a real drive (not ISO images).
+    /// Acquire the Volume ID. Tries the per-drive OEM CDB path first
+    /// when the drive reports `is_unlocked()` (extended-access state),
+    /// and falls back to the cert-based AACS mutual-auth handshake
+    /// otherwise.
+    ///
+    /// The OEM path is a single READ_BUFFER CDB built from the drive
+    /// profile's `read_vid_cdb` template. The response carries a 3-byte
+    /// header (validated against `00 22 00`) followed by the 16-byte
+    /// VID at bytes [4..20]. Crucially, no AGID setup is required —
+    /// the drive's runtime firmware serves the VID directly when in
+    /// extended-access state.
+    ///
+    /// The cert path is the standard AACS spec flow: ECDH key
+    /// agreement, bus-key derivation, then `REPORT_DISC_STRUCTURE`
+    /// format 0x80 to retrieve VID under bus-key MAC.
+    pub(super) fn read_vid(
+        session: &mut crate::drive::Drive,
+        opts: &ScanOptions,
+    ) -> Result<[u8; 16]> {
+        if session.is_unlocked() {
+            let profile = session
+                .drive_profile()
+                .ok_or(Error::DriveProfileMissing)?
+                .clone();
+            return Self::read_vid_oem(session, &profile);
+        }
+        Self::read_vid_cert(session, opts)
+    }
+
+    /// OEM VID retrieval — issues the per-drive READ_BUFFER CDB and
+    /// parses the response.
+    ///
+    /// Response layout (36 bytes):
+    ///   * [0..3]   3-byte response signature; expected `00 22 00`
+    ///   * [3]      reserved
+    ///   * [4..20]  16-byte Volume ID
+    ///   * [20..36] reserved / per-drive padding
+    fn read_vid_oem(
+        session: &mut crate::drive::Drive,
+        profile: &crate::profile::DriveProfile,
+    ) -> Result<[u8; 16]> {
+        const RESPONSE_LEN: usize = 36;
+        const EXPECTED_HEADER: [u8; 3] = [0x00, 0x22, 0x00];
+
+        let cdb = profile.read_vid_cdb.ok_or(Error::VidCdbUnavailable)?;
+        let mut buf = vec![0u8; RESPONSE_LEN];
+        let result = session.scsi_execute(
+            &cdb,
+            crate::scsi::DataDirection::FromDevice,
+            &mut buf,
+            5_000,
+        )?;
+        if result.bytes_transferred < RESPONSE_LEN {
+            tracing::warn!(
+                target: "freemkv::disc",
+                phase = "oem_vid_short_response",
+                bytes_transferred = result.bytes_transferred,
+                "OEM VID CDB returned short response"
+            );
+            return Err(Error::AacsVidRead);
+        }
+        if buf[0..3] != EXPECTED_HEADER {
+            tracing::warn!(
+                target: "freemkv::disc",
+                phase = "oem_vid_bad_header",
+                header_0 = buf[0],
+                header_1 = buf[1],
+                header_2 = buf[2],
+                "OEM VID response header mismatch"
+            );
+            return Err(Error::AacsVidRead);
+        }
+        let mut vid = [0u8; 16];
+        vid.copy_from_slice(&buf[4..20]);
+        tracing::warn!(
+            target: "freemkv::disc",
+            phase = "oem_vid_ok",
+            "OEM VID retrieved"
+        );
+        Ok(vid)
+    }
+
+    /// Cert-based VID retrieval — runs the full AACS mutual-auth
+    /// handshake and extracts VID from the bus-key-MAC'd
+    /// `REPORT_DISC_STRUCTURE` response.
+    fn read_vid_cert(session: &mut crate::drive::Drive, opts: &ScanOptions) -> Result<[u8; 16]> {
+        match Self::do_handshake_cert(session, opts) {
+            (Some(h), _) => Ok(h.volume_id),
+            (None, Some(e)) => Err(e),
+            (None, None) => Err(Error::AacsVidUnavailable),
+        }
+    }
+
+    /// SCSI handshake — drives the VID-acquisition flow and returns
+    /// a structured `HandshakeResult` for downstream key resolution.
+    /// Prefers the OEM path when `Drive::is_unlocked()` is true and
+    /// falls back to cert-based mutual auth otherwise.
+    ///
+    /// The OEM path produces only VID (no bus-key, so no
+    /// `read_data_key`); the cert path can produce both. AACS 2.0
+    /// content that needs read_data_key for bus decryption requires
+    /// the cert path.
+    ///
+    /// Returns `(handshake, error)`:
+    ///   * `(Some(_), None)`  — VID acquired
+    ///   * `(None, Some(_))`  — specific failure mode (see
+    ///     `AacsHostCertRejected` / `AacsRawReadUnsupported` /
+    ///     `AacsVidUnavailable` / `DriveProfileMissing` /
+    ///     `VidCdbUnavailable` variants in `error.rs`)
+    ///   * `(None, None)`     — handshake not attempted (no keydb;
+    ///     resolution will proceed with VID=zero and rely on path 1
+    ///     disc-hash → VUK lookup)
     pub(super) fn do_handshake(
         session: &mut crate::drive::Drive,
         opts: &ScanOptions,
-    ) -> Option<HandshakeResult> {
-        use crate::aacs::{self, KeyDb};
-
+    ) -> (Option<HandshakeResult>, Option<Error>) {
+        let unlocked = session.is_unlocked();
         tracing::warn!(
             target: "freemkv::disc",
             phase = "handshake_entry",
+            unlocked,
             "do_handshake entered"
         );
+
+        if unlocked {
+            // Try OEM VID retrieval first. If the drive's profile
+            // doesn't carry the CDB template, or the response is
+            // malformed, fall through to cert-based auth.
+            match Self::read_vid(session, opts) {
+                Ok(volume_id) => {
+                    return (
+                        Some(HandshakeResult {
+                            volume_id,
+                            read_data_key: None,
+                        }),
+                        None,
+                    );
+                }
+                Err(Error::DriveProfileMissing) | Err(Error::VidCdbUnavailable) => {
+                    tracing::warn!(
+                        target: "freemkv::disc",
+                        phase = "handshake_oem_unavailable",
+                        "OEM VID path unavailable for this drive; trying cert handshake"
+                    );
+                }
+                Err(e) => {
+                    tracing::warn!(
+                        target: "freemkv::disc",
+                        phase = "handshake_oem_failed",
+                        error_code = e.code(),
+                        "OEM VID retrieval failed; trying cert handshake"
+                    );
+                }
+            }
+        }
+
+        Self::do_handshake_cert(session, opts)
+    }
+
+    /// Cert-based AACS handshake. The legacy auth path; still used as
+    /// the fallback when the OEM VID path isn't available or fails.
+    fn do_handshake_cert(
+        session: &mut crate::drive::Drive,
+        opts: &ScanOptions,
+    ) -> (Option<HandshakeResult>, Option<Error>) {
+        use crate::aacs::{self, KeyDb};
+
         let keydb_path = match opts.resolve_keydb() {
             Some(p) => p,
             None => {
@@ -35,7 +189,7 @@ impl Disc {
                     phase = "handshake_no_keydb",
                     "no KEYDB found in search paths; handshake skipped"
                 );
-                return None;
+                return (None, None);
             }
         };
         let keydb = match KeyDb::load(&keydb_path) {
@@ -48,7 +202,12 @@ impl Disc {
                     keydb = %keydb_path.display(),
                     "KEYDB load failed; handshake skipped"
                 );
-                return None;
+                return (
+                    None,
+                    Some(Error::KeydbLoad {
+                        path: keydb_path.display().to_string(),
+                    }),
+                );
             }
         };
 
@@ -61,9 +220,36 @@ impl Disc {
             "handshake starting"
         );
 
-        const MAX_CERT_ATTEMPTS: usize = 16;
+        if host_cert_count == 0 {
+            // No host certs in keydb -> cert auth cannot proceed.
+            // Surface as RawReadUnsupported so the caller knows
+            // neither path is available on this configuration.
+            return (None, Some(Error::AacsRawReadUnsupported));
+        }
+
+        // v0.25.7 wedge fix. Pre-0.25.7 this loop fired up to 16 AACS
+        // authenticate attempts back-to-back with no pause. Each attempt
+        // is 5-10 SCSI REPORT_KEY/SEND_KEY exchanges. On a disc whose
+        // host cert isn't in our KEYDB (or one the drive rejects),
+        // that's 80-160 SCSI commands hammered at the drive in a
+        // few hundred milliseconds — and the BU40N (and most consumer
+        // optical drives) responds by entering a fast-fail firmware
+        // wedge state where every subsequent CDB returns
+        // ILLEGAL_REQUEST/INVALID_FIELD_IN_CDB (sense 05/24) until
+        // power-cycled. Hit live on rip1 2026-05-20 during a MOVIE
+        // UHD scan: KEYDB miss → 16 cert attempts in a tight loop →
+        // wedge → forced host reboot + drive disconnect to recover.
+        //
+        // Defense-in-depth: cap attempts, sleep between, and bail
+        // early on the drive's wedge sense so any later regression
+        // can't undo the protection silently.
+        const MAX_CERT_ATTEMPTS: usize = 3;
+        const PER_CERT_BACKOFF_MS: u64 = 1000;
         let mut last_err_code: Option<u16> = None;
         for (idx, hc) in keydb.host_certs.iter().take(MAX_CERT_ATTEMPTS).enumerate() {
+            if idx > 0 {
+                std::thread::sleep(std::time::Duration::from_millis(PER_CERT_BACKOFF_MS));
+            }
             match aacs::handshake::aacs_authenticate(session, &hc.private_key, &hc.certificate) {
                 Ok(mut auth) => {
                     let volume_id = match aacs::handshake::read_volume_id(session, &mut auth) {
@@ -76,7 +262,7 @@ impl Disc {
                                 error_code = e.code(),
                                 "auth ok but volume ID read failed"
                             );
-                            return None;
+                            return (None, Some(Error::AacsVidUnavailable));
                         }
                     };
                     let read_data_key = aacs::handshake::read_data_keys(session, &mut auth)
@@ -88,13 +274,33 @@ impl Disc {
                         cert_index = idx,
                         has_read_data_key = read_data_key.is_some(),
                     );
-                    return Some(HandshakeResult {
-                        volume_id,
-                        read_data_key,
-                    });
+                    return (
+                        Some(HandshakeResult {
+                            volume_id,
+                            read_data_key,
+                        }),
+                        None,
+                    );
                 }
                 Err(e) => {
-                    last_err_code = Some(e.code());
+                    let code = e.code();
+                    last_err_code = Some(code);
+                    // Drive wedge senses (any with high byte 0x05 =
+                    // ILLEGAL_REQUEST). The drive isn't merely
+                    // rejecting our cert — it's saying "I won't talk
+                    // to you anymore." Trying more certs makes the
+                    // wedge worse. Bail out immediately.
+                    let sense_key = ((code >> 8) & 0xFF) as u8;
+                    if sense_key == 0x05 {
+                        tracing::warn!(
+                            target: "freemkv::disc",
+                            phase = "handshake_wedge_detected",
+                            cert_index = idx,
+                            error_code = code,
+                            "drive returned ILLEGAL_REQUEST during auth; bailing out to avoid wedge"
+                        );
+                        return (None, Some(Error::AacsHostCertRejected));
+                    }
                     continue;
                 }
             }
@@ -105,10 +311,10 @@ impl Disc {
             host_cert_count,
             tried = host_cert_count.min(MAX_CERT_ATTEMPTS),
             last_error_code = last_err_code,
-            "all host certs in KEYDB rejected by drive"
+            "all host certs in KEYDB rejected by drive (capped at {} attempts to prevent firmware wedge)",
+            MAX_CERT_ATTEMPTS
         );
-        // All host certs failed — return None, not a fake success
-        None
+        (None, Some(Error::AacsHostCertRejected))
     }
 
     /// Resolve disc encryption — AACS 1.0, AACS 2.0, CSS, or none.
@@ -123,6 +329,7 @@ impl Disc {
         handshake: Option<&HandshakeResult>,
     ) -> Result<AacsState> {
         use crate::aacs::{self, KeyDb};
+        use crate::drm::{DrmContext, DrmProbe, DrmScheme, ResolvedScheme};
 
         let keydb = KeyDb::load(keydb_path).map_err(|_| Error::KeydbLoad {
             path: keydb_path.display().to_string(),
@@ -181,30 +388,77 @@ impl Disc {
         );
 
         // Use handshake volume ID if available, otherwise zeros
-        // (KEYDB VUK lookup by disc hash works without volume ID)
+        // (KEYDB VUK lookup by disc hash works without volume ID;
+        // paths 2/3/4 in `resolve_keys` short-circuit on the zero
+        // sentinel and don't waste cycles trying to derive against
+        // garbage input).
         let volume_id = handshake.map(|h| h.volume_id).unwrap_or([0u8; 16]);
+        let vid_available = volume_id != [0u8; 16];
         let read_data_key = handshake.and_then(|h| h.read_data_key);
 
-        // Resolve: tries all available paths — KEYDB VUK, media key, processing key, device key
-        let resolved = aacs::resolve_keys(
-            &uk_ro_data,
-            cc_data.as_deref(),
-            &volume_id,
-            &keydb,
-            mkb_data.as_deref(),
-        )
-        .ok_or(Error::AacsNoKeys)?;
+        // Resolve: tries all available paths — KEYDB VUK, media key, processing key, device key.
+        //
+        // Distinguish "we had every input and still missed" from "we
+        // never had VID so the derivation paths couldn't run." The
+        // former points at a stale keydb / unsupported MKB; the
+        // latter points at a failed handshake upstream. Path 1
+        // (disc-hash lookup) ran without VID and missed -> disc isn't
+        // in the keydb. If the caller has a handshake-failure reason
+        // it overrides this in `scan_with`.
+        let miss_error = if vid_available {
+            Error::AacsMkUnavailable
+        } else {
+            Error::AacsVukNotInKeydb
+        };
+
+        // Build a probe + context and let the dispatcher pick V10 / V20
+        // / V21. CSS is impossible here (this function is only called
+        // when /AACS exists), so we don't populate the DVD probe sector
+        // or a CSS context.
+        let probe = DrmProbe {
+            dvd_sample_sector: None,
+            content_cert: cc_data.as_deref(),
+            mkb: mkb_data.as_deref(),
+        };
+        let scheme = match DrmScheme::detect(&probe) {
+            Some(s) => s,
+            None => return Err(miss_error),
+        };
+        let providers: &[&dyn aacs::KeyProvider] = &[&keydb];
+        let aacs_ctx = aacs::ResolveContext {
+            unit_key_ro: &uk_ro_data,
+            content_cert: cc_data.as_deref(),
+            volume_id: &volume_id,
+            providers,
+            mkb: mkb_data.as_deref(),
+        };
+        let mut ctx = DrmContext {
+            aacs: Some(aacs_ctx),
+            css: None,
+        };
+        let resolved = match scheme.load(&mut ctx) {
+            Some(ResolvedScheme::Aacs(r)) => r,
+            // Resolution against /AACS inputs can only produce AACS
+            // keys. Either the dispatcher returned None (load failed)
+            // or — structurally impossible here — a CSS state. Both
+            // surface as the upstream miss-error.
+            _ => return Err(miss_error),
+        };
 
         Ok(AacsState {
-            version: if resolved.aacs2 { 2 } else { 1 },
+            version: match resolved.version {
+                aacs::AacsVersion::V10 => 1,
+                aacs::AacsVersion::V20 | aacs::AacsVersion::V21 => 2,
+            },
             bus_encryption: resolved.bus_encryption,
             mkb_version: mkb_ver,
             disc_hash: aacs::disc_hash_hex(&resolved.disc_hash),
             key_source: match resolved.key_source {
-                1 => KeySource::KeyDb,
-                2 => KeySource::KeyDbDerived,
-                3 => KeySource::ProcessingKey,
-                4 => KeySource::DeviceKey,
+                1 => KeySource::DeviceKey,
+                2 => KeySource::ProcessingKey,
+                3 => KeySource::KeyDbDerived,
+                4 => KeySource::KeyDb,
+                5 => KeySource::KeyDbUnitKeys,
                 _ => KeySource::KeyDb,
             },
             vuk: resolved.vuk,
@@ -213,4 +467,66 @@ impl Disc {
             volume_id,
         })
     }
+
+    /// Resolve encryption from a caller-supplied Unit Key (the keyserver
+    /// path). No keydb, no derivation: read `Unit_Key_RO.inf` for the disc
+    /// hash + version/bus-encryption flags, then use `unit_key` directly as
+    /// CPS unit 1's decryption key. The handshake (if any) still supplies the
+    /// volume ID and AACS 2.0 read-data key for bus decryption.
+    pub(super) fn resolve_encryption_static(
+        udf_fs: &udf::UdfFs,
+        reader: &mut dyn SectorSource,
+        unit_key: [u8; 16],
+        handshake: Option<&HandshakeResult>,
+    ) -> Result<AacsState> {
+        use crate::aacs;
+
+        let uk_ro_data = udf_fs
+            .read_file(reader, "/AACS/Unit_Key_RO.inf")
+            .or_else(|_| udf_fs.read_file(reader, "/AACS/DUPLICATE/Unit_Key_RO.inf"))
+            .map_err(|_| Error::AacsNoKeys)?;
+        let dh = aacs::disc_hash(&uk_ro_data);
+
+        let cc = udf_fs
+            .read_file(reader, "/AACS/Content000.cer")
+            .or_else(|_| udf_fs.read_file(reader, "/AACS/Content001.cer"))
+            .ok()
+            .as_deref()
+            .and_then(aacs::parse_content_cert);
+        let bus_encryption = cc.as_ref().map(|c| c.bus_encryption).unwrap_or(false);
+        let version = match cc.as_ref().map(|c| c.version) {
+            Some(aacs::AacsVersion::V10) => 1,
+            Some(_) => 2,
+            None if bus_encryption => 2,
+            None => 1,
+        };
+
+        let mkb_ver = udf_fs
+            .read_file(reader, "/AACS/MKB_RW.inf")
+            .or_else(|_| udf_fs.read_file(reader, "/AACS/MKB_RO.inf"))
+            .ok()
+            .as_deref()
+            .and_then(aacs::mkb_version);
+
+        tracing::warn!(
+            target: "freemkv::disc",
+            phase = "scan_aacs_external_uk",
+            disc_hash = %aacs::disc_hash_hex(&dh),
+            version,
+            bus_encryption,
+            "using caller-supplied unit key (keyserver path)"
+        );
+
+        Ok(AacsState {
+            version,
+            bus_encryption,
+            mkb_version: mkb_ver,
+            disc_hash: aacs::disc_hash_hex(&dh),
+            key_source: KeySource::ExternalUk,
+            vuk: None,
+            unit_keys: vec![(1, unit_key)],
+            read_data_key: handshake.and_then(|h| h.read_data_key),
+            volume_id: handshake.map(|h| h.volume_id).unwrap_or([0u8; 16]),
+        })
+    }
 }

src/disc/mapfile.rs

@@ -130,6 +130,11 @@ pub struct Mapfile {
     /// Wall-clock timestamp of the last successful `write_to_disk` (or
     /// the moment the mapfile was constructed, whichever is later).
     last_flushed: Instant,
+    /// AACS Volume ID (16 bytes) for the disc, persisted as a
+    /// `# freemkv-vid:` comment header so it survives to deferred-mux /
+    /// resume without altering the ISO payload or breaking ddrescue
+    /// data-line parsing. `None` for unencrypted / non-AACS discs.
+    vid: Option<[u8; 16]>,
 }
 
 impl Mapfile {
@@ -154,6 +159,7 @@ impl Mapfile {
             },
             dirty: false,
             last_flushed: Instant::now(),
+            vid: None,
         };
         // Eager initial persist so a resume can pick this up even if
         // `record()` is never called.
@@ -168,6 +174,7 @@ impl Mapfile {
         let mut entries = Vec::new();
         let mut saw_current_line = false;
         let mut version = String::from("unknown");
+        let mut vid: Option<[u8; 16]> = None;
         for line in text.lines() {
             let t = line.trim();
             if t.is_empty() {
@@ -178,6 +185,11 @@ impl Mapfile {
                 if let Some(v) = rest.strip_prefix("Rescue Logfile. Created by ") {
                     version = v.to_string();
                 }
+                if let Some(hex) = rest.strip_prefix("freemkv-vid:") {
+                    // Best-effort: a malformed or short VID comment is
+                    // ignored rather than failing the whole load.
+                    vid = parse_vid_hex(hex.trim());
+                }
                 continue;
             }
             // First non-comment line is the "current" state line (pos status [pass] [pass_time]).
@@ -227,6 +239,7 @@ impl Mapfile {
             stats,
             dirty: false,
             last_flushed: Instant::now(),
+            vid,
         })
     }
 
@@ -316,6 +329,22 @@ impl Mapfile {
         Ok(())
     }
 
+    /// Record the disc's 16-byte AACS Volume ID so it persists in the
+    /// mapfile's comment header. Marks the mapfile dirty; the next
+    /// `flush()` / `Drop` writes the `# freemkv-vid:` line. Does not
+    /// touch the ISO payload or the ddrescue data lines.
+    pub fn set_vid(&mut self, vid: [u8; 16]) {
+        self.vid = Some(vid);
+        self.dirty = true;
+    }
+
+    /// The disc's AACS Volume ID, if one was set or parsed from a
+    /// `# freemkv-vid:` comment on load. `None` for unencrypted /
+    /// non-AACS discs.
+    pub fn vid(&self) -> Option<[u8; 16]> {
+        self.vid
+    }
+
     pub fn entries(&self) -> &[MapEntry] {
         &self.entries
     }
@@ -388,6 +417,18 @@ impl Mapfile {
             let file = std::fs::File::create(&tmp)?;
             let mut w = std::io::BufWriter::new(file);
             writeln!(w, "# Rescue Logfile. Created by {}", self.version)?;
+            // VID comment lives in the header block. ddrescue treats any
+            // `#`-prefixed line as a comment, so this round-trips through
+            // our `load()` without affecting the `pos size status` data
+            // parser. 16 bytes → 32 lowercase hex chars.
+            if let Some(vid) = self.vid {
+                let mut hex = String::with_capacity(32);
+                for b in vid {
+                    use std::fmt::Write as _;
+                    let _ = write!(hex, "{b:02x}");
+                }
+                writeln!(w, "# freemkv-vid: {hex}")?;
+            }
             writeln!(w, "# Current pos / status / pass / pass_time")?;
             writeln!(w, "0x000000000  ?  1  0")?;
             writeln!(w, "#      pos        size  status")?;
@@ -417,6 +458,22 @@ impl Drop for Mapfile {
     }
 }
 
+/// Parse a 32-char lowercase/uppercase hex string into a 16-byte VID.
+/// Returns `None` on any malformation (wrong length, non-hex) — the
+/// caller treats a bad VID comment as simply absent rather than an
+/// error, so a corrupt header never fails a mapfile load.
+fn parse_vid_hex(s: &str) -> Option<[u8; 16]> {
+    let s = s.strip_prefix("0x").unwrap_or(s);
+    if s.len() != 32 {
+        return None;
+    }
+    let mut out = [0u8; 16];
+    for (i, b) in out.iter_mut().enumerate() {
+        *b = u8::from_str_radix(&s[i * 2..i * 2 + 2], 16).ok()?;
+    }
+    Some(out)
+}
+
 fn parse_hex(s: &str) -> io::Result<u64> {
     let s = s.strip_prefix("0x").unwrap_or(s);
     u64::from_str_radix(s, 16).map_err(|_| {
@@ -583,6 +640,79 @@ mod tests {
         let _ = std::fs::remove_file(&p);
     }
 
+    #[test]
+    fn vid_round_trips_and_data_lines_unaffected() {
+        let p = tmpfile("vid_round_trips");
+        let _ = std::fs::remove_file(&p);
+
+        // Build a mapfile with some data ranges, set a VID, persist.
+        let mut mf = Mapfile::create(&p, 1000, "test").unwrap();
+        mf.record(100, 200, SectorStatus::Finished).unwrap();
+        mf.record(500, 100, SectorStatus::Unreadable).unwrap();
+        mf.record(700, 50, SectorStatus::NonTrimmed).unwrap();
+        let vid: [u8; 16] = [
+            0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd,
+            0xee, 0xff,
+        ];
+        mf.set_vid(vid);
+        mf.flush().unwrap();
+
+        // The saved file must contain the VID comment in lowercase hex.
+        let text = std::fs::read_to_string(&p).unwrap();
+        assert!(
+            text.contains("# freemkv-vid:"),
+            "saved mapfile missing VID comment: {text}"
+        );
+        assert!(
+            text.contains("# freemkv-vid: 00112233445566778899aabbccddeeff"),
+            "VID comment format mismatch: {text}"
+        );
+
+        // load() recovers the VID and the identical data ranges.
+        let loaded = Mapfile::load(&p).unwrap();
+        assert_eq!(loaded.vid(), Some(vid));
+        assert_eq!(loaded.entries(), mf.entries());
+
+        // A mapfile WITHOUT the VID comment must parse the same +/-/?
+        // data ranges as the one WITH it (comment ignored by parser).
+        let p2 = tmpfile("vid_round_trips_novid");
+        let _ = std::fs::remove_file(&p2);
+        let mut mf2 = Mapfile::create(&p2, 1000, "test").unwrap();
+        mf2.record(100, 200, SectorStatus::Finished).unwrap();
+        mf2.record(500, 100, SectorStatus::Unreadable).unwrap();
+        mf2.record(700, 50, SectorStatus::NonTrimmed).unwrap();
+        mf2.flush().unwrap();
+        let loaded_novid = Mapfile::load(&p2).unwrap();
+        assert_eq!(loaded_novid.vid(), None);
+        assert_eq!(loaded_novid.entries(), loaded.entries());
+
+        // Malformed VID comments must not error the load (treated absent).
+        let mut bad = text.replace("00112233445566778899aabbccddeeff", "zzzz");
+        let pbad = tmpfile("vid_round_trips_bad");
+        let _ = std::fs::remove_file(&pbad);
+        std::fs::write(&pbad, &bad).unwrap();
+        let loaded_bad = Mapfile::load(&pbad).unwrap();
+        assert_eq!(loaded_bad.vid(), None);
+        assert_eq!(loaded_bad.entries(), loaded.entries());
+
+        // A load->save cycle preserves the VID (the patch-pass path).
+        bad.clear();
+        let resaved = tmpfile("vid_round_trips_resave");
+        let _ = std::fs::remove_file(&resaved);
+        let mut reloaded = Mapfile::load(&p).unwrap();
+        // Repoint at a fresh path and flush; mark dirty via a no-op record.
+        reloaded.path = resaved.clone();
+        reloaded.dirty = true;
+        reloaded.flush().unwrap();
+        let again = Mapfile::load(&resaved).unwrap();
+        assert_eq!(again.vid(), Some(vid));
+
+        let _ = std::fs::remove_file(&p);
+        let _ = std::fs::remove_file(&p2);
+        let _ = std::fs::remove_file(&pbad);
+        let _ = std::fs::remove_file(&resaved);
+    }
+
     #[test]
     fn stats_consistent_after_split_record() {
         let p = tmpfile("stats_consistent_after_split");

src/disc/mod.rs

@@ -883,8 +883,10 @@ pub struct AacsState {
     pub disc_hash: String,
     /// How keys were resolved
     pub key_source: KeySource,
-    /// Volume Unique Key (16 bytes)
-    pub vuk: [u8; 16],
+    /// Volume Unique Key (16 bytes). `None` when keys were resolved
+    /// via the [`KeySource::KeyDbUnitKeys`] path — that source delivers
+    /// pre-decrypted unit keys without a VUK to derive them from.
+    pub vuk: Option<[u8; 16]>,
     /// Decrypted unit keys (CPS unit number, key)
     pub unit_keys: Vec<(u32, [u8; 16])>,
     /// Read data key for AACS 2.0 bus decryption -- None for AACS 1.0
@@ -893,26 +895,37 @@ pub struct AacsState {
     pub volume_id: [u8; 16],
 }
 
-/// How AACS keys were resolved.
+/// How AACS keys were resolved. Variants are ordered root-of-trust →
+/// per-disc-leaf, matching the resolver's path-try order: the resolver
+/// attempts derivation from the strongest input it has first and falls
+/// back toward pre-computed per-disc material.
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum KeySource {
-    /// VUK found directly in KEYDB by disc hash
-    KeyDb,
-    /// Media key + Volume ID from KEYDB → derived VUK
-    KeyDbDerived,
-    /// MKB + processing keys → media key → VUK
-    ProcessingKey,
     /// MKB + device keys → subset-difference tree → VUK
     DeviceKey,
+    /// MKB + processing keys → media key → VUK
+    ProcessingKey,
+    /// Media key + Volume ID from KEYDB → derived VUK
+    KeyDbDerived,
+    /// VUK found directly in KEYDB by disc hash
+    KeyDb,
+    /// Pre-decrypted unit keys taken directly from KEYDB by disc hash.
+    /// No VUK present in the entry — `AacsState::vuk` is `None`.
+    KeyDbUnitKeys,
+    /// Unit key supplied directly by the caller (the keyserver path).
+    /// No keydb, no derivation — `AacsState::vuk` is `None`.
+    ExternalUk,
 }
 
 impl KeySource {
     pub fn name(&self) -> &'static str {
         match self {
-            KeySource::KeyDb => "KEYDB",
-            KeySource::KeyDbDerived => "KEYDB (derived)",
-            KeySource::ProcessingKey => "MKB + processing key",
             KeySource::DeviceKey => "MKB + device key",
+            KeySource::ProcessingKey => "MKB + processing key",
+            KeySource::KeyDbDerived => "KEYDB (derived)",
+            KeySource::KeyDb => "KEYDB",
+            KeySource::KeyDbUnitKeys => "KEYDB (unit keys)",
+            KeySource::ExternalUk => "external UK",
         }
     }
 }
@@ -932,6 +945,13 @@ pub struct ScanOptions {
     /// Path to KEYDB.cfg for AACS key lookup.
     /// If None, searches standard locations ($HOME/.config/aacs/ and /etc/aacs/).
     pub keydb_path: Option<std::path::PathBuf>,
+    /// Caller-supplied Unit Key — the second, mutually-exclusive key source
+    /// (the online-keyserver path). When set, libfreemkv skips keydb lookup
+    /// and all derivation and uses this key directly to decrypt. Takes
+    /// precedence over `keydb_path` if both are set. The caller obtains it
+    /// however it likes (e.g. POSTing the disc's `Unit_Key_RO.inf` + MKB to a
+    /// keyserver); libfreemkv stays free of any network dependency.
+    pub unit_key: Option<[u8; 16]>,
 }
 
 impl ScanOptions {
@@ -961,9 +981,9 @@ impl ScanOptions {
 /// Quick disc identification — name, format, capacity. No title/stream parsing.
 #[derive(Debug)]
 pub struct DiscId {
-    /// UDF Volume Identifier (always present, e.g. "V_FOR_VENDETTA")
+    /// UDF Volume Identifier (always present, e.g. "SAMPLE_FILM")
     pub volume_id: String,
-    /// Disc title from META/DL/bdmt_eng.xml (e.g. "V for Vendetta")
+    /// Disc title from META/DL/bdmt_eng.xml (e.g. "Sample Film")
     pub meta_title: Option<String>,
     /// Disc format (BD, UHD, DVD) — UHD vs BD requires full scan to confirm
     pub format: DiscFormat,
@@ -1043,8 +1063,11 @@ impl Disc {
     /// The session must be open and unlocked (Drive::open handles this).
     /// All disc reads use standard READ(10) via UDF -- no vendor SCSI commands.
     pub fn scan(session: &mut Drive, opts: &ScanOptions) -> Result<Self> {
-        // AACS handshake (Blu-ray/UHD)
-        let handshake = Self::do_handshake(session, opts);
+        // AACS handshake (Blu-ray/UHD). Routes through Disc::read_vid,
+        // which prefers the per-drive OEM CDB path when the drive is
+        // in the extended-access state and falls back to cert-based
+        // mutual auth otherwise.
+        let (handshake, handshake_error) = Self::do_handshake(session, opts);
 
         // Request max read speed — removes riplock on DVD
         // (BD/UHD speed is set by firmware init, but DVD needs explicit SET CD SPEED)
@@ -1059,31 +1082,56 @@ impl Disc {
             buffered.prefetch_ranges(&ranges);
         }
 
-        let mut disc = Self::scan_with(&mut buffered, capacity, handshake, opts, udf_fs)?;
+        let mut disc = Self::scan_with(
+            &mut buffered,
+            capacity,
+            handshake,
+            handshake_error,
+            opts,
+            udf_fs,
+        )?;
 
         // CSS key extraction for DVDs (bus auth → disc key → title key).
         // Must be a single auth session — can't call authenticate() separately.
+        // Route through the DRM dispatcher: probe a title sector, detect
+        // CSS if scrambled, then load via the SCSI auth path.
         if disc.css.is_none()
             && disc.content_format == ContentFormat::MpegPs
             && !disc.titles.is_empty()
         {
-            let lba = disc.titles[0].extents.iter().find_map(|ext| {
-                let mut buf = vec![0u8; 2048];
+            let mut probe_buf = vec![0u8; 2048];
+            let auth_lba = disc.titles[0].extents.iter().find_map(|ext| {
                 if session
-                    .read_sectors(ext.start_lba, 1, &mut buf, true)
+                    .read_sectors(ext.start_lba, 1, &mut probe_buf, true)
                     .is_ok()
-                    && crate::css::is_scrambled(&buf)
                 {
-                    return Some(ext.start_lba);
+                    let probe = crate::drm::DrmProbe {
+                        dvd_sample_sector: Some(&probe_buf),
+                        content_cert: None,
+                        mkb: None,
+                    };
+                    if crate::drm::DrmScheme::detect(&probe) == Some(crate::drm::DrmScheme::Css) {
+                        return Some(ext.start_lba);
+                    }
                 }
                 None
             });
 
-            if let Some(lba) = lba {
-                if let Ok(title_key) =
-                    crate::css::auth::authenticate_and_read_title_key(session, lba)
+            if let Some(lba) = auth_lba {
+                let css_ctx = crate::css::CssContext {
+                    drive: Some(session),
+                    auth_lba: Some(lba),
+                    reader: None,
+                    extents: None,
+                };
+                let mut ctx = crate::drm::DrmContext {
+                    aacs: None,
+                    css: Some(css_ctx),
+                };
+                if let Some(crate::drm::ResolvedScheme::Css(state)) =
+                    crate::drm::DrmScheme::Css.load(&mut ctx)
                 {
-                    disc.css = Some(crate::css::CssState { title_key });
+                    disc.css = Some(state);
                     disc.encrypted = true;
                 }
             }
@@ -1100,14 +1148,60 @@ impl Disc {
         opts: &ScanOptions,
     ) -> Result<Self> {
         let udf_fs = udf::read_filesystem(reader)?;
-        Self::scan_with(reader, capacity, None, opts, udf_fs)
+        Self::scan_with(reader, capacity, None, None, opts, udf_fs)
+    }
+
+    /// Read a disc's AACS key-input files from an ISO image: returns
+    /// `(Unit_Key_RO.inf, MKB)` raw bytes. For callers that resolve keys
+    /// out-of-band (the keyserver path) — POST these to the keyserver, get the
+    /// Unit Key, then scan with `ScanOptions { unit_key: Some(uk), .. }`.
+    /// libfreemkv itself never makes the network call.
+    pub fn read_aacs_inputs(iso_path: &std::path::Path) -> Result<(Vec<u8>, Vec<u8>)> {
+        let mut reader = crate::io::file_sector_source::FileSectorSource::open(iso_path)
+            .map_err(|_| Error::AacsNoKeys)?;
+        let udf_fs = udf::read_filesystem(&mut reader)?;
+        let inf = udf_fs
+            .read_file(&mut reader, "/AACS/Unit_Key_RO.inf")
+            .or_else(|_| udf_fs.read_file(&mut reader, "/AACS/DUPLICATE/Unit_Key_RO.inf"))
+            .map_err(|_| Error::AacsNoKeys)?;
+        let mkb = udf_fs
+            .read_file(&mut reader, "/AACS/MKB_RW.inf")
+            .or_else(|_| udf_fs.read_file(&mut reader, "/AACS/MKB_RO.inf"))
+            .map_err(|_| Error::AacsNoKeys)?;
+        Ok((inf, mkb))
+    }
+
+    /// Same as [`Disc::read_aacs_inputs`] but reads from a live drive. Keys are
+    /// needed *during* scan and the ISO only exists post-rip, so the keyserver
+    /// path fetches the disc's key files from the live drive before
+    /// [`Disc::scan`], POSTs them, then scans with
+    /// `ScanOptions { unit_key: Some(uk), .. }`. These files are plaintext UDF
+    /// metadata — no AACS handshake or keys are required to read them.
+    pub fn read_aacs_inputs_from_drive(drive: &mut Drive) -> Result<(Vec<u8>, Vec<u8>)> {
+        let (_, mut reader, udf_fs) = Self::read_udf(drive)?;
+        let inf = udf_fs
+            .read_file(&mut reader, "/AACS/Unit_Key_RO.inf")
+            .or_else(|_| udf_fs.read_file(&mut reader, "/AACS/DUPLICATE/Unit_Key_RO.inf"))
+            .map_err(|_| Error::AacsNoKeys)?;
+        let mkb = udf_fs
+            .read_file(&mut reader, "/AACS/MKB_RW.inf")
+            .or_else(|_| udf_fs.read_file(&mut reader, "/AACS/MKB_RO.inf"))
+            .map_err(|_| Error::AacsNoKeys)?;
+        Ok((inf, mkb))
     }
 
     /// Core scan pipeline — works with any SectorSource.
+    ///
+    /// `handshake_error` is plumbed from `do_handshake` so failures
+    /// (cert rejected, raw-read unsupported, VID read failed) are
+    /// preserved as `disc.aacs_error` for callers to render. When key
+    /// resolution succeeds despite the handshake failure (built-in
+    /// keys + disc-hash lookup hit) the error is dropped.
     fn scan_with(
         reader: &mut dyn SectorSource,
         capacity: u32,
         handshake: Option<HandshakeResult>,
+        handshake_error: Option<Error>,
         opts: &ScanOptions,
         udf_fs: udf::UdfFs,
     ) -> Result<Self> {
@@ -1115,22 +1209,44 @@ impl Disc {
         let encrypted =
             udf_fs.find_dir("/AACS").is_some() || udf_fs.find_dir("/BDMV/AACS").is_some();
 
-        let (aacs, aacs_error) = if encrypted {
+        let (aacs, aacs_error) = if !encrypted {
+            (None, None)
+        } else if let Some(unit_key) = opts.unit_key {
+            // Second key source: caller supplied the Unit Key directly
+            // (keyserver path). Skip keydb entirely.
+            match Self::resolve_encryption_static(&udf_fs, reader, unit_key, handshake.as_ref()) {
+                Ok(state) => (Some(state), None),
+                Err(e) => (None, Some(e)),
+            }
+        } else {
             match opts.resolve_keydb() {
                 Some(keydb_path) => {
                     match Self::resolve_encryption(&udf_fs, reader, &keydb_path, handshake.as_ref())
                     {
                         Ok(state) => (Some(state), None),
                         Err(e) => {
+                            // When the handshake itself failed AND resolution
+                            // bottomed out at "no keys", surface the upstream
+                            // handshake failure — it's more actionable than
+                            // the generic AacsNoKeys.
+                            let final_err = match (&e, handshake_error.as_ref()) {
+                                (
+                                    Error::AacsNoKeys
+                                    | Error::AacsVukNotInKeydb
+                                    | Error::AacsVidUnavailable,
+                                    Some(_),
+                                ) => handshake_error.unwrap(),
+                                _ => e,
+                            };
                             tracing::warn!(
                                 target: "freemkv::disc",
                                 phase = "scan_aacs_resolve_failed",
-                                error_code = e.code(),
+                                error_code = final_err.code(),
                                 keydb = %keydb_path.display(),
                                 handshake_ok = handshake.is_some(),
                                 "AACS key resolution failed"
                             );
-                            (None, Some(e))
+                            (None, Some(final_err))
                         }
                     }
                 }
@@ -1140,20 +1256,16 @@ impl Disc {
                         phase = "scan_aacs_no_keydb",
                         "encrypted disc but no KEYDB found in search paths"
                     );
-                    // Reuse KeydbLoad with sentinel path — adding a new Error
-                    // variant would be a breaking change for downstream
-                    // exhaustive matches. The path string makes the cause
-                    // unambiguous to autorip's message switch.
-                    (
-                        None,
-                        Some(crate::error::Error::KeydbLoad {
+                    // Sentinel path string lets autorip's message switch
+                    // distinguish "no keydb found anywhere" from "keydb at
+                    // <path> failed to parse".
+                    let final_err =
+                        handshake_error.unwrap_or_else(|| crate::error::Error::KeydbLoad {
                             path: String::from("<no keydb in search paths>"),
-                        }),
-                    )
+                        });
+                    (None, Some(final_err))
                 }
             }
-        } else {
-            (None, None)
         };
 
         // 3. Titles — BD (MPLS playlists) or DVD (IFO title sets)
@@ -1190,9 +1302,27 @@ impl Disc {
         let layers = if capacity > 24_000_000 { 2 } else { 1 };
         let region = DiscRegion::Free;
 
-        // 6. CSS detection for DVDs
+        // 6. CSS detection for DVDs — route through the DRM dispatcher.
+        //    Detection from a single probe sector would miss
+        //    DVDs whose first sector is unscrambled, so we go straight
+        //    to `DrmScheme::Css.load` with the crack-path context; the
+        //    crack path scans extents internally and bottoms out at
+        //    None on unencrypted media.
         let css = if content_format == ContentFormat::MpegPs && !titles.is_empty() {
-            crate::css::crack_key(reader, &titles[0].extents)
+            let css_ctx = crate::css::CssContext {
+                drive: None,
+                auth_lba: None,
+                reader: Some(reader),
+                extents: Some(&titles[0].extents),
+            };
+            let mut ctx = crate::drm::DrmContext {
+                aacs: None,
+                css: Some(css_ctx),
+            };
+            match crate::drm::DrmScheme::Css.load(&mut ctx) {
+                Some(crate::drm::ResolvedScheme::Css(s)) => Some(s),
+                _ => None,
+            }
         } else {
             None
         };
@@ -1415,6 +1545,7 @@ impl Disc {
             skip_on_error: opts.multipass,
             progress: opts.progress,
             halt: opts.halt.clone(),
+            vid: opts.vid,
         };
         self.sweep(reader, path, &sweep_opts)
     }
@@ -1506,13 +1637,22 @@ impl Disc {
         if !opts.resume {
             let _ = std::fs::remove_file(&mapfile_path);
         }
-        let map = mapfile::Mapfile::open_or_create(
+        let mut map = mapfile::Mapfile::open_or_create(
             &mapfile_path,
             total_bytes,
             concat!("libfreemkv v", env!("CARGO_PKG_VERSION")),
         )
         .map_err(|e| Error::IoError { source: e })?;
 
