v1.4.5: bump version (freemkv-unlock git-pinned for the tag)

The read_plan fix landed on the file-backed highway (build_iso_pipeline)
but the inline DiscStream (live single-pass) still passed the alternate
device-group half to the demux — a known FMTS bug on rip_mode="single".

DiscStream::with_key_map installs the proactive map and rewrites the
extent walk to the read plan, so the live single-pass path reads ONLY
our-phase units, exactly like the highway. DecryptingSectorSource gains
set_key_map for the already-constructed decorator. Non-forensic maps
return the extents unchanged, so every non-FMTS disc is byte-identical.

Test: with_key_map_reads_only_our_phase_units — a forensic Even segment
drops exactly its alternate units from the extent walk. Precommit green
on 1.86.

CHANGELOG.md

@@ -1,16 +1,189 @@
 # Changelog
 
+## [1.4.5] — 2026-07-18
+
+### Fixed
+
+- **FMTS (AACS 2.1) forensic discs now mux to a clean, single-variant stream.** A
+  forensic segment interleaves the local device group's variant with a foreign
+  group's at the aligned-unit level. The mux decrypted only our half but left the
+  foreign half in the buffer as ciphertext, on the assumption that the demuxer
+  "drops untouched ciphertext cleanly." It does not — a foreign unit's bytes hit a
+  tracked PID at the 192-byte stride, mis-parse, and trip the demux's concealed-gap
+  keyframe resync, which discards good frames of ours around every segment (visible
+  playback glitches). `AacsKeyMap::read_plan` now turns the map into the title's
+  read plan: every default / CPS unit, plus inside a forensic segment **only our
+  phase's units**. The foreign half is never read, decrypted, or handed to the
+  demux. On a retail 4K UHD title this took concealed-gap resyncs from **349 → 0**
+  and recovered ~2 GB of previously-dropped frames. Wired into **both** mux paths —
+  the file-backed highway (`build_iso_pipeline`) and the inline live-drive
+  `DiscStream` (`with_key_map`) — so single- and multi-pass FMTS rips are both clean.
+
+### Changed
+
+- **Key-bearing types redact their `Debug` output.** Every type that carries key
+  material (device keys, processing keys, unit keys, media keys, VUKs, resolved
+  chains, CSS/AACS state, …) now prints a `<redacted>` marker instead of the bytes,
+  so no key can reach a log or panic message. Each is covered by a test asserting no
+  key byte appears.
+- **Hex parsing is centralized and case-insensitive.** A single set of canonical
+  `0x`/`0X`-tolerant hex→integer parsers replaces scattered ad-hoc parsing (this is
+  what silently dropped keydb device keys written with an uppercase `0X` prefix).
+- **Internal-only public surface narrowed to `pub(crate)`, and duplicate
+  `foo_with_X` methods collapsed to one** — no behavioral change, smaller API.
+
+## [1.4.4] — 2026-07-17
+
+### Fixed
+
+- **Online key requests are no longer silently dropped on discs that yield few
+  sample units.** The online key source refuses any request carrying fewer than
+  `MIN_SAMPLE_UNITS` (8) encrypted-content samples — too few can match an
+  incidental unit rather than the one asked about (a false positive, most acute on
+  AACS 2.1 forensic-variant content). autorip gathered only 4, so every online
+  lookup was skipped before it ever reached the key service and surfaced to the
+  user as "key service down." autorip's sample count is now tied to
+  `MIN_SAMPLE_UNITS` with a **compile-time floor**, so it can never regress below
+  the minimum again.
+
+### Changed
+
+- **The online request is assembled from a proven-sufficient sample set.** New
+  `DecodeSampleSet` (`libfreemkv::keysource`) wraps the content-unit samples and
+  can only be constructed with at least `MIN_SAMPLE_UNITS` of them — so an online
+  key request cannot be built from too few samples. The minimum is validated once,
+  at construction, rather than by a runtime check a caller could forget.
+
+## [1.4.3] — 2026-07-17
+
+### Changed
+
+- **`MIN_SAMPLE_UNITS` moved to the base crate.** The minimum sample count an
+  online key request must carry now has a single definition in
+  `libfreemkv::keysource`; `freemkv-keysources` re-exports it, so the online source
+  and libfreemkv's own forensic query size their requests from one shared value.
+- **The online unit-key reply is parsed as a list.** A response carries either a
+  single Unit Key (ordinary disc) or the full ordered set (an AACS 2.1
+  forensic-variant disc); the client accepts both and maps array position to
+  forensic index.
+
+### Added
+
+- **Forensic-variant online query samples the anchor segment.** On an AACS 2.1
+  forensic-variant disc the online key query draws its sample from the first
+  forensic segment (index 1) — one canonical, deterministic sample — instead of an
+  arbitrary segment.
+
+## [1.4.2] — 2026-07-15
+
+### Fixed
+
+- **Mux no longer nulls decryptable video or storms the key server on a
+  bad-encoded region.** 1.4.1 relaxed the decrypt gate but left the surrounding
+  machinery in place. On a unit whose key *decrypted* but whose plaintext didn't
+  reassemble to clean MPEG-TS, the read path still restored ciphertext, tallied
+  loss, and re-asked the online key server (forever returning the same correct key)
+  while the mux concealed the unit as NULL TS. The root cause: *"did a key produce
+  clean TS?"* was used as the verdict *"did we decrypt?"* — they are not the same.
+  A correct key can decrypt content with broken encoding; broken TS is a muxer
+  concern, never a decrypt verdict.
+
+### Changed
+
+- **One decrypt authority; policy at the caller.** `decrypt_sectors` is now a
+  pure decrypt: applies the CPS unit key in place, leaves plaintext, and reports
+  unverified bytes. It never restores ciphertext, nulls, or re-fetches a key.
+  Clean-TS status is only a key-*selection* hint (multi-CPS) or a read-*verify*
+  signal (sweep/patch). Callers own the policy: the mux passes decrypted bytes
+  through unconditionally (the demuxer handles bad TS); sweep/patch treat an
+  unverified unit as a failed read and re-