+        // Persist the disc's AACS Volume ID into the mapfile header so it
+        // survives to deferred-mux / resume. ddrescue-safe (comment line);
+        // does not touch the ISO payload. On a resume-load the VID is
+        // already present, but re-setting it (idempotent) covers the case
+        // where Pass 1 created the mapfile before the VID was known.
+        if let Some(vid) = opts.vid {
+            map.set_vid(vid);
+        }
+
         // ISO file: if resuming and mapfile has Finished ranges, open existing;
         // otherwise create fresh and pre-size to total_bytes (sparse holes for
         // non-tried regions).
@@ -1984,6 +2124,11 @@ pub struct CopyOptions<'a> {
     pub multipass: bool,
     pub progress: Option<&'a dyn crate::progress::Progress>,
     pub halt: Option<std::sync::Arc<std::sync::atomic::AtomicBool>>,
+    /// AACS Volume ID (16 bytes) to persist into the mapfile during
+    /// Pass 1 so it survives to deferred-mux / resume. `None` for
+    /// unencrypted / non-AACS discs. Caller wires this from
+    /// `Disc::aacs.volume_id`.
+    pub vid: Option<[u8; 16]>,
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -2005,6 +2150,9 @@ pub struct SweepOptions<'a> {
     pub skip_on_error: bool,
     pub progress: Option<&'a dyn crate::progress::Progress>,
     pub halt: Option<std::sync::Arc<std::sync::atomic::AtomicBool>>,
+    /// AACS Volume ID (16 bytes) persisted into the mapfile when the
+    /// sweep creates / opens it. `None` for unencrypted discs.
+    pub vid: Option<[u8; 16]>,
 }
 
 /// Options for [`Disc::patch`] (Pass N retry pass over bad ranges).
@@ -2515,6 +2663,7 @@ mod tests {
             multipass: true,
             progress: None,
             halt: None,
+            vid: None,
         };
         let result = disc.copy(&mut reader, &iso_path, &opts);
         assert!(
@@ -2539,6 +2688,7 @@ mod tests {
             multipass: true,
             progress: None,
             halt: None,
+            vid: None,
         };
         let result = disc.copy(&mut reader, std::path::Path::new("/dev/null"), &opts);
         assert!(
@@ -2569,6 +2719,7 @@ mod tests {
             multipass: false,
             progress: None,
             halt: None,
+            vid: None,
         };
         let result = disc.copy(&mut reader, std::path::Path::new("/dev/null"), &opts);
         assert!(
@@ -2598,6 +2749,7 @@ mod tests {
             multipass: true,
             progress: None,
             halt: None,
+            vid: None,
         };
         let sweep_result = disc.copy(&mut reader, &iso_path, &sweep_opts);
         assert!(
@@ -2615,6 +2767,7 @@ mod tests {
             multipass: true,
             progress: None,
             halt: None,
+            vid: None,
         };
         let patch_result = disc.copy(&mut reader2, &iso_path, &patch_opts);
         assert!(
@@ -2647,6 +2800,7 @@ mod tests {
             multipass: true,
             progress: None,
             halt: None,
+            vid: None,
         };
         let _sweep_result = disc.copy(&mut reader, &iso_path, &sweep_opts).unwrap();
 
@@ -2659,6 +2813,7 @@ mod tests {
             multipass: true,
             progress: None,
             halt: None,
+            vid: None,
         };
         let patch_result = disc.copy(&mut reader2, std::path::Path::new("/dev/null"), &patch_opts);
         assert!(
@@ -2691,6 +2846,7 @@ mod tests {
             multipass: false,
             progress: None,
             halt: None,
+            vid: None,
         };
         let result = disc.copy(&mut reader, &iso_path, &opts);
         let r = result.expect("100-batch clean sweep should succeed");

src/disc/read_error.rs

@@ -334,7 +334,7 @@ const FAIL_PAUSE_SECS: u64 = 5;
 /// FIRST read failure after a clean run, before the drive has had a
 /// chance to cycle in retries that push it toward fast-fail).
 ///
-/// Empirical: 2026-05-11 Dune Pt 2 wedge incident showed 7 medium
+/// Empirical: a 2026-05-11 wedge incident showed 7 medium
 /// errors in 6.5 seconds (~1s per attempt + ~1s pause) push the
 /// BU40N's firmware into IllegalRequest fast-fail mode permanently.
 /// Once there, only physical eject + reload clears it. Giving the

src/drive/mod.rs

@@ -184,6 +184,13 @@ impl Drive {
         self.profile.is_some()
     }
 
+    /// Borrow the matched drive profile, if any. Used by callers that
+    /// need to issue per-drive OEM CDB templates (e.g. the OEM VID
+    /// retrieval path in `disc::encrypt`).
+    pub fn drive_profile(&self) -> Option<&DriveProfile> {
+        self.profile.as_ref()
+    }
+
     /// Access the SCSI transport for direct commands (used by CSS/AACS auth).
     pub fn scsi_mut(&mut self) -> &mut dyn ScsiTransport {
         self.scsi.as_mut()
@@ -432,6 +439,27 @@ impl Drive {
         }
     }
 
+    /// True if the drive is currently in the extended-access state.
+    ///
+    /// Detected by the platform driver during `init()` from the unlock
+    /// response's mode markers. When true:
+    ///   - SCSI READ_10 returns plaintext sectors (no AACS bus
+    ///     encryption applied)
+    ///   - VID retrieval works via the per-drive OEM CDB in
+    ///     [`DriveProfile`] without the cert-based AACS handshake
+    ///   - Disc-side Host Revocation List enforcement is effectively
+    ///     bypassed by the alternate data path
+    ///
+    /// AACS layer code branches on this: if true, issue the OEM
+    /// `read_vid_cdb` to retrieve VID directly; if false, fall back
+    /// to the cert-based mutual-auth handshake.
+    pub fn is_unlocked(&self) -> bool {
+        match self.driver {
+            Some(ref d) => d.is_unlocked(),
+            None => false,
+        }
+    }
+
     /// Read sectors from the disc. Single-shot — no inline retries, no
     /// SCSI reset.
     ///
@@ -501,7 +529,7 @@ impl Drive {
 
                 // /dev/sr0 pread fallback (Linux only). The kernel
                 // sr_mod driver auto-retries failed reads (~5× per
-                // command). Empirically (BU40N + Dune Part 2 UHD,
+                // command). Empirically (BU40N + a UHD disc,
                 // 2026-05-08) dd via /dev/sr0 recovers ~50% of bad
                 // sectors that a single-shot SG_IO READ misses.
                 #[cfg(target_os = "linux")]

src/drm/mod.rs

@@ -0,0 +1,289 @@
+//! Top-level DRM scheme dispatch.
+//!
+//! Four content-protection schemes ride through a single
+//! detect-then-load pipeline:
+//!
+//! | Scheme              | Discriminator                                  |
+//! |---------------------|------------------------------------------------|
+//! | [`DrmScheme::Css`]  | DVD probe sector flagged scrambled             |
+//! | [`DrmScheme::Aacs10`] | Content cert type byte `0x00`                |
+//! | [`DrmScheme::Aacs20`] | Content cert type byte `!= 0x00`, no Variant |
+//! | [`DrmScheme::Aacs21`] | Content cert + MKB records `0x82` / `0x83`   |
+//!
+//! Detection happens from a [`DrmProbe`] (raw inputs the caller has
+//! already extracted from the disc); resolution runs through a
+//! [`DrmContext`] (the full set of inputs the loaders need).
+//!
+//! The AACS 2.1 arm is wired but disabled. The dispatcher leaves
+//! [`crate::aacs::resolve_keys_v21`] reachable as a library entry point
+//! for fixture-driven validation, but production consumers go through
+//! [`DrmScheme::load`], which short-circuits V21 to `None` until the
+//! Variant chain has a real Variant-scheme disc to validate against.
+
+use crate::aacs;
+use crate::css;
+
+/// Which content-protection scheme governs a disc.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum DrmScheme {
+    /// DVD Content Scramble System.
+    Css,
+    /// AACS 1.0 — original BD-ROM.
+    Aacs10,
+    /// AACS 2.0 — UHD-BD, classical Media Key chain.
+    Aacs20,
+    /// AACS 2.1 — UHD-BD with Media Key Variant chain.
+    Aacs21,
+}
+
+/// Inputs to [`DrmScheme::detect`]. All borrows — caller retains
+/// ownership.
+pub struct DrmProbe<'a> {
+    /// 2048-byte sample sector from inside a DVD title's extents. Used
+    /// only for CSS scramble-flag detection. `None` for non-DVD discs.
+    pub dvd_sample_sector: Option<&'a [u8]>,
+    /// Content Certificate file bytes (typically `/AACS/Content000.cer`).
+    /// `None` when the disc has no AACS directory.
+    pub content_cert: Option<&'a [u8]>,
+    /// MKB file bytes (typically `/AACS/MKB_RW.inf`). Required to
+    /// distinguish AACS 2.0 from AACS 2.1.
+    pub mkb: Option<&'a [u8]>,
+}
+
+/// Inputs to [`DrmScheme::load`]. Carries everything needed by either
+/// the AACS or CSS loader.
+pub struct DrmContext<'a> {
+    /// AACS resolver inputs — required when the scheme is any AACS
+    /// variant.
+    pub aacs: Option<aacs::ResolveContext<'a>>,
+    /// CSS resolver inputs — required when the scheme is [`DrmScheme::Css`].
+    pub css: Option<css::CssContext<'a>>,
+}
+
+/// Resolved key material, tagged by scheme.
+#[derive(Debug)]
+pub enum ResolvedScheme {
+    Css(css::CssState),
+    Aacs(aacs::ResolvedKeys),
+}
+
+impl DrmScheme {
+    /// Detect which DRM scheme protects the disc described by `probe`.
+    ///
+    /// Returns `None` for unencrypted media. The order is intentional:
+    /// CSS is checked first (DVD-format probe), then AACS (Blu-ray
+    /// format).
+    pub fn detect(probe: &DrmProbe<'_>) -> Option<DrmScheme> {
+        // CSS — DVD probe sector carries the scramble flag.
+        if let Some(sector) = probe.dvd_sample_sector {
+            if css::is_scrambled(sector) {
+                return Some(DrmScheme::Css);
+            }
+        }
+
+        // AACS — content cert type byte distinguishes V10 from V20+.
+        // V21 promotion requires MKB Variant records.
+        let cc = probe.content_cert.and_then(aacs::parse_content_cert)?;
+        match cc.version {
+            aacs::AacsVersion::V10 => Some(DrmScheme::Aacs10),
+            aacs::AacsVersion::V20 | aacs::AacsVersion::V21 => {
+                if let Some(mkb) = probe.mkb {
+                    let recs = aacs::variants::walk_mkb(mkb);
+                    if aacs::variants::is_variant_mkb(&recs) {
+                        return Some(DrmScheme::Aacs21);
+                    }
+                }
+                Some(DrmScheme::Aacs20)
+            }
+        }
+    }
+
+    /// Run key resolution for this scheme against `ctx`.
+    ///
+    /// Returns `None` when the scheme's resolver could not produce keys
+    /// (missing context, KEYDB miss, failed crypto walk, etc.) or when
+    /// the scheme itself is gated off (see the inline comment on the
+    /// `Aacs21` arm).
+    pub fn load(self, ctx: &mut DrmContext<'_>) -> Option<ResolvedScheme> {
+        match self {
+            DrmScheme::Css => ctx
+                .css
+                .as_mut()
+                .and_then(css::resolve)
+                .map(ResolvedScheme::Css),
+            DrmScheme::Aacs10 => ctx
+                .aacs
+                .as_ref()
+                .and_then(aacs::resolve_keys_v1)
+                .map(ResolvedScheme::Aacs),
+            DrmScheme::Aacs20 => ctx
+                .aacs
+                .as_ref()
+                .and_then(aacs::resolve_keys_v2)
+                .map(ResolvedScheme::Aacs),
+            // AACS 2.1 derivation is wired but disabled. KCD validation
+            // against a Variant-scheme disc is pending. To enable,
+            // uncomment the line below.
+            // DrmScheme::Aacs21 => ctx
+            //     .aacs
+            //     .as_ref()
+            //     .and_then(aacs::resolve_keys_v21)
+            //     .map(ResolvedScheme::Aacs),
+            DrmScheme::Aacs21 => None,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // Build a minimal cert: type byte + bus-encryption byte + 6 zero
+    // cc_id bytes.
+    fn cert(type_byte: u8) -> Vec<u8> {
+        let mut v = vec![0u8; 8];
+        v[0] = type_byte;
+        v
+    }
+
+    // Synthetic AACS 2.x MKB with no Variant records.
+    fn mkb_classical() -> Vec<u8> {
+        vec![
+            0x10, 0x00, 0x00, 0x0C, 0x48, 0x14, 0x10, 0x03, 0x00, 0x00, 0x00, 0x4D,
+        ]
+    }
+
+    // Synthetic AACS 2.x MKB with a 0x82 + 0x83 record pair.
+    fn mkb_with_variant() -> Vec<u8> {
+        let mut m = mkb_classical();
+        m.extend_from_slice(&[0x82, 0x00, 0x00, 0x14]);
+        m.extend_from_slice(&[0xEE; 16]);
+        m.extend_from_slice(&[0x83, 0x00, 0x00, 0x14]);
+        m.extend_from_slice(&[0x55; 16]);
+        m
+    }
+
+    // Synthetic scrambled DVD sector — byte 0x14 carries the CSS
+    // scramble flag in bits 4-5.
+    fn scrambled_dvd_sector() -> Vec<u8> {
+        let mut s = vec![0u8; 2048];
+        s[0x14] = 0x30;
+        s
+    }
+
+    #[test]
+    fn detect_returns_none_for_unencrypted() {
+        let probe = DrmProbe {
+            dvd_sample_sector: None,
+            content_cert: None,
+            mkb: None,
+        };
+        assert_eq!(DrmScheme::detect(&probe), None);
+    }
+
+    #[test]
+    fn detect_returns_css_for_scrambled_dvd() {
+        let sector = scrambled_dvd_sector();
+        let probe = DrmProbe {
+            dvd_sample_sector: Some(&sector),
+            content_cert: None,
+            mkb: None,
+        };
+        assert_eq!(DrmScheme::detect(&probe), Some(DrmScheme::Css));
+    }
+
+    #[test]
+    fn detect_returns_aacs10_for_type0_cert() {
+        let c = cert(0x00);
+        let probe = DrmProbe {
+            dvd_sample_sector: None,
+            content_cert: Some(&c),
+            mkb: None,
+        };
+        assert_eq!(DrmScheme::detect(&probe), Some(DrmScheme::Aacs10));
+    }
+
+    #[test]
+    fn detect_returns_aacs20_for_type1_cert_no_variant() {
+        let c = cert(0x01);
+        let mkb = mkb_classical();
+        let probe = DrmProbe {
+            dvd_sample_sector: None,
+            content_cert: Some(&c),
+            mkb: Some(&mkb),
+        };
+        assert_eq!(DrmScheme::detect(&probe), Some(DrmScheme::Aacs20));
+    }
+
+    #[test]
+    fn detect_returns_aacs21_for_type1_cert_with_variant() {
+        let c = cert(0x01);
+        let mkb = mkb_with_variant();
+        let probe = DrmProbe {
+            dvd_sample_sector: None,
+            content_cert: Some(&c),
+            mkb: Some(&mkb),
+        };
+        assert_eq!(DrmScheme::detect(&probe), Some(DrmScheme::Aacs21));
+    }
+
+    #[test]
+    fn detect_returns_aacs20_when_mkb_absent() {
+        // Type-1 cert but no MKB to upgrade with -> Aacs20.
+        let c = cert(0x01);
+        let probe = DrmProbe {
+            dvd_sample_sector: None,
+            content_cert: Some(&c),
+            mkb: None,
+        };
+        assert_eq!(DrmScheme::detect(&probe), Some(DrmScheme::Aacs20));
+    }
+
+    #[test]
+    fn load_aacs21_returns_none() {
+        // The Aacs21 dispatch arm is commented out; load() must
+        // return None until KCD validation lands.
+        let uk_ro = vec![0u8; 256];
+        let vid = [0u8; 16];
+        let keydb = aacs::KeyDb::empty();
+        let providers: &[&dyn aacs::KeyProvider] = &[&keydb];
+        let ctx_aacs = aacs::ResolveContext {
+            unit_key_ro: &uk_ro,
+            content_cert: None,
+            volume_id: &vid,
+            providers,
+            mkb: None,
+        };
+        let mut ctx = DrmContext {
+            aacs: Some(ctx_aacs),
+            css: None,
+        };
+        assert!(DrmScheme::Aacs21.load(&mut ctx).is_none());
+    }
+
+    /// Exercises the V21 helper directly. Gated `#[ignore]` because
+    /// the chain reaches `MediaKeyVariantError::VariantsTableUnavailable`
+    /// without a real Variant-scheme disc to fix the per-uv table
+    /// layout against — running it here would assert only the
+    /// not-yet-wired error code. Kept as a wiring smoke-test for
+    /// future enablement.
+    #[test]
+    #[ignore]
+    fn resolve_keys_v21_helper_exists() {
+        let uk_ro = vec![0u8; 256];
+        let vid = [0xAAu8; 16];
+        let keydb = aacs::KeyDb::empty();
+        let providers: &[&dyn aacs::KeyProvider] = &[&keydb];
+        let mkb = mkb_with_variant();
+        let ctx = aacs::ResolveContext {
+            unit_key_ro: &uk_ro,
+            content_cert: None,
+            volume_id: &vid,
+            providers,
+            mkb: Some(&mkb),
+        };
+        // Just confirm the symbol is callable; we don't assert on the
+        // result.
+        let _ = aacs::resolve_keys_v21(&ctx);
+    }
+}

src/error.rs

@@ -71,6 +71,13 @@ pub const E_AACS_VID_MAC: u16 = 7010;
 pub const E_AACS_DATA_KEY: u16 = 7011;
 pub const E_DECRYPT_FAILED: u16 = 7013;
 pub const E_CSS_AUTH_FAILED: u16 = 7014;
+pub const E_AACS_HOST_CERT_REJECTED: u16 = 7015;
+pub const E_AACS_RAW_READ_UNSUPPORTED: u16 = 7016;
+pub const E_AACS_VID_UNAVAILABLE: u16 = 7017;
+pub const E_AACS_MK_UNAVAILABLE: u16 = 7018;
+pub const E_AACS_VUK_NOT_IN_KEYDB: u16 = 7019;
+pub const E_DRIVE_PROFILE_MISSING: u16 = 7020;
+pub const E_VID_CDB_UNAVAILABLE: u16 = 7021;
 
 // Keydb (8xxx)
 pub const E_KEYDB_CONNECT: u16 = 8000;
@@ -222,6 +229,30 @@ pub enum Error {
     AacsDataKey,
     DecryptFailed,
     CssAuthFailed,
+    /// Host certificate rejected by the drive's revocation list (HRL hit).
+    /// All available host certs failed mutual auth on this drive.
+    AacsHostCertRejected,
+    /// Drive cannot be put into raw-read mode and standard AACS cert
+    /// auth failed. No path to decryption remains.
+    AacsRawReadUnsupported,
+    /// Volume ID could not be retrieved from the drive (neither via cert
+    /// auth nor via the alternate VID read path). Downstream of step 1
+    /// of the AACS chain.
+    AacsVidUnavailable,
+    /// No available path produced a Media Key (no MK+VID in keydb, no
+    /// PK match, no DK derivation).
+    AacsMkUnavailable,
+    /// Disc-hash lookup in the keydb missed and no other path is
+    /// available (typically because VID is missing).
+    AacsVukNotInKeydb,
+    /// Drive identity did not match any bundled profile; per-drive CDB
+    /// templates aren't available so the OEM VID retrieval path can't
+    /// run.
+    DriveProfileMissing,
+    /// Drive's profile is present but doesn't carry a VID-retrieval CDB
+    /// template (older profile blob, or a drive class without an OEM
+    /// VID path).
+    VidCdbUnavailable,
 
     // Keydb (8xxx)
     KeydbConnect {
@@ -307,6 +338,13 @@ impl Error {
             Error::AacsDataKey => E_AACS_DATA_KEY,
             Error::DecryptFailed => E_DECRYPT_FAILED,
             Error::CssAuthFailed => E_CSS_AUTH_FAILED,
+            Error::AacsHostCertRejected => E_AACS_HOST_CERT_REJECTED,
+            Error::AacsRawReadUnsupported => E_AACS_RAW_READ_UNSUPPORTED,
+            Error::AacsVidUnavailable => E_AACS_VID_UNAVAILABLE,
+            Error::AacsMkUnavailable => E_AACS_MK_UNAVAILABLE,
+            Error::AacsVukNotInKeydb => E_AACS_VUK_NOT_IN_KEYDB,
+            Error::DriveProfileMissing => E_DRIVE_PROFILE_MISSING,
+            Error::VidCdbUnavailable => E_VID_CDB_UNAVAILABLE,
             Error::KeydbConnect { .. } => E_KEYDB_CONNECT,
             Error::KeydbHttp { .. } => E_KEYDB_HTTP,
             Error::KeydbInvalid => E_KEYDB_INVALID,

src/halt.rs

@@ -71,6 +71,20 @@ impl Default for Halt {
     }
 }
 
+/// Shared poll interval for halt-aware loops.
+///
+/// `bounded_syscall` checks the cancellation flag and the deadline
+/// every [`POLL_INTERVAL`] while blocked on a worker; the same
+/// cadence governs `Pipeline::send_with_halt`'s `try_send` retry.
+/// 250 ms is the sweet spot between responsiveness (operator presses
+/// Stop, sees it take effect within ~quarter-second) and waste
+/// (atomic load + clock read is cheap but not free at thousands of
+/// hertz).
+///
+/// Centralised here so the half-dozen halt-polling loops across `io`
+/// can't drift apart silently.
+pub const POLL_INTERVAL: std::time::Duration = std::time::Duration::from_millis(250);
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/io/bounded.rs

@@ -54,15 +54,7 @@ use std::sync::mpsc::{RecvTimeoutError, sync_channel};
 use std::thread;
 use std::time::{Duration, Instant};
 
-use crate::halt::Halt;
-
-/// Granularity of the halt poll. The receive loop wakes every
-/// [`POLL_INTERVAL`] to (a) check the [`Halt`] token, then (b) check
-/// the overall deadline, then go back to waiting. 250 ms is a
-/// pragmatic balance: short enough that human-driven `/api/stop` feels
-/// responsive (< 0.5 s p99), long enough that the polling overhead is
-/// negligible against multi-second syscalls.
-const POLL_INTERVAL: Duration = Duration::from_millis(250);
+use crate::halt::{Halt, POLL_INTERVAL};
 
 /// Failure outcome from a bounded syscall wrapper.
 #[derive(Debug)]

src/io/byte_channel.rs

@@ -16,9 +16,6 @@
 //! The underlying mpsc channel is created with a very large slot count
 //! so the byte cap (not the slot count) is the real backpressure. Slot
 //! count is only there to give the kernel a small chunk to wake on.
-//!
-//! See `(internal)/memory/project_buffering_architecture.md` §
-//! Pipeline channel — sizing.
 
 use std::sync::mpsc::{Receiver as MpscReceiver, RecvError, SendError, SyncSender, sync_channel};
 use std::sync::{Arc, Condvar, Mutex};

src/io/byte_prefetcher.rs

@@ -0,0 +1,146 @@
+//! `BytePrefetcher` — `std::io::Read` analogue of
+//! [`crate::sector::PrefetchedSectorSource`].
+//!
+//! Spawns a producer thread that fills a bounded pool of `Vec<u8>`
+//! chunks from the underlying reader and ships them through a
+//! channel; the consumer pulls filled chunks, uses them, and sends
+//! the empty `Vec<u8>` back through a recycle channel so the
+//! producer can re-fill in place. Result: zero allocations and zero
+//! cross-thread frees in the steady-state hot loop.
+//!
+//! This is the byte-stream half of the freemkv mux highway —
+//! `BytePrefetcher` feeds [`crate::mux::demux_thread::DemuxThread`]
+//! for `m2ts://`, `network://`, `stdio://`, and any other stream
+//! whose source is an `io::Read` rather than a `SectorSource`.
+
+use crate::halt::Halt;
+use crossbeam_channel::{Receiver, Sender, bounded};
+use std::io::Read;
+use std::thread::JoinHandle;
+
+/// Items flowing through the forward channel.
+pub type Batch = std::io::Result<Vec<u8>>;
+
+/// Forward channel depth — how many filled buffers the producer can
+/// stay ahead by. Two is enough to absorb a moderate consumer stall
+/// without piling up bytes.
+const FORWARD_DEPTH: usize = 2;
+
+/// Recycle channel depth = forward + 1 so the producer always has at
+/// least one buffer to fill while the consumer holds one.
+const RECYCLE_DEPTH: usize = FORWARD_DEPTH + 1;
+
+/// Default chunk size — 16 MiB matches the ISO-mux sector batch and
+/// is large enough that per-chunk overhead is amortised; small
+/// enough that the in-flight memory footprint stays bounded.
+pub const DEFAULT_CHUNK_BYTES: usize = 16 * 1024 * 1024;
+
+/// Returned from [`BytePrefetcher::into_channels`]. Owns the
+/// producer-thread join handle so dropping the shell joins the
+/// producer.
+pub struct PrefetchShell {
+    producer: Option<JoinHandle<()>>,
+}
+
+impl Drop for PrefetchShell {
+    fn drop(&mut self) {
+        if let Some(h) = self.producer.take() {
+            let _ = h.join();
+        }
+    }
+}
+
+/// Spawned byte prefetcher. Drop joins the producer thread.
+pub struct BytePrefetcher {
+    rx: Receiver<Batch>,
+    recycle_tx: Sender<Vec<u8>>,
+    producer: Option<JoinHandle<()>>,
+}
+
+impl BytePrefetcher {
+    /// Spawn the producer thread. `reader` must be `Send` because it
+    /// moves into the thread. `chunk_bytes` is the size of each
+    /// recycled buffer; pick the natural batch size of the
+    /// downstream demuxer (16 MiB for the BD-TS mux pipeline).
+    pub fn new<R: Read + Send + 'static>(
+        mut reader: R,
+        chunk_bytes: usize,
+        halt: Option<Halt>,
+    ) -> Self {
+        let (tx, rx) = bounded::<Batch>(FORWARD_DEPTH);
+        let (recycle_tx, recycle_rx) = bounded::<Vec<u8>>(RECYCLE_DEPTH);
+
+        // Seed the recycle pool. Without these the first
+        // `recycle_rx.recv()` would block forever (no consumer has
+        // returned a buffer yet).
+        for _ in 0..RECYCLE_DEPTH {
+            let _ = recycle_tx.send(vec![0u8; chunk_bytes]);
+        }
+
+        let producer = std::thread::Builder::new()
+            .name("freemkv-byte-prefetch".into())
+            .spawn(move || {
+                loop {
+                    if halt.as_ref().map(|h| h.is_cancelled()).unwrap_or(false) {
+                        return;
+                    }
+                    let mut buf = match recycle_rx.recv() {
+                        Ok(b) => b,
+                        Err(_) => return, // consumer dropped both channels
+                    };
+                    // Re-expose the full extent (previous iteration
+                    // may have truncated after a short read).
+                    if buf.len() < chunk_bytes {
+                        buf.resize(chunk_bytes, 0);
+                    } else {
+                        // SAFETY: capacity is at least chunk_bytes
+                        // after construction.
+                        unsafe { buf.set_len(chunk_bytes) };
+                    }
+                    // Read up to one full chunk. Short reads are
+                    // valid and common — pipe `truncate` so the
+                    // consumer sees only the bytes that arrived.
+                    let n = match reader.read(&mut buf[..]) {
+                        Ok(0) => return, // EOF — drop tx, consumer sees RecvError
+                        Ok(n) => n,
+                        Err(e) => {
+                            let _ = tx.send(Err(e));
+                            return;
+                        }
+                    };
+                    buf.truncate(n);
+                    if tx.send(Ok(buf)).is_err() {
+                        return; // consumer dropped
+                    }
+                }
+            })
+            .expect("freemkv-byte-prefetch thread spawn failed");
+
+        Self {
+            rx,
+            recycle_tx,
+            producer: Some(producer),
+        }
+    }
+
+    /// Peel off the channels for zero-copy pipeline consumption. The
+    /// caller (typically [`crate::mux::demux_thread::DemuxThread`])
+    /// drains `rx`, runs the demuxer in place on each filled buffer,
+    /// and recycles back through `recycle_tx`.
+    pub fn into_channels(self) -> (Receiver<Batch>, Sender<Vec<u8>>, PrefetchShell) {
+        let mut me = self;
+        let producer = me.producer.take();
+        let rx = me.rx.clone();
+        let recycle = me.recycle_tx.clone();
+        std::mem::forget(me);
+        (rx, recycle, PrefetchShell { producer })
+    }
+}
+
+impl Drop for BytePrefetcher {
+    fn drop(&mut self) {
+        if let Some(h) = self.producer.take() {
+            let _ = h.join();
+        }
+    }
+}

src/io/file_sector_source/linux.rs

@@ -44,3 +44,22 @@ pub(super) fn drop_window(file: &File, start: u64, len: u64) {
         );
     }
 }
+
+/// Async-prefetch `len` bytes at `offset` into the page cache. The
+/// kernel `readahead(2)` syscall queues the I/O and returns
+/// immediately — it does NOT wait for completion. Called right after
+/// each consumed read so the next batch's I/O overlaps with the
+/// caller's processing of the current batch (decrypt + demux + mux).
+///
+/// Without this hint, with a synchronous demux consumer running at
+/// ~50 MB/s and a single-spindle disk capable of ~150 MB/s, the disk
+/// sits idle ~70% of each iteration because kernel readahead alone
+/// (capped at `/sys/block/<dev>/queue/read_ahead_kb`, default 128 KB)
+/// can only pre-stage a tiny slice of the next batch. An explicit
+/// `readahead()` of the same size as the current batch tells the
+/// kernel to queue the full next-batch read now.
+pub(super) fn prefetch(file: &File, offset: u64, len: u64) {
+    unsafe {
+        libc::readahead(file.as_raw_fd(), offset as i64, len as usize);
+    }
+}

src/io/file_sector_source/macos.rs

@@ -44,3 +44,19 @@ pub(super) fn hint_sequential(file: &File, len_bytes: u64) {
 /// less prone to the pin-everything pathology that triggers the
 /// regression on Linux NFS clients.
 pub(super) fn drop_window(_file: &File, _start: u64, _len: u64) {}
+
+/// Async-prefetch the byte range `[offset, offset+len)`. macOS uses
+/// the same `fcntl(F_RDADVISE, &radvisory)` primitive as the open-
+/// time sequential hint, just targeted at a moving window instead of
+/// the whole file. The kernel queues I/O for the requested range and
+/// returns immediately.
+pub(super) fn prefetch(file: &File, offset: u64, len: u64) {
+    let bytes = (len as i64).min(RDADVISE_MAX_BYTES);
+    let mut ra = RadAdvisory {
+        ra_offset: offset as libc::off_t,
+        ra_count: bytes as libc::c_int,
+    };
+    unsafe {
+        libc::fcntl(file.as_raw_fd(), F_RDADVISE, &mut ra);
+    }
+}

src/io/file_sector_source/mod.rs

@@ -1,39 +1,43 @@
 //! [`FileSectorSource`] — read 2048-byte sectors from an ISO file on
-//! disk, with an internal 32 MiB read-ahead buffer.
+//! disk via direct `seek + read_exact` (`pread`-equivalent) calls,
+//! letting the kernel's own readahead policy manage prefetch.
 //!
-//! ## Why the buffer
+//! ## Why no app-level buffer
 //!
-//! On NFS-mounted ISOs, an unbuffered `pread(2048)` per sector pays an
-//! NFS round-trip for every sector. With `rsize=1 MiB` and a 100-150 ms
-//! NFS RTT, that's three orders of magnitude more round trips than
-//! necessary — the muxer goes read-bound on every read, even though
-//! the local NFS client could deliver MB/s on bigger requests.
+//! Pre-0.21.3 this source held a 32 MiB (later 4 MiB) read-ahead
+//! buffer to amortise per-sector NFS round-trips. Empirically that
+//! buffer hurt: 32 MiB refills bursted the NFS TCP connection hard
+//! enough to starve the concurrent writer, and even a 4 MiB window
+//! gave the kernel less freedom to pipeline reads with writes. Direct
+//! pread per call lets Linux's readahead widen as it detects the
+//! sequential pattern, and naturally interleaves with writeback.
 //!
-//! Internally this source keeps a [`READAHEAD_BUF_BYTES`] (32 MiB)
-//! window pre-read from the file. `read_sectors(lba, count)` slices
-//! into the window if `[lba, lba+count)` is contained in it; otherwise
-//! the window is refilled (full-size aligned to the requested LBA's
-//! buffer position).
+//! ## DONTNEED on the consumed window
 //!
-//! ## Access pattern assumption
+//! Without page-cache eviction an 85 GB streaming ISO read pins the
+//! entire file in memory, starves the concurrent writer, and collapses
+//! mux throughput (observed: 2.7 MB/s mux on 0.21.5 vs. 70 MB/s
+//! isolated NFS reads). Every [`READ_DROP_CHUNK_BYTES`] of consumed
+//! bytes we call `posix_fadvise(DONTNEED)` over that window, mirroring
+//! the write-side [`crate::io::writeback::WritebackPipeline`] policy.
 //!
-//! The buffer is sized for **forward-sequential** reads (sweep, mux).
-//! Reverse-mode patch is range-local, so a refill per range works out
-//! fine (the buffer covers the whole range for typical bad-range
-//! sizes). Random-access reads thrash the buffer — at which point the
-//! 32 MiB pre-read is wasted work. We accept that: the use case is
-//! mux + sweep, both forward-sequential.
-//!
-//! Backward seeks rebuffer from the new LBA; partial reads at EOF
-//! return only the bytes that exist (the underlying file is shorter
-//! than a full buffer slot).
-//!
-//! ## Platform open hints
+//! ## Platform open hint
 //!
 //! On `open()` each platform issues its "sequential access expected"
-//! hint to the kernel so OS-level readahead widens. The hint lives in
-//! a per-OS sibling module ([`linux::hint_sequential`] et al.) — no
-//! inline `#[cfg]` in this file.
+//! hint so OS-level readahead widens. The hint and the DONTNEED call
+//! live in per-OS sibling modules ([`linux::hint_sequential`] et al.)
+//! — no inline `#[cfg]` in this file.
+//!
+//! ## Read-ahead prefetch
+//!
+//! After every consumed read we issue an OS-level prefetch hint for
+//! the next equivalent-sized window (`platform::prefetch`). The
+//! kernel queues that I/O asynchronously and returns immediately, so
+//! the next batch's read overlaps with the caller's processing of
+//! the current batch (decrypt + demux + mux). Without this the disk
+//! sits idle ~70% of each iteration because kernel SEQUENTIAL
+//! readahead alone (capped at `read_ahead_kb`, default 128 KB) is
+//! far smaller than our 16 MiB app-level batch.
 
 #[cfg(target_os = "linux")]
 mod linux;
@@ -60,66 +64,48 @@ use std::path::Path;
 use crate::error::{Error, Result};
 use crate::sector::SectorSource;
 
-/// Internal read-ahead buffer size. 32 MiB amortises one NFS round
-/// trip across ~16 k sectors — three orders of magnitude fewer trips
-/// than per-sector pread, and large enough to coast through a typical
-/// NFS server commit blip.
-///
-/// 0.21.2: shrunk from 32 MiB → 4 MiB. On NFS-backed ISOs with
-/// concurrent NFS writes (the mux phase), a 32 MiB refill bursts the
-/// TCP connection hard enough to starve the writer thread, observed
-/// empirically as a ~3× drop in sustained mux throughput on the
-/// rip1/unraid-1 setup. 4 MiB matches `rsize=1 MiB` × 4 round-trips
-/// and interleaves cleanly with writes.
-///
-/// Tweakable. Named const, not a magic number.
-pub const READAHEAD_BUF_BYTES: usize = 4 * 1024 * 1024;
-
 const SECTOR_SIZE: usize = 2048;
-/// Sectors per refill: [`READAHEAD_BUF_BYTES`] / [`SECTOR_SIZE`]. The
-/// buffer always tries to hold this many, except at the tail of the
-/// file where less data exists.
-const BUF_SECTORS: u32 = (READAHEAD_BUF_BYTES / SECTOR_SIZE) as u32;
 
-/// SectorSource backed by a file (ISO image) with an internal
-/// `READAHEAD_BUF_BYTES`-sized read-ahead window.
-///
-/// `read_sectors` is satisfied from the buffer when possible; otherwise
-/// a full-buffer refill is issued at the requested LBA's position and
-/// the call is re-tried against the freshly populated window.
 /// Bytes-read threshold per `posix_fadvise(DONTNEED)` drop on the
 /// read side. Mirrors `WRITEBACK_CHUNK_BYTES` so the read-side page
 /// cache stays bounded the same way the write side does.
 ///
-/// 0.21.6: re-added after empirical discovery that Phase 1 had silently
-/// dropped this from the pre-Phase-1 (0.20.7) hot path. Without it,
-/// 85 GB of streaming ISO reads pin the entire file in the kernel page
-/// cache, starving the MKV writeback and collapsing mux throughput
-/// (observed: 2.7 MB/s mux on 0.21.5 vs. 70 MB/s isolated NFS reads).
-const READ_DROP_CHUNK_BYTES: u64 = 32 * 1024 * 1024;
+/// 32 MiB is the empirically tuned value on the rip1 test bed (single
+/// 7200rpm HDD via SATA): smaller windows (8 / 16 MiB) shorten the
+/// kernel-readahead overlap and slow the producer; larger windows
+/// (64 / 128 MiB) let the page cache pin enough of the ISO to
+/// pressure concurrent writes. Override via `FREEMKV_READ_DROP_CHUNK_MIB`.
+const READ_DROP_CHUNK_BYTES_DEFAULT: u64 = 32 * 1024 * 1024;
 
+fn read_drop_chunk_bytes() -> u64 {
+    std::env::var("FREEMKV_READ_DROP_CHUNK_MIB")
+        .ok()
+        .and_then(|v| v.parse::<u64>().ok())
+        .filter(|&n| n > 0)
+        .map(|n| n * 1024 * 1024)
+        .unwrap_or(READ_DROP_CHUNK_BYTES_DEFAULT)
+}
+
+/// SectorSource backed by a file (ISO image). Every `read_sectors`
+/// call is a direct `seek + read_exact` against the underlying file
+/// — kernel readahead handles prefetch, and every
+/// [`READ_DROP_CHUNK_BYTES_DEFAULT`] bytes of consumed data the
+/// platform's `DONTNEED` hook drops the consumed window from the
+/// page cache to bound memory pressure.
 pub struct FileSectorSource {
     file: File,
     /// Total file size in sectors. Constant after construction;
     /// surfaced via [`SectorSource::capacity_sectors`].
     capacity: u32,
-    /// 0.21.3+: the app-level buffer is no longer touched on the hot
-    /// path (every `read_sectors` is a direct pread). The fields are
-    /// retained so a future per-source-type policy (e.g. a local-disk
-    /// source where batched reads ARE beneficial) can re-enable
-    /// buffering cleanly without re-plumbing the struct.
-    #[allow(dead_code)]
-    buf: Box<[u8]>,
-    #[allow(dead_code)]
-    buf_start_lba: u32,
-    buf_len_sectors: u32,
-    /// 0.21.6: bytes read since the last DONTNEED drop. Drives the
-    /// per-`READ_DROP_CHUNK_BYTES` page-cache eviction in read_sectors.
+    /// Bytes read since the last DONTNEED drop. Drives the per-
+    /// [`read_drop_chunk_bytes`] page-cache eviction in read_sectors.
     bytes_read_since_drop: u64,
-    /// 0.21.6: file offset at which the current drop window starts.
-    /// The next DONTNEED drops from `drop_window_start` for
+    /// File offset at which the current drop window starts. The next
+    /// DONTNEED drops from `drop_window_start` for
     /// `bytes_read_since_drop` bytes.
     drop_window_start: u64,
+    /// Cached drop chunk size (resolved from env once at open).
+    drop_chunk_bytes: u64,
 }
 
 impl FileSectorSource {
@@ -148,59 +134,14 @@ impl FileSectorSource {
         // FS doesn't honour it).
         platform::hint_sequential(&file, len);
 
-        // Pre-allocate the buffer once. `vec![0u8; N].into_boxed_slice()`
-        // is the canonical way to fix the allocation size up-front;
-        // `Vec::with_capacity` would leave `len == 0` and force callers
-        // to do unsafe length manipulation to write into it.
-        let buf = vec![0u8; READAHEAD_BUF_BYTES].into_boxed_slice();
-
         Ok(Self {
             file,
             capacity,
-            buf,
-            buf_start_lba: 0,
-            buf_len_sectors: 0,
             bytes_read_since_drop: 0,
             drop_window_start: 0,
+            drop_chunk_bytes: read_drop_chunk_bytes(),
         })
     }
-
-    /// True if `[lba, lba + count)` is wholly inside the current
-    /// buffer window. `count == 0` is vacuously true.
-    #[allow(dead_code)]
-    fn buffer_covers(&self, lba: u32, count: u32) -> bool {
-        if self.buf_len_sectors == 0 {
-            return false;
-        }
-        let end = match lba.checked_add(count) {
-            Some(e) => e,
-            None => return false,
-        };
-        let buf_end = self.buf_start_lba.saturating_add(self.buf_len_sectors);
-        lba >= self.buf_start_lba && end <= buf_end
-    }
-
-    /// Refill the buffer so it starts at `lba`. Read as many sectors
-    /// as we have buffer space AND file capacity for. Caller has
-    /// already checked `lba < capacity`.
-    #[allow(dead_code)]
-    fn refill(&mut self, lba: u32) -> Result<()> {
-        debug_assert!(lba < self.capacity, "refill past capacity");
-        // Don't read past EOF — clamp the request to remaining
-        // sectors. partial-buffer-at-EOF behaviour is intentional.
-        let want = BUF_SECTORS.min(self.capacity - lba);
-        let want_bytes = want as usize * SECTOR_SIZE;
-        let offset = lba as u64 * SECTOR_SIZE as u64;
-        self.file
-            .seek(SeekFrom::Start(offset))
-            .map_err(|e| Error::IoError { source: e })?;
-        self.file
-            .read_exact(&mut self.buf[..want_bytes])
-            .map_err(|e| Error::IoError { source: e })?;
-        self.buf_start_lba = lba;
-        self.buf_len_sectors = want;
-        Ok(())
-    }
 }
 
 impl SectorSource for FileSectorSource {
@@ -226,20 +167,6 @@ impl SectorSource for FileSectorSource {
         if count == 0 {
             return Ok(0);
         }
-        // 0.21.3: bypass the application-level buffer entirely.
-        //
-        // Empirically the 32 MiB readahead window (0.21.0–0.21.1) and the
-        // 4 MiB shrink (0.21.2) both regressed mux throughput vs the
-        // pre-Phase-1 0.20.7 baseline on NFS bidirectional workloads
-        // (sweep ~25 MB/s OK; mux dropped from 18 → 7-8 → 5-6 MB/s).
-        // Direct pread per call lets the kernel's own readahead policy
-        // run, which interleaves naturally with concurrent NFS writes on
-        // the same TCP connection.
-        //
-        // Buffer fields are retained (currently unused on this path) so
-        // any future per-source policy can be reintroduced without
-        // re-plumbing structure. `refill` / `buffer_covers` are kept too
-        // (still exercised by the tests so the API contract is locked).
         let offset = lba as u64 * SECTOR_SIZE as u64;
         self.file
             .seek(SeekFrom::Start(offset))
@@ -247,15 +174,21 @@ impl SectorSource for FileSectorSource {
         self.file
             .read_exact(&mut out[..bytes])
             .map_err(|e| Error::IoError { source: e })?;
-        self.buf_len_sectors = 0;
 
-        // 0.21.6: periodic page-cache eviction on the read side. Without
+        // Queue the next batch's read with the kernel before the
+        // caller starts processing what we just returned. readahead()
+        // is non-blocking — it queues I/O and returns, so the kernel
+        // pulls those pages into cache while the consumer (decrypt +
+        // demux + mux) runs. Next read_sectors call hits a warm cache.
+        platform::prefetch(&self.file, offset + bytes as u64, bytes as u64);
+
+        // Periodic page-cache eviction on the read side. Without
         // this, an 85 GB streaming ISO read pins the entire file in
-        // kernel page cache, which starves concurrent NFS writes (the
-        // MKV output) and collapses mux throughput. Mirrors the
-        // write-side WritebackPipeline's DONTNEED policy.
+        // the kernel page cache, which starves concurrent writes and
+        // collapses mux throughput. Mirrors the write-side
+        // WritebackPipeline's DONTNEED policy.
         self.bytes_read_since_drop += bytes as u64;
-        if self.bytes_read_since_drop >= READ_DROP_CHUNK_BYTES {
+        if self.bytes_read_since_drop >= self.drop_chunk_bytes {
             let drop_start = self.drop_window_start;
             let drop_len = self.bytes_read_since_drop;
             platform::drop_window(&self.file, drop_start, drop_len);
@@ -287,11 +220,15 @@ mod tests {
         f.flush().unwrap();
     }
 
+    /// Sectors used by spanning-boundary tests. Pick something that
+    /// exercises multi-megabyte reads without making test ISOs huge.
+    /// 8192 sectors = 16 MiB — large enough to cross any readahead
+    /// chunk size we set the kernel hint to.
+    const TEST_SPAN_SECTORS: u32 = 8192;
+
     #[test]
     fn sequential_reads_match_file() {
-        // Two full buffer windows + a tail = exercise refill across
-        // boundaries.
-        let total = BUF_SECTORS * 2 + 17;
+        let total = TEST_SPAN_SECTORS * 2 + 17;
         let dir = tempdir().unwrap();
         let path = dir.path().join("seq.iso");
         make_iso(&path, total);
@@ -311,28 +248,15 @@ mod tests {
     }
 
     #[test]
-    fn multi_sector_read_spanning_buffer_boundary() {
-        // A read that lands exactly on the last sector of the buffer
-        // plus the first sector of the next refill must rebuffer
-        // mid-read. Bypass path triggers when count > BUF_SECTORS; we
-        // want the in-window path, so count stays small but
-        // straddles the boundary.
-        let total = BUF_SECTORS * 2;
+    fn multi_sector_read_across_chunk_boundary() {
+        let total = TEST_SPAN_SECTORS * 2;
         let dir = tempdir().unwrap();
         let path = dir.path().join("span.iso");
         make_iso(&path, total);
 
         let mut src = FileSectorSource::open(&path).unwrap();
 
-        // Prime: read sector 0. (0.21.3+: app-level buffer is bypassed,
-        // so we don't assert internal buf state here — just exercise
-        // the read path.)
-        let mut got = vec![0u8; SECTOR_SIZE];
-        src.read_sectors(0, 1, &mut got, false).unwrap();
-
-        // Now read 4 sectors crossing what used to be the buffer
-        // boundary. Still a valid SectorSource-contract test.
-        let span_lba = BUF_SECTORS - 2;
+        let span_lba = TEST_SPAN_SECTORS - 2;
         let mut buf4 = vec![0u8; SECTOR_SIZE * 4];
         src.read_sectors(span_lba, 4, &mut buf4, false).unwrap();
         for i in 0..4 {
@@ -345,10 +269,10 @@ mod tests {
     }
 
     #[test]
-    fn backward_seek_rebuffers() {
-        // Read forward across two windows, then jump back to sector
-        // 0. Buffer must refill from the start.
-        let total = BUF_SECTORS * 2 + 5;
+    fn backward_seek_reads_correct_bytes() {
+        // Read forward then jump back: the SectorSource contract is
+        // byte-correctness regardless of access pattern.
+        let total = TEST_SPAN_SECTORS * 2 + 5;
         let dir = tempdir().unwrap();
         let path = dir.path().join("back.iso");
         make_iso(&path, total);
@@ -356,24 +280,17 @@ mod tests {
         let mut src = FileSectorSource::open(&path).unwrap();
         let mut got = vec![0u8; SECTOR_SIZE];
 
-        // Forward to the second window.
-        src.read_sectors(BUF_SECTORS + 1, 1, &mut got, false)
+        src.read_sectors(TEST_SPAN_SECTORS + 1, 1, &mut got, false)
             .unwrap();
-
-        // Backward to sector 0. (0.21.3+: app-level buffer is bypassed
-        // so we only assert the byte-level contract, not internal
-        // buffer state.)
         src.read_sectors(0, 1, &mut got, false).unwrap();
         assert!(got.iter().all(|b| *b == 0));
     }
 
     #[test]
-    fn partial_buffer_at_eof() {
-        // File is smaller than one buffer window. The buffer must
-        // populate with only the available sectors and reads must
-        // still succeed.
+    fn read_at_eof_returns_correct_bytes() {
+        // File smaller than the readahead chunk — reads near EOF must
+        // still return correct bytes.
         let total: u32 = 100;
-        assert!(total < BUF_SECTORS);
         let dir = tempdir().unwrap();
         let path = dir.path().join("small.iso");
         make_iso(&path, total);
@@ -382,39 +299,27 @@ mod tests {
         assert_eq!(src.capacity_sectors(), total);
 
         let mut got = vec![0u8; SECTOR_SIZE];
-        // First read at sector 0.
         src.read_sectors(0, 1, &mut got, false).unwrap();
-
-        // Read the very last sector. (0.21.3+: app-level buffer is
-        // bypassed; the test still verifies that EOF-region reads
-        // return correct bytes.)
         src.read_sectors(total - 1, 1, &mut got, false).unwrap();
         let expected = ((total - 1) & 0xff) as u8;
         assert!(got.iter().all(|b| *b == expected));
     }
 
     #[test]
-    fn oversized_read_bypasses_buffer() {
-        // A request larger than the buffer must not deadlock the
-        // refill (which only loads BUF_SECTORS at a time). Bypass
-        // path handles it via direct pread.
-        let total = BUF_SECTORS + 100;
+    fn large_single_read() {
+        // A multi-MB single read must work — the implementation has
+        // no app-level chunking, so this just exercises the direct
+        // pread path on a larger request.
+        let total = TEST_SPAN_SECTORS + 100;
         let dir = tempdir().unwrap();
-        let path = dir.path().join("over.iso");
+        let path = dir.path().join("big.iso");
         make_iso(&path, total);
 
         let mut src = FileSectorSource::open(&path).unwrap();
-        // Read more than BUF_SECTORS in one call. count is u16, so we
-        // can't actually exceed BUF_SECTORS (16k) — but the path also
-        // triggers via `out.len() / SECTOR_SIZE > BUF_SECTORS` check
-        // implicitly because count > BUF_SECTORS. BUF_SECTORS for
-        // 32 MiB is 16384, which does fit in u16 (max 65535). Cap
-        // at BUF_SECTORS + 1 to exercise the bypass.
-        let req = (BUF_SECTORS + 1) as u16;
+        let req = (TEST_SPAN_SECTORS + 1) as u16;
         let req_bytes = req as usize * SECTOR_SIZE;
         let mut big = vec![0u8; req_bytes];
         src.read_sectors(0, req, &mut big, false).unwrap();
-        // Spot-check sector 0 and the last requested sector.
         assert!(big[..SECTOR_SIZE].iter().all(|b| *b == 0));
         let last_lba = req as u32 - 1;
         let exp = (last_lba & 0xff) as u8;
@@ -425,4 +330,32 @@ mod tests {
                 .all(|b| *b == exp)
         );
     }
+
+    #[test]
+    fn drop_chunk_size_env_override() {
+        // Explicit 8 MiB via env var.
+        // SAFETY: tests in this crate are single-threaded per the
+        // default cargo test harness, but std::env::set_var is
+        // declared `unsafe` since Rust 2024 (it can race with other
+        // threads / TLS). For a test that runs in-process before any
+        // FileSectorSource construction this is safe in practice.
+        unsafe {
+            std::env::set_var("FREEMKV_READ_DROP_CHUNK_MIB", "8");
+        }
+        assert_eq!(read_drop_chunk_bytes(), 8 * 1024 * 1024);
+
+        unsafe {
+            std::env::remove_var("FREEMKV_READ_DROP_CHUNK_MIB");
+        }
+        assert_eq!(read_drop_chunk_bytes(), READ_DROP_CHUNK_BYTES_DEFAULT);
+
+        // Garbage env value falls back to default.
+        unsafe {
+            std::env::set_var("FREEMKV_READ_DROP_CHUNK_MIB", "not-a-number");
+        }
+        assert_eq!(read_drop_chunk_bytes(), READ_DROP_CHUNK_BYTES_DEFAULT);
+        unsafe {
+            std::env::remove_var("FREEMKV_READ_DROP_CHUNK_MIB");
+        }
+    }
 }

src/io/file_sector_source/other.rs

@@ -7,3 +7,5 @@ use std::fs::File;
 pub(super) fn hint_sequential(_file: &File, _len_bytes: u64) {}
 
 pub(super) fn drop_window(_file: &File, _start: u64, _len: u64) {}
+
+pub(super) fn prefetch(_file: &File, _offset: u64, _len: u64) {}

src/io/file_sector_source/windows.rs

@@ -22,3 +22,9 @@ pub(super) fn hint_sequential(_file: &File, _len_bytes: u64) {
 /// equivalent. The kernel does its own working-set management. No-op
 /// for now.
 pub(super) fn drop_window(_file: &File, _start: u64, _len: u64) {}
+
+/// Windows async-prefetch hint. With FILE_FLAG_SEQUENTIAL_SCAN at
+/// open the kernel already prefetches aggressively, so there's no
+/// per-range hint we'd add on top. No-op stub for parity with the
+/// posix platforms.
+pub(super) fn prefetch(_file: &File, _offset: u64, _len: u64) {}

src/io/mod.rs

@@ -11,35 +11,37 @@
 //! to exhibit the same pathology for this access pattern.
 //!
 //! `FileSectorSource` is the read-side dual — it implements
-//! [`crate::sector::SectorSource`] for an ISO file with an internal
-//! 32 MiB read-ahead buffer that amortises NFS round-trip latency
-//! across thousands of sector reads.
+//! [`crate::sector::SectorSource`] for an ISO file using direct
+//! `pread`-equivalent calls so the kernel's own readahead policy runs
+//! (which interleaves naturally with the concurrent writeback). It
+//! pairs that with periodic `posix_fadvise(DONTNEED)` drops on the
+//! consumed window so an 85 GB streaming ISO read doesn't fill the
+//! page cache and starve the concurrent MKV write.
 //!
 //! `Pipeline` + `Sink` (0.18) is the generic producer/consumer primitive
 //! used by sweep, patch, and mux to overlap reads with writes via a
 //! bounded channel + dedicated consumer thread.
 //!
 //! `byte_channel` is a byte-sized producer/consumer channel for the
-//! mux pipeline, sized to absorb worst-case input read stalls (see
-//! `(internal)/memory/project_buffering_architecture.md`).
+//! mux pipeline, sized to absorb worst-case input read stalls.
 
 pub(crate) mod bounded;
 pub mod byte_channel;
+pub mod byte_prefetcher;
 pub mod file_sector_source;
 pub mod sink;
 mod writeback;
 mod writeback_file;
 
+#[cfg(target_os = "macos")]
+pub(crate) mod platform_macos;
+
 pub mod pipeline;
 
 pub(crate) use writeback_file::WritebackFile;
 
-// Re-exports for the 0.18 redesign. Sweep + patch are both wired up
-// (disc/sweep.rs, disc/patch.rs); mux migrates separately in autorip.
-// `WRITE_THROUGH_DEPTH` is patch-specific and has no other in-tree
-// caller — the targeted `#[allow]` keeps the re-export visible without
-// dragging the rest of the module under `dead_code`.
-#[allow(unused_imports)]
+// Re-exports for the 0.18 redesign. Sweep, patch, and mux are all
+// wired up (disc/sweep.rs, disc/patch.rs, autorip's ripper/mux.rs).
 pub use pipeline::{
     DEFAULT_PIPELINE_DEPTH, Flow, Pipeline, READ_PIPELINE_DEPTH, Sink, WRITE_PIPELINE_DEPTH,
     WRITE_THROUGH_DEPTH,

src/io/pipeline.rs

@@ -9,7 +9,6 @@
 //! sweep (migrated to `disc/sweep.rs::SweepSink`), patch, and mux.
 //! 0.18 collapses all three onto this primitive; sweep is in,
 //! patch and mux migrate in later 0.18 slices.
-//! See `(internal)/memory/0_18_redesign.md` for the full picture.
 //!
 //! ## Cancellation and error semantics
 //!
@@ -53,26 +52,24 @@ use crate::halt::Halt;
 /// caller has already lost the rip.
 pub const JOIN_TIMEOUT_SECS: u64 = 600;
 
-/// Polling slice for the halt-aware send/finish loops. Mirrors the
-/// `bounded_syscall` cadence (250 ms) so halt observation feels equally
-/// responsive across both primitives.
-const POLL_INTERVAL: Duration = Duration::from_millis(250);
-
 /// Halt-check cadence for the send loop. Producer blocks on
 /// [`crossbeam_channel::Sender::send_timeout`] for this slice — the
 /// kernel wakes it the instant the consumer drains a slot, so on the
 /// happy path there's no throughput cap from this primitive at all
 /// (the cap is whatever the underlying medium can sustain). When the
-/// consumer is genuinely wedged, the timeout fires every 250 ms and
-/// the producer checks the halt token; that's the latency a stop
-/// request will observe.
+/// consumer is genuinely wedged, the timeout fires every
+/// [`crate::halt::POLL_INTERVAL`] and the producer checks the halt
+/// token; that's the latency a stop request will observe.
+///
+/// Single source of truth lives in [`crate::halt::POLL_INTERVAL`]
+/// (also used by `bounded_syscall`). Aliased here for readability of
+/// the send/finish call sites below.
 ///
 /// 0.21.7 replaced an old `std::sync::mpsc::sync_channel` + 50 ms
 /// `thread::sleep` polling loop that capped mux throughput at
-/// ~20 frames/sec ≈ 1 MB/s on saturated channels. See
-/// (internal)/memory/feedback_send_with_halt_poll_throttle.md
-/// for the multi-day diagnostic that surfaced it.
-const SEND_HALT_CHECK_INTERVAL: Duration = Duration::from_millis(250);
+/// ~20 frames/sec ≈ 1 MB/s on saturated channels.
+use crate::halt::POLL_INTERVAL;
+const SEND_HALT_CHECK_INTERVAL: Duration = POLL_INTERVAL;
 
 /// Check if verbose debug logging is enabled via FREEMKV_DEBUG env var.
 pub fn debug_enabled() -> bool {
@@ -100,8 +97,7 @@ pub const WRITE_PIPELINE_DEPTH: usize = 16;
 /// Channel depth for write-through pipelines. Each `send` fully
 /// drains before the next can enqueue. Use this when the producer
 /// must observe consumer side-effects (e.g. mapfile state) before
-/// emitting the next item.
-#[allow(dead_code)]
+/// emitting the next item. Currently used by `disc::patch`.
 pub const WRITE_THROUGH_DEPTH: usize = 1;
 
 /// Outcome of [`Sink::apply`]: either keep feeding items
@@ -162,11 +158,10 @@ impl<I: Send + 'static, R: Send + 'static> Pipeline<I, R> {
     /// propagated rather than panicked.
     ///
     /// Sweep uses [`Pipeline::spawn_named`] directly so the consumer
-    /// thread shows up as `freemkv-sweep-consumer`; this function has
-    /// no in-tree caller yet. Patch and mux migrate in later 0.18
-    /// slices. The targeted `#[allow]` is removed when one of them
-    /// lands on the default name.
-    #[allow(dead_code)]
+    /// thread shows up as `freemkv-sweep-consumer`; mux uses
+    /// `freemkv-mux-consumer`. `Pipeline::spawn` (this function, with
+    /// the default name) is used by `disc::patch` and by the unit
+    /// tests in this module.
     pub fn spawn<S: Sink<I, Output = R>>(depth: usize, sink: S) -> Result<Self, Error> {
         Self::spawn_named("freemkv-pipeline-consumer", depth, sink)
     }

src/io/platform_macos.rs

@@ -0,0 +1,38 @@
+//! Shared macOS `fcntl(F_PREALLOCATE)` definitions.
+//!
+//! The `libc` crate doesn't expose these symbols across all macOS SDK
+//! versions, so we define them locally with values from
+//! `/usr/include/sys/fcntl.h`. Two call sites (
+//! [`crate::io::writeback_file`] and [`crate::io::sink::preallocate`])
+//! need the same constants and `fstore_t` layout — keeping a single
+//! source of truth here prevents the two copies from drifting.
+//!
+//! Module-level cfg gate lives in the parent (`io/mod.rs`); this file
+//! is only compiled on macOS, so no inner `#![cfg]` is needed.
+
+/// `fcntl(F_PREALLOCATE)` command number from `sys/fcntl.h`.
+pub(crate) const F_PREALLOCATE: libc::c_int = 42;
+
+/// Anchor preallocation at the current physical EOF.
+pub(crate) const F_PEOFPOSMODE: libc::c_int = 3;
+
+/// Prefer a contiguous allocation. Try this first; on `EINVAL` (no
+/// contiguous run of that size), fall back to `F_ALLOCATEALL`.
+pub(crate) const F_ALLOCATECONTIG: libc::c_uint = 0x0000_0002;
+
+/// Allow non-contiguous allocation. Stronger guarantee than just
+/// asking for `F_ALLOCATECONTIG` because the kernel will piece
+/// together fragments rather than failing.
+pub(crate) const F_ALLOCATEALL: libc::c_uint = 0x0000_0004;
+
+/// `fstore_t` from `sys/fcntl.h`. `repr(C)` because we hand it to
+/// `fcntl(F_PREALLOCATE)` which writes through the pointer.
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub(crate) struct Fstore {
+    pub fst_flags: libc::c_uint,
+    pub fst_posmode: libc::c_int,
+    pub fst_offset: libc::off_t,
+    pub fst_length: libc::off_t,
+    pub fst_bytesalloc: libc::off_t,
+}

src/io/sink/mod.rs

@@ -20,9 +20,6 @@
 //! 4 MiB buffer for the common local-disk case; `WritebackFile`
 //! (separate module) wraps a `File` with the adaptive-chunk
 //! `sync_file_range` machinery for the Linux+NFS case.
-//!
-//! See `(internal)/memory/project_buffering_architecture.md` for
-//! the full design and the source/sink matrix.
 
 use std::io::{Seek, Write};
 

src/io/sink/preallocate/macos.rs

@@ -7,23 +7,9 @@
 use std::fs::File;
 use std::os::unix::io::AsRawFd;
 
-// Mirror the Darwin `fstore_t` struct from `<sys/fcntl.h>`. libc on
-// some Rust toolchains/versions doesn't ship this binding, so define
-// it locally with the layout the kernel ABI requires.
-#[repr(C)]
-struct Fstore {
-    fst_flags: libc::c_uint,
-    fst_posmode: libc::c_int,
-    fst_offset: libc::off_t,
-    fst_length: libc::off_t,
-    fst_bytesalloc: libc::off_t,
-}
-
-// Constants from <sys/fcntl.h>.
-const F_PREALLOCATE: libc::c_int = 42;
-const F_ALLOCATECONTIG: libc::c_uint = 0x0000_0002;
-const F_ALLOCATEALL: libc::c_uint = 0x0000_0004;
-const F_PEOFPOSMODE: libc::c_int = 3;
+use crate::io::platform_macos::{
+    F_ALLOCATEALL, F_ALLOCATECONTIG, F_PEOFPOSMODE, F_PREALLOCATE, Fstore,
+};
 
 pub(super) fn preallocate_impl(file: &File, size_bytes: u64) {
     let fd = file.as_raw_fd();

src/io/sink/socket.rs

@@ -47,7 +47,7 @@ impl SocketSink {
     /// writing. `sndbuf_bytes`, when present, is forwarded to
     /// `setsockopt(SO_SNDBUF)` as a kernel hint — the OS may clamp it.
     ///
-    /// `addr` accepts anything `ToSocketAddrs` does: `"10.0.0.1:1234"`,
+    /// `addr` accepts anything `ToSocketAddrs` does: `"192.0.2.1:1234"`,
     /// `("host", 1234)`, a `SocketAddr`, etc.
     pub fn connect<A: ToSocketAddrs>(addr: A, sndbuf_bytes: Option<usize>) -> io::Result<Self> {
         let stream = TcpStream::connect(addr)?;

src/io/writeback/linux.rs

@@ -22,48 +22,34 @@
 //! fast storage (NVMe) sees smaller chunks to keep cache pressure
 //! tight. Bounds: [4 MiB, 256 MiB].
 //!
-//! ## Medium-agnostic by construction
+//! ## NFS escape hatch
 //!
-//! `sync_file_range(WAIT_AFTER)` runs on every medium (local FS, NFS,
-//! etc.). It bounds the dirty-page set at ~2 × `chunk_bytes` by
-//! waiting for each chunk's kernel writeback to complete before
-//! advancing. There is no `if is_nfs` branch in the hot path. The
-//! safety net described below ([`WAIT_AFTER_TIMEOUT`]) handles wedged
-//! filesystems generically: if a particular FS proves unable to ack
-//! `WAIT_AFTER` within the deadline, the pipeline flips to `degraded`
-//! and skips for the rest of its life. That covers the original
-//! NFS-hang concern (network partition, server stuck on commit)
-//! without baking the failure mode into a per-FS branch.
+//! `sync_file_range(WAIT_AFTER)` on an NFS-mounted file can block
+//! indefinitely waiting for the server's commit ack. If the server
+//! never acks (network partition, server-side hang, slow commit), the
+//! syscall never returns and the consumer thread is stuck inside the
+//! kernel — `/api/stop` can't reach it because halt is cooperative.
 //!
-//! **No `posix_fadvise(DONTNEED)` after the wait.** Earlier revisions
-//! evicted the just-WAIT_AFTER'd range from the page cache on the
-//! theory that bounding *dirty* pages required also bounding *clean*
-//! pages. That was unnecessary and counterproductive: clean cached
-//! pages cost nothing (the kernel reclaims them under LRU when memory
-//! is needed) and DONTNEED forces a read-modify-write on any
-//! subsequent in-window write — exactly the pattern matroska
-//! cluster-size backpatches produce, costing ~40-50% of measured NFS
-//! write bandwidth in empirical tests 2026-05-15/16.
-//!
-//! Medium detection happens *exactly once*, at construction, and
-//! produces *exactly one* value: the initial `chunk_bytes` seed for
-//! the autotuner. The detector's job is to give the autotuner a
-//! decent starting point on cold start; from there p95 of WAIT_AFTER
-//! latency drives all subsequent decisions, identically on every
-//! medium.
+//! When `fstatfs` reports the file lives on an NFS mount
+//! (`f_type == NFS_SUPER_MAGIC`), the pipeline skips the WAIT_AFTER +
+//! `posix_fadvise(DONTNEED)` dance entirely. NFS clients have their
+//! own buffering and commit semantics that handle dirty-page bounds
+//! without us forcing the issue. The async `SYNC_FILE_RANGE_WRITE`
+//! kickoff still runs (non-blocking by spec) so writeback still gets
+//! a nudge.
 //!
 //! ## Defence in depth: WAIT_AFTER timeout
 //!
-//! A degraded disk, wedged NFS server, or odd FS driver could in
-//! principle hang inside WAIT_AFTER. Each call runs on a worker
-//! thread with a 30s recv_timeout on its result channel
-//! ([`crate::io::bounded::bounded_syscall`]). On timeout the pipeline
-//! flips to `degraded`, logs a loud error, and skips WAIT_AFTER for
-//! the rest of its life. The worker thread is intentionally leaked —
-//! it unwinds whenever the syscall eventually returns or the process
-//! exits. The mux continues; the original dirty-burst pathology
-//! re-emerges only on the specific (medium, server, FS) combination
-//! that actually wedged.
+//! Even on local storage, a degraded disk or odd filesystem driver
+//! could in principle wedge inside WAIT_AFTER. Each WAIT_AFTER call
+//! runs on a worker thread with a 30s recv_timeout on its result
+//! channel. On timeout we log a loud error, set a `degraded` flag,
+//! and from then on skip WAIT_AFTER + DONTNEED for the rest of the
+//! pipeline's life (same shape as the NFS path). The worker thread
+//! is intentionally leaked — it unwinds whenever the syscall
+//! eventually returns or the process exits. The mux continues; the
+//! original dirty-burst pathology re-emerges but the rip can still
+//! finish instead of freezing.
 
 use std::collections::VecDeque;
 use std::fs::File;
@@ -101,9 +87,11 @@ pub(crate) struct WritebackPipeline {
     /// Count of chunks emitted (used to space out periodic
     /// `debug!` size snapshots).
     chunk_count: u64,
-    /// What `detect_storage_class` saw at construction. Carried for
-    /// diagnostic logging only — *not* keyed off in the hot path.
-    storage_class: StorageClass,
+    /// True when the underlying file is on an NFS mount. NFS makes
+    /// WAIT_AFTER unsafe (can block forever on missing server ack), so
+    /// we skip it entirely and let the NFS client handle commit on
+    /// close.
+    is_nfs: bool,
     /// Set the first time WAIT_AFTER exceeds [`WAIT_AFTER_TIMEOUT`].
     /// Once set, behaviour matches the NFS path for the rest of the
     /// pipeline's life. Wrapped in `Arc` only because both this
@@ -120,25 +108,13 @@ impl WritebackPipeline {
     /// returned `WritebackPipeline` MUST be dropped before `file`
     /// itself, or kept inside the same struct that owns `file` — the
     /// alias is unchecked.
-    ///
-    /// `chunk_bytes_hint` is the caller's preferred starting chunk
-    /// size; the constructor overrides it with a medium-specific
-    /// initial seed if `detect_storage_class` recognises the fd's
-    /// filesystem. The autotuner then drives the value from there
-    /// based on measured `WAIT_AFTER` latency, identically on every
-    /// medium.
-    pub(crate) fn new(file: &File, start_pos: u64, chunk_bytes_hint: u64) -> Self {
+    pub(crate) fn new(file: &File, start_pos: u64, chunk_bytes: u64) -> Self {
         let fd = file.as_raw_fd();
-        let (class, seed) = detect_storage_class(fd);
-        // Medium-aware initial seed: bias toward bigger chunks on
-        // slow-commit media so the autotuner doesn't waste a minute
-        // climbing from a too-small starting value. A returned seed
-        // of 0 means "the detector has no opinion; use the caller's
-        // hint". All subsequent tuning is medium-agnostic.
-        let chunk_bytes = if seed > 0 { seed } else { chunk_bytes_hint };
+        let is_nfs = detect_nfs(fd);
         tracing::info!(
             target: "mux",
-            "WritebackPipeline fd={fd} storage_class={class:?} chunk_bytes={chunk_bytes}"
+            "WritebackPipeline fd={fd} is_nfs={is_nfs} chunk_bytes={chunk_bytes} strategy={}",
+            if is_nfs { "nfs-skip-wait" } else { "wait+dontneed" }
         );
         Self {
             fd,
@@ -147,18 +123,17 @@ impl WritebackPipeline {
             pending: None,
             wait_after_window: VecDeque::with_capacity(ADAPTIVE_WINDOW),
             chunk_count: 0,
-            storage_class: class,
+            is_nfs,
             degraded: Arc::new(AtomicBool::new(false)),
         }
     }
 
-    /// True if we should bypass the WAIT_AFTER finalisation step. The
-    /// pipeline only skips after `WAIT_AFTER` has *empirically* hung
-    /// past [`WAIT_AFTER_TIMEOUT`] on this particular fd. No per-FS
-    /// branch — the failure is detected, not predicted.
+    /// True if we should bypass the WAIT_AFTER + DONTNEED finalisation
+    /// step. NFS always bypasses; local storage bypasses once the
+    /// pipeline has flipped to degraded after a WAIT_AFTER timeout.
     #[inline]
     fn skip_wait(&self) -> bool {
-        self.degraded.load(Ordering::Relaxed)
+        self.is_nfs || self.degraded.load(Ordering::Relaxed)
     }
 
     /// Caller advanced the file position to `pos`. If a chunk boundary
@@ -181,29 +156,40 @@ impl WritebackPipeline {
         }
         if let Some((prev_off, prev_len)) = self.pending.take() {
             if self.skip_wait() {
-                // Degraded path (set only after an empirical
-                // WAIT_AFTER timeout on this fd). We still advance
-                // `pending` so the next call has a stable cycle.
+                // NFS branch (or degraded fallback after a prior
+                // timeout): the WAIT_AFTER + DONTNEED dance is what
+                // hangs on NFS — skip it. We still advance `pending`
+                // so the next call has a stable cycle.
             } else {
+                // Normal local-storage branch with belt-and-braces
+                // timeout. If WAIT_AFTER hangs > WAIT_AFTER_TIMEOUT
+                // we mark the pipeline degraded, log a loud error,
+                // and fall through to the skip path on subsequent
+                // calls.
                 match wait_after_with_timeout(self.fd, prev_off, prev_len) {
                     Some(ms) => {
                         wait_ms = ms;
-                        // Deliberately NO `posix_fadvise(DONTNEED)`
-                        // here. See module-level docs: evicting clean
-                        // pages costs us read-modify-write on
-                        // matroska cluster backpatches and gains
-                        // nothing — the kernel will reclaim clean
-                        // pages under LRU when memory is needed.
+                        let t_fadv = Instant::now();
+                        unsafe {
+                            libc::posix_fadvise(
+                                self.fd,
+                                prev_off as i64,
+                                prev_len as i64,
+                                libc::POSIX_FADV_DONTNEED,
+                            );
+                        }
+                        fadvise_ms = t_fadv.elapsed().as_millis() as u64;
                         self.record_wait(wait_ms);
                     }
                     None => {
-                        // Timeout branch: this fd's FS or server is
-                        // unable to ack WAIT_AFTER. Flip to skip mode
-                        // for the rest of the pipeline's life.
+                        // Timeout branch: switch to NFS-style skip
+                        // for the rest of the pipeline's life. Do
+                        // NOT call DONTNEED — if WAIT_AFTER hasn't
+                        // returned, the pages aren't safely flushed.
                         self.degraded.store(true, Ordering::Relaxed);
                         tracing::error!(
                             target: "mux",
-                            "WritebackPipeline WAIT_AFTER timed out after {}s on chunk off={} len={}, marking writeback degraded (subsequent chunks will skip WAIT_AFTER)",
+                            "WritebackPipeline WAIT_AFTER timed out after {}s on chunk off={} len={}, marking writeback degraded (subsequent chunks will skip WAIT_AFTER + DONTNEED)",
                             WAIT_AFTER_TIMEOUT.as_secs(),
                             prev_off,
                             prev_len
@@ -215,10 +201,9 @@ impl WritebackPipeline {
         self.pending = Some((chunk_off as u64, chunk_len as u64));
         self.last_flush_pos = pos;
         self.chunk_count += 1;
-        let _ = fadvise_ms;
         tracing::trace!(
             target: "mux",
-            "WritebackPipeline chunk off={} len={} sync_file_range_ms={wait_ms} chunk_bytes={} skip_wait={}",
+            "WritebackPipeline chunk off={} len={} sync_file_range_ms={wait_ms} fadvise_ms={fadvise_ms} chunk_bytes={} skip_wait={}",
             chunk_off,
             chunk_len,
             self.chunk_bytes,
@@ -227,10 +212,10 @@ impl WritebackPipeline {
         if self.chunk_count % SIZE_LOG_INTERVAL == 0 {
             tracing::debug!(
                 target: "mux",
-                "WritebackPipeline chunk_bytes={} after {} chunks storage_class={:?} degraded={}",
+                "WritebackPipeline chunk_bytes={} after {} chunks is_nfs={} degraded={}",
                 self.chunk_bytes,
                 self.chunk_count,
-                self.storage_class,
+                self.is_nfs,
                 self.degraded.load(Ordering::Relaxed),
             );
         }
@@ -282,84 +267,55 @@ impl WritebackPipeline {
         if let Some((prev_off, prev_len)) = self.pending.take() {
             tracing::debug!(
                 target: "mux",
-                "WritebackPipeline finalize chunk off={prev_off} len={prev_len} skip_wait={} storage_class={:?} degraded={}",
+                "WritebackPipeline finalize chunk off={prev_off} len={prev_len} skip_wait={} is_nfs={} degraded={}",
                 self.skip_wait(),
-                self.storage_class,
+                self.is_nfs,
                 self.degraded.load(Ordering::Relaxed),
             );
             if self.skip_wait() {
+                // NFS / degraded: skip WAIT_AFTER + DONTNEED. close()
+                // / sync_all() handle commit through their normal
+                // paths.
                 return;
             }
-            if wait_after_with_timeout(self.fd, prev_off, prev_len).is_none() {
-                self.degraded.store(true, Ordering::Relaxed);
-                tracing::error!(
-                    target: "mux",
-                    "WritebackPipeline finalize WAIT_AFTER timed out after {}s on chunk off={prev_off} len={prev_len}, marking writeback degraded",
-                    WAIT_AFTER_TIMEOUT.as_secs(),
-                );
+            match wait_after_with_timeout(self.fd, prev_off, prev_len) {
+                Some(_ms) => unsafe {
+                    libc::posix_fadvise(
+                        self.fd,
+                        prev_off as i64,
+                        prev_len as i64,
+                        libc::POSIX_FADV_DONTNEED,
+                    );
+                },
+                None => {
+                    self.degraded.store(true, Ordering::Relaxed);
+                    tracing::error!(
+                        target: "mux",
+                        "WritebackPipeline finalize WAIT_AFTER timed out after {}s on chunk off={prev_off} len={prev_len}, marking writeback degraded",
+                        WAIT_AFTER_TIMEOUT.as_secs(),
+                    );
+                }
             }
         }
     }
 }
 
-/// Coarse classification of the medium an open file is on. Used only
-/// at construction to seed the autotuner with a sensible initial
-/// `chunk_bytes`. Never branched on in the hot path.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub(crate) enum StorageClass {
-    /// `fstatfs.f_type == NFS_SUPER_MAGIC`. Slow-commit; seed a
-    /// generous initial chunk so the autotuner doesn't waste cycles
-    /// climbing from a too-small value.
-    Nfs,
-    /// Anything else we successfully stat'd. Local FS, tmpfs, ZFS,
-    /// network FS we don't have a constant for, etc. Use the caller's
-    /// hint as the seed.
-    Other,
-    /// `fstatfs` failed. Caller's hint wins.
-    Unknown,
-}
-
-/// Probe the FS class via `fstatfs` and return both the class label
-/// and a recommended `chunk_bytes` seed. `seed == 0` means "no
-/// medium-specific recommendation; use the caller's hint." Failure
-/// modes default to `Unknown` + seed 0 so the caller's hint applies.
+/// Probe whether `fd` lives on an NFS mount. Thin wrapper around
+/// [`crate::platform::fs_type::detect_fd`] so writeback policy and
+/// general-purpose fs-type classification stay in sync (same magic
+/// numbers, same musl-vs-glibc cast handling).
 ///
-/// This is the single medium-detection point in the whole writeback
-/// pipeline. Everything else is medium-agnostic.
-fn detect_storage_class(fd: RawFd) -> (StorageClass, u64) {
-    // `libc::statfs` is repr(C) with a fixed layout; zeroing is the
-    // documented init pattern for the kernel uapi struct.
-    let mut buf: libc::statfs = unsafe { std::mem::zeroed() };
-    let rc = unsafe { libc::fstatfs(fd, &mut buf) };
-    if rc != 0 {
-        let errno = std::io::Error::last_os_error();
-        tracing::warn!(
-            target: "mux",
-            "WritebackPipeline fstatfs(fd={fd}) failed: {errno} — defaulting to Unknown",
-        );
-        return (StorageClass::Unknown, 0);
-    }
-    // `f_type` is signed (`__fsword_t`) on glibc and unsigned
-    // (`c_ulong`) on musl. Cast both sides to i64 for a portable
-    // comparison. On glibc x86_64 both already are i64 — clippy flags
-    // the cast as unnecessary on that target only, but we need it for
-    // musl, so silence the lint.
-    #[allow(clippy::unnecessary_cast)]
-    let f_type = buf.f_type as i64;
-    #[allow(clippy::unnecessary_cast)]
-    let nfs_magic = libc::NFS_SUPER_MAGIC as i64;
-    if f_type == nfs_magic {
-        // NFS commit ack typically ~10-30 ms RTT. The autotuner grows
-        // by doubling when p95 > 200 ms — so starting at 32 MiB it
-        // would never grow on a healthy NFS. Seed at 64 MiB so the
-        // commit cadence amortizes properly from the first chunk.
-        (StorageClass::Nfs, 64 * 1024 * 1024)
-    } else {
-        // Local FS / unknown remote FS. Caller's hint (typically 32
-        // MiB) is a fine starting point; autotuner adjusts from
-        // measured latency.
-        (StorageClass::Other, 0)
-    }
+/// Fails open: any classification other than NFS counts as "not NFS"
+/// (including `Unknown` on `fstatfs` error) — better to run the
+/// normal local-storage path on a misdetected NFS mount and surface
+/// the freeze loudly via [`WAIT_AFTER_TIMEOUT`] than to needlessly
+/// disable writeback bounding on every local file because of a
+/// transient stat error.
+fn detect_nfs(fd: RawFd) -> bool {
+    matches!(
+        crate::platform::fs_type::detect_fd(fd),
+        crate::platform::fs_type::FsType::Nfs
+    )
 }
 
 /// Run `sync_file_range(WAIT_AFTER)` on a worker thread and wait up
@@ -387,3 +343,117 @@ fn wait_after_with_timeout(fd: RawFd, off: u64, len: u64) -> Option<u64> {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::NamedTempFile;
+
+    /// Helper: build a `WritebackPipeline` over a local tempfile. On
+    /// every test rig (linux dev box, CI) the tempfile lives on a
+    /// local FS, so `is_nfs=false` and `skip_wait` returns false until
+    /// we explicitly mark the pipeline degraded.
+    fn local_pipeline(chunk_bytes: u64) -> (NamedTempFile, WritebackPipeline) {
+        let f = NamedTempFile::new().expect("tempfile create");
+        let pipeline = WritebackPipeline::new(f.as_file(), 0, chunk_bytes);
+        (f, pipeline)
+    }
+
+    #[test]
+    fn new_pipeline_starts_active() {
+        let (_f, p) = local_pipeline(32 * 1024 * 1024);
+        assert!(!p.is_nfs, "local tempfile must not classify as NFS");
+        assert!(!p.degraded.load(Ordering::Relaxed));
+        assert!(!p.skip_wait(), "fresh local pipeline must not skip wait");
+    }
+
+    #[test]
+    fn degraded_flag_short_circuits_wait() {
+        let (_f, p) = local_pipeline(32 * 1024 * 1024);
+        assert!(!p.skip_wait());
+        p.degraded.store(true, Ordering::Relaxed);
+        assert!(
+            p.skip_wait(),
+            "degraded flag must force the wait+dontneed bypass"
+        );
+    }
+
+    #[test]
+    fn record_wait_grows_chunk_on_high_p95() {
+        let (_f, mut p) = local_pipeline(16 * 1024 * 1024);
+        // Fill the window with samples above the grow threshold.
+        for _ in 0..ADAPTIVE_WINDOW {
+            p.record_wait(ADAPTIVE_GROW_MS + 50);
+        }
+        assert!(
+            p.chunk_bytes > 16 * 1024 * 1024,
+            "chunk should have grown; got {}",
+            p.chunk_bytes
+        );
+        assert!(p.chunk_bytes <= CHUNK_BYTES_MAX);
+    }
+
+    #[test]
+    fn record_wait_shrinks_chunk_on_low_p95() {
+        let (_f, mut p) = local_pipeline(64 * 1024 * 1024);
+        for _ in 0..ADAPTIVE_WINDOW {
+            p.record_wait(1); // well under ADAPTIVE_SHRINK_MS
+        }
+        assert!(
+            p.chunk_bytes < 64 * 1024 * 1024,
+            "chunk should have shrunk; got {}",
+            p.chunk_bytes
+        );
+        assert!(p.chunk_bytes >= CHUNK_BYTES_MIN);
+    }
+
+    #[test]
+    fn record_wait_no_op_below_window_fill() {
+        let (_f, mut p) = local_pipeline(16 * 1024 * 1024);
+        let initial = p.chunk_bytes;
+        // Only push a few samples; window not full → no adaptation.
+        for _ in 0..(ADAPTIVE_WINDOW - 1) {
+            p.record_wait(ADAPTIVE_GROW_MS + 100);
+        }
+        assert_eq!(
+            p.chunk_bytes, initial,
+            "chunk must not change before window is full"
+        );
+    }
+
+    #[test]
+    fn record_wait_clamps_to_chunk_bounds() {
+        // Grow past the max.
+        let (_f, mut p) = local_pipeline(CHUNK_BYTES_MAX);
+        for _ in 0..ADAPTIVE_WINDOW {
+            p.record_wait(ADAPTIVE_GROW_MS + 1000);
+        }
+        assert_eq!(p.chunk_bytes, CHUNK_BYTES_MAX, "must clamp to MAX");
+
+        // Shrink past the min.
+        let (_f, mut p) = local_pipeline(CHUNK_BYTES_MIN);
+        for _ in 0..ADAPTIVE_WINDOW {
+            p.record_wait(0);
+        }
+        assert_eq!(p.chunk_bytes, CHUNK_BYTES_MIN, "must clamp to MIN");
+    }
+
+    #[test]
+    fn detect_nfs_local_file_is_false() {
+        // Local tempfile must not classify as NFS. This locks in the
+        // consolidation through `crate::platform::fs_type::detect_fd`.
+        let f = NamedTempFile::new().expect("tempfile create");
+        use std::os::unix::io::AsRawFd;
+        assert!(!detect_nfs(f.as_file().as_raw_fd()));
+    }
+
+    #[test]
+    fn note_progress_below_chunk_is_noop() {
+        let (_f, mut p) = local_pipeline(32 * 1024 * 1024);
+        // No-op return before crossing the first chunk boundary.
+        let before = p.chunk_count;
+        p.note_progress(1024); // < 32 MiB
+        assert_eq!(p.chunk_count, before);
+        assert!(p.pending.is_none());
+    }
+}

src/io/writeback_file/macos.rs

@@ -16,31 +16,14 @@ use std::io;
 use std::os::unix::io::AsRawFd;
 use std::time::Duration;
 
-/// libc `F_PREALLOCATE` — not exposed by the `libc` crate on all macOS
-/// SDK versions, so define it here.
-const F_PREALLOCATE: libc::c_int = 42;
-/// Allocate from current EOF.
-const F_PEOFPOSMODE: libc::c_int = 3;
-/// Hint: contiguous extent preferred.
-const F_ALLOCATECONTIG: libc::c_uint = 0x00000002;
-/// Allocate all the requested bytes (fall back to non-contig if needed).
-const F_ALLOCATEALL: libc::c_uint = 0x00000004;
+use crate::io::platform_macos::{
+    F_ALLOCATEALL, F_ALLOCATECONTIG, F_PEOFPOSMODE, F_PREALLOCATE, Fstore,
+};
 
 /// `fcntl(F_FULLFSYNC)` opcode. Documented in `man 2 fcntl` on macOS;
 /// not in the `libc` crate as a named constant.
 const F_FULLFSYNC: libc::c_int = 51;
 
-/// `fstore_t` layout matches `sys/fcntl.h`. Repr is C-stable so we can
-/// build it manually.
-#[repr(C)]
-struct Fstore {
-    fst_flags: libc::c_uint,
-    fst_posmode: libc::c_int,
-    fst_offset: libc::off_t,
-    fst_length: libc::off_t,
-    fst_bytesalloc: libc::off_t,
-}
-
 pub(super) fn preallocate(file: &File, size_bytes: u64) {
     let mut fst = Fstore {
         fst_flags: F_ALLOCATECONTIG | F_ALLOCATEALL,

src/io/writeback_file/mod.rs

@@ -73,9 +73,21 @@ use std::path::Path;
 use super::writeback::WritebackPipeline;
 
 /// Granularity at which the Linux writeback pipeline issues
-/// `sync_file_range` / `posix_fadvise(DONTNEED)` pairs. 32 MiB is the
-/// historical default — bounded-cache pressure stays at ~2 × this size.
-const WRITEBACK_CHUNK_BYTES: u64 = 32 * 1024 * 1024;
+/// `sync_file_range` pairs. 32 MiB is the empirically best value on
+/// the rip1 test bed (NFS to unraid-1 over 1 GbE, single-disk SAS):
+/// 8 MiB / 64 MiB / 128 MiB all measured worse in the 0.21.x mux
+/// iteration runs. Override via `FREEMKV_WRITEBACK_CHUNK_MIB` —
+/// faster backends (NVMe, RAID) may tolerate larger windows.
+const WRITEBACK_CHUNK_BYTES_DEFAULT: u64 = 32 * 1024 * 1024;
+
+fn writeback_chunk_bytes() -> u64 {
+    std::env::var("FREEMKV_WRITEBACK_CHUNK_MIB")
+        .ok()
+        .and_then(|v| v.parse::<u64>().ok())
+        .filter(|&n| n > 0)
+        .map(|n| n * 1024 * 1024)
+        .unwrap_or(WRITEBACK_CHUNK_BYTES_DEFAULT)
+}
 
 pub(crate) struct WritebackFile {
     file: File,
@@ -90,7 +102,7 @@ impl WritebackFile {
     /// or appended files).
     pub(crate) fn new(mut file: File) -> io::Result<Self> {
         let pos = file.stream_position()?;
-        let pipeline = WritebackPipeline::new(&file, pos, WRITEBACK_CHUNK_BYTES);
+        let pipeline = WritebackPipeline::new(&file, pos, writeback_chunk_bytes());
         Ok(Self {
             file,
             pipeline,

src/labels/bdmt.rs

@@ -38,7 +38,7 @@ use std::collections::BTreeMap;
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize, Default)]
 pub struct DiscMetadata {
     /// Localized titles, keyed by 3-char ISO 639-2 lang code
-    /// (e.g. "eng" → "Dune Part Two")
+    /// (e.g. "eng" → "Aurora Drift")
     pub titles: BTreeMap<String, String>,
     /// First-line / short description, per lang
     pub descriptions: BTreeMap<String, String>,
@@ -146,7 +146,7 @@ pub(crate) fn parse_bdmt_xml(_lang_code: &str, xml_text: &str) -> Option<BdmtFie
 }
 
 /// Reject candidate description strings that are themselves XML
-/// fragments — observed on disc-04 (Top Gun: Maverick), where
+/// fragments — observed on a captured disc, where
 /// `<di:description>` contained `<di:thumbnail href="…"/>` child
 /// elements and no actual prose. Surfacing that raw to the JSON
 /// output is worse than dropping the field entirely.
@@ -210,10 +210,10 @@ mod tests {
         // carrier inside a <discInfo> root.
         let xml = r#"<?xml version="1.0" encoding="UTF-8"?>
 <discInfo xmlns:di="urn:BDA:bdmv;disclibmeta">
-  <di:name>Dune Part Two</di:name>
+  <di:name>Aurora Drift</di:name>
 </discInfo>"#;
         let (title, desc, set) = parse_bdmt_xml("eng", xml).expect("title should parse");
-        assert_eq!(title, "Dune Part Two");
+        assert_eq!(title, "Aurora Drift");
         assert_eq!(desc, None);
         assert_eq!(set, None);
     }
@@ -223,12 +223,12 @@ mod tests {
         // <di:title> is the alternate carrier; should be picked up
         // when <di:name> is absent.
         let xml = r#"<discInfo xmlns:di="urn:BDA:bdmv;disclibmeta">
-  <di:title>The Matrix</di:title>
-  <di:description>A film about computers.</di:description>
+  <di:title>Echo Chamber</di:title>
+  <di:description>A film about machines.</di:description>
 </discInfo>"#;
         let (title, desc, _) = parse_bdmt_xml("eng", xml).unwrap();
-        assert_eq!(title, "The Matrix");
-        assert_eq!(desc.as_deref(), Some("A film about computers."));
+        assert_eq!(title, "Echo Chamber");
+        assert_eq!(desc.as_deref(), Some("A film about machines."));
     }
 
     #[test]
@@ -238,17 +238,17 @@ mod tests {
         // titleName inside tableOfContents.
         let xml = r#"<discInfo xmlns:di="urn:BDA:bdmv;disclibmeta">
   <di:tableOfContents>
-    <di:titleName>Inside Out 2</di:titleName>
+    <di:titleName>Feelings Two</di:titleName>
   </di:tableOfContents>
 </discInfo>"#;
         let (title, _, _) = parse_bdmt_xml("eng", xml).unwrap();
-        assert_eq!(title, "Inside Out 2");
+        assert_eq!(title, "Feelings Two");
     }
 
     #[test]
     fn extract_box_set_position() {
         let xml = r#"<discInfo xmlns:di="urn:BDA:bdmv;disclibmeta">
-  <di:name>LOTR Disc 2</di:name>
+  <di:name>Box Set Disc 2</di:name>
   <di:discNumber>2</di:discNumber>
   <di:numSets>5</di:numSets>
 </discInfo>"#;
@@ -287,11 +287,11 @@ mod tests {
         // would. This exercises the BTreeMap key handling without
         // needing a UdfFs.
         let eng_xml = r#"<discInfo xmlns:di="urn:BDA:bdmv;disclibmeta">
-  <di:name>Dune Part Two</di:name>
+  <di:name>Aurora Drift</di:name>
 </discInfo>"#;
         let fra_xml = r#"<discInfo xmlns:di="urn:BDA:bdmv;disclibmeta">
-  <di:name>Dune Deuxième Partie</di:name>
-  <di:description>Suite du film de 2021.</di:description>
+  <di:name>Aurora Drift (Partie Deux)</di:name>
+  <di:description>Suite du film fictif.</di:description>
 </discInfo>"#;
 
         let mut meta = DiscMetadata::default();
@@ -310,16 +310,16 @@ mod tests {
 
         assert_eq!(
             meta.titles.get("eng").map(String::as_str),
-            Some("Dune Part Two")
+            Some("Aurora Drift")
         );
         assert_eq!(
             meta.titles.get("fra").map(String::as_str),
-            Some("Dune Deuxième Partie")
+            Some("Aurora Drift (Partie Deux)")
         );
         assert!(meta.descriptions.get("eng").is_none());
         assert_eq!(
             meta.descriptions.get("fra").map(String::as_str),
-            Some("Suite du film de 2021.")
+            Some("Suite du film fictif.")
         );
         assert_eq!(meta.disc_number, None);
     }
@@ -342,21 +342,21 @@ mod tests {
 
     #[test]
     fn description_with_only_child_xml_is_dropped() {
-        // Real-world bug from disc-04 (Top Gun: Maverick, 2026-05-11
+        // Real-world bug from a captured disc (2026-05-11
         // capture): <di:description> contained only <di:thumbnail/>
         // child elements with no actual prose. The previous parser
         // surfaced the raw XML fragment as the description string.
         // Now we reject candidates that begin with `<`.
         let xml = r#"<discInfo>
-            <di:name>Top Gun: Maverick</di:name>
+            <di:name>Skyline Run</di:name>
             <di:description>
-              <di:thumbnail href="tgm_meta_sm.jpg" />
-              <di:thumbnail href="tgm_meta_lg.jpg" />
+              <di:thumbnail href="sample_meta_sm.jpg" />
+              <di:thumbnail href="sample_meta_lg.jpg" />
             </di:description>
         </discInfo>"#;
         let (title, description, _) =
             parse_bdmt_xml("eng", xml).expect("title is present so parse must succeed");
-        assert_eq!(title, "Top Gun: Maverick");
+        assert_eq!(title, "Skyline Run");
         assert!(
             description.is_none(),
             "description containing only XML children must be dropped, got {description:?}"
@@ -381,10 +381,10 @@ mod tests {
     #[test]
     fn whitespace_in_title_is_trimmed() {
         let xml = r#"<discInfo><di:name>
-            Dune Part Two
+            Aurora Drift
         </di:name></discInfo>"#;
         let (title, _, _) = parse_bdmt_xml("eng", xml).unwrap();
-        assert_eq!(title, "Dune Part Two");
+        assert_eq!(title, "Aurora Drift");
     }
 
     #[test]

src/labels/dbp.rs

@@ -7,8 +7,7 @@
 //! Stream labels live as plain ASCII strings inside compiled `.class`
 //! files in the jar — a quirk of the menu-rendering layer encoding
 //! its TextField positions and content as constant strings the
-//! Java compiler retained in the class string pool. Format observed
-//! in the corpus (Civil War UHD, 2024):
+//! Java compiler retained in the class string pool. Observed format:
 //!
 //! ```text
 //! LTextField,Audio1,English Dolby Atmos,Fontstrip_Composite,...

src/labels/deluxe.rs

@@ -1,83 +1,65 @@
 //! Deluxe BD-J framework — `com/bydeluxe/bluray/` package signature.
 //!
-//! Used by major studios (Disney, Warner, others) for their UHD
-//! BD-J authoring. Detected on discs whose `/BDMV/JAR/<x>.jar`
-//! contains a `com/bydeluxe/` directory entry.
+//! Detected on discs whose `/BDMV/JAR/<x>.jar` contains a
+//! `com/bydeluxe/` directory entry.
 //!
-//! ## Why this parser exists
+//! ## What this parser reads
 //!
-//! Deluxe-authored discs store stream labels as **ordinal references
-//! into obfuscated enum classes**. The label text isn't a literal
-//! string in any anchor pattern (unlike dbp's `TextField,...` rows).
-//! Instead, the binding code is roughly:
-//!
-//! ```java
-//! streamTable.put(1, new AudioSlot(LanguageEnum.English,
-//!                                  CodecEnum.ATMOS_HD_AUDIO,
-//!                                  PurposeEnum.Normal));
-//! ```
-//!
-//! The class names `LanguageEnum`, `CodecEnum`, `PurposeEnum`, and
-//! `AudioSlot` are obfuscated per-disc (`be.class`, `ma.class`,
-//! `lp.class`, etc.) — no name pattern survives the obfuscator. But
-//! the **shape of `<clinit>`** is framework-stable:
+//! Deluxe-authored discs store stream labels as ordinal references into
+//! enum classes whose names are obfuscated per-disc, so a name-based
+//! match won't work. The label data is instead recovered by matching on
+//! the **shape of each enum's `<clinit>`**, which is framework-stable:
 //!
 //! | Enum | Signature |
 //! |---|---|
 //! | Language | 70 `ldc` operations in `<clinit>`, sequence starts `English, French, Spanish, Dutch, ...` |
 //! | Purpose | 8 ldcs starting `Normal, Commentary, PiP, Trivia, ...` |
 //! | VideoFormat | 7 ldcs starting `HD, HDR10 Plus, HD Dolby, ...` |
-//! | Region | 22 ldcs starting `USA_D1, LIC1, LIC2, LIC3, ...` (Disney only) |
-//! | Studio | 6 ldcs starting `Disney, Marvel, Pixar, ...` (Disney only) |
-//! | Codec | ~46 `new` instructions, 0 ldcs in `<clinit>` (codec strings live in subclasses) |
+//! | Region | 22 ldcs starting `USA_D1, LIC1, LIC2, LIC3, ...` |
+//! | Studio | 6 ldcs starting `Disney, Marvel, Pixar, ...` |
+//! | Codec | many `new` instructions, 0 ldcs in `<clinit>` (codec strings live in subclasses) |
 //!
-//! Match on the SHAPE, not the name, and the parser survives obfuscation.
+//! Matching on the shape rather than the class name keeps the parser
+//! working across obfuscation variants.
 //!
 //! ## Implementation phases
 //!
 //! - **Phase A** — master enum identification (`identify_master_enums`).
 //!   Walks every `.class`'s `<clinit>` ldc sequence and matches against
 //!   the framework-stable fingerprints. Output: `Vec<(label, MasterEnum)>`
-//!   with full ordinal → string-value tables. **Empirically verified**
-//!   on disc-01 (Disney) + disc-09 (Warner).
+//!   with full ordinal → string-value tables.
 //!
 //! - **Phase B** — codec enum subclass walk (`decode_codec_enum`).
-//!   The codec enum's `<clinit>` has ~46 `new` instructions and zero
+//!   The codec enum's `<clinit>` has many `new` instructions and zero
 //!   string ldcs — codec name strings live in the subclasses each
 //!   `new` constructs. Walks every referenced subclass's constant
-//!   pool, extracts the codec name string. **Structural shape
-//!   verified** on disc-01 (ma.class, 41 `new` ops) + disc-09
-//!   (ea.class, 46 `new` ops); per-subclass string extraction
-//!   designed against the published Java enum compilation convention
-//!   (each enum value's `<init>` is called with its name string as
-//!   the first arg).
+//!   pool, extracts the codec name string, following the standard Java
+//!   enum compilation convention (each enum value's `<init>` is called
+//!   with its name string as the first arg).
 //!
 //! - **Phase C** — binding-class identification (`find_binding_classes`).
 //!   The per-stream table is built by some class via repeated
 //!   `getstatic` references to the master enums identified in A.
 //!   That class has the highest such `getstatic` count in the jar.
-//!   **Heuristic shape**; precise threshold may need tuning.
+//!   Heuristic shape; precise threshold may need tuning.
 //!
 //! - **Phase D** — binding-class bytecode decoder (`decode_binding`).
 //!   Walks the binding class's `<clinit>` with a tiny symbolic stack
 //!   machine. For each `new X / dup / ... / invokespecial X.<init>`
 //!   sequence, collects the int values and enum-reference operands
 //!   between the `dup` and the constructor call, then emits a
-//!   `DecodedStream`. **Mechanism verified** in unit tests against
-//!   synthetic class fixtures; the **signal-to-StreamLabel mapping**
-//!   (which arg is stream index? which is language? audio vs
-//!   subtitle?) uses a documented heuristic that needs corpus-disc
-//!   verification — see `interpret_stream` for the mapping rules.
+//!   `DecodedStream`. The signal-to-StreamLabel mapping (which arg is
+//!   stream index? which is language? audio vs subtitle?) uses a
+//!   heuristic — see `interpret_streams` for the mapping rules.
 //!
 //! ## Confidence
 //!
 //! [`parse`] returns `Some(ParseResult::medium(labels))` when Phases A
 //! through D produce at least one stream — `Medium` because the
-//! signal-to-label mapping is heuristic until real disc bytecode
-//! confirms the binding pattern. Once verified the parser can promote
-//! to `High`. `None` when the disc isn't Deluxe-authored or when
-//! decoding produces zero streams (a recognized-but-broken state that
-//! the analyzer still surfaces via `parsers_detected`).
+//! signal-to-label mapping is heuristic. `None` when the disc isn't
+//! Deluxe-authored or when decoding produces zero streams (a
+//! recognized-but-broken state that the analyzer still surfaces via
+//! `parsers_detected`).
 
 use super::class_reader::{
     AASTORE, BIPUSH, ClassFile, CodeAttribute, ConstantPool, CpInfo, GETSTATIC, ICONST_0, ICONST_1,
@@ -559,10 +541,9 @@ fn clinit_news_and_ldcs(
 /// candidates ordered by descending getstatic count, filtered to a
 /// minimum concentration of master-enum references.
 ///
-/// Empirically (POC v0.3 dumps): on disc-01 the audio binding class
-///   (`ma.class`) has ~82 getstatic refs, the subtitle binding
-///   (`ko.class`) has ~63. Both share the master Language + Purpose
-///   enums.
+/// A disc that splits the table commonly has one audio binding class
+/// with the most getstatic refs and a subtitle binding class with
+/// somewhat fewer; both share the master Language + Purpose enums.
 pub(crate) fn find_binding_classes(
     archive: &mut jar::Jar,
     master_enum_classes: &HashSet<&str>,
@@ -641,10 +622,9 @@ pub(crate) enum StackVal {
     /// name (e.g. `DOLBY_AC3_AUDIO`, `DOLBY_LOSSLESS_AUDIO`) is the
     /// codec identifier. Deluxe binding constructors take a
     /// `LCodingType;` arg directly — codecs are NOT a Deluxe-internal
-    /// enum (Phase B's codec-subclass walk was based on a wrong
-    /// assumption; the actual codec source is the standard BD-J API
-    /// enum). Discovered via deluxe-poc v0.3 binding-bytecode dump
-    /// against disc-01 (Disney) + disc-09 (Warner) on 2026-05-10.
+    /// enum; the codec source is the standard BD-J API `CodingType`
+    /// enum, so the binding constructor's codec arg is read straight
+    /// from that getstatic operand.
     CodingType(String),
     /// An uninitialized `new` object — popped by the matching
     /// invokespecial.
@@ -988,11 +968,10 @@ impl MasterEnumTable {
 // ── interpret_streams: Constructions → StreamLabels ─────────────────────────
 
 /// Convert the per-construction tuples from Phase D into
-/// [`StreamLabel`]s. Pattern verified against corpus discs via
-/// deluxe-poc v0.3 binding-bytecode dump (2026-05-10):
+/// [`StreamLabel`]s. Two binding-constructor shapes are handled:
 ///
-/// Disney binding (5-arg): `BindingType.<init>(I, Lbe;, Llp;, I, LCodingType;)V`
-/// Warner binding (4-arg): `BindingType.<init>(I, Law;, Lgp;, LCodingType;)V`
+/// 5-arg: `BindingType.<init>(I, Lang;, Lpurpose;, I, LCodingType;)V`
+/// 4-arg: `BindingType.<init>(I, Lang;, Lpurpose;, LCodingType;)V`
 ///
 /// Args are identified by **TYPE**, not position:
 /// - First `EnumRef{kind: "Language"}` → audio/subtitle language
@@ -1098,11 +1077,10 @@ fn interpret_streams(constructions: &[Construction], master: &MasterEnumTable) -
 /// getstatic operands on Deluxe binding classes) to a human-readable
 /// codec hint string.
 ///
-/// CodingType is the standard BD-J API enum; values are documented
-/// in the BD-J specification and verified empirically against the
-/// binding-bytecode dumps in `(internal)/research/deluxe-poc/data/`.
-/// Unknown field names pass through unchanged so unfamiliar codecs
-/// still surface something rather than going silent.
+/// CodingType is the standard BD-J API enum; values are documented in
+/// the BD-J specification. Unknown field names pass through unchanged
+/// so unfamiliar codecs still surface something rather than going
+/// silent.
 fn coding_type_to_codec_hint(field: &str) -> &str {
     match field {
         // Lossless / hi-res.

src/labels/mod.rs

@@ -954,7 +954,7 @@ mod gap_fill_tests {
 
     #[test]
     fn partial_yield_fills_gaps_keeps_framework() {
-        // Oppenheimer-style: framework matched but only labeled 2 of 6 audios.
+        // Partial-coverage case: framework matched but only labeled 2 of 6 audios.
         let mut framework = vec![
             label(StreamLabelType::Audio, 1, "eng", "Atmos"),
             label(StreamLabelType::Audio, 4, "eng", "Commentary"),

src/labels/pixelogic.rs

@@ -37,14 +37,47 @@ pub fn parse(reader: &mut dyn SectorSource, udf: &UdfFs) -> Option<ParseResult>
     // but the corpus surfaced something we don't catalogue.
     let saw_unknown = AtomicBool::new(false);
 
+    let labels = assign_labels(&strings, &saw_unknown);
+
+    if labels.is_empty() {
+        return None;
+    }
+    let confidence = if saw_unknown.load(Ordering::Relaxed) {
+        Confidence::Medium
+    } else {
+        Confidence::High
+    };
+    Some(ParseResult { labels, confidence })
+}
+
+/// Walk the extracted token strings of the feature section and emit a
+/// `StreamLabel` per editorial token, numbered in STN order. Split out
+/// from `parse` so the section/numbering logic is unit-testable without
+/// a `SectorSource`/`UdfFs`.
+fn assign_labels(strings: &[String], saw_unknown: &AtomicBool) -> Vec<StreamLabel> {
+    // The authoritative per-feature stream list lives in the `FPL_`
+    // (FeaturePLaylist) section, in STN order. `SEG_*` entries are menu
+    // segments (intros, logos, disclaimers, previews) that can also carry
+    // stray stream tokens — e.g. a `SEG_MainFeature` preview segment that
+    // lists only a commentary track. Anchoring on such a segment grabs the
+    // wrong streams and misnumbers them. So when the project ships any
+    // `FPL_` playlist, anchor exclusively on it; only fall back to
+    // `SEG_MainFeature` on discs that have no `FPL_` section at all.
+    let has_fpl = strings.iter().any(|s| s.starts_with("FPL_"));
+
     let mut labels = Vec::new();
     let mut in_feature = false;
     let mut audio_num: u16 = 0;
     let mut sub_num: u16 = 0;
 
-    for s in &strings {
+    for s in strings {
         // Detect feature section start
-        if s.starts_with("FPL_") || s.starts_with("SEG_MainFeature") {
+        let is_start = if has_fpl {
+            s.starts_with("FPL_")
+        } else {
+            s.starts_with("SEG_MainFeature")
+        };
+        if is_start {
             if in_feature {
                 break;
             }
@@ -63,7 +96,25 @@ pub fn parse(reader: &mut dyn SectorSource, udf: &UdfFs) -> Option<ParseResult>
             continue;
         }
 
-        if let Some(label) = parse_token_inner(s, Some(&saw_unknown)) {
+        // Generic audio-slot placeholder. Pixelogic lists each audio stream
+        // in the playlist as either an editorial `{lang}_{codec}_…` token OR
+        // a bare `Audio Stream N` placeholder when no editorial label was
+        // authored. The placeholder carries nothing to label, but it DOES
+        // occupy an STN slot — so it must advance `audio_num`. Otherwise a
+        // later editorial token (e.g. a lone `eng_ACOM_` commentary sitting
+        // at STN slot 4, behind three unlabelled main tracks) collapses onto
+        // slot 1 and its Commentary purpose lands on the main feature track.
+        //
+        // Only audio is corrected here: subtitle (`PG Stream N`) numbering is
+        // left exactly as-is — the corpus snapshots show forced/commentary
+        // subtitle tokens already align with STN without counting the
+        // placeholders, and counting them regresses several discs.
+        if s.starts_with("Audio Stream") {
+            audio_num += 1;
+            continue;
+        }
+
+        if let Some(label) = parse_token_inner(s, Some(saw_unknown)) {
             match label.stream_type {
                 StreamLabelType::Audio => {
                     audio_num += 1;
@@ -83,15 +134,7 @@ pub fn parse(reader: &mut dyn SectorSource, udf: &UdfFs) -> Option<ParseResult>
         }
     }
 
-    if labels.is_empty() {
-        return None;
-    }
-    let confidence = if saw_unknown.load(Ordering::Relaxed) {
-        Confidence::Medium
-    } else {
-        Confidence::High
-    };
-    Some(ParseResult { labels, confidence })
+    labels
 }
 
 fn parse_token_inner(s: &str, saw_unknown: Option<&AtomicBool>) -> Option<StreamLabel> {
@@ -250,4 +293,75 @@ mod tests {
         assert!(parse_token_inner("XX_MLP_", None).is_none());
         assert!(parse_token_inner("ENG_MLP_", None).is_none()); // uppercase not accepted as ISO 639-2
     }
+
+    fn strs(v: &[&str]) -> Vec<String> {
+        v.iter().map(|s| s.to_string()).collect()
+    }
+
+    #[test]
+    fn assign_labels_numbers_commentary_behind_placeholders() {
+        // Observed case: the FPL_MainFeature playlist lists three unlabelled main
+        // audio tracks as `Audio Stream N` placeholders, then a lone
+        // `eng_ACOM_` commentary at STN slot 4. The commentary must land on
+        // audio #4, not collapse onto #1 (which would tag the main feature
+        // track as commentary).
+        let flag = AtomicBool::new(false);
+        let tokens = strs(&[
+            "FPL_MainFeature",
+            "Audio Stream 1",
+            "Audio Stream 2",
+            "Audio Stream 3",
+            "eng_ACOM_",
+        ]);
+        let labels = assign_labels(&tokens, &flag);
+        let audio: Vec<_> = labels
+            .iter()
+            .filter(|l| l.stream_type == StreamLabelType::Audio)
+            .collect();
+        assert_eq!(audio.len(), 1, "only the commentary carries a label");
+        assert_eq!(audio[0].stream_number, 4, "commentary is STN slot 4");
+        assert_eq!(audio[0].purpose, LabelPurpose::Commentary);
+        assert_eq!(audio[0].language, "eng");
+    }
+
+    #[test]
+    fn assign_labels_prefers_fpl_over_seg_mainfeature() {
+        // A `SEG_MainFeature` menu/preview segment carries a stray commentary
+        // token, but the real playlist is `FPL_MainFeature`. When an FPL_
+        // section exists, the SEG_ one must be ignored as an anchor — so we
+        // number from the FPL playlist, putting the commentary at slot 2.
+        let flag = AtomicBool::new(false);
+        let tokens = strs(&[
+            "SEG_MainFeature",
+            "eng_ACOM_", // stray token in the menu segment — must be ignored
+            "FPL_MainFeature",
+            "Audio Stream 1",
+            "eng_ACOM_",
+        ]);
+        let labels = assign_labels(&tokens, &flag);
+        let audio: Vec<_> = labels
+            .iter()
+            .filter(|l| l.stream_type == StreamLabelType::Audio)
+            .collect();
+        assert_eq!(audio.len(), 1);
+        assert_eq!(audio[0].stream_number, 2, "numbered from the FPL playlist");
+        assert_eq!(audio[0].purpose, LabelPurpose::Commentary);
+    }
+
+    #[test]
+    fn assign_labels_falls_back_to_seg_without_fpl() {
+        // Discs with no FPL_ playlist still anchor on SEG_MainFeature.
+        let flag = AtomicBool::new(false);
+        let tokens = strs(&["SEG_MainFeature", "eng_MLP_", "spa_AC3_"]);
+        let labels = assign_labels(&tokens, &flag);
+        let audio: Vec<_> = labels
+            .iter()
+            .filter(|l| l.stream_type == StreamLabelType::Audio)
+            .collect();
+        assert_eq!(audio.len(), 2);
+        assert_eq!(audio[0].stream_number, 1);
+        assert_eq!(audio[0].language, "eng");
+        assert_eq!(audio[1].stream_number, 2);
+        assert_eq!(audio[1].language, "spa");
+    }
 }

src/labels/vocab.rs

@@ -10,8 +10,7 @@
 //! - English text → [`LabelPurpose`] (Commentary / Descriptive / etc.).
 //! - English text → [`LabelQualifier`] (SDH / Forced / Descriptive Service).
 //!
-//! Rules of engagement (carried over from
-//! `(internal)/memory/feedback_label_data_rules.md`):
+//! Rules of engagement:
 //!
 //! 1. Only map values we are 100% certain about — published codec
 //!    names, well-known ISO 639-2 mappings, vendor-documented purpose

src/lib.rs

@@ -77,6 +77,7 @@ pub mod css;
 pub mod decrypt;
 pub mod disc;
 pub mod drive;
+pub mod drm;
 pub mod error;
 pub mod event;
 pub mod halt;
@@ -154,7 +155,7 @@ pub use profile::DriveProfile;
 // don't touch `DecryptKeys` directly — `DiscStream::new(reader, title, keys, …)`
 // accepts whatever `Disc::decrypt_keys()` returned. `decrypt_sectors()` is
 // for callers that operate on raw sector buffers (e.g. ISO patching).
-pub use decrypt::{DecryptKeys, decrypt_sectors};
+pub use decrypt::{DecryptKeys, decrypt_sectors, decrypt_threads, set_decrypt_threads};
 
 // ─── Disc structure ─────────────────────────────────────────────────────────
 //
@@ -211,9 +212,11 @@ pub use mux::{InputOptions, StreamUrl, input, output, parse_url};
 // are the ISO-on-disk implementations. [`DecryptingSectorSource`] is the
 // single decrypt-on-read decorator (AACS / CSS / none) — wrap any
 // `SectorSource` to get plaintext sectors out.
+pub use mux::build_iso_pipeline;
 pub use scsi::{DriveInfo, ScsiSense, ScsiTransport, drive_has_disc, list_drives};
 pub use sector::{
-    DecryptingSectorSource, FileSectorSink, FileSectorSource, SectorSink, SectorSource,
+    DecryptingSectorSource, FileSectorSink, FileSectorSource, PrefetchedSectorSource, SectorSink,
+    SectorSource,
 };
 pub use speed::DriveSpeed;
 pub use udf::{UdfFs, read_filesystem};

src/mux/codec/ac3.rs

@@ -76,6 +76,7 @@ impl CodecParser for Ac3Parser {
                 pts_ns,
                 keyframe: true,
                 data: data[start..start + frame_size].to_vec(),
+                duration_ns: None,
             });
             pos = start + frame_size;
         }

src/mux/codec/dts.rs

@@ -86,6 +86,7 @@ impl CodecParser for DtsParser {
                 pts_ns,
                 keyframe: true,
                 data: data[start..start + total_size].to_vec(),
+                duration_ns: None,
             });
             pos = start + total_size;
         }

src/mux/codec/dvdsub.rs

@@ -30,6 +30,7 @@ impl CodecParser for DvdSubParser {
             pts_ns,
             keyframe: true,
             data: pes.data.clone(),
+            duration_ns: None,
         }]
     }
 

src/mux/codec/h264.rs

@@ -85,6 +85,7 @@ impl CodecParser for H264Parser {
             pts_ns,
             keyframe,
             data: frame_data,
+            duration_ns: None,
         }]
     }
 
@@ -176,14 +177,16 @@ impl<'a> Iterator for NalIterator<'a> {
 }
 
 /// Find the position of the next start code (00 00 01) at or after `from`.
+///
+/// Backed by `memchr::memmem::find` for SIMD-accelerated bytestring
+/// search. On AVX2-capable x86_64 this runs ~5–10× the byte-by-byte
+/// scan that preceded it; on a 200 KB UHD HEVC frame the saving is
+/// in the hundreds of microseconds per call.
 pub fn find_start_code(data: &[u8], from: usize) -> Option<usize> {
     if data.len() < from + 3 {
         return None;
     }
-    // Range excludes last 2 bytes since we read 3 bytes at each position.
-    // data.len()-2 as exclusive upper bound means last checked index is data.len()-3,
-    // which accesses data[len-3], data[len-2], data[len-1] — all valid.
-    (from..data.len() - 2).find(|&i| data[i] == 0x00 && data[i + 1] == 0x00 && data[i + 2] == 0x01)
+    memchr::memmem::find(&data[from..], b"\x00\x00\x01").map(|rel| from + rel)
 }
 
 /// Skip past the start code at position `pos`, returning the first byte after it.

src/mux/codec/hevc.rs

@@ -52,7 +52,10 @@ impl CodecParser for HevcParser {
         let pts_ns = pes.dts.or(pes.pts).map(pts_to_ns).unwrap_or(0);
         let data = &pes.data;
         let mut keyframe = false;
-        let mut frame_data = Vec::new();
+        // Pre-size: output is ~input bytes with a few 4-byte length
+        // prefixes added. UHD frames are 150-300 KB; the unsized Vec
+        // growth chain otherwise reallocs 5-7× per frame.
+        let mut frame_data = Vec::with_capacity(data.len() + 64);
 
         // Single-pass NAL scan: extract params, detect keyframes, build length-prefixed output
         let mut pos = 0;
@@ -107,6 +110,7 @@ impl CodecParser for HevcParser {
             pts_ns,
             keyframe,
             data: frame_data,
+            duration_ns: None,
         }]
     }
 

src/mux/codec/lpcm.rs

@@ -44,6 +44,7 @@ impl CodecParser for LpcmParser {
             pts_ns,
             keyframe: true,
             data: pes.data[BD_LPCM_HEADER_SIZE..].to_vec(),
+            duration_ns: None,
         }]
     }
 

src/mux/codec/mod.rs

@@ -29,6 +29,13 @@ pub struct Frame {
     pub keyframe: bool,
     /// Frame data (elementary stream bytes).
     pub data: Vec<u8>,
+    /// Optional duration in nanoseconds — only set by parsers that
+    /// can compute one (currently PGS, which pairs a display PCS
+    /// with the following empty PCS). When `Some`, the MKV muxer
+    /// emits a `BlockGroup` with `BlockDuration` instead of a
+    /// `SimpleBlock`; without it players guess the display interval
+    /// (subtitles linger past their end-time).
+    pub duration_ns: Option<u64>,
 }
 
 /// Convert 90kHz PTS to nanoseconds (round to nearest).
@@ -71,6 +78,7 @@ impl CodecParser for PassthroughParser {
             pts_ns,
             keyframe: self.keyframe,
             data: pes.data.clone(),
+            duration_ns: None,
         }]
     }
 

src/mux/codec/mpeg2.rs

@@ -194,6 +194,7 @@ impl CodecParser for Mpeg2Parser {
             pts_ns,
             keyframe,
             data: pes.data.clone(),
+            duration_ns: None,
         }]
     }
 

src/mux/codec/pgs.rs

@@ -1,12 +1,32 @@
 //! HDMV PGS (Presentation Graphics Stream) subtitle parser.
 //!
-//! PGS segments: PCS, WDS, PDS, ODS, END.
-//! Each PES packet contains one or more segments.
-//! All segments are keyframes (no inter-segment dependencies).
+//! PGS segments: PCS, WDS, PDS, ODS, END. Each PES packet starts with
+//! one of those (segment_type byte at offset 0).
+//!
+//! Subtitle display lifecycle (BD spec):
+//! - A "display" PCS (number_of_composition_objects > 0) starts a
+//!   visible subtitle. Its WDS/PDS/ODS follow.
+//! - A later "empty" PCS (number_of_composition_objects == 0) clears
+//!   the screen.
+//!
+//! For Matroska output we collapse that pair into one block with
+//! `BlockDuration` set to (clear_pts - display_pts). Without a
+//! duration, hardware players linger on the last bitmap until the
+//! next subtitle replaces it — which can be many seconds, and on a
+//! disc where the final subtitle has no follower, until end of file.
 
 use super::{CodecParser, Frame, PesPacket, pts_to_ns};
 
-pub struct PgsParser;
+const SEGMENT_PCS: u8 = 0x16;
+// Offset within the PES payload at which number_of_composition_objects
+// lives in a PCS: 3-byte segment header + 10 bytes of PCS fields
+// (video_w/h, frame_rate, comp_num, comp_state, palette_update,
+// palette_id_ref) = 13.
+const PCS_NUM_OBJECTS_OFFSET: usize = 13;
+
+pub struct PgsParser {
+    pending: Option<(i64, Vec<u8>)>,
+}
 
 impl Default for PgsParser {
     fn default() -> Self {
@@ -16,7 +36,7 @@ impl Default for PgsParser {
 
 impl PgsParser {
     pub fn new() -> Self {
-        Self
+        Self { pending: None }
     }
 }
 
@@ -26,11 +46,63 @@ impl CodecParser for PgsParser {
             return Vec::new();
         }
         let pts_ns = pes.pts.map(pts_to_ns).unwrap_or(0);
-        vec![Frame {
-            pts_ns,
-            keyframe: true,
-            data: pes.data.clone(),
-        }]
+
+        let is_pcs = pes.data[0] == SEGMENT_PCS;
+        let pcs_num_objects = if is_pcs && pes.data.len() > PCS_NUM_OBJECTS_OFFSET {
+            Some(pes.data[PCS_NUM_OBJECTS_OFFSET])
+        } else {
+            None
+        };
+
+        let mut out = Vec::new();
+        match pcs_num_objects {
+            // Clear/empty PCS — closes any pending display. Drop the
+            // clear segment itself; BlockDuration covers the screen
+            // wipe.
+            Some(0) => {
+                if let Some((start_pts, data)) = self.pending.take() {
+                    let duration = pts_ns.saturating_sub(start_pts).max(0) as u64;
+                    out.push(Frame {
+                        pts_ns: start_pts,
+                        keyframe: true,
+                        data,
+                        duration_ns: Some(duration),
+                    });
+                }
+            }
+            // Display PCS — start a new pending. If a prior display
+            // was never explicitly cleared (replace-without-clear),
+            // emit it with the new PCS's PTS as its end.
+            Some(_) => {
+                if let Some((start_pts, data)) = self.pending.take() {
+                    let duration = pts_ns.saturating_sub(start_pts).max(0) as u64;
+                    out.push(Frame {
+                        pts_ns: start_pts,
+                        keyframe: true,
+                        data,
+                        duration_ns: Some(duration),
+                    });
+                }
+                self.pending = Some((pts_ns, pes.data.clone()));
+            }
+            // Non-PCS first segment — either a continuation of the
+            // current display set, or non-standard layout. If we have
+            // a pending display, append; otherwise emit as-is.
+            None => {
+                if let Some((_, ref mut buf)) = self.pending {
+                    buf.extend_from_slice(&pes.data);
+                } else {
+                    out.push(Frame {
+                        pts_ns,
+                        keyframe: true,
+                        data: pes.data.clone(),
+                        duration_ns: None,
+                    });
+                }
+            }
+        }
+
+        out
     }
 
     fn codec_private(&self) -> Option<Vec<u8>> {
@@ -52,29 +124,60 @@ mod tests {
         }
     }
 
-    #[test]
-    fn parse_basic_segment() {
-        let mut parser = PgsParser::new();
-        // PGS segment data (PCS = presentation composition segment)
-        let data = vec![0x16, 0x00, 0x00, 0x11, 0x01, 0x02, 0x03];
-        let pes = make_pes(data.clone(), Some(90000));
-        let frames = parser.parse(&pes);
-
-        assert_eq!(frames.len(), 1);
-        assert_eq!(frames[0].data, data);
-        assert_eq!(frames[0].pts_ns, 1_000_000_000);
+    // Minimum-viable PCS bytes: type 0x16, segment_length (2 bytes),
+    // then 11 bytes of PCS fields ending in number_of_composition_objects.
+    fn pcs_bytes(num_objects: u8) -> Vec<u8> {
+        let mut v = vec![SEGMENT_PCS, 0x00, 0x0B];
+        v.extend_from_slice(&[0x07, 0x80, 0x04, 0x38]); // 1920x1080
+        v.push(0x10); // frame_rate
+        v.extend_from_slice(&[0x00, 0x01]); // composition_number
+        v.push(0x80); // composition_state = EpochStart
+        v.push(0x00); // palette_update + reserved
+        v.push(0x00); // palette_id_ref
+        v.push(num_objects);
+        v
     }
 
     #[test]
-    fn all_keyframes() {
+    fn display_then_clear_yields_duration() {
         let mut parser = PgsParser::new();
-        for i in 0..3 {
-            let data = vec![0x16, 0x00, i];
-            let pes = make_pes(data, Some(90000 * i as i64));
-            let frames = parser.parse(&pes);
-            assert_eq!(frames.len(), 1);
-            assert!(frames[0].keyframe, "PGS segment should always be keyframe");
-        }
+
+        // Display PCS at PTS 90000 (= 1s)
+        let display = pcs_bytes(1);
+        let frames = parser.parse(&make_pes(display.clone(), Some(90000)));
+        assert!(frames.is_empty(), "display PCS should be pending");
+
+        // Empty PCS at PTS 270000 (= 3s)
+        let clear = pcs_bytes(0);
+        let frames = parser.parse(&make_pes(clear, Some(270000)));
+        assert_eq!(frames.len(), 1);
+        assert_eq!(frames[0].pts_ns, 1_000_000_000);
+        assert_eq!(frames[0].duration_ns, Some(2_000_000_000));
+        assert_eq!(frames[0].data, display);
+    }
+
+    #[test]
+    fn replace_without_clear_still_emits_prior_with_duration() {
+        let mut parser = PgsParser::new();
+        let _ = parser.parse(&make_pes(pcs_bytes(1), Some(90000)));
+        let frames = parser.parse(&make_pes(pcs_bytes(1), Some(180000)));
+        assert_eq!(frames.len(), 1);
+        assert_eq!(frames[0].pts_ns, 1_000_000_000);
+        assert_eq!(frames[0].duration_ns, Some(1_000_000_000));
+    }
+
+    #[test]
+    fn non_pcs_segment_appends_to_pending() {
+        let mut parser = PgsParser::new();
+        let _ = parser.parse(&make_pes(pcs_bytes(1), Some(90000)));
+        // ODS-like segment (type 0x15)
+        let frames = parser.parse(&make_pes(vec![0x15, 0x00, 0x02, 0xAA, 0xBB], Some(90000)));
+        assert!(frames.is_empty());
+        // Clear closes the set; data should include the appended bytes.
+        let frames = parser.parse(&make_pes(pcs_bytes(0), Some(180000)));
+        assert_eq!(frames.len(), 1);
+        let data = &frames[0].data;
+        assert!(data.windows(5).any(|w| w == [0x15, 0x00, 0x02, 0xAA, 0xBB]));
     }
 
     #[test]

src/mux/codec/truehd.rs

@@ -139,6 +139,7 @@ impl CodecParser for TrueHdParser {
                 pts_ns: self.next_pts_ns,
                 keyframe: is_major_sync,
                 data: self.buf[..unit_bytes].to_vec(),
+                duration_ns: None,
             });
             self.buf.drain(..unit_bytes);
             self.next_pts_ns += AU_DURATION_NS;

src/mux/codec/vc1.rs

@@ -96,6 +96,7 @@ impl CodecParser for Vc1Parser {
             pts_ns: ts_ns,
             keyframe,
             data: frame_data.to_vec(),
+            duration_ns: None,
         }]
     }
 

src/mux/demux_thread.rs

@@ -0,0 +1,350 @@
+//! `DemuxThread` — runs the read+decrypt+demux pipeline on a
+//! dedicated thread, feeding completed `PesPacket` batches to the
+//! caller via a bounded channel.
+//!
+//! ## Why a second worker thread
+//!
+//! With [`crate::sector::PrefetchedSectorSource`] alone, read+decrypt
+//! already runs on a producer thread; the *consumer* (main) thread
+//! still serialises `ts_demuxer.feed` (M2TS parsing) with the codec
+//! parsers. Profiling on the rip1 testbed showed feed at ~37 % and
+//! codec parse at ~44 % of consumer wall time — i.e. feed is heavy
+//! enough that pipelining it with parse pays for itself.
+//!
+//! Splitting them: feed runs in [`DemuxThread`]; the consumer thread
+//! receives `Vec<PesPacket>` batches and runs codec parse + frame
+//! emission only. Total throughput becomes `1/max(feed, parse)`
+//! instead of `1/(feed + parse)`.
+//!
+//! ## Lifecycle
+//!
+//! [`DemuxThread::spawn`] takes ownership of the inner reader and the
+//! demuxer state, returns a handle plus a `Receiver<DemuxBatch>`.
+//! Dropping the handle closes the channel which signals the thread
+//! to exit; the join in `Drop::drop` is bounded.
+
+use crate::halt::Halt;
+use crate::sector::SectorSource;
+use crossbeam_channel::{Receiver, Sender, bounded};
+use std::thread::JoinHandle;
+
+/// Output channel depth. Two batches in flight keeps the consumer
+/// (codec parser) busy without piling up demuxed bytes if it stalls.
+const DEMUX_CHANNEL_DEPTH: usize = 2;
+
+/// One demuxed batch flowing from the demux thread to the consumer.
+pub enum DemuxBatch {
+    /// Successfully demuxed PesPackets — non-empty.
+    Ts(Vec<super::ts::PesPacket>),
+    Ps(Vec<super::ps::PsPacket>),
+    /// Underlying reader returned an error. Terminal.
+    Err(std::io::Error),
+}
+
+/// Spawned demux thread. Drop joins.
+///
+/// In zero-copy mode the thread also owns an opaque
+/// `producer_shell: Option<Box<dyn Send>>` — the join handle of the
+/// upstream producer (sector or byte prefetcher). Dropping the
+/// `DemuxThread` runs the shell's `Drop`, which joins the producer.
+/// `Box<dyn Send>` rather than a concrete type so the same demux
+/// worker can be wired behind either prefetcher kind.
+pub struct DemuxThread {
+    handle: Option<JoinHandle<()>>,
+    #[allow(dead_code)]
+    producer_shell: Option<Box<dyn Send>>,
+}
+
+impl DemuxThread {
+    /// Spawn the demux thread. Returns the thread handle and a
+    /// receiver for [`DemuxBatch`] items.
+    ///
+    /// `reader` is the fully-composed read+decrypt stack (e.g.
+    /// [`PrefetchedSectorSource`](crate::sector::PrefetchedSectorSource)
+    /// wrapping
+    /// [`DecryptingSectorSource`](crate::sector::DecryptingSectorSource)).
+    /// `extents` is what the thread walks; it issues one
+    /// `read_sectors` per batch of `batch_sectors` sectors (aligned
+    /// to 3-sector AACS units when possible).
+    pub fn spawn<S: SectorSource + Send + 'static>(
+        mut reader: S,
+        extents: Vec<crate::disc::Extent>,
+        batch_sectors: u16,
+        halt: Option<Halt>,
+        ts: Option<super::ts::TsDemuxer>,
+        ps: Option<super::ps::PsDemuxer>,
+    ) -> (Self, Receiver<DemuxBatch>) {
+        let (tx, rx) = bounded::<DemuxBatch>(DEMUX_CHANNEL_DEPTH);
+        let mut ts = ts;
+        let mut ps = ps;
+
+        let handle = std::thread::Builder::new()
+            .name("freemkv-demux".into())
+            .spawn(move || {
+                let mut buf = vec![0u8; batch_sectors as usize * 2048];
+                let mut ext_idx = 0usize;
+                let mut offset: u32 = 0;
+                let prof = std::env::var_os("FREEMKV_PROFILE").is_some();
+                let mut prof_started = std::time::Instant::now();
+                let mut prof_last_dump = prof_started;
+                let mut prof_read_ns: u128 = 0;
+                let mut prof_feed_ns: u128 = 0;
+                let mut prof_send_ns: u128 = 0;
+                let mut prof_bytes: u64 = 0;
+                while ext_idx < extents.len() {
+                    if halt.as_ref().map(|h| h.is_cancelled()).unwrap_or(false) {
+                        return;
+                    }
+                    let ext = &extents[ext_idx];
+                    let remaining = ext.sector_count.saturating_sub(offset);
+                    if remaining == 0 {
+                        ext_idx += 1;
+                        offset = 0;
+                        continue;
+                    }
+                    let mut sectors = remaining.min(batch_sectors as u32) as u16;
+                    if sectors >= 3 {
+                        sectors -= sectors % 3;
+                    }
+                    let bytes = sectors as usize * 2048;
+                    if buf.len() < bytes {
+                        buf.resize(bytes, 0);
+                    }
+                    let lba = ext.start_lba + offset;
+                    let t0 = if prof {
+                        Some(std::time::Instant::now())
+                    } else {
+                        None
+                    };
+                    let n = match reader.read_sectors(lba, sectors, &mut buf[..bytes], false) {
+                        Ok(n) => n,
+                        Err(e) => {
+                            let _ = tx.send(DemuxBatch::Err(e.into()));
+                            return;
+                        }
+                    };
+                    let t1 = if prof {
+                        Some(std::time::Instant::now())
+                    } else {
+                        None
+                    };
+                    offset += sectors as u32;
+
+                    // Demux this batch immediately so the channel
+                    // carries already-parsed PesPackets, not raw
+                    // sector bytes.
+                    if let Some(ref mut d) = ts {
+                        let pkts = d.feed(&buf[..n]);
+                        let t2 = if prof {
+                            Some(std::time::Instant::now())
+                        } else {
+                            None
+                        };
+                        if !pkts.is_empty() && tx.send(DemuxBatch::Ts(pkts)).is_err() {
+                            return; // consumer dropped
+                        }
+                        let t3 = if prof {
+                            Some(std::time::Instant::now())
+                        } else {
+                            None
+                        };
+                        if prof {
+                            prof_read_ns += t1.unwrap().duration_since(t0.unwrap()).as_nanos();
+                            prof_feed_ns += t2.unwrap().duration_since(t1.unwrap()).as_nanos();
+                            prof_send_ns += t3.unwrap().duration_since(t2.unwrap()).as_nanos();
+                            prof_bytes += n as u64;
+                            let now = t3.unwrap();
+                            if now.duration_since(prof_last_dump)
+                                >= std::time::Duration::from_secs(5)
+                            {
+                                let el = now.duration_since(prof_started).as_millis().max(1);
+                                let mbps = prof_bytes as u128 * 1000 / 1_000_000 / el;
+                                eprintln!(
+                                    "[demux] elapsed={}ms in={}MB/s read={}% feed={}% send={}%",
+                                    el,
+                                    mbps,
+                                    prof_read_ns / 10_000 / el,
+                                    prof_feed_ns / 10_000 / el,
+                                    prof_send_ns / 10_000 / el,
+                                );
+                                prof_last_dump = now;
+                                prof_started = now;
+                                prof_read_ns = 0;
+                                prof_feed_ns = 0;
+                                prof_send_ns = 0;
+                                prof_bytes = 0;
+                            }
+                        }
+                    } else if let Some(ref mut d) = ps {
+                        let pkts = d.feed(&buf[..n]);
+                        if !pkts.is_empty() && tx.send(DemuxBatch::Ps(pkts)).is_err() {
+                            return;
+                        }
+                    }
+                }
+                // EOF — emit any flushed packets too.
+                if let Some(ref mut d) = ts {
+                    let tail = d.flush();
+                    if !tail.is_empty() {
+                        let _ = tx.send(DemuxBatch::Ts(tail));
+                    }
+                } else if let Some(ref mut d) = ps {
+                    let tail = d.flush();
+                    if !tail.is_empty() {
+                        let _ = tx.send(DemuxBatch::Ps(tail));
+                    }
+                }
+                // Sender drops here -> consumer sees RecvError → EOF.
+            })
+            .expect("freemkv-demux thread spawn failed");
+
+        (
+            Self {
+                handle: Some(handle),
+                producer_shell: None,
+            },
+            rx,
+        )
+    }
+
+    /// Zero-copy variant. Instead of taking a `SectorSource` and
+    /// memcpy-ing through its `read_sectors` API, this constructor
+    /// consumes the prefetch channels directly: filled buffers come
+    /// in via `prefetch_rx`, the demux thread feeds them, then
+    /// returns them to `recycle_tx` for the producer to re-fill.
+    /// Eliminates the 16 MiB memcpy per batch that the SectorSource
+    /// adapter incurred (and, with the producer-side recycling pool,
+    /// also eliminates the per-batch heap alloc / cross-thread free
+    /// that was costing 40 %+ of demux-thread time before).
+    ///
+    /// `producer_shell` is an opaque handle whose only purpose is to
+    /// outlive the demux thread and join the upstream producer when
+    /// dropped. Both
+    /// [`crate::sector::PrefetchedSectorSource::into_channels`] and
+    /// [`crate::io::byte_prefetcher::BytePrefetcher::into_channels`]
+    /// hand back a shell that fits — pass either.
+    pub fn spawn_zero_copy<S: Send + 'static>(
+        prefetch_rx: Receiver<std::io::Result<Vec<u8>>>,
+        recycle_tx: Sender<Vec<u8>>,
+        producer_shell: S,
+        halt: Option<Halt>,
+        ts: Option<super::ts::TsDemuxer>,
+        ps: Option<super::ps::PsDemuxer>,
+    ) -> (Self, Receiver<DemuxBatch>) {
+        let (tx, rx) = bounded::<DemuxBatch>(DEMUX_CHANNEL_DEPTH);
+        let mut ts = ts;
+        let mut ps = ps;
+
+        let handle = std::thread::Builder::new()
+            .name("freemkv-demux".into())
+            .spawn(move || {
+                let prof = std::env::var_os("FREEMKV_PROFILE").is_some();
+                let mut prof_started = std::time::Instant::now();
+                let mut prof_last_dump = prof_started;
+                let mut prof_read_ns: u128 = 0;
+                let mut prof_feed_ns: u128 = 0;
+                let mut prof_bytes: u64 = 0;
+                loop {
+                    if halt.as_ref().map(|h| h.is_cancelled()).unwrap_or(false) {
+                        return;
+                    }
+                    let t0 = if prof {
+                        Some(std::time::Instant::now())
+                    } else {
+                        None
+                    };
+                    let buf = match prefetch_rx.recv() {
+                        Ok(Ok(b)) => b,
+                        Ok(Err(e)) => {
+                            let _ = tx.send(DemuxBatch::Err(e));
+                            return;
+                        }
+                        Err(_) => break, // producer done → EOF
+                    };
+                    let t1 = if prof {
+                        Some(std::time::Instant::now())
+                    } else {
+                        None
+                    };
+                    let n = buf.len();
+                    if let Some(ref mut d) = ts {
+                        let pkts = d.feed(&buf);
+                        let t2 = if prof {
+                            Some(std::time::Instant::now())
+                        } else {
+                            None
+                        };
+                        // Recycle the buffer back to the producer
+                        // before pushing the demuxed packets. If the
+                        // recycle channel is closed the producer has
+                        // exited; we drop the buffer and continue.
+                        let _ = recycle_tx.send(buf);
+                        if !pkts.is_empty() && tx.send(DemuxBatch::Ts(pkts)).is_err() {
+                            return;
+                        }
+                        if prof {
+                            prof_read_ns += t1.unwrap().duration_since(t0.unwrap()).as_nanos();
+                            prof_feed_ns += t2.unwrap().duration_since(t1.unwrap()).as_nanos();
+                            prof_bytes += n as u64;
+                            let now = std::time::Instant::now();
+                            if now.duration_since(prof_last_dump)
+                                >= std::time::Duration::from_secs(5)
+                            {
+                                let el = now.duration_since(prof_started).as_millis().max(1);
+                                let mbps = prof_bytes as u128 * 1000 / 1_000_000 / el;
+                                eprintln!(
+                                    "[demux] elapsed={}ms in={}MB/s read={}% feed={}%",
+                                    el,
+                                    mbps,
+                                    prof_read_ns / 10_000 / el,
+                                    prof_feed_ns / 10_000 / el,
+                                );
+                                prof_last_dump = now;
+                                prof_started = now;
+                                prof_read_ns = 0;
+                                prof_feed_ns = 0;
+                                prof_bytes = 0;
+                            }
+                        }
+                    } else if let Some(ref mut d) = ps {
+                        let pkts = d.feed(&buf);
+                        let _ = recycle_tx.send(buf);
+                        if !pkts.is_empty() && tx.send(DemuxBatch::Ps(pkts)).is_err() {
+                            return;
+                        }
+                    } else {
+                        let _ = recycle_tx.send(buf);
+                    }
+                }
+                // Flush tail packets at EOF.
+                if let Some(ref mut d) = ts {
+                    let tail = d.flush();
+                    if !tail.is_empty() {
+                        let _ = tx.send(DemuxBatch::Ts(tail));
+                    }
+                } else if let Some(ref mut d) = ps {
+                    let tail = d.flush();
+                    if !tail.is_empty() {
+                        let _ = tx.send(DemuxBatch::Ps(tail));
+                    }
+                }
+            })
+            .expect("freemkv-demux thread spawn failed");
+
+        (
+            Self {
+                handle: Some(handle),
+                producer_shell: Some(Box::new(producer_shell)),
+            },
+            rx,
+        )
+    }
+}
+
+impl Drop for DemuxThread {
+    fn drop(&mut self) {
+        if let Some(h) = self.handle.take() {
+            let _ = h.join();
+        }
+    }
+}

src/mux/disc.rs

@@ -1,7 +1,7 @@
 //! DiscStream — read any disc (physical drive or ISO file) → PES frames.
 //!
 //! One stream type for all disc sources. The source is a SectorSource —
-//! Drive (hardware) or IsoSectorReader (file). DiscStream doesn't care.
+//! Drive (hardware) or FileSectorSource (file). DiscStream doesn't care.
 //!
 //! Read-only. For disc→ISO (raw sector copy), use `Disc::copy()`.
 
@@ -149,7 +149,11 @@ pub struct DiscStream {
     // a percent without a separate API call.
     bytes_total_extents: u64,
 
-    // PES output
+    // PES output — single-threaded inline demux + codec parse. The
+    // pipeline-mode mux (3-stage threaded) lives in
+    // [`super::pipelined_stream::PipelinedPesStream`]; this type is
+    // the legacy in-thread path for live-disc reads where adaptive
+    // batch retry on bad sectors lives in `fill_extents`.
     ts_demuxer: Option<super::ts::TsDemuxer>,
     ps_demuxer: Option<super::ps::PsDemuxer>,
     parsers: Vec<(u16, Box<dyn super::codec::CodecParser>)>,
@@ -403,6 +407,71 @@ impl DiscStream {
     }
 }
 
+/// Per-stage profiling state — populated only when `FREEMKV_PROFILE`
+/// is set. Dumps a percentage breakdown to stderr every
+/// [`PROFILE_INTERVAL`]. Zero overhead in normal runs (Option check
+/// is the only added cost).
+struct StageProf {
+    started: std::time::Instant,
+    last_dump: std::time::Instant,
+    fill_ns: u128,
+    feed_ns: u128,
+    consume_ns: u128,
+    bytes_in: u64,
+}
+
+const PROFILE_INTERVAL: std::time::Duration = std::time::Duration::from_secs(5);
+
+thread_local! {
+    static STAGE_PROF: std::cell::RefCell<Option<StageProf>> = const { std::cell::RefCell::new(None) };
+}
+
+fn prof_active() -> bool {
+    std::env::var_os("FREEMKV_PROFILE").is_some()
+}
+
+fn prof_tick(stage: &str, ns: u128, bytes: u64) {
+    STAGE_PROF.with(|cell| {
+        let mut slot = cell.borrow_mut();
+        if slot.is_none() {
+            if !prof_active() {
+                return;
+            }
+            let now = std::time::Instant::now();
+            *slot = Some(StageProf {
+                started: now,
+                last_dump: now,
+                fill_ns: 0,
+                feed_ns: 0,
+                consume_ns: 0,
+                bytes_in: 0,
+            });
+        }
+        let p = slot.as_mut().unwrap();
+        match stage {
+            "fill" => p.fill_ns += ns,
+            "feed" => p.feed_ns += ns,
+            "consume" => p.consume_ns += ns,
+            _ => {}
+        }
+        p.bytes_in += bytes;
+        let now = std::time::Instant::now();
+        if now.duration_since(p.last_dump) < PROFILE_INTERVAL {
+            return;
+        }
+        let elapsed_ms = now.duration_since(p.started).as_millis().max(1);
+        let fill_pct = p.fill_ns / 10_000 / elapsed_ms;
+        let feed_pct = p.feed_ns / 10_000 / elapsed_ms;
+        let consume_pct = p.consume_ns / 10_000 / elapsed_ms;
+        let mbps = p.bytes_in as u128 * 1000 / 1_000_000 / elapsed_ms;
+        eprintln!(
+            "[profile] elapsed={}ms in={}MB/s fill={}% feed={}% consume={}%",
+            elapsed_ms, mbps, fill_pct, feed_pct, consume_pct,
+        );
+        p.last_dump = now;
+    });
+}
+
 impl crate::pes::Stream for DiscStream {
     fn read(&mut self) -> io::Result<Option<crate::pes::PesFrame>> {
         if let Some(frame) = self.pending_frames.pop_front() {
@@ -414,6 +483,7 @@ impl crate::pes::Stream for DiscStream {
         }
 
         loop {
+            let t0 = std::time::Instant::now();
             if !self.fill_extents()? {
                 self.eof = true;
                 // Flush demuxer — last PES packet may still be in the assembler
@@ -475,6 +545,8 @@ impl crate::pes::Stream for DiscStream {
             }
 
             let bytes = self.buf_valid;
+            let t1 = std::time::Instant::now();
+            prof_tick("fill", t1.duration_since(t0).as_nanos(), bytes as u64);
             // Plaintext: the wrapped reader (DecryptingSectorSource)
             // applied AACS / CSS in-place during fill_extents'
             // read_sectors call. The pre-0.18 inline decrypt step
@@ -482,21 +554,42 @@ impl crate::pes::Stream for DiscStream {
 
             if let Some(ref mut demuxer) = self.ts_demuxer {
                 let packets = demuxer.feed(&self.read_buf[..bytes]);
-                for pes in &packets {
-                    if let Some((_, track)) =
-                        self.pid_to_track.iter().find(|(pid, _)| *pid == pes.pid)
+                let t2 = std::time::Instant::now();
+                prof_tick("feed", t2.duration_since(t1).as_nanos(), 0);
+                let skip_parse = std::env::var_os("FREEMKV_SKIP_PARSE").is_some();
+                for pes in packets {
+                    if let Some((_, track)) = self
+                        .pid_to_track
+                        .iter()
+                        .find(|(pid, _)| *pid == pes.pid)
+                        .copied()
                     {
-                        if let Some((_, parser)) =
+                        if skip_parse {
+                            // Profiling escape hatch — bypass the codec
+                            // parser and pass the raw PES bytes straight
+                            // through as a single PesFrame. Lets us
+                            // attribute consumer-thread time to
+                            // "demux + framing" vs "codec parse".
+                            self.pending_frames.push_back(crate::pes::PesFrame {
+                                track,
+                                pts: pes.pts.map(super::codec::pts_to_ns).unwrap_or(0),
+                                keyframe: false,
+                                data: pes.data,
+                                duration_ns: None,
+                            });
+                        } else if let Some((_, parser)) =
                             self.parsers.iter_mut().find(|(pid, _)| *pid == pes.pid)
                         {
-                            for frame in parser.parse(pes) {
+                            for frame in parser.parse(&pes) {
                                 self.pending_frames.push_back(
-                                    crate::pes::PesFrame::from_codec_frame(*track, frame),
+                                    crate::pes::PesFrame::from_codec_frame(track, frame),
                                 );
                             }
                         }
                     }
                 }
+                let t3 = std::time::Instant::now();
+                prof_tick("consume", t3.duration_since(t2).as_nanos(), 0);
             } else if let Some(ref mut demuxer) = self.ps_demuxer {
                 let packets = demuxer.feed(&self.read_buf[..bytes]);
                 for ps in &packets {
@@ -570,6 +663,13 @@ impl crate::pes::Stream for DiscStream {
     }
 
     fn headers_ready(&self) -> bool {
+        // FREEMKV_SKIP_PARSE bypasses codec parsers entirely for
+        // bottleneck profiling, so codec_private is never populated.
+        // Pretend headers are ready immediately in that mode so the
+        // CLI loop doesn't hang waiting for them.
+        if std::env::var_os("FREEMKV_SKIP_PARSE").is_some() {
+            return true;
+        }
         for (idx, s) in self.title.streams.iter().enumerate() {
             if let crate::disc::Stream::Video(v) = s {
                 if !v.secondary && self.codec_private(idx).is_none() {
@@ -579,6 +679,10 @@ impl crate::pes::Stream for DiscStream {
         }
         true
     }
+
+    fn errors(&self) -> u64 {
+        self.errors
+    }
 }
 
 #[cfg(test)]

src/mux/ebml.rs

@@ -321,6 +321,12 @@ pub const EBML_DOC_TYPE_READ_VERSION: u32 = 0x4285;
 // Segment
 pub const SEGMENT: u32 = 0x1853_8067;
 
+// SeekHead
+pub const SEEK_HEAD: u32 = 0x114D_9B74;
+pub const SEEK: u32 = 0x4DBB;
+pub const SEEK_ID: u32 = 0x53AB;
+pub const SEEK_POSITION: u32 = 0x53AC;
+
 // Segment Info
 pub const INFO: u32 = 0x1549_A966;
 pub const TIMESTAMP_SCALE: u32 = 0x2A_D7B1;
@@ -366,6 +372,9 @@ pub const BIT_DEPTH: u32 = 0x6264;
 pub const CLUSTER: u32 = 0x1F43_B675;
 pub const CLUSTER_TIMESTAMP: u32 = 0xE7;
 pub const SIMPLE_BLOCK: u32 = 0xA3;
+pub const BLOCK_GROUP: u32 = 0xA0;
+pub const BLOCK: u32 = 0xA1;
+pub const BLOCK_DURATION: u32 = 0x9B;
 
 // Cues
 pub const CUES: u32 = 0x1C53_BB6B;

src/mux/iso.rs

@@ -1,101 +0,0 @@
-//! ISO sector reader — file-backed SectorSource for Blu-ray ISO images.
-//!
-//! An ISO is a flat image of 2048-byte sectors. Sector N starts at byte offset N * 2048.
-//! Used by DiscStream::open_iso() and Disc::scan_image().
-
-use crate::error::{Error, Result};
-use crate::sector::SectorSource;
-use std::fs::File;
-use std::io::{Read, Seek, SeekFrom};
-use std::path::Path;
-
-const SECTOR_SIZE: u64 = 2048;
-
-/// File-backed sector reader for ISO images.
-pub struct IsoSectorReader {
-    file: File,
-    capacity: u32,
-}
-
-impl IsoSectorReader {
-    pub fn open(path: &str) -> std::io::Result<Self> {
-        let file = File::open(Path::new(path))?;
-        let size = file.metadata()?.len();
-        let sectors = size / SECTOR_SIZE;
-        if sectors > u32::MAX as u64 {
-            return Err(crate::error::Error::IsoTooLarge {
-                path: path.to_string(),
-            }
-            .into());
-        }
-        let capacity = sectors as u32;
-        Ok(Self { file, capacity })
-    }
-
-    pub fn capacity_sectors(&self) -> u32 {
-        self.capacity
-    }
-}
-
-impl SectorSource for IsoSectorReader {
-    fn read_sectors(
-        &mut self,
-        lba: u32,
-        count: u16,
-        buf: &mut [u8],
-        _recovery: bool,
-    ) -> Result<usize> {
-        let bytes = count as usize * SECTOR_SIZE as usize;
-        self.file
-            .seek(SeekFrom::Start(lba as u64 * SECTOR_SIZE))
-            .map_err(|e| Error::IoError { source: e })?;
-        self.file
-            .read_exact(&mut buf[..bytes])
-            .map_err(|e| Error::IoError { source: e })?;
-        Ok(bytes)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn iso_reader_read_sectors() {
-        let mut data = vec![0u8; 4 * SECTOR_SIZE as usize];
-        for i in 0..4u8 {
-            let offset = i as usize * SECTOR_SIZE as usize;
-            data[offset] = i + 1;
-            data[offset + 2047] = i + 100;
-        }
-
-        let dir = std::env::temp_dir().join("freemkv_test_iso_read");
-        std::fs::write(&dir, &data).unwrap();
-
-        let mut reader = IsoSectorReader::open(dir.to_str().unwrap()).unwrap();
-        assert_eq!(reader.capacity_sectors(), 4);
-
-        let mut buf = [0u8; 2048];
-        reader.read_sectors(0, 1, &mut buf, true).unwrap();
-        assert_eq!(buf[0], 1);
-        assert_eq!(buf[2047], 100);
-
-        reader.read_sectors(2, 1, &mut buf, true).unwrap();
-        assert_eq!(buf[0], 3);
-        assert_eq!(buf[2047], 102);
-
-        std::fs::remove_file(&dir).ok();
-    }
-
-    #[test]
-    fn iso_reader_capacity() {
-        let data = vec![0u8; 10 * SECTOR_SIZE as usize];
-        let dir = std::env::temp_dir().join("freemkv_test_iso_cap");
-        std::fs::write(&dir, &data).unwrap();
-
-        let reader = IsoSectorReader::open(dir.to_str().unwrap()).unwrap();
-        assert_eq!(reader.capacity_sectors(), 10);
-
-        std::fs::remove_file(&dir).ok();
-    }
-}

src/mux/m2ts.rs

@@ -1,57 +1,21 @@
-//! M2tsStream — BD transport stream with embedded metadata header.
+//! M2tsStream — BD transport stream write sink.
 //!
-//! Write: prepends FMKV metadata header, then muxes PES frames into BD-TS.
-//! Read: extracts metadata header (or scans PMT), then demuxes BD-TS into PES frames.
+//! Write: prepends FMKV metadata header, then muxes PES frames into
+//! BD-TS. The read direction lives on the pipeline highway —
+//! `m2ts://` URLs route through
+//! [`super::resolve::input`] → `build_m2ts_pipeline` →
+//! [`super::pipelined_stream::PipelinedPesStream`], so this type is
+//! write-only.
 
-use super::{meta, ts};
+use super::meta;
 use crate::disc::{DiscTitle, Stream as DiscStream};
-use std::io::{self, Read, Write};
+use std::io::{self, Write};
 
-type PesSetup = (
-    Vec<u16>,
-    Vec<(u16, Box<dyn super::codec::CodecParser>)>,
-    Vec<(u16, usize)>,
-);
-
-/// Size of initial scan buffer for PMT/stream detection.
-const SCAN_SIZE: usize = 1024 * 1024;
-
-enum Mode {
-    Write {
-        muxer: super::tsmux::TsMuxer<Box<dyn Write + Send>>,
-    },
-    Read {
-        reader: Box<dyn Read + Send>,
-    },
-}
-
-/// Read as many bytes as possible into buf (multiple read calls if needed).
-/// Bounded by buf.len() — caller controls max bytes read.
-fn read_fill(r: &mut impl Read, buf: &mut [u8]) -> io::Result<usize> {
-    let mut total = 0;
-    while total < buf.len() {
-        match r.read(&mut buf[total..]) {
-            Ok(0) => break,
-            Ok(n) => total += n,
-            Err(e) if e.kind() == io::ErrorKind::Interrupted => continue,
-            Err(e) => return Err(e),
-        }
-    }
-    Ok(total)
-}
-
-/// BD transport stream with embedded metadata.
+/// BD transport stream write sink with embedded FMKV metadata
+/// header.
 pub struct M2tsStream {
     disc_title: DiscTitle,
-    mode: Mode,
-    // PES support
-    demuxer: Option<ts::TsDemuxer>,
-    parsers: Vec<(u16, Box<dyn super::codec::CodecParser>)>,
-    pending_frames: std::collections::VecDeque<crate::pes::PesFrame>,
-    pid_to_track: Vec<(u16, usize)>,
-    pes_eof: bool,
-    /// Codec private data per stream (from FMKV header).
-    stored_codec_privates: Vec<Option<Vec<u8>>>,
+    muxer: super::tsmux::TsMuxer<Box<dyn Write + Send>>,
 }
 
 impl M2tsStream {
@@ -81,205 +45,153 @@ impl M2tsStream {
         }
         Ok(Self {
             disc_title: title.clone(),
-            mode: Mode::Write { muxer },
-            demuxer: None,
-            parsers: Vec::new(),
-            pending_frames: std::collections::VecDeque::new(),
-            pid_to_track: Vec::new(),
-            pes_eof: false,
-            stored_codec_privates: Vec::new(),
-        })
-    }
-
-    fn setup_pes(streams: &[DiscStream]) -> PesSetup {
-        let mut pids = Vec::new();
-        let mut parsers: Vec<(u16, Box<dyn super::codec::CodecParser>)> = Vec::new();
-        let mut pid_to_track = Vec::new();
-        for (i, s) in streams.iter().enumerate() {
-            let (pid, codec) = match s {
-                DiscStream::Video(v) => (v.pid, v.codec),
-                DiscStream::Audio(a) => (a.pid, a.codec),
-                DiscStream::Subtitle(s) => (s.pid, s.codec),
-            };
-            pids.push(pid);
-            pid_to_track.push((pid, i));
-            parsers.push((pid, super::codec::parser_for_codec(codec, None)));
-        }
-        (pids, parsers, pid_to_track)
-    }
-
-    /// Open an M2TS stream for reading. Takes any Read source — file, pipe, socket.
-    ///
-    /// Tries FMKV metadata header first. Falls back to PMT scan of first 1 MB.
-    pub fn open(mut reader: impl Read + Send + 'static) -> io::Result<Self> {
-        // Read first chunk — enough for FMKV header or PMT scan
-        let mut head = vec![0u8; SCAN_SIZE];
-        let head_len = read_fill(&mut reader, &mut head)?;
-        head.truncate(head_len);
-
-        // Try FMKV metadata header from the buffered head
-        let mut cursor = io::Cursor::new(&head);
-        if let Ok(Some(m)) = meta::read_header(&mut cursor) {
-            let header_end = cursor.position() as usize;
-            let title = m.to_title();
-            let (pids, parsers, pid_to_track) = Self::setup_pes(&title.streams);
-            // Chain: remaining head bytes + rest of reader
-            let remaining_head = &head[header_end..];
-            let chain: Box<dyn Read + Send> =
-                Box::new(io::Cursor::new(remaining_head.to_vec()).chain(reader));
-            return Ok(Self {
-                disc_title: title.clone(),
-                mode: Mode::Read { reader: chain },
-                demuxer: if pids.is_empty() {
-                    None
-                } else {
-                    Some(ts::TsDemuxer::new(&pids))
-                },
-                parsers,
-                pending_frames: std::collections::VecDeque::new(),
-                pid_to_track,
-                pes_eof: false,
-                stored_codec_privates: title.codec_privates,
-            });
-        }
-
-        // No FMKV header — scan head for PMT
-        let streams = ts::scan_streams(&head)
-            .ok_or_else(|| -> io::Error { crate::error::Error::NoStreams.into() })?;
-
-        let (pids, parsers, pid_to_track) = Self::setup_pes(&streams);
-
-        // Chain: full head (it's all TS data) + rest of reader
-        let chain: Box<dyn Read + Send> = Box::new(io::Cursor::new(head).chain(reader));
-
-        Ok(Self {
-            disc_title: DiscTitle {
-                duration_secs: 0.0, // unknown without seeking
-                streams,
-                ..DiscTitle::empty()
-            },
-            mode: Mode::Read { reader: chain },
-            demuxer: if pids.is_empty() {
-                None
-            } else {
-                Some(ts::TsDemuxer::new(&pids))
-            },
-            parsers,
-            pending_frames: std::collections::VecDeque::new(),
-            pid_to_track,
-            pes_eof: false,
-            stored_codec_privates: Vec::new(),
+            muxer,
         })
     }
 }
 
 impl crate::pes::Stream for M2tsStream {
     fn read(&mut self) -> io::Result<Option<crate::pes::PesFrame>> {
-        if let Some(frame) = self.pending_frames.pop_front() {
-            return Ok(Some(frame));
-        }
-        if self.pes_eof {
-            return Ok(None);
-        }
-
-        loop {
-            let reader = match &mut self.mode {
-                Mode::Read { reader } => reader,
-                _ => return Err(crate::error::Error::StreamWriteOnly.into()),
-            };
-            let mut buf = vec![0u8; 192 * 1024];
-            let n = reader.read(&mut buf)?;
-            if n == 0 {
-                self.pes_eof = true;
-                // Flush demuxer — last PES packet may still be in the assembler
-                if let Some(ref mut demuxer) = self.demuxer {
-                    for pes in &demuxer.flush() {
-                        if let Some((_, track)) =
-                            self.pid_to_track.iter().find(|(pid, _)| *pid == pes.pid)
-                        {
-                            if let Some((_, parser)) =
-                                self.parsers.iter_mut().find(|(pid, _)| *pid == pes.pid)
-                            {
-                                for frame in parser.parse(pes) {
-                                    self.pending_frames.push_back(
-                                        crate::pes::PesFrame::from_codec_frame(*track, frame),
-                                    );
-                                }
-                            }
-                        }
-                    }
-                }
-                return Ok(self.pending_frames.pop_front());
-            }
-
-            if let Some(ref mut demuxer) = self.demuxer {
-                let packets = demuxer.feed(&buf[..n]);
-                for pes in &packets {
-                    if let Some((_, track)) =
-                        self.pid_to_track.iter().find(|(pid, _)| *pid == pes.pid)
-                    {
-                        if let Some((_, parser)) =
-                            self.parsers.iter_mut().find(|(pid, _)| *pid == pes.pid)
-                        {
-                            for frame in parser.parse(pes) {
-                                self.pending_frames.push_back(
-                                    crate::pes::PesFrame::from_codec_frame(*track, frame),
-                                );
-                            }
-                        }
-                    }
-                }
-            }
-
-            if let Some(frame) = self.pending_frames.pop_front() {
-                return Ok(Some(frame));
-            }
-        }
+        // Write-only sink. The m2ts:// read direction is served by
+        // `super::resolve::build_m2ts_pipeline` →
+        // `PipelinedPesStream`; routing through this type for reads
+        // was removed when the highway became the only ingress.
+        Err(crate::error::Error::StreamWriteOnly.into())
     }
 
     fn write(&mut self, frame: &crate::pes::PesFrame) -> io::Result<()> {
-        match &mut self.mode {
-            Mode::Write { muxer } => muxer.write_frame(frame.track, frame.pts, &frame.data),
-            Mode::Read { .. } => Err(crate::error::Error::StreamReadOnly.into()),
-        }
+        self.muxer
+            .write_frame(frame.track, frame.pts, frame.keyframe, &frame.data)
     }
 
     fn finish(&mut self) -> io::Result<()> {
-        match &mut self.mode {
-            Mode::Write { muxer } => muxer.finish(),
-            Mode::Read { .. } => Ok(()),
-        }
+        self.muxer.finish()
     }
 
     fn info(&self) -> &crate::disc::DiscTitle {
         &self.disc_title
     }
 
-    fn codec_private(&self, track: usize) -> Option<Vec<u8>> {
-        // First check stored codec_privates from FMKV header
-        if let Some(Some(cp)) = self.stored_codec_privates.get(track) {
-            return Some(cp.clone());
+    fn codec_private(&self, _track: usize) -> Option<Vec<u8>> {
+        // Write side doesn't have parsers; codec_private flows in
+        // via the title metadata at `create` time and gets baked
+        // into the FMKV header. Nothing to surface back here.
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::disc::{
+        Codec, ColorSpace, ContentFormat, DiscTitle, FrameRate, HdrFormat, Resolution,
+        Stream as DiscStream, VideoStream,
+    };
+    use crate::pes::{PesFrame, Stream as PesStreamTrait};
+
+    const VIDEO_PID: u16 = 0x1011;
+
+    fn make_title() -> DiscTitle {
+        DiscTitle {
+            playlist: String::new(),
+            playlist_id: 0,
+            duration_secs: 0.0,
+            size_bytes: 0,
+            clips: Vec::new(),
+            streams: vec![DiscStream::Video(VideoStream {
+                pid: VIDEO_PID,
+                codec: Codec::Hevc,
+                resolution: Resolution::R1080p,
+                frame_rate: FrameRate::F24,
+                hdr: HdrFormat::Sdr,
+                color_space: ColorSpace::Bt709,
+                secondary: false,
+                label: String::new(),
+            })],
+            chapters: Vec::new(),
+            extents: Vec::new(),
+            content_format: ContentFormat::BdTs,
+            codec_privates: vec![Some({
+                // Minimal hvcC with one VPS-like array entry.
+                let marker: &[u8] = &[0x40, 0x01, 0x0C, 0x01];
+                let mut hvcc = vec![0u8; 22];
+                hvcc.push(1); // numArrays
+                hvcc.push(32);
+                hvcc.extend_from_slice(&1u16.to_be_bytes()); // numNalus
+                hvcc.extend_from_slice(&(marker.len() as u16).to_be_bytes());
+                hvcc.extend_from_slice(marker);
+                hvcc
+            })],
+        }
+    }
+
+    fn fake_idr_pes_data() -> Vec<u8> {
+        // 4-byte length prefix + NAL: type 19 (IDR_W_RADL).
+        let mut nal = vec![(19u8 << 1) & 0x7E, 0x01];
+        for i in 0..200 {
+            nal.push((i & 0xFF) as u8);
         }
-        // Fall back to parser-extracted codec_private
-        let pid = self
-            .pid_to_track
-            .iter()
-            .find(|(_, idx)| *idx == track)
-            .map(|(pid, _)| *pid)?;
-        self.parsers
-            .iter()
-            .find(|(p, _)| *p == pid)
-            .and_then(|(_, parser)| parser.codec_private())
+        let mut out = Vec::with_capacity(4 + nal.len());
+        out.extend_from_slice(&(nal.len() as u32).to_be_bytes());
+        out.extend_from_slice(&nal);
+        out
     }
 
-    fn headers_ready(&self) -> bool {
-        for (idx, s) in self.disc_title.streams.iter().enumerate() {
-            if let crate::disc::Stream::Video(v) = s {
-                if !v.secondary && self.codec_private(idx).is_none() {
-                    return false;
-                }
-            }
+    /// Writer wrapper that shares an Arc<Mutex<Vec<u8>>> so the test can
+    /// inspect the bytes after the muxer drops.
+    struct SharedSink(std::sync::Arc<std::sync::Mutex<Vec<u8>>>);
+    impl Write for SharedSink {
+        fn write(&mut self, b: &[u8]) -> io::Result<usize> {
+            self.0.lock().unwrap().extend_from_slice(b);
+            Ok(b.len())
         }
-        true
+        fn flush(&mut self) -> io::Result<()> {
+            Ok(())
+        }
+    }
+
+    #[test]
+    fn m2ts_stream_forwards_keyframe_to_rai() {
+        let title = make_title();
+        let shared = std::sync::Arc::new(std::sync::Mutex::new(Vec::<u8>::new()));
+        let sink = SharedSink(shared.clone());
+        let mut stream = M2tsStream::create(sink, &title).unwrap();
+        let frame = PesFrame {
+            track: 0,
+            pts: 0,
+            keyframe: true,
+            data: fake_idr_pes_data(),
+            duration_ns: None,
+        };
+        stream.write(&frame).unwrap();
+        stream.finish().unwrap();
+        drop(stream);
+
+        let buf = shared.lock().unwrap().clone();
+
+        // Skip FMKV metadata header via meta::read_header.
+        let mut cursor = std::io::Cursor::new(&buf);
+        let _meta = super::meta::read_header(&mut cursor)
+            .unwrap()
+            .expect("FMKV header present");
+        let header_end = cursor.position() as usize;
+        let ts_bytes = &buf[header_end..];
+
+        // Find first PUSI packet on VIDEO_PID; verify RAI in AF flags.
+        let pkt = ts_bytes
+            .chunks(192)
+            .find(|p| {
+                let h = &p[4..];
+                let pid = (((h[1] & 0x1F) as u16) << 8) | h[2] as u16;
+                pid == VIDEO_PID && (h[1] & 0x40) != 0
+            })
+            .expect("video PUSI packet present");
+        let h = &pkt[4..];
+        let afc = (h[3] >> 4) & 0x03;
+        assert!(afc & 0b10 != 0, "AF must be present");
+        let af_len = h[4] as usize;
+        assert!(af_len >= 1, "AF length must include flags byte");
+        let flags = h[5];
+        assert_eq!(flags & 0x40, 0x40, "RAI bit set");
     }
 }

src/mux/m2ts_mux/mod.rs

@@ -161,16 +161,21 @@ impl<W: Write> M2tsMux<W> {
     }
 
     /// Write one video PES frame. `data` is either length-prefixed
-    /// NALUs (MKV-style) or already Annex B; both are accepted.
-    pub fn write_video(&mut self, pts_ns: i64, data: &[u8]) -> io::Result<()> {
+    /// NALUs (MKV-style) or already Annex B; both are accepted. `keyframe`
+    /// drives the random_access_indicator bit on the first packet of this
+    /// PES (and gates codec_private NAL prepending — those only attach to
+    /// the first keyframe).
+    pub fn write_video(&mut self, pts_ns: i64, keyframe: bool, data: &[u8]) -> io::Result<()> {
         let pts_90k = self.base_relative_pts(pts_ns);
         // PCR comes "before" the PTS it timestamps; clamp at 0 for the
         // first frame so we don't underflow.
         let pcr = pts_90k.saturating_sub(PCR_LEAD_90KHZ);
 
-        // Annex-B-ify the frame and prepend VPS/SPS/PPS once.
+        // Annex-B-ify the frame and prepend VPS/SPS/PPS once, on the
+        // FIRST keyframe (not first frame — non-key frames before the
+        // first keyframe can't carry params usefully).
         let mut es = Vec::with_capacity(data.len() + 64);
-        if !self.params_written {
+        if keyframe && !self.params_written {
             if let Some(cp) = &self.video_codec_private {
                 let payload = hvcc_payload(cp);
                 if !payload.is_empty() {
@@ -184,7 +189,7 @@ impl<W: Write> M2tsMux<W> {
         es.extend_from_slice(&annex_b);
 
         let pes = build_video_pes(pts_90k, &es);
-        self.write_pes(PID_VIDEO, &pes, Some(pcr))
+        self.write_pes(PID_VIDEO, &pes, Some(pcr), keyframe)
     }
 
     /// Write one audio PES frame. Returns `Ok(())` and silently drops
@@ -197,7 +202,7 @@ impl<W: Write> M2tsMux<W> {
         }
         let pts_90k = self.base_relative_pts(pts_ns);
         let pes = build_audio_pes(pts_90k, data);
-        self.write_pes(PID_AUDIO, &pes, None)
+        self.write_pes(PID_AUDIO, &pes, None, false)
     }
 
     /// Drain the underlying writer. No TS-level trailer is mandatory —
@@ -234,7 +239,13 @@ impl<W: Write> M2tsMux<W> {
     /// The fit-the-tail logic on the last packet of the PES uses
     /// stuffing rather than a separate small packet, which is the
     /// standard MPEG-TS convention.
-    fn write_pes(&mut self, pid: u16, pes: &[u8], pcr: Option<u64>) -> io::Result<()> {
+    fn write_pes(
+        &mut self,
+        pid: u16,
+        pes: &[u8],
+        pcr: Option<u64>,
+        is_keyframe_video: bool,
+    ) -> io::Result<()> {
         // PSI cadence is enforced per TS packet — interleave a fresh
         // PAT+PMT into the packet stream every PSI_INTERVAL_PACKETS so
         // long single-PES emissions (e.g. one 60 KB video frame) don't
@@ -250,11 +261,21 @@ impl<W: Write> M2tsMux<W> {
                 && (self.packets_written == 0
                     || self.video_packets_since_pcr >= PCR_INTERVAL_PACKETS);
 
-            let af_body: Vec<u8> = if attach_pcr {
+            // RAI rides only the FIRST packet of a keyframe video PES.
+            let attach_rai = first && is_keyframe_video && pid == PID_VIDEO;
+
+            let mut af_body: Vec<u8> = if attach_pcr {
                 build_pcr_adaptation(pcr.unwrap_or(0))
             } else {
                 Vec::new()
             };
+            if attach_rai {
+                if af_body.is_empty() {
+                    af_body.push(0x40); // flags: RAI only
+                } else {
+                    af_body[0] |= 0x40; // OR RAI into existing PCR flags
+                }
+            }
 
             let remaining = pes.len() - offset;
             // Capacity for payload given AF body and 1-byte AF length.
@@ -510,7 +531,7 @@ fn build_pcr_adaptation(pcr_90k: u64) -> Vec<u8> {
     // elementary_stream_priority(1) | PCR_flag(1) | OPCR_flag(1) |
     // splicing_point_flag(1) | transport_private_data_flag(1) |
     // adaptation_field_extension_flag(1) | PCR(48b).
-    let mut af = vec![0x50]; // PCR_flag=1, random_access_indicator=1
+    let mut af = vec![0x10]; // PCR_flag=1; RAI is OR'd in by the caller when applicable
     let pcr_base = pcr_90k & 0x1_FFFF_FFFF; // 33-bit
     let pcr_ext: u16 = 0; // 9-bit, we keep it zero (no sub-tick precision)
     // Encode PCR: 33b base | 6b reserved | 9b extension = 48b
@@ -598,7 +619,7 @@ mod tests {
         let mut frame = Vec::new();
         frame.extend_from_slice(&4u32.to_be_bytes());
         frame.extend_from_slice(&[0x40, 0x01, 0x0C, 0x01]);
-        mux.write_video(0, &frame).unwrap();
+        mux.write_video(0, true, &frame).unwrap();
         mux.finish().unwrap();
         drop(mux);
 
@@ -619,7 +640,7 @@ mod tests {
         let mut frame = Vec::new();
         frame.extend_from_slice(&3u32.to_be_bytes());
         frame.extend_from_slice(&[0x40, 0x01, 0x0C]);
-        mux.write_video(0, &frame).unwrap();
+        mux.write_video(0, true, &frame).unwrap();
         mux.write_audio(20_000_000, &[0x0B, 0x77, 0x12, 0x34])
             .unwrap();
         mux.finish().unwrap();
@@ -641,7 +662,7 @@ mod tests {
         let mut frame = Vec::new();
         frame.extend_from_slice(&(big.len() as u32).to_be_bytes());
         frame.extend_from_slice(&big);
-        mux.write_video(0, &frame).unwrap();
+        mux.write_video(0, true, &frame).unwrap();
         mux.finish().unwrap();
         drop(mux);
 
@@ -663,7 +684,7 @@ mod tests {
             let mut frame = Vec::new();
             frame.extend_from_slice(&3u32.to_be_bytes());
             frame.extend_from_slice(&[0xAA, 0xBB, 0xCC]);
-            mux.write_video(pts, &frame).unwrap();
+            mux.write_video(pts, pts == 0, &frame).unwrap();
         }
         mux.finish().unwrap();
         drop(mux);
@@ -678,4 +699,130 @@ mod tests {
             assert_eq!(w[1], (w[0] + 1) & 0x0F);
         }
     }
+
+    /// Return the adaptation field body (length byte stripped) for one
+    /// 188-byte TS packet, or None when the packet has no AF.
+    fn af_body(packet: &[u8]) -> Option<Vec<u8>> {
+        let afc = (packet[3] >> 4) & 0x03;
+        if afc & 0b10 == 0 {
+            return None;
+        }
+        let af_len = packet[4] as usize;
+        if af_len == 0 {
+            return Some(Vec::new());
+        }
+        Some(packet[5..5 + af_len].to_vec())
+    }
+
+    #[test]
+    fn rai_set_on_keyframe_pes_packet() {
+        let mut sink: Vec<u8> = Vec::new();
+        let mut mux = M2tsMux::new(&mut sink);
+        let mut frame = Vec::new();
+        frame.extend_from_slice(&4u32.to_be_bytes());
+        frame.extend_from_slice(&[0x40, 0x01, 0x0C, 0x01]);
+        mux.write_video(0, true, &frame).unwrap();
+        mux.finish().unwrap();
+        drop(mux);
+
+        // Find the first PUSI packet on PID_VIDEO.
+        let pkt = sink
+            .chunks(188)
+            .find(|p| u16::from_be_bytes([p[1] & 0x1F, p[2]]) == PID_VIDEO && (p[1] & 0x40) != 0)
+            .expect("video PUSI packet exists");
+        let af = af_body(pkt).expect("AF present on first packet of keyframe video PES");
+        assert!(!af.is_empty(), "AF flags byte present");
+        assert_eq!(af[0] & 0x40, 0x40, "RAI bit set");
+    }
+
+    #[test]
+    fn pcr_packet_without_keyframe_has_rai_clear() {
+        let mut sink: Vec<u8> = Vec::new();
+        let mut mux = M2tsMux::new(&mut sink);
+        // First frame is the keyframe (gates codec_private; also gets PCR).
+        let mut frame0 = Vec::new();
+        frame0.extend_from_slice(&4u32.to_be_bytes());
+        frame0.extend_from_slice(&[0x40, 0x01, 0x0C, 0x01]);
+        mux.write_video(0, true, &frame0).unwrap();
+        // Push enough non-key video frames to cross PCR_INTERVAL_PACKETS
+        // video packets so a later PCR-bearing packet exists.
+        // Each frame is ~50 KB → ~270 packets, well over 40.
+        let big: Vec<u8> = (0..(50 * 1024)).map(|i| (i & 0xff) as u8).collect();
+        for i in 1..3 {
+            let mut frame = Vec::new();
+            frame.extend_from_slice(&(big.len() as u32).to_be_bytes());
+            frame.extend_from_slice(&big);
+            mux.write_video((i as i64) * 40_000_000, false, &frame)
+                .unwrap();
+        }
+        mux.finish().unwrap();
+        drop(mux);
+
+        // The first PUSI video packet carries PCR + RAI (keyframe).
+        // A later video PUSI packet with AF + PCR but NOT keyframe must
+        // have RAI clear.
+        let video_pusi: Vec<&[u8]> = sink
+            .chunks(188)
+            .filter(|p| u16::from_be_bytes([p[1] & 0x1F, p[2]]) == PID_VIDEO && (p[1] & 0x40) != 0)
+            .collect();
+        assert!(
+            video_pusi.len() >= 2,
+            "expected ≥2 video PES starts, got {}",
+            video_pusi.len()
+        );
+        // Find a later one with AF that carries PCR (flags & 0x10 set).
+        let later_pcr = video_pusi
+            .iter()
+            .skip(1)
+            .find_map(|p| {
+                let af = af_body(p)?;
+                if !af.is_empty() && (af[0] & 0x10) != 0 {
+                    Some(af)
+                } else {
+                    None
+                }
+            })
+            .expect("later PCR-bearing PUSI exists");
+        assert_eq!(
+            later_pcr[0] & 0x40,
+            0,
+            "RAI must be clear on non-keyframe PCR packet"
+        );
+    }
+
+    #[test]
+    fn keyframe_video_with_pcr_combines_flags() {
+        // PCR attaches only when video_packets_since_pcr >=
+        // PCR_INTERVAL_PACKETS (40). The very first video packet emits a
+        // PAT+PMT first, so packets_written != 0 and attach_pcr is false on
+        // frame 0. We push: keyframe (no PCR) → many non-key (drives the
+        // PCR counter past the interval) → second keyframe (PCR + RAI).
+        let mut sink: Vec<u8> = Vec::new();
+        let mut mux = M2tsMux::new(&mut sink);
+        let mut small = Vec::new();
+        small.extend_from_slice(&4u32.to_be_bytes());
+        small.extend_from_slice(&[0x40, 0x01, 0x0C, 0x01]);
+        mux.write_video(0, true, &small).unwrap();
+        // ~50 KB ≈ 270 packets — well over PCR_INTERVAL_PACKETS.
+        let big: Vec<u8> = (0..(50 * 1024)).map(|i| (i & 0xff) as u8).collect();
+        let mut big_frame = Vec::new();
+        big_frame.extend_from_slice(&(big.len() as u32).to_be_bytes());
+        big_frame.extend_from_slice(&big);
+        mux.write_video(40_000_000, false, &big_frame).unwrap();
+        // Now a second keyframe — must combine RAI (keyframe) and PCR
+        // (counter exceeded).
+        mux.write_video(80_000_000, true, &small).unwrap();
+        mux.finish().unwrap();
+        drop(mux);
+
+        // Collect video PUSI packets and find the third (second keyframe).
+        let video_pusi: Vec<&[u8]> = sink
+            .chunks(188)
+            .filter(|p| u16::from_be_bytes([p[1] & 0x1F, p[2]]) == PID_VIDEO && (p[1] & 0x40) != 0)
+            .collect();
+        assert!(video_pusi.len() >= 3, "three video PES starts expected");
+        let af = af_body(video_pusi[2]).expect("AF present");
+        assert!(!af.is_empty(), "AF flags byte present");
+        assert_eq!(af[0], 0x50, "flags == RAI | PCR");
+    }
 }

src/mux/mkv.rs

@@ -87,11 +87,19 @@ impl MkvTrack {
     }
 
     pub fn audio(a: &AudioStream) -> Self {
+        // Codec ID strings must distinguish the DTS family — strict
+        // players (Plex transcoder, some hardware decoders, some AV
+        // receivers) reject lossless DTS-HD MA payload when the
+        // track advertises plain `A_DTS` because it implies the
+        // bitstream is the 1.5 Mbps "core" only. Fix is just to
+        // emit the right ID per BD-STN codec field.
         let codec_id = match a.codec {
             Codec::Ac3 => "A_AC3",
             Codec::Ac3Plus => "A_EAC3",
             Codec::TrueHd => "A_TRUEHD",
-            Codec::DtsHdMa | Codec::DtsHdHr | Codec::Dts => "A_DTS",
+            Codec::DtsHdMa => "A_DTS/MA",
+            Codec::DtsHdHr => "A_DTS/HR",
+            Codec::Dts => "A_DTS",
             Codec::Lpcm => "A_PCM/INT/BIG",
             _ => "A_AC3",
         };
@@ -159,6 +167,12 @@ struct CuePoint {
     cluster_pos: u64, // relative to Segment start
 }
 
+/// SeekHead entry that needs its 8-byte SeekPosition back-patched after Cues are written.
+struct SeekPositionFixup {
+    target_id: u32,
+    value_offset: u64, // absolute file offset of the 8-byte SeekPosition value
+}
+
 /// MKV muxer. Call write_frame() for each frame, then finish() at the end.
 pub struct MkvMuxer<W: Write + Seek> {
     writer: W,
@@ -170,6 +184,10 @@ pub struct MkvMuxer<W: Write + Seek> {
     base_pts_ms: Option<i64>,
     cues: Vec<CuePoint>,
     frame_count: u64,
+    seek_fixups: Vec<SeekPositionFixup>,
+    info_offset: u64,
+    tracks_offset: u64,
+    chapters_offset: Option<u64>,
 }
 
 /// New cluster every 5 seconds.
@@ -200,7 +218,34 @@ impl<W: Write + Seek> MkvMuxer<W> {
         ebml::write_unknown_size(&mut writer)?;
         let segment_start = writer.stream_position()?;
 
+        // SeekHead with fixed-width SeekPosition placeholders. Order: Info, Tracks, [Chapters], Cues.
+        let mut seek_fixups: Vec<SeekPositionFixup> = Vec::new();
+        let seekhead_pos = ebml::start_master(&mut writer, ebml::SEEK_HEAD)?;
+        let mut targets: Vec<u32> = vec![ebml::INFO, ebml::TRACKS];
+        if !chapters.is_empty() {
+            targets.push(ebml::CHAPTERS);
+        }
+        targets.push(ebml::CUES);
+        let seek_id_be = (ebml::SEEK as u16).to_be_bytes();
+        let seek_inner_id_be = (ebml::SEEK_ID as u16).to_be_bytes();
+        let seek_pos_id_be = (ebml::SEEK_POSITION as u16).to_be_bytes();
+        for target_id in &targets {
+            writer.write_all(&[seek_id_be[0], seek_id_be[1], 0x92])?;
+            writer.write_all(&[seek_inner_id_be[0], seek_inner_id_be[1], 0x84])?;
+            writer.write_all(&target_id.to_be_bytes())?;
+            writer.write_all(&[seek_pos_id_be[0], seek_pos_id_be[1], 0x88])?;
+            let value_offset = writer.stream_position()?;
+            writer.write_all(&[0u8; 8])?;
+            seek_fixups.push(SeekPositionFixup {
+                target_id: *target_id,
+                value_offset,
+            });
+        }
+        ebml::end_master(&mut writer, seekhead_pos)?;
+
         // Info
+        let info_start = writer.stream_position()?;
+        let info_offset = info_start - segment_start;
         let info_pos = ebml::start_master(&mut writer, ebml::INFO)?;
         ebml::write_uint(&mut writer, ebml::TIMESTAMP_SCALE, 1_000_000)?; // 1ms precision
         if duration_secs > 0.0 {
@@ -215,6 +260,8 @@ impl<W: Write + Seek> MkvMuxer<W> {
         ebml::end_master(&mut writer, info_pos)?;
 
         // Tracks
+        let tracks_start = writer.stream_position()?;
+        let tracks_offset = tracks_start - segment_start;
         let tracks_pos = ebml::start_master(&mut writer, ebml::TRACKS)?;
         for (i, track) in tracks.iter().enumerate() {
             let entry_pos = ebml::start_master(&mut writer, ebml::TRACK_ENTRY)?;
@@ -302,7 +349,10 @@ impl<W: Write + Seek> MkvMuxer<W> {
         ebml::end_master(&mut writer, tracks_pos)?;
 
         // Chapters
+        let mut chapters_offset: Option<u64> = None;
         if !chapters.is_empty() {
+            let chapters_start = writer.stream_position()?;
+            chapters_offset = Some(chapters_start - segment_start);
             let chapters_pos = ebml::start_master(&mut writer, ebml::CHAPTERS)?;
             let edition_pos = ebml::start_master(&mut writer, ebml::EDITION_ENTRY)?;
             for (i, ch) in chapters.iter().enumerate() {
@@ -330,42 +380,60 @@ impl<W: Write + Seek> MkvMuxer<W> {
             base_pts_ms: None,
             cues: Vec::new(),
             frame_count: 0,
+            seek_fixups,
+            info_offset,
+            tracks_offset,
+            chapters_offset,
         })
     }
 
     /// Write a single frame.
+    ///
+    /// When `duration_ns` is `Some`, the frame is emitted as a
+    /// `BlockGroup` with `BlockDuration` so the player knows exactly
+    /// when to remove the on-screen artifact (the practical case is
+    /// PGS subtitles — without it, the last bitmap lingers until the
+    /// next display set replaces it). Otherwise a plain `SimpleBlock`.
     pub fn write_frame(
         &mut self,
         track_idx: usize,
         pts_ns: i64,
         keyframe: bool,
         data: &[u8],
+        duration_ns: Option<u64>,
     ) -> io::Result<()> {
         let raw_ms = pts_ns / 1_000_000;
         let base = *self.base_pts_ms.get_or_insert(raw_ms);
         let pts_ms = raw_ms - base;
 
-        // Start new cluster if needed
-        if !self.cluster_open || (pts_ms - self.cluster_ts_ms) >= CLUSTER_DURATION_MS {
-            if self.cluster_open {
-                // Close current cluster (it's a master with unknown size — we use known size)
-                // Actually, for streaming we keep clusters open-ended. Just start a new one.
+        // Cluster boundaries must coincide with a video keyframe so every
+        // Cues entry resolves to a seekable IDR at the cluster start.
+        let is_video_key = keyframe && track_idx == 0;
+        let needs_new_cluster = !self.cluster_open
+            || (is_video_key && (pts_ms - self.cluster_ts_ms) >= CLUSTER_DURATION_MS);
+
+        if needs_new_cluster {
+            if !is_video_key {
+                return Ok(());
             }
             self.start_cluster(pts_ms)?;
-
-            // Add cue point at cluster start for keyframes (video track 0)
-            if keyframe && track_idx == 0 {
-                self.cues.push(CuePoint {
-                    timestamp_ms: pts_ms,
-                    track: track_idx + 1,
-                    cluster_pos: self.cluster_pos - self.segment_start,
-                });
-            }
+            self.cues.push(CuePoint {
+                timestamp_ms: pts_ms,
+                track: track_idx + 1,
+                cluster_pos: self.cluster_pos - self.segment_start,
+            });
         }
 
-        // Write SimpleBlock
         let relative_ts = (pts_ms - self.cluster_ts_ms) as i16;
-        self.write_simple_block(track_idx + 1, relative_ts, keyframe, data)?;
+        match duration_ns {
+            Some(dur_ns) => {
+                let duration_ms = (dur_ns / 1_000_000).max(1);
+                self.write_block_group(track_idx + 1, relative_ts, keyframe, data, duration_ms)?;
+            }
+            None => {
+                self.write_simple_block(track_idx + 1, relative_ts, keyframe, data)?;
+            }
+        }
         self.frame_count += 1;
 
         Ok(())
@@ -377,6 +445,8 @@ impl<W: Write + Seek> MkvMuxer<W> {
         self.end_cluster()?;
 
         // Write Cues
+        let cues_start = self.writer.stream_position()?;
+        let cues_offset = cues_start - self.segment_start;
         if !self.cues.is_empty() {
             let cues_pos = ebml::start_master(&mut self.writer, ebml::CUES)?;
             for cue in &self.cues {
@@ -395,6 +465,21 @@ impl<W: Write + Seek> MkvMuxer<W> {
             ebml::end_master(&mut self.writer, cues_pos)?;
         }
 
+        // Back-patch SeekHead SeekPosition values now that all element offsets are known.
+        for fixup in &self.seek_fixups {
+            let offset = match fixup.target_id {
+                ebml::INFO => self.info_offset,
+                ebml::TRACKS => self.tracks_offset,
+                ebml::CHAPTERS => self.chapters_offset.unwrap_or(0),
+                ebml::CUES => cues_offset,
+                _ => 0,
+            };
+            self.writer
+                .seek(std::io::SeekFrom::Start(fixup.value_offset))?;
+            self.writer.write_all(&offset.to_be_bytes())?;
+        }
+        self.writer.seek(std::io::SeekFrom::End(0))?;
+
         self.writer.flush()?;
         Ok(())
     }
@@ -447,6 +532,34 @@ impl<W: Write + Seek> MkvMuxer<W> {
 
         Ok(())
     }
+
+    fn write_block_group(
+        &mut self,
+        track_num: usize,
+        relative_ts: i16,
+        keyframe: bool,
+        data: &[u8],
+        duration_ms: u64,
+    ) -> io::Result<()> {
+        let track_vint = if track_num < 0x80 {
+            vec![(track_num as u8) | 0x80]
+        } else {
+            vec![0x40 | ((track_num >> 8) as u8), track_num as u8]
+        };
+        let flags: u8 = if keyframe { 0x80 } else { 0x00 };
+        let block_size = track_vint.len() + 2 + 1 + data.len();
+
+        let bg_pos = ebml::start_master(&mut self.writer, ebml::BLOCK_GROUP)?;
+        ebml::write_id(&mut self.writer, ebml::BLOCK)?;
+        ebml::write_size(&mut self.writer, block_size as u64)?;
+        self.writer.write_all(&track_vint)?;
+        self.writer.write_all(&relative_ts.to_be_bytes())?;
+        self.writer.write_all(&[flags])?;
+        self.writer.write_all(data)?;
+        ebml::write_uint(&mut self.writer, ebml::BLOCK_DURATION, duration_ms)?;
+        ebml::end_master(&mut self.writer, bg_pos)?;
+        Ok(())
+    }
 }
 
 // ============================================================
@@ -556,7 +669,7 @@ mod tests {
         let tracks = [make_video_track()];
         let mut muxer = MkvMuxer::new(buf, &tracks, None, 60.0, &[]).unwrap();
         muxer
-            .write_frame(0, 0, true, &[0xDE, 0xAD, 0xBE, 0xEF])
+            .write_frame(0, 0, true, &[0xDE, 0xAD, 0xBE, 0xEF], None)
             .unwrap();
         let data = muxer.writer.into_inner();
         assert!(
@@ -594,7 +707,9 @@ mod tests {
         let writer = SharedWriter(shared.clone());
         let tracks = [make_video_track()];
         let mut muxer = MkvMuxer::new(writer, &tracks, Some("Cue Test"), 60.0, &[]).unwrap();
-        muxer.write_frame(0, 0, true, &[0x01, 0x02, 0x03]).unwrap();
+        muxer
+            .write_frame(0, 0, true, &[0x01, 0x02, 0x03], None)
+            .unwrap();
         muxer.finish().unwrap();
 
         let data = shared.lock().unwrap().clone().into_inner();
@@ -610,13 +725,17 @@ mod tests {
         let tracks = [make_video_track(), make_audio_track()];
         let mut muxer = MkvMuxer::new(buf, &tracks, Some("Multi"), 120.0, &[]).unwrap();
         // Write frames to both tracks
-        muxer.write_frame(0, 0, true, &[0x00, 0x00, 0x01]).unwrap();
-        muxer.write_frame(1, 0, false, &[0x0B, 0x77, 0x00]).unwrap();
         muxer
-            .write_frame(0, 40_000_000, false, &[0x00, 0x00, 0x01])
+            .write_frame(0, 0, true, &[0x00, 0x00, 0x01], None)
             .unwrap();
         muxer
-            .write_frame(1, 32_000_000, false, &[0x0B, 0x77, 0x01])
+            .write_frame(1, 0, false, &[0x0B, 0x77, 0x00], None)
+            .unwrap();
+        muxer
+            .write_frame(0, 40_000_000, false, &[0x00, 0x00, 0x01], None)
+            .unwrap();
+        muxer
+            .write_frame(1, 32_000_000, false, &[0x0B, 0x77, 0x01], None)
             .unwrap();
         // Should not panic
         let data = muxer.writer.into_inner();
@@ -631,10 +750,12 @@ mod tests {
 
         // Record position before first frame
         let pos_before_kf = muxer.writer.position();
-        muxer.write_frame(0, 0, true, &[0xAA]).unwrap();
+        muxer.write_frame(0, 0, true, &[0xAA], None).unwrap();
         let pos_after_kf = muxer.writer.position();
 
-        muxer.write_frame(0, 1_000_000, false, &[0xBB]).unwrap();
+        muxer
+            .write_frame(0, 1_000_000, false, &[0xBB], None)
+            .unwrap();
         let pos_after_nkf = muxer.writer.position();
 
         let data = muxer.writer.into_inner();
@@ -812,4 +933,422 @@ mod tests {
             "FlagForced element should not be present for non-forced subtitle"
         );
     }
+
+    // ============================================================
+    // Seekability tests: SeekHead, keyframe-aligned clusters, Cues
+    // ============================================================
+
+    use std::sync::{Arc, Mutex};
+
+    /// Writer that lets the test inspect the buffer after `finish()` consumes the muxer.
+    struct SharedWriter(Arc<Mutex<Cursor<Vec<u8>>>>);
+    impl Write for SharedWriter {
+        fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+            self.0.lock().unwrap().write(buf)
+        }
+        fn flush(&mut self) -> io::Result<()> {
+            self.0.lock().unwrap().flush()
+        }
+    }
+    impl Seek for SharedWriter {
+        fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
+            self.0.lock().unwrap().seek(pos)
+        }
+    }
+
+    /// Build interleaved frames at 24 fps video (IDR every gop_secs) + 48 kHz audio (1024 samples per frame).
+    fn frames_for(duration_secs: f64, gop_secs: f64) -> Vec<(usize, i64, bool, Vec<u8>)> {
+        let video_interval_ns: i64 = 1_000_000_000 / 24;
+        let audio_interval_ns: i64 = (1024i64 * 1_000_000_000) / 48_000;
+        let gop_frames = (gop_secs * 24.0).round() as i64;
+
+        let mut out: Vec<(usize, i64, bool, Vec<u8>)> = Vec::new();
+        let total_ns = (duration_secs * 1_000_000_000.0) as i64;
+
+        let mut vi: i64 = 0;
+        loop {
+            let pts = vi * video_interval_ns;
+            if pts >= total_ns {
+                break;
+            }
+            let keyframe = vi % gop_frames == 0;
+            out.push((0, pts, keyframe, vec![0xAB; 64]));
+            vi += 1;
+        }
+
+        let mut ai: i64 = 0;
+        loop {
+            let pts = ai * audio_interval_ns;
+            if pts >= total_ns {
+                break;
+            }
+            out.push((1, pts, true, vec![0xCD; 32]));
+            ai += 1;
+        }
+
+        out.sort_by_key(|f| f.1);
+        out
+    }
+
+    /// Mux frames through a SharedWriter and return the final buffer.
+    fn mux_to_bytes(
+        tracks: &[MkvTrack],
+        chapters: &[Chapter],
+        frames: &[(usize, i64, bool, Vec<u8>)],
+    ) -> (Vec<u8>, u64) {
+        let shared = Arc::new(Mutex::new(Cursor::new(Vec::new())));
+        let writer = SharedWriter(shared.clone());
+        let mut muxer = MkvMuxer::new(writer, tracks, None, 0.0, chapters).unwrap();
+        for (t, pts, kf, data) in frames {
+            muxer.write_frame(*t, *pts, *kf, data, None).unwrap();
+        }
+        let frame_count = muxer.frame_count;
+        muxer.finish().unwrap();
+        let data = shared.lock().unwrap().clone().into_inner();
+        (data, frame_count)
+    }
+
+    /// Find the Segment header in the buffer and return (segment_id_pos, segment_start_pos).
+    /// segment_start = position immediately after Segment's id + size bytes.
+    fn locate_segment(data: &[u8]) -> (usize, usize) {
+        let segment_id_pos = find_id(data, ebml::SEGMENT).expect("segment id not found");
+        // Segment is written via write_id + write_unknown_size: 4 byte id + 8 byte size
+        (segment_id_pos, segment_id_pos + 4 + 8)
+    }
+
+    /// Walk Segment's top-level children. Returns Vec<(id, data_start_offset, data_size)>
+    /// where data_start_offset is absolute file offset and data_size is the element body size.
+    fn segment_children(data: &[u8]) -> Vec<(u32, usize, u64)> {
+        let (_, seg_start) = locate_segment(data);
+        let mut out = Vec::new();
+        let mut cursor = Cursor::new(&data[seg_start..]);
+        while (cursor.position() as usize) < data.len() - seg_start {
+            let pos_before = cursor.position();
+            let (id, size, hdr_len) = match ebml::read_element_header(&mut cursor) {
+                Ok(v) => v,
+                Err(_) => break,
+            };
+            let data_abs = seg_start + pos_before as usize + hdr_len;
+            out.push((id, data_abs, size));
+            // Skip the body to advance to the next element.
+            cursor
+                .seek(io::SeekFrom::Current(size as i64))
+                .expect("seek past element body");
+        }
+        out
+    }
+
+    /// Find every Cluster: returns Vec<(cluster_data_start_abs, cluster_data_size, cluster_timestamp_ms)>.
+    fn find_clusters(data: &[u8]) -> Vec<(usize, u64, u64)> {
+        let mut out = Vec::new();
+        for (id, body_start, body_size) in segment_children(data) {
+            if id == ebml::CLUSTER {
+                let mut cursor = Cursor::new(&data[body_start..body_start + body_size as usize]);
+                let (tid, tsize, _) = ebml::read_element_header(&mut cursor).unwrap();
+                assert_eq!(
+                    tid,
+                    ebml::CLUSTER_TIMESTAMP,
+                    "cluster must start with timestamp"
+                );
+                let ts = ebml::read_uint_val(&mut cursor, tsize as usize).unwrap();
+                out.push((body_start, body_size, ts));
+            }
+        }
+        out
+    }
+
+    /// Parse the first SimpleBlock that appears in a cluster body slice.
+    /// Returns (track_num, flags_byte). track_num decoded from VINT.
+    fn first_simple_block(cluster_body: &[u8]) -> (u64, u8) {
+        let mut cursor = Cursor::new(cluster_body);
+        loop {
+            let (id, size, _) = ebml::read_element_header(&mut cursor).unwrap();
+            if id == ebml::SIMPLE_BLOCK {
+                let body_start = cursor.position() as usize;
+                // Decode track VINT.
+                let b0 = cluster_body[body_start];
+                let (track_num, vint_len) = if b0 & 0x80 != 0 {
+                    ((b0 & 0x7F) as u64, 1usize)
+                } else if b0 & 0x40 != 0 {
+                    let b1 = cluster_body[body_start + 1];
+                    ((((b0 & 0x3F) as u64) << 8) | b1 as u64, 2)
+                } else {
+                    panic!("unsupported track vint width");
+                };
+                let flags = cluster_body[body_start + vint_len + 2];
+                return (track_num, flags);
+            }
+            // Skip non-SimpleBlock child.
+            cursor.seek(io::SeekFrom::Current(size as i64)).unwrap();
+        }
+    }
+
+    /// Parse the Cues element body into Vec<(cue_time, cue_track, cue_cluster_position)>.
+    fn parse_cues(data: &[u8]) -> Vec<(u64, u64, u64)> {
+        let mut out = Vec::new();
+        let (cues_id, cues_body_start, cues_body_size) = segment_children(data)
+            .into_iter()
+            .find(|(id, _, _)| *id == ebml::CUES)
+            .expect("cues element not found");
+        assert_eq!(cues_id, ebml::CUES);
+        let cues_body = &data[cues_body_start..cues_body_start + cues_body_size as usize];
+        let mut cursor = Cursor::new(cues_body);
+        while (cursor.position() as usize) < cues_body.len() {
+            let (id, size, _) = ebml::read_element_header(&mut cursor).unwrap();
+            assert_eq!(id, ebml::CUE_POINT);
+            let cp_end = cursor.position() + size;
+            let mut cue_time = 0u64;
+            let mut cue_track = 0u64;
+            let mut cue_pos = 0u64;
+            while cursor.position() < cp_end {
+                let (sid, ssize, _) = ebml::read_element_header(&mut cursor).unwrap();
+                match sid {
+                    ebml::CUE_TIME => {
+                        cue_time = ebml::read_uint_val(&mut cursor, ssize as usize).unwrap();
+                    }
+                    ebml::CUE_TRACK_POSITIONS => {
+                        let ctp_end = cursor.position() + ssize;
+                        while cursor.position() < ctp_end {
+                            let (iid, isize_, _) = ebml::read_element_header(&mut cursor).unwrap();
+                            match iid {
+                                ebml::CUE_TRACK => {
+                                    cue_track =
+                                        ebml::read_uint_val(&mut cursor, isize_ as usize).unwrap();
+                                }
+                                ebml::CUE_CLUSTER_POSITION => {
+                                    cue_pos =
+                                        ebml::read_uint_val(&mut cursor, isize_ as usize).unwrap();
+                                }
+                                _ => {
+                                    cursor.seek(io::SeekFrom::Current(isize_ as i64)).unwrap();
+                                }
+                            }
+                        }
+                    }
+                    _ => {
+                        cursor.seek(io::SeekFrom::Current(ssize as i64)).unwrap();
+                    }
+                }
+            }
+            out.push((cue_time, cue_track, cue_pos));
+        }
+        out
+    }
+
+    /// Parse the SeekHead body into Vec<(seek_id, seek_position)>.
+    fn parse_seekhead(data: &[u8]) -> Vec<(u32, u64)> {
+        let mut out = Vec::new();
+        let (sh_id, sh_body_start, sh_body_size) = segment_children(data)
+            .into_iter()
+            .find(|(id, _, _)| *id == ebml::SEEK_HEAD)
+            .expect("seekhead not found");
+        assert_eq!(sh_id, ebml::SEEK_HEAD);
+        let sh_body = &data[sh_body_start..sh_body_start + sh_body_size as usize];
+        let mut cursor = Cursor::new(sh_body);
+        while (cursor.position() as usize) < sh_body.len() {
+            let (id, size, _) = ebml::read_element_header(&mut cursor).unwrap();
+            assert_eq!(id, ebml::SEEK);
+            let seek_end = cursor.position() + size;
+            let mut seek_id_val: u32 = 0;
+            let mut seek_pos_val: u64 = 0;
+            while cursor.position() < seek_end {
+                let (sid, ssize, _) = ebml::read_element_header(&mut cursor).unwrap();
+                match sid {
+                    ebml::SEEK_ID => {
+                        let raw = ebml::read_uint_val(&mut cursor, ssize as usize).unwrap();
+                        seek_id_val = raw as u32;
+                    }
+                    ebml::SEEK_POSITION => {
+                        seek_pos_val = ebml::read_uint_val(&mut cursor, ssize as usize).unwrap();
+                    }
+                    _ => {
+                        cursor.seek(io::SeekFrom::Current(ssize as i64)).unwrap();
+                    }
+                }
+            }
+            out.push((seek_id_val, seek_pos_val));
+        }
+        out
+    }
+
+    #[test]
+    fn cluster_starts_only_on_video_keyframe() {
+        let tracks = [make_video_track(), make_audio_track()];
+        let frames = frames_for(30.0, 1.0);
+        let (data, _) = mux_to_bytes(&tracks, &[], &frames);
+        let clusters = find_clusters(&data);
+        assert!(!clusters.is_empty(), "expected at least one cluster");
+        for (body_start, body_size, _ts) in clusters {
+            let body = &data[body_start..body_start + body_size as usize];
+            // Skip past the CLUSTER_TIMESTAMP element first.
+            let mut cursor = Cursor::new(body);
+            let (tid, tsize, _) = ebml::read_element_header(&mut cursor).unwrap();
+            assert_eq!(tid, ebml::CLUSTER_TIMESTAMP);
+            cursor.seek(io::SeekFrom::Current(tsize as i64)).unwrap();
+            let after_ts = cursor.position() as usize;
+            let (track_num, flags) = first_simple_block(&body[after_ts..]);
+            assert_eq!(
+                track_num, 1,
+                "first block in cluster must be track 1 (video)"
+            );
+            assert_eq!(
+                flags & 0x80,
+                0x80,
+                "first block in cluster must have keyframe flag set, got 0x{:02X}",
+                flags
+            );
+        }
+    }
+
+    #[test]
+    fn cue_count_equals_cluster_count() {
+        let tracks = [make_video_track(), make_audio_track()];
+        let frames = frames_for(30.0, 1.0);
+        let (data, _) = mux_to_bytes(&tracks, &[], &frames);
+        let clusters = find_clusters(&data);
+        let cues = parse_cues(&data);
+        assert_eq!(
+            clusters.len(),
+            cues.len(),
+            "cluster count {} != cue count {}",
+            clusters.len(),
+            cues.len()
+        );
+        // For 30s @ 5s min cluster duration with 1s GOP, expect 6 clusters / 6 cues.
+        assert_eq!(
+            clusters.len(),
+            6,
+            "expected 6 clusters for 30s @ 5s cluster duration"
+        );
+    }
+
+    #[test]
+    fn cue_positions_resolve_to_clusters() {
+        let tracks = [make_video_track(), make_audio_track()];
+        let frames = frames_for(30.0, 1.0);
+        let (data, _) = mux_to_bytes(&tracks, &[], &frames);
+        let (_, seg_start) = locate_segment(&data);
+        let cues = parse_cues(&data);
+        assert!(!cues.is_empty());
+        for (_time, _track, pos) in cues {
+            let abs = seg_start + pos as usize;
+            let mut cursor = Cursor::new(&data[abs..]);
+            let (id, _size, _hdr_len) = ebml::read_element_header(&mut cursor).unwrap();
+            assert_eq!(
+                id,
+                ebml::CLUSTER,
+                "cue position 0x{:X} did not resolve to a cluster",
+                pos
+            );
+        }
+    }
+
+    #[test]
+    fn cue_times_match_cluster_timestamps() {
+        let tracks = [make_video_track(), make_audio_track()];
+        let frames = frames_for(30.0, 1.0);
+        let (data, _) = mux_to_bytes(&tracks, &[], &frames);
+        let (_, seg_start) = locate_segment(&data);
+        let cues = parse_cues(&data);
+        for (time, _track, pos) in cues {
+            let abs = seg_start + pos as usize;
+            let mut cursor = Cursor::new(&data[abs..]);
+            let (id, size, _hdr_len) = ebml::read_element_header(&mut cursor).unwrap();
+            assert_eq!(id, ebml::CLUSTER);
+            let body_start = abs + (cursor.position() as usize);
+            let body = &data[body_start..body_start + size as usize];
+            let mut bc = Cursor::new(body);
+            let (tid, tsize, _) = ebml::read_element_header(&mut bc).unwrap();
+            assert_eq!(tid, ebml::CLUSTER_TIMESTAMP);
+            let cluster_ts = ebml::read_uint_val(&mut bc, tsize as usize).unwrap();
+            assert_eq!(
+                cluster_ts, time,
+                "cluster timestamp {} != cue time {}",
+                cluster_ts, time
+            );
+        }
+    }
+
+    #[test]
+    fn seekhead_is_first_child_of_segment() {
+        let tracks = [make_video_track(), make_audio_track()];
+        let (data, _) = mux_to_bytes(&tracks, &[], &frames_for(10.0, 1.0));
+        let children = segment_children(&data);
+        assert!(!children.is_empty());
+        assert_eq!(
+            children[0].0,
+            ebml::SEEK_HEAD,
+            "first child of segment must be SeekHead, got id 0x{:X}",
+            children[0].0
+        );
+    }
+
+    #[test]
+    fn seekhead_points_to_real_elements() {
+        let tracks = [make_video_track(), make_audio_track()];
+        let (data, _) = mux_to_bytes(&tracks, &[], &frames_for(10.0, 1.0));
+        let (_, seg_start) = locate_segment(&data);
+        let entries = parse_seekhead(&data);
+        let required = [ebml::INFO, ebml::TRACKS, ebml::CUES];
+        for &want_id in &required {
+            let entry = entries
+                .iter()
+                .find(|(id, _)| *id == want_id)
+                .unwrap_or_else(|| panic!("seekhead missing entry for id 0x{:X}", want_id));
+            let abs = seg_start + entry.1 as usize;
+            let mut cursor = Cursor::new(&data[abs..]);
+            let (got_id, _, _) = ebml::read_element_header(&mut cursor).unwrap();
+            assert_eq!(
+                got_id, want_id,
+                "seekhead entry for 0x{:X} resolves to wrong id 0x{:X}",
+                want_id, got_id
+            );
+        }
+    }
+
+    #[test]
+    fn seekhead_omits_chapters_when_empty() {
+        let tracks = [make_video_track()];
+        let (data, _) = mux_to_bytes(&tracks, &[], &frames_for(5.0, 1.0));
+        let entries = parse_seekhead(&data);
+        assert_eq!(
+            entries.len(),
+            3,
+            "expected 3 seek entries (Info, Tracks, Cues), got {}",
+            entries.len()
+        );
+        assert!(
+            entries.iter().all(|(id, _)| *id != ebml::CHAPTERS),
+            "seekhead should not contain Chapters entry when chapters are empty"
+        );
+    }
+
+    #[test]
+    fn pre_first_keyframe_frames_dropped() {
+        let tracks = [make_video_track()];
+        let frames = vec![
+            (0usize, 0i64, false, vec![0x11; 16]),
+            (0usize, 41_000_000i64, true, vec![0x22; 16]),
+        ];
+        let (data, frame_count) = mux_to_bytes(&tracks, &[], &frames);
+        assert_eq!(frame_count, 1, "muxer.frame_count must equal 1");
+        let clusters = find_clusters(&data);
+        assert_eq!(clusters.len(), 1, "expected exactly one cluster");
+        let (body_start, body_size, _ts) = clusters[0];
+        let body = &data[body_start..body_start + body_size as usize];
+        let mut cursor = Cursor::new(body);
+        // Skip CLUSTER_TIMESTAMP.
+        let (tid, tsize, _) = ebml::read_element_header(&mut cursor).unwrap();
+        assert_eq!(tid, ebml::CLUSTER_TIMESTAMP);
+        cursor.seek(io::SeekFrom::Current(tsize as i64)).unwrap();
+        let mut sb_count = 0;
+        while (cursor.position() as usize) < body.len() {
+            let (id, sz, _) = ebml::read_element_header(&mut cursor).unwrap();
+            if id == ebml::SIMPLE_BLOCK {
+                sb_count += 1;
+            }
+            cursor.seek(io::SeekFrom::Current(sz as i64)).unwrap();
+        }
+        assert_eq!(sb_count, 1, "expected exactly one SimpleBlock in output");
+    }
 }

src/mux/mkvstream.rs

@@ -138,6 +138,7 @@ impl crate::pes::Stream for MkvStream {
                         pts: pts_ms * 1_000_000, // ms → ns
                         keyframe,
                         data,
+                        duration_ns: None,
                     }));
                 }
                 _ => {
@@ -150,9 +151,13 @@ impl crate::pes::Stream for MkvStream {
 
     fn write(&mut self, frame: &crate::pes::PesFrame) -> io::Result<()> {
         match &mut self.mode {
-            Mode::Write { muxer: Some(m) } => {
-                m.write_frame(frame.track, frame.pts, frame.keyframe, &frame.data)
-            }
+            Mode::Write { muxer: Some(m) } => m.write_frame(
+                frame.track,
+                frame.pts,
+                frame.keyframe,
+                &frame.data,
+                frame.duration_ns,
+            ),
             Mode::Write { muxer: None } => Ok(()),
             Mode::Read(_) => Err(crate::error::Error::StreamReadOnly.into()),
         }

src/mux/mod.rs

@@ -6,7 +6,7 @@
 //! ```text
 //! let mut input = input("iso://Disc.iso", &opts)?;
 //! let title = input.info().clone();
-//! let mut output = output("mkv://Dune.mkv", &title)?;
+//! let mut output = output("mkv://Movie.mkv", &title)?;
 //! while let Ok(Some(frame)) = input.read() {
 //!     output.write(&frame)?;
 //! }
@@ -17,8 +17,9 @@
 
 // Public modules — types here are intentionally part of the consumable API.
 pub mod codec;
+pub mod demux_thread;
 pub mod disc;
-pub mod iso;
+pub mod pipelined_stream;
 pub mod resolve;
 
 // Internal modules — implementation details. Their *types* are re-exported
@@ -54,11 +55,12 @@ pub(crate) mod ts;
 pub(crate) mod tsmux;
 
 pub use disc::DiscStream;
-pub use iso::IsoSectorReader;
 pub use m2ts::M2tsStream;
 pub use mkvstream::MkvStream;
 pub use network::NetworkStream;
 pub use null::NullStream;
+pub use pipelined_stream::PipelinedPesStream;
+pub use resolve::build_iso_pipeline;
 pub use resolve::{InputOptions, StreamUrl, input, output, parse_url};
 pub use stdio::StdioStream;
 

src/mux/network.rs

@@ -186,6 +186,7 @@ mod tests {
             pts: 90000,
             keyframe: true,
             data: vec![0x47; 192],
+            duration_ns: None,
         };
         pes::Stream::write(&mut writer, &frame).unwrap();
         pes::Stream::finish(&mut writer).unwrap();

src/mux/null.rs

@@ -47,6 +47,7 @@ mod tests {
             pts: 0,
             keyframe: true,
             data: vec![0x01, 0x02, 0x03],
+            duration_ns: None,
         };
         sink.write(&frame).unwrap();
         let _ = sink.info();

src/mux/pipelined_stream.rs

@@ -0,0 +1,226 @@
+//! `PipelinedPesStream` — the read-side of the freemkv mux
+//! highway.
+//!
+//! Given a [`crate::mux::demux_thread::DemuxThread`] (which has the
+//! producer + demux workers already spawned), a set of codec
+//! parsers, and the title metadata, this struct implements
+//! [`crate::pes::Stream`] by running codec parse on the caller's
+//! thread and emitting `PesFrame`s one at a time.
+//!
+//! The pipeline runs three threads in parallel:
+//!
+//! ```text
+//! Thread A: read + decrypt   (PrefetchedSectorSource / BytePrefetcher)
+//! Thread B: M2TS demux       (DemuxThread)
+//! Thread C: codec parse      (this struct, on the caller's thread)
+//! ```
+//!
+//! Communication between A→B and B→C is via bounded channels with
+//! recycled buffer pools — no allocations or memcpys in the steady-
+//! state hot loop.
+//!
+//! This is the *only* read-side `Stream` impl in tree. Both ISO file
+//! mux ([`crate::mux::resolve`]) and BD-TS file mux ([`crate::mux::M2tsStream`])
+//! return a `PipelinedPesStream`; the differences are in how the
+//! producer thread (A) is configured — sector-aligned reads with
+//! AACS decrypt for ISO, raw byte reads for M2TS.
+
+use super::codec::CodecParser;
+use super::demux_thread::{DemuxBatch, DemuxThread};
+use super::ts::PesPacket;
+use crate::disc::DiscTitle;
+use crate::pes::{PesFrame, Stream};
+use crossbeam_channel::Receiver;
+use std::io;
+
+/// Stream impl that consumes pre-demuxed `PesPacket` batches from a
+/// [`DemuxThread`] and runs codec parse on the caller's thread.
+pub struct PipelinedPesStream {
+    title: DiscTitle,
+    parsers: Vec<(u16, Box<dyn CodecParser>)>,
+    pid_to_track: Vec<(u16, usize)>,
+
+    demux_rx: Receiver<DemuxBatch>,
+    /// Kept alive so dropping this stream joins the demux + producer
+    /// workers deterministically. Never poked directly after spawn.
+    #[allow(dead_code)]
+    demux_thread: DemuxThread,
+
+    pending_frames: std::collections::VecDeque<PesFrame>,
+    eof: bool,
+}
+
+impl PipelinedPesStream {
+    /// Wire up the stream. Caller has already spawned the
+    /// `DemuxThread` (which in turn owns the producer); we take the
+    /// receiver end + the join handle bundle so cleanup is bounded
+    /// on drop.
+    pub fn new(
+        demux_thread: DemuxThread,
+        demux_rx: Receiver<DemuxBatch>,
+        title: DiscTitle,
+        parsers: Vec<(u16, Box<dyn CodecParser>)>,
+        pid_to_track: Vec<(u16, usize)>,
+    ) -> Self {
+        Self {
+            title,
+            parsers,
+            pid_to_track,
+            demux_rx,
+            demux_thread,
+            pending_frames: std::collections::VecDeque::new(),
+            eof: false,
+        }
+    }
+
+    /// Pull one batch of `PesPacket`s from the demux thread, run
+    /// codec parse on each, enqueue resulting `PesFrame`s on
+    /// `pending_frames`. Returns Ok(true) on success, Ok(false) on
+    /// EOF (channel closed cleanly), Err on demuxer error.
+    fn pump_one_batch(&mut self) -> io::Result<bool> {
+        match self.demux_rx.recv() {
+            Ok(DemuxBatch::Ts(packets)) => {
+                self.consume_ts(packets);
+                Ok(true)
+            }
+            Ok(DemuxBatch::Ps(packets)) => {
+                self.consume_ps(packets);
+                Ok(true)
+            }
+            Ok(DemuxBatch::Err(e)) => Err(e),
+            Err(_) => Ok(false),
+        }
+    }
+
+    fn consume_ts(&mut self, packets: Vec<PesPacket>) {
+        let skip_parse = std::env::var_os("FREEMKV_SKIP_PARSE").is_some();
+        for pes in packets {
+            if let Some((_, track)) = self
+                .pid_to_track
+                .iter()
+                .find(|(pid, _)| *pid == pes.pid)
+                .copied()
+            {
+                if skip_parse {
+                    // Profiling escape hatch — bypass codec parser.
+                    self.pending_frames.push_back(PesFrame {
+                        track,
+                        pts: pes.pts.map(super::codec::pts_to_ns).unwrap_or(0),
+                        keyframe: false,
+                        data: pes.data,
+                        duration_ns: None,
+                    });
+                } else if let Some((_, parser)) =
+                    self.parsers.iter_mut().find(|(pid, _)| *pid == pes.pid)
+                {
+                    for frame in parser.parse(&pes) {
+                        self.pending_frames
+                            .push_back(PesFrame::from_codec_frame(track, frame));
+                    }
+                }
+            }
+        }
+    }
+
+    fn consume_ps(&mut self, packets: Vec<super::ps::PsPacket>) {
+        for ps in packets {
+            let track = match ps.stream_id {
+                0xE0..=0xEF => 0,
+                0xC0..=0xDF => 1,
+                0xBD => ps
+                    .sub_stream_id
+                    .map(|s| (s & 0x1F) as usize + 1)
+                    .unwrap_or(1),
+                _ => continue,
+            };
+            if track >= self.title.streams.len() {
+                continue;
+            }
+            let pid = self
+                .pid_to_track
+                .iter()
+                .find(|(_, idx)| *idx == track)
+                .map(|(p, _)| *p)
+                .unwrap_or(0);
+            let pes = PesPacket {
+                pid,
+                pts: ps.pts.map(|p| p as i64),
+                dts: ps.dts.map(|d| d as i64),
+                data: ps.data,
+            };
+            if let Some((_, parser)) = self.parsers.iter_mut().find(|(p, _)| *p == pid) {
+                for frame in parser.parse(&pes) {
+                    self.pending_frames
+                        .push_back(PesFrame::from_codec_frame(track, frame));
+                }
+            }
+        }
+    }
+}
+
+impl Stream for PipelinedPesStream {
+    fn read(&mut self) -> io::Result<Option<PesFrame>> {
+        if let Some(frame) = self.pending_frames.pop_front() {
+            return Ok(Some(frame));
+        }
+        if self.eof {
+            return Ok(None);
+        }
+        loop {
+            match self.pump_one_batch()? {
+                true => {
+                    if let Some(frame) = self.pending_frames.pop_front() {
+                        return Ok(Some(frame));
+                    }
+                    // Batch contained no trackable packets — pull again.
+                }
+                false => {
+                    self.eof = true;
+                    return Ok(self.pending_frames.pop_front());
+                }
+            }
+        }
+    }
+
+    fn write(&mut self, _: &PesFrame) -> io::Result<()> {
+        Err(crate::error::Error::StreamReadOnly.into())
+    }
+
+    fn finish(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+
+    fn info(&self) -> &DiscTitle {
+        &self.title
+    }
+
+    fn headers_ready(&self) -> bool {
+        // Match the previous DiscStream semantics: video tracks need
+        // codec_private before the consumer can write the container
+        // header. FREEMKV_SKIP_PARSE forces ready (no parser ever
+        // populates codec_private in that mode).
+        if std::env::var_os("FREEMKV_SKIP_PARSE").is_some() {
+            return true;
+        }
+        for (idx, s) in self.title.streams.iter().enumerate() {
+            if let crate::disc::Stream::Video(v) = s {
+                if !v.secondary && self.codec_private(idx).is_none() {
+                    return false;
+                }
+            }
+        }
+        true
+    }
+
+    fn codec_private(&self, track: usize) -> Option<Vec<u8>> {
+        let pid = self
+            .pid_to_track
+            .iter()
+            .find(|(_, idx)| *idx == track)
+            .map(|(p, _)| *p)?;
+        self.parsers
+            .iter()
+            .find(|(p, _)| *p == pid)
+            .and_then(|(_, parser)| parser.codec_private())
+    }
+}

src/mux/resolve.rs

@@ -15,11 +15,13 @@
 //! Bare paths without a scheme are rejected.
 //! For disc→ISO (raw sector copy), use `Disc::copy()` instead.
 
-use super::disc::DiscStream;
 use super::network::NetworkStream;
 use super::null::NullStream;
+use super::pipelined_stream::PipelinedPesStream;
 use super::stdio::StdioStream;
 use super::{M2tsStream, MkvStream};
+use crate::disc::{ContentFormat, DiscTitle};
+use crate::sector::SectorSource;
 use std::io;
 use std::path::{Path, PathBuf};
 
@@ -161,6 +163,9 @@ fn validate_network_addr(addr: &str) -> io::Result<()> {
 #[derive(Default)]
 pub struct InputOptions {
     pub keydb_path: Option<String>,
+    /// Caller-supplied Unit Key (keyserver path) — the second, mutually
+    /// exclusive key source. Takes precedence over `keydb_path`.
+    pub unit_key: Option<[u8; 16]>,
     pub title_index: Option<usize>,
     /// Skip decryption — return raw encrypted bytes.
     pub raw: bool,
@@ -179,13 +184,16 @@ pub fn input(url: &str, opts: &InputOptions) -> io::Result<Box<dyn crate::pes::S
         }
         StreamUrl::Iso { ref path } => {
             validate_file_path(path, "iso")?;
-            let scan_opts = match &opts.keydb_path {
-                Some(p) => crate::disc::ScanOptions {
-                    keydb_path: Some(p.into()),
-                },
-                None => crate::disc::ScanOptions::default(),
+            let scan_opts = crate::disc::ScanOptions {
+                keydb_path: opts.keydb_path.as_ref().map(Into::into),
+                unit_key: opts.unit_key,
             };
-            let mut reader = super::iso::IsoSectorReader::open(&path.to_string_lossy())?;
+            // FileSectorSource is the sole file-backed sector source.
+            // It carries the platform-tuned SEQUENTIAL fadvise hint
+            // (so the kernel readahead window widens) and the periodic
+            // DONTNEED page-cache eviction that bounds memory pressure
+            // when the mux output is being written to the same disk.
+            let mut reader = crate::io::file_sector_source::FileSectorSource::open(path)?;
             let capacity = reader.capacity_sectors();
             let disc = crate::disc::Disc::scan_image(&mut reader, capacity, &scan_opts)
                 .map_err(|e| -> io::Error { e.into() })?;
@@ -203,21 +211,40 @@ pub fn input(url: &str, opts: &InputOptions) -> io::Result<Box<dyn crate::pes::S
             let title = disc.titles[idx].clone();
             let keys = disc.decrypt_keys();
             let format = disc.content_format;
-            // ISO file: use large batch size (16 MB) — sequential read from fast storage, no bad sectors.
-            // Physical drives need small batches for adaptive error handling and retry logic.
+            // ISO file: 16 MiB batch — sequential read from fast
+            // storage, no bad sectors. Measured optimum on the rip1
+            // testbed; bumping to 32 MiB regressed (more cache
+            // pressure, longer per-batch latency starves the consumer
+            // between iterations). Physical drives keep smaller
+            // batches for adaptive error handling.
             const ISO_MUX_BATCH_SECTORS: u16 = 8192;
-            let mut stream =
-                DiscStream::new(Box::new(reader), title, keys, ISO_MUX_BATCH_SECTORS, format);
-            if opts.raw {
-                stream.set_raw();
-            }
+
+            // Pass `DecryptKeys::None` to the decrypt decorator when
+            // --raw is set — the read stack still flows through the
+            // same producer+demux+parse pipeline, just without the
+            // AACS / CSS step. Single highway for all ISO reads.
+            let effective_keys = if opts.raw {
+                crate::decrypt::DecryptKeys::None
+            } else {
+                keys
+            };
+            let stream = build_iso_pipeline(
+                reader,
+                title,
+                effective_keys,
+                ISO_MUX_BATCH_SECTORS,
+                format,
+                None,
+                None,
+            );
             Ok(Box::new(stream))
         }
         StreamUrl::M2ts { ref path } => {
             validate_file_path(path, "m2ts")?;
             let file = std::fs::File::open(path)?;
             let reader = std::io::BufReader::with_capacity(IO_BUF_SIZE, file);
-            Ok(Box::new(M2tsStream::open(reader)?))
+            let stream = build_m2ts_pipeline(reader)?;
+            Ok(Box::new(stream))
         }
         StreamUrl::Mkv { ref path } => {
             validate_file_path(path, "mkv")?;
@@ -281,3 +308,137 @@ pub fn output(
         }
     }
 }
+
+/// Demuxer-side state derived from a `DiscTitle`: the codec parser
+/// table (keyed by PID), the PID-to-track index map, and an initial
+/// `TsDemuxer` / `PsDemuxer` (whichever the content format calls
+/// for).
+type DemuxState = (
+    Vec<(u16, Box<dyn super::codec::CodecParser>)>,
+    Vec<(u16, usize)>,
+    Option<super::ts::TsDemuxer>,
+    Option<super::ps::PsDemuxer>,
+);
+
+/// Build the title's codec parser table + initial `TsDemuxer` /
+/// `PsDemuxer`. Used by both the ISO and M2TS pipeline builders.
+fn build_demux_state(title: &DiscTitle, format: ContentFormat) -> DemuxState {
+    let mut pids = Vec::new();
+    let mut parsers = Vec::new();
+    let mut pid_to_track = Vec::new();
+    for (idx, s) in title.streams.iter().enumerate() {
+        let (pid, codec) = match s {
+            crate::disc::Stream::Video(v) => (v.pid, v.codec),
+            crate::disc::Stream::Audio(a) => (a.pid, a.codec),
+            crate::disc::Stream::Subtitle(s) => (s.pid, s.codec),
+        };
+        pids.push(pid);
+        pid_to_track.push((pid, idx));
+        parsers.push((pid, super::codec::parser_for_codec(codec, None)));
+    }
+    let (ts, ps) = match format {
+        ContentFormat::MpegPs => (None, Some(super::ps::PsDemuxer::new())),
+        ContentFormat::BdTs => {
+            if pids.is_empty() {
+                (None, None)
+            } else {
+                (Some(super::ts::TsDemuxer::new(&pids)), None)
+            }
+        }
+    };
+    (parsers, pid_to_track, ts, ps)
+}
+
+/// Assemble the ISO mux pipeline (read+decrypt → demux → parse) for
+/// a `FileSectorSource`-backed reader. Returns the resulting
+/// `PipelinedPesStream`.
+pub fn build_iso_pipeline<S: SectorSource + Send + 'static>(
+    reader: S,
+    title: DiscTitle,
+    keys: crate::decrypt::DecryptKeys,
+    batch_sectors: u16,
+    format: ContentFormat,
+    halt: Option<crate::halt::Halt>,
+    event_fn: Option<crate::sector::prefetched::EventFn>,
+) -> PipelinedPesStream {
+    let extents = title.extents.clone();
+    let decrypting =
+        crate::sector::DecryptingSectorSource::new(Box::new(reader) as Box<dyn SectorSource>, keys);
+    let prefetched = crate::sector::PrefetchedSectorSource::new_with_events(
+        decrypting,
+        extents,
+        batch_sectors,
+        halt.clone(),
+        event_fn,
+    );
+    let (rx, recycle_tx, shell) = prefetched.into_channels();
+
+    let (parsers, pid_to_track, ts, ps) = build_demux_state(&title, format);
+    let (demux_thread, demux_rx) =
+        super::demux_thread::DemuxThread::spawn_zero_copy(rx, recycle_tx, shell, halt, ts, ps);
+    PipelinedPesStream::new(demux_thread, demux_rx, title, parsers, pid_to_track)
+}
+
+/// Assemble the M2TS file mux pipeline (read → demux → parse) for a
+/// byte-stream reader. Scans the head for FMKV header or PMT/PAT,
+/// rebuilds the title metadata, then wraps a chained reader (head +
+/// remainder) in a `BytePrefetcher` feeding the demux + parse
+/// threads.
+fn build_m2ts_pipeline<R: std::io::Read + Send + 'static>(
+    mut reader: R,
+) -> io::Result<PipelinedPesStream> {
+    use super::meta;
+    use std::io::Read;
+
+    const M2TS_SCAN_BYTES: usize = 1024 * 1024;
+    let mut head = vec![0u8; M2TS_SCAN_BYTES];
+    let head_len = {
+        let mut filled = 0;
+        while filled < head.len() {
+            match reader.read(&mut head[filled..])? {
+                0 => break,
+                n => filled += n,
+            }
+        }
+        filled
+    };
+    head.truncate(head_len);
+
+    // Try FMKV metadata header first; fall back to PMT scan.
+    let mut cursor = io::Cursor::new(&head);
+    let (title, head_consumed) = if let Ok(Some(m)) = meta::read_header(&mut cursor) {
+        (m.to_title(), cursor.position() as usize)
+    } else {
+        let streams = super::ts::scan_streams(&head)
+            .ok_or_else(|| -> io::Error { crate::error::Error::NoStreams.into() })?;
+        let t = DiscTitle {
+            duration_secs: 0.0,
+            streams,
+            ..DiscTitle::empty()
+        };
+        (t, 0)
+    };
+
+    // Chain: any un-consumed head bytes + the remainder of the
+    // reader. The demuxer sees a contiguous M2TS byte stream.
+    let remaining_head = head[head_consumed..].to_vec();
+    let chained: Box<dyn Read + Send> = Box::new(io::Cursor::new(remaining_head).chain(reader));
+
+    let prefetcher = crate::io::byte_prefetcher::BytePrefetcher::new(
+        chained,
+        crate::io::byte_prefetcher::DEFAULT_CHUNK_BYTES,
+        None,
+    );
+    let (rx, recycle_tx, shell) = prefetcher.into_channels();
+
+    let (parsers, pid_to_track, ts, ps) = build_demux_state(&title, ContentFormat::BdTs);
+    let (demux_thread, demux_rx) =
+        super::demux_thread::DemuxThread::spawn_zero_copy(rx, recycle_tx, shell, None, ts, ps);
+    Ok(PipelinedPesStream::new(
+        demux_thread,
+        demux_rx,
+        title,
+        parsers,
+        pid_to_track,
+    ))
+}

src/mux/ts.rs

@@ -37,11 +37,20 @@ struct PesAssembler {
     active: bool,
 }
 
+/// Initial capacity for a fresh PES buffer. Sized to cover the
+/// common BD-TS audio / subtitle PES outright (a few KB to ~16 KB).
+/// Video PES (typically 150–300 KB on UHD) will grow this via the
+/// standard Vec doubling, but the doublings hit the allocator's
+/// slab caches instead of the 64-page first-touch faults that the
+/// previous `Vec::with_capacity(256 * 1024)` triggered on every PES
+/// boundary.
+const PES_BUFFER_INIT_CAP: usize = 16 * 1024;
+
 impl PesAssembler {
     fn new(pid: u16) -> Self {
         Self {
             pid,
-            buffer: Vec::with_capacity(256 * 1024),
+            buffer: Vec::with_capacity(PES_BUFFER_INIT_CAP),
             pts: None,
             dts: None,
             active: false,
@@ -55,7 +64,7 @@ impl PesAssembler {
                 pid: self.pid,
                 pts: self.pts,
                 dts: self.dts,
-                data: std::mem::replace(&mut self.buffer, Vec::with_capacity(256 * 1024)),
+                data: std::mem::replace(&mut self.buffer, Vec::with_capacity(PES_BUFFER_INIT_CAP)),
             })
         } else {
             self.buffer.clear();
@@ -124,97 +133,54 @@ impl TsDemuxer {
         }
     }
 
-    /// Feed a chunk of BD transport stream data. Handles non-192-byte-aligned input
-    /// by buffering leftover bytes between calls. Returns completed PES packets.
+    /// Feed a chunk of BD transport stream data. Handles non-192-byte-
+    /// aligned input by buffering leftover bytes between calls. Returns
+    /// completed PES packets.
+    ///
+    /// 16 MiB ISO batches never divide evenly into 192-byte BD-TS
+    /// packets, so every call after the first carries a ~64-byte
+    /// remainder. The pre-0.24 implementation handled this by building
+    /// a `combined` Vec containing remainder + the entire new input —
+    /// a 16 MiB+ memcpy on every call. Now we splice exactly one
+    /// boundary packet from a stack buffer, then process the rest of
+    /// `data` in place. Zero-copy on the bulk path; one 192-byte copy
+    /// on the boundary.
     pub fn feed(&mut self, data: &[u8]) -> Vec<PesPacket> {
         let mut completed = Vec::with_capacity(4);
-
-        // Prepend any remainder from previous call
-        let mut combined: Vec<u8> = Vec::new();
-        let work: &[u8] = if !self.remainder.is_empty() {
-            combined.reserve(self.remainder.len() + data.len());
-            combined.extend_from_slice(&self.remainder);
-            combined.extend_from_slice(data);
-            self.remainder.clear();
-            &combined
-        } else {
-            data
-        };
-
         let mut offset = 0;
 
-        while offset + BD_TS_PACKET_SIZE <= work.len() {
-            let packet = &work[offset..offset + BD_TS_PACKET_SIZE];
-            offset += BD_TS_PACKET_SIZE;
-
-            // Skip 4-byte TP_extra_header, check sync byte
-            if packet[4] != SYNC_BYTE {
-                continue;
-            }
-
-            let ts = &packet[4..]; // 188-byte standard TS packet
-
-            // Parse TS header
-            let pid = (((ts[1] & 0x1F) as u16) << 8) | ts[2] as u16;
-            let pusi = ts[1] & 0x40 != 0; // Payload Unit Start Indicator
-            let adaptation = (ts[3] >> 4) & 0x03;
-
-            // Check if we're tracking this PID
-            let idx = if (pid as usize) < self.pid_index.len() {
-                self.pid_index[pid as usize]
-            } else {
-                -1
-            };
-            if idx < 0 {
-                continue;
-            }
-            let asm = &mut self.assemblers[idx as usize];
-
-            // Find payload start (skip adaptation field if present)
-            let payload_start = if adaptation == 0x03 || adaptation == 0x02 {
-                // Adaptation field present
-                let af_len = ts[4] as usize;
-                if af_len > 183 {
-                    continue; // Malformed: AF length exceeds TS payload
-                }
-                5 + af_len
-            } else {
-                4
-            };
-
-            if payload_start >= TS_PACKET_SIZE {
-                continue;
-            }
-
-            // No payload
-            if adaptation == 0x02 {
-                continue;
-            }
-
-            let payload = &ts[payload_start..];
-
-            if pusi {
-                // New PES packet starts here — parse PES header
-                let (pts, dts, pes_data_start) = parse_pes_header(payload);
-                if let Some(prev) = asm.start(pts, dts) {
-                    completed.push(prev);
-                }
-                if pes_data_start < payload.len() {
-                    asm.push(&payload[pes_data_start..]);
-                }
-            } else {
-                // Continuation of current PES packet
-                asm.push(payload);
+        // Boundary packet: if a partial packet was left from the last
+        // call, complete it from the head of `data` without touching
+        // the rest of `data`.
+        if !self.remainder.is_empty() {
+            let need = BD_TS_PACKET_SIZE - self.remainder.len();
+            if data.len() < need {
+                // Still not a full packet — accumulate and wait.
+                self.remainder.extend_from_slice(data);
+                return completed;
             }
+            let mut boundary = [0u8; BD_TS_PACKET_SIZE];
+            boundary[..self.remainder.len()].copy_from_slice(&self.remainder);
+            boundary[self.remainder.len()..].copy_from_slice(&data[..need]);
+            self.remainder.clear();
+            self.process_packet(&boundary, &mut completed);
+            offset = need;
         }
 
-        // Save leftover bytes for next call (cap at one packet to prevent unbounded growth)
-        if offset < work.len() {
-            let leftover = &work[offset..];
+        // Aligned-packets fast path — reads directly out of `data`.
+        while offset + BD_TS_PACKET_SIZE <= data.len() {
+            let packet = &data[offset..offset + BD_TS_PACKET_SIZE];
+            offset += BD_TS_PACKET_SIZE;
+            self.process_packet(packet, &mut completed);
+        }
+
+        // Save leftover bytes for next call (cap at one packet to
+        // prevent unbounded growth on a desynchronised stream).
+        if offset < data.len() {
+            let leftover = &data[offset..];
             if leftover.len() < BD_TS_PACKET_SIZE {
                 self.remainder.extend_from_slice(leftover);
             } else {
-                // More than one full packet leftover — something is wrong, discard
                 self.remainder.clear();
             }
         }
@@ -222,6 +188,65 @@ impl TsDemuxer {
         completed
     }
 
+    /// Demux a single 192-byte BD-TS packet (4-byte TP_extra_header +
+    /// 188-byte TS). Routes payload bytes into the per-PID
+    /// `PesAssembler`; completed PES packets are pushed onto
+    /// `completed` so the caller's allocation amortises across the
+    /// batch.
+    fn process_packet(&mut self, packet: &[u8], completed: &mut Vec<PesPacket>) {
+        // Sync byte check skips malformed packets.
+        if packet[4] != SYNC_BYTE {
+            return;
+        }
+        let ts = &packet[4..]; // 188-byte standard TS packet
+
+        let pid = (((ts[1] & 0x1F) as u16) << 8) | ts[2] as u16;
+        let pusi = ts[1] & 0x40 != 0; // Payload Unit Start Indicator
+        let adaptation = (ts[3] >> 4) & 0x03;
+
+        let idx = if (pid as usize) < self.pid_index.len() {
+            self.pid_index[pid as usize]
+        } else {
+            -1
+        };
+        if idx < 0 {
+            return;
+        }
+        let asm = &mut self.assemblers[idx as usize];
+
+        let payload_start = if adaptation == 0x03 || adaptation == 0x02 {
+            let af_len = ts[4] as usize;
+            if af_len > 183 {
+                return; // Malformed: AF length exceeds TS payload
+            }
+            5 + af_len
+        } else {
+            4
+        };
+
+        if payload_start >= TS_PACKET_SIZE {
+            return;
+        }
+        // adaptation == 0x02 → AF only, no payload.
+        if adaptation == 0x02 {
+            return;
+        }
+
+        let payload = &ts[payload_start..];
+
+        if pusi {
+            let (pts, dts, pes_data_start) = parse_pes_header(payload);
+            if let Some(prev) = asm.start(pts, dts) {
+                completed.push(prev);
+            }
+            if pes_data_start < payload.len() {
+                asm.push(&payload[pes_data_start..]);
+            }
+        } else {
+            asm.push(payload);
+        }
+    }
+
     /// Flush all assemblers, returning any remaining PES packets.
     pub fn flush(&mut self) -> Vec<PesPacket> {
         let mut completed = Vec::new();

src/mux/tsmux.rs

@@ -42,28 +42,39 @@ impl<W: Write> TsMuxer<W> {
     /// Write a PES frame as BD-TS packets.
     /// Video frame data is expected as length-prefixed NALUs (MKV/PES format)
     /// and is converted to Annex B for transport stream.
-    pub fn write_frame(&mut self, track: usize, pts_ns: i64, data: &[u8]) -> io::Result<()> {
+    pub fn write_frame(
+        &mut self,
+        track: usize,
+        pts_ns: i64,
+        keyframe: bool,
+        data: &[u8],
+    ) -> io::Result<()> {
         if track >= self.pids.len() {
             return Ok(()); // unknown track, skip
         }
-        let base = *self.base_pts_ns.get_or_insert(pts_ns);
-        let pts_ns = pts_ns - base;
-
         let pid = self.pids[track];
         let is_video = (0x1011..=0x101F).contains(&pid);
 
-        // For video: convert length-prefixed NALUs to Annex B (start codes)
-        // On first keyframe, prepend parameter sets from codec_private
+        // Drop non-key video before any keyframe — decoder has no IDR or
+        // parameter sets to anchor on.
+        if is_video && !keyframe && !self.params_written[track] {
+            return Ok(());
+        }
+
+        let base = *self.base_pts_ns.get_or_insert(pts_ns);
+        let pts_ns = pts_ns - base;
+
+        // For video: convert length-prefixed NALUs to Annex B (start codes).
+        // Prepend codec_private parameter sets on the FIRST keyframe only.
         let es_data = if is_video && !data.is_empty() {
             let mut annex_b = Vec::new();
-            // Prepend codec_private parameter sets on first keyframe
-            if !self.params_written[track] {
+            if keyframe && !self.params_written[track] {
                 if let Some(ref cp) = self.codec_privates[track] {
                     if let Some(params) = hvcc_to_annex_b(cp) {
                         annex_b.extend_from_slice(&params);
-                        self.params_written[track] = true;
                     }
                 }
+                self.params_written[track] = true;
             }
             annex_b.extend_from_slice(&length_prefixed_to_annex_b(data));
             annex_b
@@ -85,8 +96,24 @@ impl<W: Write> TsMuxer<W> {
         let mut first = true;
         while offset < pes_packet.len() {
             let remaining = pes_packet.len() - offset;
-            let payload_len = remaining.min(TS_PAYLOAD);
-            let need_stuffing = payload_len < TS_PAYLOAD;
+
+            // Invariant: TP_extra(4) + TS_header(4) + AF(af_bytes) + payload(payload_len) = 192,
+            // i.e. af_bytes + payload_len = TS_PAYLOAD (184).
+            // RAI on first packet of a keyframe video PES requires AF with flags=0x40.
+            let want_rai = first && keyframe && is_video;
+
+            // Pick payload_len and af_bytes per case.
+            let (af_bytes, payload_len): (usize, usize) = if want_rai {
+                // Minimum AF = 2 bytes (length=1, flags=0x40). Payload caps at 182.
+                let max_payload = TS_PAYLOAD - 2;
+                let p = remaining.min(max_payload);
+                (TS_PAYLOAD - p, p)
+            } else if remaining >= TS_PAYLOAD {
+                (0, TS_PAYLOAD) // no AF, full payload
+            } else {
+                // Stuffing-only AF, payload = remaining.
+                (TS_PAYLOAD - remaining, remaining)
+            };
 
             // TP_extra_header (4 bytes — arrival time, set to 0)
             let tp_extra = [0u8; 4];
@@ -102,38 +129,45 @@ impl<W: Write> TsMuxer<W> {
                 ts_header[1] |= 0x40; // PUSI
             }
             ts_header[2] = pid as u8;
-            ts_header[3] = 0x10 | cc; // no adaptation, has payload
+            ts_header[3] = if af_bytes > 0 {
+                0x30 | cc // AF + payload
+            } else {
+                0x10 | cc // payload only
+            };
 
-            if need_stuffing {
-                // Adaptation field for stuffing
-                let stuff_len = TS_PAYLOAD - payload_len;
-                ts_header[3] = 0x30 | cc; // adaptation + payload
+            self.writer.write_all(&tp_extra)?;
+            self.writer.write_all(&ts_header)?;
 
-                self.writer.write_all(&tp_extra)?;
-                self.writer.write_all(&ts_header)?;
-
-                // Write adaptation field: length byte + flags byte + 0xFF padding
-                // stuff_len == 1: AF length = 0 (just the length byte, no flags)
-                // stuff_len >= 2: AF length = stuff_len-1, flags = 0, rest 0xFF
+            if af_bytes > 0 {
                 static STUFF_FF: [u8; 184] = [0xFF; 184];
-                if stuff_len == 1 {
-                    self.writer.write_all(&[0u8])?; // adaptation_field_length = 0
+                if want_rai {
+                    // RAI AF: length byte + flags(0x40) + (af_bytes - 2) stuffing.
+                    let af_len_field = (af_bytes - 1) as u8;
+                    self.writer.write_all(&[af_len_field])?;
+                    self.writer.write_all(&[0x40u8])?;
+                    let stuff = af_bytes - 2;
+                    if stuff > 0 {
+                        self.writer.write_all(&STUFF_FF[..stuff])?;
+                    }
                 } else {
-                    self.writer.write_all(&[(stuff_len - 1) as u8])?; // AF length
-                    self.writer.write_all(&[0u8])?; // flags
-                    if stuff_len > 2 {
-                        self.writer.write_all(&STUFF_FF[..stuff_len - 2])?;
+                    // Stuffing-only AF.
+                    // af_bytes == 1: length=0, no flags.
+                    // af_bytes >= 2: length = af_bytes-1, flags=0, rest 0xFF.
+                    if af_bytes == 1 {
+                        self.writer.write_all(&[0u8])?;
+                    } else {
+                        self.writer.write_all(&[(af_bytes - 1) as u8])?;
+                        self.writer.write_all(&[0u8])?;
+                        if af_bytes > 2 {
+                            self.writer.write_all(&STUFF_FF[..af_bytes - 2])?;
+                        }
                     }
                 }
-                self.writer
-                    .write_all(&pes_packet[offset..offset + payload_len])?;
-            } else {
-                self.writer.write_all(&tp_extra)?;
-                self.writer.write_all(&ts_header)?;
-                self.writer
-                    .write_all(&pes_packet[offset..offset + payload_len])?;
             }
 
+            self.writer
+                .write_all(&pes_packet[offset..offset + payload_len])?;
+
             offset += payload_len;
             first = false;
         }
@@ -257,3 +291,206 @@ fn length_prefixed_to_annex_b(data: &[u8]) -> Vec<u8> {
     }
     out
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const BD_PACKET_SIZE: usize = 192;
+    const VIDEO_PID: u16 = 0x1011;
+
+    /// Parsed BD-TS packet (192 bytes total: 4 TP_extra + 4 TS header + 184 body).
+    struct TsPacket {
+        pid: u16,
+        pusi: bool,
+        #[allow(dead_code)]
+        cc: u8,
+        /// Adaptation field body (length byte stripped) when present.
+        af: Option<Vec<u8>>,
+        /// Payload bytes (after AF, if any).
+        payload: Vec<u8>,
+    }
+
+    /// Walk 192-byte BD-TS packets.
+    fn parse_bd_ts(buf: &[u8]) -> Vec<TsPacket> {
+        let mut out = Vec::new();
+        for chunk in buf.chunks(BD_PACKET_SIZE) {
+            if chunk.len() != BD_PACKET_SIZE {
+                break;
+            }
+            // Skip TP_extra_header (4 bytes), parse TS header.
+            let h = &chunk[4..];
+            assert_eq!(h[0], 0x47, "bad sync byte");
+            let pusi = (h[1] & 0x40) != 0;
+            let pid = (((h[1] & 0x1F) as u16) << 8) | h[2] as u16;
+            let afc = (h[3] >> 4) & 0x03;
+            let cc = h[3] & 0x0F;
+            let body = &h[4..]; // 184 bytes
+
+            let (af, payload) = match afc {
+                0b01 => (None, body.to_vec()),
+                0b11 => {
+                    let af_len = body[0] as usize;
+                    let af_body = body[1..1 + af_len].to_vec();
+                    let payload = body[1 + af_len..].to_vec();
+                    (Some(af_body), payload)
+                }
+                0b10 => {
+                    let af_len = body[0] as usize;
+                    (Some(body[1..1 + af_len].to_vec()), Vec::new())
+                }
+                _ => (None, Vec::new()),
+            };
+
+            out.push(TsPacket {
+                pid,
+                pusi,
+                cc,
+                af,
+                payload,
+            });
+        }
+        out
+    }
+
+    /// Build a fake HEVC NAL with a 4-byte length prefix.
+    /// nal_type=19/20 are IDR; 1 is non-key (TRAIL_N/R).
+    fn fake_hevc_nal(nal_type: u8, body_len: usize) -> Vec<u8> {
+        let mut nal = Vec::with_capacity(2 + body_len);
+        // 2-byte NAL header: forbidden_zero(1)=0 | nal_unit_type(6) | layer_id(6)=0 | tid_plus1(3)=1
+        nal.push((nal_type & 0x3F) << 1);
+        nal.push(0x01);
+        for i in 0..body_len {
+            nal.push((i & 0xFF) as u8);
+        }
+        let mut framed = Vec::with_capacity(4 + nal.len());
+        framed.extend_from_slice(&(nal.len() as u32).to_be_bytes());
+        framed.extend_from_slice(&nal);
+        framed
+    }
+
+    #[test]
+    fn keyframe_param_threads_through() {
+        let mut sink: Vec<u8> = Vec::new();
+        {
+            let mut mux = TsMuxer::new(&mut sink, &[VIDEO_PID]);
+            let idr = fake_hevc_nal(19, 100);
+            mux.write_frame(0, 0, true, &idr).unwrap();
+            let p = fake_hevc_nal(1, 80);
+            mux.write_frame(0, 41_000_000, false, &p).unwrap();
+            mux.finish().unwrap();
+        }
+        assert!(!sink.is_empty());
+        let packets = parse_bd_ts(&sink);
+        assert!(packets.iter().any(|p| p.pid == VIDEO_PID && p.pusi));
+    }
+
+    #[test]
+    fn rai_set_on_first_packet_of_keyframe_pes() {
+        let mut sink: Vec<u8> = Vec::new();
+        {
+            let mut mux = TsMuxer::new(&mut sink, &[VIDEO_PID]);
+            let idr = fake_hevc_nal(19, 200);
+            mux.write_frame(0, 0, true, &idr).unwrap();
+            mux.finish().unwrap();
+        }
+        let packets = parse_bd_ts(&sink);
+        let first_pusi = packets
+            .iter()
+            .find(|p| p.pid == VIDEO_PID && p.pusi)
+            .expect("video PUSI packet exists");
+        let af = first_pusi.af.as_ref().expect("AF present on keyframe PES");
+        assert!(!af.is_empty(), "AF body has flags byte");
+        assert_eq!(af[0] & 0x40, 0x40, "RAI bit set");
+    }
+
+    #[test]
+    fn rai_clear_on_non_keyframe_pes() {
+        let mut sink: Vec<u8> = Vec::new();
+        {
+            let mut mux = TsMuxer::new(&mut sink, &[VIDEO_PID]);
+            let idr = fake_hevc_nal(19, 100);
+            mux.write_frame(0, 0, true, &idr).unwrap();
+            let p = fake_hevc_nal(1, 100);
+            mux.write_frame(0, 41_000_000, false, &p).unwrap();
+            mux.finish().unwrap();
+        }
+        let packets = parse_bd_ts(&sink);
+        // Second PUSI packet on the video PID belongs to the non-key frame.
+        let pusi_video: Vec<&TsPacket> = packets
+            .iter()
+            .filter(|p| p.pid == VIDEO_PID && p.pusi)
+            .collect();
+        assert!(pusi_video.len() >= 2, "two PUSI packets expected");
+        let second = pusi_video[1];
+        match &second.af {
+            None => {}
+            Some(af) if af.is_empty() => {} // length=0 case
+            Some(af) => assert_eq!(af[0] & 0x40, 0, "RAI must be clear on non-key PES"),
+        }
+    }
+
+    #[test]
+    fn codec_private_prepended_only_on_first_keyframe() {
+        // Build a minimal hvcC with one recognizable NAL.
+        let marker: &[u8] = &[0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE];
+        let mut hvcc = vec![0u8; 22];
+        hvcc.push(1); // numArrays
+        hvcc.push(32); // VPS NAL type byte (high bits arbitrary)
+        hvcc.extend_from_slice(&1u16.to_be_bytes()); // numNalus
+        hvcc.extend_from_slice(&(marker.len() as u16).to_be_bytes());
+        hvcc.extend_from_slice(marker);
+
+        let mut sink: Vec<u8> = Vec::new();
+        {
+            let mut mux = TsMuxer::new(&mut sink, &[VIDEO_PID]);
+            mux.set_codec_private(0, hvcc);
+            // Non-IDR before any IDR: should be dropped.
+            let p = fake_hevc_nal(1, 50);
+            mux.write_frame(0, 0, false, &p).unwrap();
+            // IDR: should carry codec_private NALs prepended.
+            let idr = fake_hevc_nal(19, 50);
+            mux.write_frame(0, 41_000_000, true, &idr).unwrap();
+            mux.finish().unwrap();
+        }
+        let packets = parse_bd_ts(&sink);
+        // Concatenate all video PID payloads in emission order.
+        let video_bytes: Vec<u8> = packets
+            .iter()
+            .filter(|p| p.pid == VIDEO_PID)
+            .flat_map(|p| p.payload.clone())
+            .collect();
+        // marker bytes must appear in the stream (codec_private was prepended).
+        let pos_marker = video_bytes
+            .windows(marker.len())
+            .position(|w| w == marker)
+            .expect("codec_private marker bytes present in TS payload");
+        // Find IDR body byte (0x26 = (19<<1)). pos_idr must be AFTER marker.
+        let idr_header = (19u8 << 1) & 0x7E;
+        let pos_idr = video_bytes
+            .iter()
+            .position(|&b| b == idr_header)
+            .expect("IDR NAL header present in TS payload");
+        assert!(
+            pos_marker < pos_idr,
+            "codec_private must precede IDR in TS payload"
+        );
+    }
+
+    #[test]
+    fn non_key_before_first_keyframe_dropped() {
+        let mut sink: Vec<u8> = Vec::new();
+        {
+            let mut mux = TsMuxer::new(&mut sink, &[VIDEO_PID]);
+            let p = fake_hevc_nal(1, 80);
+            mux.write_frame(0, 0, false, &p).unwrap();
+            mux.finish().unwrap();
+        }
+        // Nothing should be emitted for that PID.
+        let packets = parse_bd_ts(&sink);
+        assert!(
+            !packets.iter().any(|p| p.pid == VIDEO_PID),
+            "non-key before first keyframe must be dropped"
+        );
+    }
+}

src/pes.rs

@@ -17,6 +17,10 @@ pub struct PesFrame {
     pub keyframe: bool,
     /// Raw elementary stream data (NAL units, audio samples, etc).
     pub data: Vec<u8>,
+    /// Optional duration in nanoseconds. In-memory only; not part of
+    /// the on-wire serialization. Currently set by the PGS parser so
+    /// the MKV muxer can emit `BlockDuration`.
+    pub duration_ns: Option<u64>,
 }
 
 impl PesFrame {
@@ -64,6 +68,7 @@ impl PesFrame {
             pts,
             keyframe,
             data,
+            duration_ns: None,
         }))
     }
 
@@ -74,6 +79,7 @@ impl PesFrame {
             pts: frame.pts_ns,
             keyframe: frame.keyframe,
             data: frame.data,
+            duration_ns: frame.duration_ns,
         }
     }
 }
@@ -115,6 +121,16 @@ pub trait Stream: Send {
     fn headers_ready(&self) -> bool {
         true
     }
+
+    /// Cumulative count of read errors the stream skipped past (e.g.
+    /// zero-filled bad sectors on a live drive). Default `0` for
+    /// streams that don't have a notion of skip-on-error (file ISO,
+    /// network, stdio, the pipeline highway, etc.); concrete impls
+    /// with adaptive retry (`DiscStream` on the drive single-pass
+    /// path) override.
+    fn errors(&self) -> u64 {
+        0
+    }
 }
 
 /// Wraps any output stream and counts bytes written.
@@ -183,6 +199,7 @@ mod tests {
             pts,
             keyframe: track == 0 && pts == 0,
             data: vec![track as u8, (pts & 0xff) as u8, 0xAA],
+            duration_ns: None,
         }
     }
 

src/platform/fs_type/linux.rs

@@ -6,6 +6,7 @@
 
 use std::ffi::CString;
 use std::os::unix::ffi::OsStrExt;
+use std::os::unix::io::RawFd;
 use std::path::Path;
 
 use super::FsType;
@@ -18,6 +19,27 @@ const XFS_SUPER_MAGIC: i64 = 0x5846_5342;
 const BTRFS_SUPER_MAGIC: i64 = 0x9123_683E;
 const TMPFS_MAGIC: i64 = 0x0102_1994;
 
+/// Classify an `f_type` magic from `statfs`/`fstatfs`. Single source
+/// of truth for the magic comparisons used by both the path-based
+/// (`detect_impl`) and fd-based (`detect_fd_impl`) entry points.
+///
+/// Cast to `i64` because `statfs::f_type` is signed `__fsword_t` on
+/// glibc and unsigned `c_ulong` on musl; a portable comparison needs a
+/// common type. On glibc x86_64 both already are i64 — clippy flags
+/// the cast as unnecessary on that target only, but we need it for
+/// musl.
+#[allow(clippy::unnecessary_cast)]
+fn classify_f_type(f_type: i64) -> FsType {
+    let nfs_magic = libc::NFS_SUPER_MAGIC as i64;
+    if f_type == nfs_magic {
+        return FsType::Nfs;
+    }
+    match f_type {
+        EXT2_SUPER_MAGIC | XFS_SUPER_MAGIC | BTRFS_SUPER_MAGIC | TMPFS_MAGIC => FsType::Local,
+        _ => FsType::Unknown,
+    }
+}
+
 pub(super) fn detect_impl(path: &Path) -> FsType {
     let cpath = match CString::new(path.as_os_str().as_bytes()) {
         Ok(c) => c,
@@ -30,20 +52,19 @@ pub(super) fn detect_impl(path: &Path) -> FsType {
     if rc != 0 {
         return FsType::Unknown;
     }
-    // `f_type` is signed (`__fsword_t`) on glibc and unsigned
-    // (`c_ulong`) on musl. Cast both sides to i64 for a portable
-    // comparison. On glibc x86_64 both already are i64 — clippy flags
-    // the cast as unnecessary on that target only, but we need it for
-    // musl, so silence the lint.
     #[allow(clippy::unnecessary_cast)]
-    let f_type = buf.f_type as i64;
+    classify_f_type(buf.f_type as i64)
+}
+
+/// fd-based variant of [`detect_impl`]. Same return semantics. Used
+/// by the writeback pipeline, which knows the open `File` but not its
+/// original path.
+pub(super) fn detect_fd_impl(fd: RawFd) -> FsType {
+    let mut buf: libc::statfs = unsafe { std::mem::zeroed() };
+    let rc = unsafe { libc::fstatfs(fd, &mut buf) };
+    if rc != 0 {
+        return FsType::Unknown;
+    }
     #[allow(clippy::unnecessary_cast)]
-    let nfs_magic = libc::NFS_SUPER_MAGIC as i64;
-    if f_type == nfs_magic {
-        return FsType::Nfs;
-    }
-    match f_type {
-        EXT2_SUPER_MAGIC | XFS_SUPER_MAGIC | BTRFS_SUPER_MAGIC | TMPFS_MAGIC => FsType::Local,
-        _ => FsType::Unknown,
-    }
+    classify_f_type(buf.f_type as i64)
 }

src/platform/fs_type/mod.rs

@@ -51,6 +51,9 @@ use other::detect_impl;
 #[cfg(target_os = "windows")]
 use windows::detect_impl;
 
+#[cfg(target_os = "linux")]
+use linux::detect_fd_impl;
+
 /// Best-effort classification of the filesystem under `path`.
 ///
 /// Falls back to [`FsType::Unknown`] on any syscall error or unrecognised
@@ -60,6 +63,25 @@ pub fn detect(path: &Path) -> FsType {
     detect_impl(path)
 }
 
+/// fd-based classification. Same return semantics as [`detect`], but
+/// takes a `RawFd` so callers that only have an open file (notably
+/// [`crate::io::writeback::WritebackPipeline`]) don't have to
+/// round-trip through the path.
+///
+/// Only implemented on Linux; other platforms return
+/// [`FsType::Unknown`] (none of them have a writeback policy that
+/// keys off this classification today).
+#[cfg(target_os = "linux")]
+pub fn detect_fd(fd: std::os::unix::io::RawFd) -> FsType {
+    detect_fd_impl(fd)
+}
+
+#[cfg(not(target_os = "linux"))]
+#[allow(dead_code)] // API parity with the linux impl; callers cfg-gate.
+pub fn detect_fd(_fd: i32) -> FsType {
+    FsType::Unknown
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/platform/mod.rs

@@ -18,4 +18,19 @@ pub(crate) trait PlatformDriver: Send {
 
     /// True after successful init().
     fn is_ready(&self) -> bool;
+
+    /// True if the drive is currently in the extended-access state —
+    /// per-drive runtime firmware uploaded AND the unlock response's
+    /// marker bytes confirm the mode is live. When true:
+    ///   - host can issue the per-drive OEM CDBs in
+    ///     [`crate::profile::DriveProfile`]
+    ///   - VID retrieval works via the OEM CDB path (no cert-based
+    ///     mutual auth required)
+    ///   - SCSI READ_10 returns plaintext sectors (no bus encryption)
+    ///
+    /// Default `false` — platforms without this mode always report
+    /// inactive.
+    fn is_unlocked(&self) -> bool {
+        false
+    }
 }

src/platform/mt1959/mod.rs

@@ -25,8 +25,16 @@ const SUB_CMD_INIT: u8 = 0x12;
 const SUB_CMD_PROBE: u8 = 0x14;
 const UNLOCK_RESPONSE_SIZE: u8 = 64;
 const VALIDATE_RESPONSE_SIZE: u8 = 4;
+/// Primary mode marker at bytes [12..16] of the unlock response — set
+/// by the platform firmware when the runtime image is loaded and the
+/// extended-access surface is live.
 const FIRMWARE_ACTIVE_OFFSET: usize = 12;
 const FIRMWARE_ACTIVE_SIG: [u8; 4] = [0x4D, 0x4D, 0x6B, 0x76];
+/// Secondary mode marker repeated through bytes [16..64] of the unlock
+/// response. Confirms the runtime firmware is the one driving the
+/// response, not a stale image's residual buffer.
+const FIRMWARE_MODE_OFFSET: usize = 16;
+const FIRMWARE_MODE_SIG: [u8; 4] = [0x4C, 0x62, 0x44, 0x72];
 
 // ── Init address (per disc type) ──────────────────────────────────────
 const INIT_ADDR_BD: u16 = 0x0100;
@@ -46,7 +54,18 @@ pub struct Mt1959 {
     pub(crate) profile: DriveProfile,
     pub(crate) mode: u8,
     pub(crate) buffer_id: u8,
-    pub(crate) unlocked: bool,
+    /// True after `run_init` has completed the unlock handshake (and any
+    /// required firmware upload). Gates probe + downstream control
+    /// commands; says nothing about whether the drive is in
+    /// extended-access mode.
+    pub(crate) init_complete: bool,
+    /// True when the unlock response carried both the per-drive
+    /// signature AND the primary mode marker at offset 12 AND the
+    /// secondary mode marker at offset 16. When true the drive is in
+    /// the extended-access state — host can issue the per-drive
+    /// OEM CDBs and read sectors without the cert-based AACS bus
+    /// encryption / mutual-auth gate.
+    unlocked: bool,
     probed: bool,
 }
 
@@ -61,6 +80,7 @@ impl Mt1959 {
             profile,
             mode,
             buffer_id,
+            init_complete: false,
             unlocked: false,
             probed: false,
         }
@@ -141,7 +161,20 @@ impl Mt1959 {
             return Err(Error::UnlockFailed);
         }
 
-        self.unlocked = true;
+        // Extended-access state is active when BOTH the per-drive
+        // signature matched AND the response carries the secondary
+        // marker at offset 16 (repeated through bytes 16..64) AND the
+        // primary mode marker at [12..16] is present. The active-mode
+        // marker at [12..16] is the primary gate; the [16..20] marker
+        // is the redundant confirmation the firmware writes through
+        // the rest of the response. Requiring both before we tell the
+        // upper layer "OEM path is live" keeps any partial / corrupted
+        // response from steering us off the cert-auth fallback.
+        self.unlocked = response.len() >= FIRMWARE_MODE_OFFSET + 4
+            && response[FIRMWARE_ACTIVE_OFFSET..FIRMWARE_ACTIVE_OFFSET + 4] == FIRMWARE_ACTIVE_SIG
+            && response[FIRMWARE_MODE_OFFSET..FIRMWARE_MODE_OFFSET + 4] == FIRMWARE_MODE_SIG;
+
+        self.init_complete = true;
         Ok(response)
     }
 
@@ -177,11 +210,11 @@ impl Mt1959 {
     // ── Init (unlock + firmware) ───────────────────────────────────────
 
     fn run_init(&mut self, scsi: &mut dyn ScsiTransport) -> Result<()> {
-        let mut unlocked = false;
+        let mut succeeded = false;
         for _attempt in 0..3 {
             match self.do_unlock(scsi) {
                 Ok(_) => {
-                    unlocked = true;
+                    succeeded = true;
                     break;
                 }
                 Err(Error::SignatureMismatch { .. }) => {
@@ -202,7 +235,7 @@ impl Mt1959 {
                 }
             }
         }
-        if !unlocked {
+        if !succeeded {
             return Err(Error::UnlockFailed);
         }
         Ok(())
@@ -214,14 +247,14 @@ impl Mt1959 {
     /// per region. Two passes, then SET_CD_SPEED(max). After this the
     /// drive manages per-zone speeds internally.
     fn run_probe(&mut self, scsi: &mut dyn ScsiTransport) -> Result<()> {
-        if !self.unlocked {
+        if !self.init_complete {
             self.do_unlock(scsi)?;
         }
 
         // Detect disc type from capacity to select probe mode.
         // BD:  3C 01 44 12 01 00 00 00 04 00  (init_addr = 0x0100)
         // UHD: 3C 01 44 12 02 00 00 00 04 00  (init_addr = 0x0200)
-        // Verified from MakeMKV strace: BD and UHD use different init addresses.
+        // Empirically verified via SCSI capture: BD and UHD use different init addresses.
         let cap_cdb = [
             SCSI_READ_CAPACITY,
             0x00,
@@ -313,14 +346,14 @@ impl Mt1959 {
 
 impl PlatformDriver for Mt1959 {
     fn init(&mut self, scsi: &mut dyn ScsiTransport) -> Result<()> {
-        if self.unlocked {
+        if self.init_complete {
             return Ok(());
         }
         self.run_init(scsi)
     }
 
     fn probe_disc(&mut self, scsi: &mut dyn ScsiTransport) -> Result<()> {
-        if !self.unlocked {
+        if !self.init_complete {
             // Don't retry init here — if init() failed, probing can't work either.
             // Retrying causes repeated USB bus resets on BU40N.
             return Ok(());
@@ -332,6 +365,152 @@ impl PlatformDriver for Mt1959 {
     }
 
     fn is_ready(&self) -> bool {
+        self.init_complete
+    }
+
+    fn is_unlocked(&self) -> bool {
         self.unlocked
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::profile::{DriveProfile, Identity};
+    use crate::scsi::{DataDirection, ScsiResult, ScsiTransport};
+
+    /// Minimal mock transport that returns a scripted response to the
+    /// next `execute()` call. Only used for verifying that `do_unlock`
+    /// classifies the response correctly — no general SCSI coverage.
+    struct ScriptedTransport {
+        response: Vec<u8>,
+    }
+
+    impl ScsiTransport for ScriptedTransport {
+        fn execute(
+            &mut self,
+            _cdb: &[u8],
+            _dir: DataDirection,
+            data: &mut [u8],
+            _timeout_ms: u32,
+        ) -> Result<ScsiResult> {
+            let n = self.response.len().min(data.len());
+            data[..n].copy_from_slice(&self.response[..n]);
+            Ok(ScsiResult {
+                status: 0,
+                bytes_transferred: n,
+                sense: [0u8; 32],
+            })
+        }
+    }
+
+    fn fixture_profile(signature: [u8; 4]) -> DriveProfile {
+        DriveProfile {
+            identity: Identity {
+                vendor_id: "TEST".into(),
+                product_revision: String::new(),
+                vendor_specific: String::new(),
+                firmware_date: String::new(),
+            },
+            signature,
+            firmware: Vec::new(),
+            unlock_init_value: 0,
+            unlock_response_size: 0,
+            read_vid_cdb: None,
+            read_disc_keys_cdb: None,
+            drive_nominal_speed_cdb: None,
+            set_speed_max_cdb: None,
+            read10_raw_2sec_cdb: None,
+            read10_raw_1sec_cdb: None,
+            read_buffer_verify_cdb: None,
+            write_buffer_cdb: None,
+            read_buffer_unlock_cdb: None,
+            speed_zone_table: None,
+            speed_calc_table: None,
+        }
+    }
+
+    /// Build a synthetic 64-byte unlock response.
+    ///
+    /// `mode_marker`: bytes [12..16]. Pass `FIRMWARE_ACTIVE_SIG` for the
+    /// active-mode primary marker.
+    /// `id_marker`:   bytes [16..20] (and repeated through [20..64] in
+    /// real responses; only [16..20] is checked).
+    fn build_response(signature: [u8; 4], mode_marker: [u8; 4], id_marker: [u8; 4]) -> Vec<u8> {
+        let mut r = vec![0u8; 64];
+        r[0..4].copy_from_slice(&signature);
+        // bytes [4..12] left as zeros (version + reserved per format)
+        r[12..16].copy_from_slice(&mode_marker);
+        // Real firmware repeats the secondary marker through [16..64];
+        // the parser only checks [16..20], so we just write the marker
+        // once.
+        r[16..20].copy_from_slice(&id_marker);
+        r
+    }
+
+    #[test]
+    fn do_unlock_sets_unlocked_when_both_markers_present() {
+        let sig = [0x99, 0x9E, 0xC3, 0x75];
+        let response = build_response(sig, FIRMWARE_ACTIVE_SIG, FIRMWARE_MODE_SIG);
+        let mut transport = ScriptedTransport { response };
+        let mut mt = Mt1959::new(fixture_profile(sig), false);
+
+        let raw = mt.do_unlock(&mut transport).expect("unlock should succeed");
+        assert_eq!(raw.len(), 64);
+        assert!(mt.init_complete, "init_complete set after success");
+        assert!(
+            mt.is_unlocked(),
+            "both markers present -> extended-access state"
+        );
+    }
+
+    #[test]
+    fn do_unlock_init_complete_but_not_unlocked_when_id_marker_missing() {
+        // Primary mode marker present (so init passes) but the
+        // secondary marker is replaced with zeros — drive isn't in
+        // extended-access state.
+        let sig = [0x99, 0x9E, 0xC3, 0x75];
+        let response = build_response(sig, FIRMWARE_ACTIVE_SIG, [0u8; 4]);
+        let mut transport = ScriptedTransport { response };
+        let mut mt = Mt1959::new(fixture_profile(sig), false);
+
+        mt.do_unlock(&mut transport).expect("unlock should succeed");
+        assert!(mt.init_complete);
+        assert!(
+            !mt.is_unlocked(),
+            "missing secondary marker -> not in extended-access state"
+        );
+    }
+
+    #[test]
+    fn do_unlock_rejects_signature_mismatch() {
+        let response = build_response(
+            [0xAA, 0xBB, 0xCC, 0xDD],
+            FIRMWARE_ACTIVE_SIG,
+            FIRMWARE_MODE_SIG,
+        );
+        let mut transport = ScriptedTransport { response };
+        let mut mt = Mt1959::new(fixture_profile([0x99, 0x9E, 0xC3, 0x75]), false);
+
+        let err = mt.do_unlock(&mut transport).unwrap_err();
+        assert!(matches!(err, Error::SignatureMismatch { .. }));
+        assert!(!mt.init_complete);
+        assert!(!mt.is_unlocked());
+    }
+
+    #[test]
+    fn do_unlock_rejects_inactive_mode_marker() {
+        // Signature matches but the primary marker at [12..16] is
+        // missing -> drive is not in active mode; init_complete and the
+        // unlocked flag must both stay false.
+        let sig = [0x99, 0x9E, 0xC3, 0x75];
+        let response = build_response(sig, [0u8; 4], FIRMWARE_MODE_SIG);
+        let mut transport = ScriptedTransport { response };
+        let mut mt = Mt1959::new(fixture_profile(sig), false);
+
+        let err = mt.do_unlock(&mut transport).unwrap_err();
+        assert!(matches!(err, Error::UnlockFailed));
+        assert!(!mt.init_complete);
+        assert!(!mt.is_unlocked());
+    }
+}

src/profile.rs

@@ -35,6 +35,42 @@ pub struct DriveProfile {
     pub signature: [u8; 4],
     #[serde(default, deserialize_with = "deserialize_base64")]
     pub firmware: Vec<u8>,
+
+    // ── OEM-extended-access CDB templates ──────────────────────────────
+    //
+    // All optional — older profile blobs that pre-date the CDB capture
+    // pipeline simply omit these fields and decode as `None`. Encoded
+    // in the JSON as lowercase hex strings without separators
+    // (e.g. `"3c014410e29100002400"` for a 10-byte CDB).
+    #[serde(default)]
+    pub unlock_init_value: u8,
+    #[serde(default)]
+    pub unlock_response_size: u8,
+
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_10")]
+    pub read_vid_cdb: Option<[u8; 10]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_10")]
+    pub read_disc_keys_cdb: Option<[u8; 10]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_12")]
+    pub drive_nominal_speed_cdb: Option<[u8; 12]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_12")]
+    pub set_speed_max_cdb: Option<[u8; 12]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_10")]
+    pub read10_raw_2sec_cdb: Option<[u8; 10]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_10")]
+    pub read10_raw_1sec_cdb: Option<[u8; 10]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_10")]
+    pub read_buffer_verify_cdb: Option<[u8; 10]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_10")]
+    pub write_buffer_cdb: Option<[u8; 10]>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes_10")]
+    pub read_buffer_unlock_cdb: Option<[u8; 10]>,
+
+    // Per-drive identifier tables — variable-length hex strings.
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes")]
+    pub speed_zone_table: Option<Vec<u8>>,
+    #[serde(default, deserialize_with = "deserialize_opt_hex_bytes")]
+    pub speed_calc_table: Option<Vec<u8>>,
 }
 
 /// Chipset + variant — determined by which section the profile was found in.
@@ -99,6 +135,78 @@ where
         .map_err(serde::de::Error::custom)
 }
 
+// ── Fixed-length hex deserializers for CDB templates ────────────────────
+//
+// Profile JSON encodes CDBs as lowercase hex strings without separators.
+// An empty string / null / missing field decodes as `None`.
+
+fn parse_hex_bytes(s: &str) -> std::result::Result<Vec<u8>, &'static str> {
+    if s.len() % 2 != 0 {
+        return Err("odd hex length");
+    }
+    let mut out = Vec::with_capacity(s.len() / 2);
+    for i in (0..s.len()).step_by(2) {
+        let byte = u8::from_str_radix(&s[i..i + 2], 16).map_err(|_| "invalid hex digit")?;
+        out.push(byte);
+    }
+    Ok(out)
+}
+
+fn deserialize_opt_hex_bytes_10<'de, D>(
+    deserializer: D,
+) -> std::result::Result<Option<[u8; 10]>, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    let opt: Option<String> = Option::deserialize(deserializer)?;
+    let Some(s) = opt else { return Ok(None) };
+    if s.is_empty() {
+        return Ok(None);
+    }
+    let bytes = parse_hex_bytes(&s).map_err(serde::de::Error::custom)?;
+    if bytes.len() != 10 {
+        return Err(serde::de::Error::custom("expected 10 bytes"));
+    }
+    let mut out = [0u8; 10];
+    out.copy_from_slice(&bytes);
+    Ok(Some(out))
+}
+
+fn deserialize_opt_hex_bytes_12<'de, D>(
+    deserializer: D,
+) -> std::result::Result<Option<[u8; 12]>, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    let opt: Option<String> = Option::deserialize(deserializer)?;
+    let Some(s) = opt else { return Ok(None) };
+    if s.is_empty() {
+        return Ok(None);
+    }
+    let bytes = parse_hex_bytes(&s).map_err(serde::de::Error::custom)?;
+    if bytes.len() != 12 {
+        return Err(serde::de::Error::custom("expected 12 bytes"));
+    }
+    let mut out = [0u8; 12];
+    out.copy_from_slice(&bytes);
+    Ok(Some(out))
+}
+
+fn deserialize_opt_hex_bytes<'de, D>(
+    deserializer: D,
+) -> std::result::Result<Option<Vec<u8>>, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    let opt: Option<String> = Option::deserialize(deserializer)?;
+    let Some(s) = opt else { return Ok(None) };
+    if s.is_empty() {
+        return Ok(None);
+    }
+    let bytes = parse_hex_bytes(&s).map_err(serde::de::Error::custom)?;
+    Ok(Some(bytes))
+}
+
 // ── Loading ────────────────────────────────────────────────────────────
 
 const BUNDLED_PROFILES: &str = include_str!("../profiles.json");

src/sector/mod.rs

@@ -6,7 +6,7 @@
 //! ISO images are opened for read OR write at construction time.
 //!
 //! - [`SectorSource`] is implemented by `Drive` (hardware) and
-//!   [`FileSectorSource`] / `IsoSectorReader` (file-backed).
+//!   [`FileSectorSource`] (file-backed).
 //! - [`SectorSink`] is implemented by [`FileSectorSink`]
 //!   (ISO-backed) and sweep/patch consumer adapters.
 //! - [`DecryptingSectorSource`] is a decorator that wraps any
@@ -15,6 +15,7 @@
 
 pub mod decrypting;
 pub mod file;
+pub mod prefetched;
 
 use crate::error::Result;
 
@@ -112,3 +113,4 @@ pub trait SectorSink: Send {
 pub use crate::io::file_sector_source::FileSectorSource;
 pub use decrypting::DecryptingSectorSource;
 pub use file::FileSectorSink;
+pub use prefetched::PrefetchedSectorSource;

src/sector/prefetched.rs

@@ -0,0 +1,285 @@
+//! `PrefetchedSectorSource` — runs the wrapped read+decrypt in a
+//! dedicated producer thread and surfaces the prepared plaintext
+//! buffers on demand via a bounded channel.
+//!
+//! ## Why
+//!
+//! The mux consumer (demux + codec parsing + frame output) is
+//! single-threaded by nature (streams are sequential). The mux
+//! producer (read sectors + AACS decrypt) is also single-threaded
+//! per-call but does CPU-heavy work (AES per 6144-byte unit). Running
+//! both on the same thread means the disk and decrypt cores sit idle
+//! while the demux runs, and vice versa.
+//!
+//! Splitting them across two threads with a bounded channel between
+//! lets both run in parallel — peak throughput becomes
+//! `min(producer_rate, consumer_rate)` instead of
+//! `1 / (1/producer + 1/consumer)`.
+//!
+//! ## Lifecycle
+//!
+//! The producer thread is spawned by [`PrefetchedSectorSource::new`].
+//! It walks the supplied extent list in order, reads the configured
+//! batch size at each LBA, and sends the resulting plaintext buffer
+//! into a [`crossbeam_channel::bounded`] channel of small depth (so
+//! the producer stays a couple of batches ahead without unbounded
+//! memory growth).
+//!
+//! When the channel sender drops (either because all extents were
+//! served or because the [`Halt`] token cancelled), the consumer
+//! observes `RecvError` on the next `read_sectors` and treats it as
+//! end-of-stream. Errors from the underlying reader are forwarded
+//! verbatim through the channel.
+//!
+//! ## Read API
+//!
+//! `read_sectors` ignores its `lba`/`count` arguments — the producer
+//! has already chosen what to read, in the order the extents dictate.
+//! This is sound for the mux read path, which always walks extents
+//! sequentially and never seeks. For random-access callers (sweep
+//! patch retries) this wrapper is the wrong tool — they should keep
+//! reading the underlying source directly.
+
+use crate::error::Result;
+use crate::event::{Event, EventKind};
+use crate::halt::Halt;
+use crate::sector::SectorSource;
+use crossbeam_channel::{Receiver, Sender, bounded};
+use std::thread::JoinHandle;
+
+/// Producer-thread event callback. Fires `BytesRead` after every
+/// successful batch read so the consumer side can update a UI
+/// progress indicator without polling. `Send + 'static` because the
+/// callback runs on the producer thread.
+pub type EventFn = Box<dyn Fn(Event) + Send + 'static>;
+
+const PREFETCH_CHANNEL_DEPTH: usize = 2;
+
+/// Smallest sector source the producer will issue per read. AACS
+/// alignment requires multiples of 3 sectors so a unit doesn't span
+/// two reads.
+const SECTOR_ALIGNMENT: u16 = 3;
+
+/// Item flowing through the prefetch forward channel.
+pub type Batch = std::result::Result<Vec<u8>, std::io::Error>;
+
+/// Producer-thread-backed [`SectorSource`] decorator. Construct it
+/// with the real reader, the extent list to walk, and the batch
+/// size; the wrapper spawns the producer immediately and starts
+/// filling the channel.
+pub struct PrefetchedSectorSource {
+    rx: Receiver<Batch>,
+    /// Recycle channel — consumer returns drained buffers here; the
+    /// producer re-fills them in place. Lets the producer/consumer
+    /// reuse a fixed pool of `PREFETCH_CHANNEL_DEPTH+1` buffers
+    /// instead of `Vec::new()`-ing one per batch (musl mallocng
+    /// cross-thread alloc/free was the dominant cost in the demux
+    /// thread before this).
+    recycle_tx: Sender<Vec<u8>>,
+    /// Joined on drop so producer cleanup runs deterministically.
+    producer: Option<JoinHandle<()>>,
+    /// Cumulative bytes drained by `read_sectors` calls. Exposed via
+    /// [`capacity_sectors`] indirectly: the consumer-side state needs
+    /// this to advance its position bookkeeping in lockstep with what
+    /// the producer fed.
+    total_sectors: u32,
+}
+
+impl PrefetchedSectorSource {
+    /// Spawn the producer thread. `reader` must already be the fully
+    /// composed read+decrypt stack (e.g.
+    /// [`DecryptingSectorSource`](crate::sector::DecryptingSectorSource))
+    /// — every byte the producer emits is what the consumer's demux
+    /// will feed to its codec parsers.
+    pub fn new<S>(
+        reader: S,
+        extents: Vec<crate::disc::Extent>,
+        batch_sectors: u16,
+        halt: Option<Halt>,
+    ) -> Self
+    where
+        S: SectorSource + Send + 'static,
+    {
+        Self::new_with_events(reader, extents, batch_sectors, halt, None)
+    }
+
+    /// Same as [`new`] but with a callback fired from the producer
+    /// thread after each successful batch — used by autorip's mux
+    /// path to surface `BytesRead` progress to the UI without the
+    /// consumer thread having to poll.
+    pub fn new_with_events<S>(
+        mut reader: S,
+        extents: Vec<crate::disc::Extent>,
+        batch_sectors: u16,
+        halt: Option<Halt>,
+        event_fn: Option<EventFn>,
+    ) -> Self
+    where
+        S: SectorSource + Send + 'static,
+    {
+        let total_sectors: u32 = extents.iter().map(|e| e.sector_count).sum();
+        let bytes_total_extents: u64 = extents.iter().map(|e| e.sector_count as u64 * 2048).sum();
+        let (tx, rx) = bounded::<Batch>(PREFETCH_CHANNEL_DEPTH);
+        let (recycle_tx, recycle_rx) = bounded::<Vec<u8>>(PREFETCH_CHANNEL_DEPTH + 1);
+        let batch_bytes = batch_sectors as usize * 2048;
+
+        // Seed the recycle pool so the producer always has a buffer
+        // to fill on the first iteration. Without these, the first
+        // `recycle_rx.recv()` would block forever (no consumer has
+        // returned a buffer yet).
+        for _ in 0..(PREFETCH_CHANNEL_DEPTH + 1) {
+            let _ = recycle_tx.send(vec![0u8; batch_bytes]);
+        }
+
+        let producer = std::thread::Builder::new()
+            .name("freemkv-prefetch".into())
+            .spawn(move || {
+                let mut ext_idx = 0usize;
+                let mut offset: u32 = 0;
+                let mut bytes_read_total: u64 = 0;
+                while ext_idx < extents.len() {
+                    if halt.as_ref().map(|h| h.is_cancelled()).unwrap_or(false) {
+                        return;
+                    }
+                    let extent = &extents[ext_idx];
+                    let remaining = extent.sector_count.saturating_sub(offset);
+                    if remaining == 0 {
+                        ext_idx += 1;
+                        offset = 0;
+                        continue;
+                    }
+                    let mut sectors = remaining.min(batch_sectors as u32) as u16;
+                    if sectors >= SECTOR_ALIGNMENT {
+                        sectors -= sectors % SECTOR_ALIGNMENT;
+                    }
+                    let bytes = sectors as usize * 2048;
+                    let mut buf = match recycle_rx.recv() {
+                        Ok(b) => b,
+                        Err(_) => return, // consumer dropped both channels
+                    };
+                    if buf.len() < bytes {
+                        buf.resize(bytes, 0);
+                    } else {
+                        // Re-expose the full extent; previous truncate
+                        // shrank the visible len without freeing pages.
+                        // SAFETY: capacity is at least `bytes` after
+                        // construction with `vec![0u8; batch_bytes]`.
+                        unsafe { buf.set_len(bytes) };
+                    }
+                    let lba = extent.start_lba + offset;
+                    match reader.read_sectors(lba, sectors, &mut buf[..bytes], false) {
+                        Ok(n) => {
+                            buf.truncate(n);
+                            bytes_read_total = bytes_read_total.saturating_add(n as u64);
+                            if let Some(ref f) = event_fn {
+                                f(Event {
+                                    kind: EventKind::BytesRead {
+                                        bytes: bytes_read_total,
+                                        total: bytes_total_extents,
+                                    },
+                                });
+                            }
+                            if tx.send(Ok(buf)).is_err() {
+                                return; // consumer dropped
+                            }
+                            offset += sectors as u32;
+                        }
+                        Err(e) => {
+                            let _ = tx.send(Err(e.into()));
+                            return;
+                        }
+                    }
+                }
+                // Drop tx implicitly — consumer sees RecvError → EOF.
+            })
+            .expect("freemkv-prefetch producer spawn failed");
+
+        Self {
+            rx,
+            recycle_tx,
+            producer: Some(producer),
+            total_sectors,
+        }
+    }
+
+    /// Peel off the receivers for zero-copy pipeline mode. The
+    /// caller (typically [`super::super::mux::demux_thread::DemuxThread`])
+    /// pulls buffers from `rx`, consumes them, and pushes the empty
+    /// `Vec<u8>` back through `recycle_tx` so the producer can
+    /// re-fill it. The producer-thread `JoinHandle` stays with the
+    /// returned `PrefetchedSectorSource` shell; drop that to join.
+    ///
+    /// Returns `(forward_rx, recycle_tx, shell)`. The shell only
+    /// holds the join handle and total_sectors for `capacity_sectors`
+    /// queries; its `SectorSource` impl becomes invalid after this
+    /// call (data has been moved out).
+    pub fn into_channels(self) -> (Receiver<Batch>, Sender<Vec<u8>>, PrefetchShell) {
+        let total = self.total_sectors;
+        // Drop the SectorSource side; transfer the producer join
+        // handle to a shell that just waits on Drop.
+        let mut me = self;
+        let producer = me.producer.take();
+        let rx = me.rx.clone();
+        let recycle = me.recycle_tx.clone();
+        std::mem::forget(me);
+        (rx, recycle, PrefetchShell { producer, total })
+    }
+}
+
+/// Returned from [`PrefetchedSectorSource::into_channels`]. Owns the
+/// producer thread join handle so dropping the shell joins the
+/// producer, even though the channels have been peeled off.
+pub struct PrefetchShell {
+    producer: Option<JoinHandle<()>>,
+    #[allow(dead_code)]
+    total: u32,
+}
+
+impl Drop for PrefetchShell {
+    fn drop(&mut self) {
+        if let Some(h) = self.producer.take() {
+            let _ = h.join();
+        }
+    }
+}
+
+impl Drop for PrefetchedSectorSource {
+    fn drop(&mut self) {
+        // Dropping the receiver closes the channel, which makes the
+        // next producer `send` return Err and exits the loop. Joining
+        // here gives us a deterministic shutdown — no detached thread
+        // can outlive the source.
+        if let Some(h) = self.producer.take() {
+            let _ = h.join();
+        }
+    }
+}
+
+impl SectorSource for PrefetchedSectorSource {
+    fn capacity_sectors(&self) -> u32 {
+        self.total_sectors
+    }
+
+    fn read_sectors(
+        &mut self,
+        _lba: u32,
+        _count: u16,
+        buf: &mut [u8],
+        _recovery: bool,
+    ) -> Result<usize> {
+        // The producer has already decided the next batch. lba/count
+        // are advisory; the consumer's fill_extents will advance its
+        // own bookkeeping using the returned byte count, not the
+        // requested count.
+        match self.rx.recv() {
+            Ok(Ok(filled)) => {
+                let n = filled.len().min(buf.len());
+                buf[..n].copy_from_slice(&filled[..n]);
+                Ok(n)
+            }
+            Ok(Err(e)) => Err(crate::error::Error::IoError { source: e }),
+            // Channel closed (producer finished or panicked).
+            Err(_) => Ok(0),
+        }
+    }
+}

tests/crypto_tests.rs

@@ -724,7 +724,7 @@ fn aacs_parse_unit_key_ro_minimal() {
         data[key_pos + i] = (0xA0 + i) as u8;
     }
 
-    let result = aacs::parse_unit_key_ro(&data, false);
+    let result = aacs::parse_unit_key_ro(&data, aacs::AacsVersion::V10);
     assert!(
         result.is_some(),
         "parse_unit_key_ro should succeed on valid data"

tests/disc_tests.rs

@@ -135,6 +135,7 @@ fn scan_options_default() {
 fn scan_options_with_keydb() {
     let opts = ScanOptions {
         keydb_path: Some(("/tmp/KEYDB.cfg").into()),
+        ..Default::default()
     };
     assert_eq!(
         opts.keydb_path.as_ref().unwrap().to_str().unwrap(),
@@ -147,6 +148,7 @@ fn scan_options_with_keydb_pathbuf() {
     let path = std::path::PathBuf::from("/home/user/.config/aacs/KEYDB.cfg");
     let opts = ScanOptions {
         keydb_path: Some(path.clone()),
+        ..Default::default()
     };
     assert_eq!(opts.keydb_path.unwrap(), path);
 }
@@ -517,6 +519,7 @@ fn resolve_encryption_no_keydb() {
     // No keydb configured and no standard keydb on the system
     let opts = ScanOptions {
         keydb_path: Some(("/nonexistent/path/KEYDB.cfg").into()),
+        ..Default::default()
     };
     let disc = Disc::scan_image(&mut reader, 1000, &opts).unwrap();
 

tests/scsi_error_decoding.rs

@@ -9,9 +9,7 @@
 //! [`ScsiSense::is_*`].
 //!
 //! The actual `ioctl(SG_IO, ...)` call is impossible to mock without a
-//! kernel — see
-//! `(internal)/docs/audits/2026-04-26-scsi-architecture-research.md`
-//! for why the audit recommends against libc shims here. These tests
+//! kernel, so libc shims are deliberately avoided here. These tests
 //! therefore pin the *contract* every backend must satisfy via a mock
 //! `ScsiTransport`:
 //!

tests/streams.rs

@@ -77,21 +77,21 @@ fn parse_url_disc_device() {
 
 #[test]
 fn parse_url_mkv() {
-    let u = parse_url("mkv://Dune.mkv");
+    let u = parse_url("mkv://Movie.mkv");
     assert_eq!(u.scheme(), "mkv");
-    assert_eq!(u.path_str(), "Dune.mkv");
+    assert_eq!(u.path_str(), "Movie.mkv");
 }
 
 #[test]
 fn parse_url_network() {
-    let u = parse_url("network://10.0.0.1:9000");
+    let u = parse_url("network://192.0.2.10:9000");
     assert_eq!(u.scheme(), "network");
-    assert_eq!(u.path_str(), "10.0.0.1:9000");
+    assert_eq!(u.path_str(), "192.0.2.10:9000");
 }
 
 #[test]
 fn parse_url_bare_path_rejected() {
-    let u = parse_url("Dune.mkv");
+    let u = parse_url("Movie.mkv");
     assert_eq!(u.scheme(), "unknown");
 }
 
@@ -104,21 +104,21 @@ fn parse_url_null() {
 
 #[test]
 fn parse_url_m2ts_with_path() {
-    let u = parse_url("m2ts:///tmp/Dune.m2ts");
+    let u = parse_url("m2ts:///tmp/Movie.m2ts");
     assert_eq!(u.scheme(), "m2ts");
-    assert_eq!(u.path_str(), "/tmp/Dune.m2ts");
+    assert_eq!(u.path_str(), "/tmp/Movie.m2ts");
 }
 
 #[test]
 fn parse_url_m2ts_relative() {
-    let u = parse_url("m2ts://Dune.m2ts");
+    let u = parse_url("m2ts://Movie.m2ts");
     assert_eq!(u.scheme(), "m2ts");
-    assert_eq!(u.path_str(), "Dune.m2ts");
+    assert_eq!(u.path_str(), "Movie.m2ts");
 }
 
 #[test]
 fn open_input_bare_path_errors() {
-    let result = libfreemkv::input("Dune.mkv", &libfreemkv::InputOptions::default());
+    let result = libfreemkv::input("Movie.mkv", &libfreemkv::InputOptions::default());
     assert!(result.is_err());
     let msg = match result {
         Err(e) => e.to_string(),
@@ -134,7 +134,7 @@ fn open_input_bare_path_errors() {
 #[test]
 fn open_output_bare_path_errors() {
     let dt = sample_disc_title();
-    let result = libfreemkv::output("Dune.mkv", &dt);
+    let result = libfreemkv::output("Movie.mkv", &dt);
     assert!(result.is_err());
     let msg = match result {
         Err(e) => e.to_string(),
@@ -195,7 +195,7 @@ fn open_output_disc_errors() {
 
 #[test]
 fn open_input_network_no_port_errors() {
-    let result = libfreemkv::input("network://10.0.0.1", &libfreemkv::InputOptions::default());
+    let result = libfreemkv::input("network://192.0.2.1", &libfreemkv::InputOptions::default());
     assert!(result.is_err());
     let msg = match result {
         Err(e) => e.to_string(),
@@ -301,6 +301,7 @@ fn m2ts_stream_write_read() {
             pts: i as i64 * 1_000_000,
             keyframe: i == 0,
             data: vec![i; 100],
+            duration_ns: None,
         };
         PesStream::write(&mut stream, &frame).unwrap();
     }
@@ -322,6 +323,7 @@ fn m2ts_pes_frame_roundtrip() {
         pts: 1_234_567_890,
         keyframe: true,
         data: vec![0xDE; 200],
+        duration_ns: None,
     };
 
     let mut buf = Vec::new();
@@ -589,6 +591,7 @@ fn mkvstream_write_finish() {
             pts: i as i64 * 1_000_000,
             keyframe: i == 0,
             data: vec![i; 100],
+            duration_ns: None,
         };
         PesStream::write(&mut stream, &frame).unwrap();
     }
@@ -650,6 +653,7 @@ fn mkvstream_roundtrip_bdts() {
             pts: i as i64 * 1_000_000,
             keyframe: true,
             data: vec![i; 100],
+            duration_ns: None,
         };
         PesStream::write(&mut stream, &frame).unwrap();
     }
@@ -842,6 +846,7 @@ fn mkvstream_e2e_h264_produces_valid_mkv() {
         pts: 1_000_000_000, // 1 second in ns
         keyframe: true,
         data: es_data,
+        duration_ns: None,
     };
     PesStream::write(&mut stream2, &frame1).unwrap();
 
@@ -851,6 +856,7 @@ fn mkvstream_e2e_h264_produces_valid_mkv() {
         pts: 1_041_700_000, // ~1 frame later in ns
         keyframe: false,
         data: es_data2,
+        duration_ns: None,
     };
     PesStream::write(&mut stream2, &frame2).unwrap();
     PesStream::finish(&mut stream2).unwrap();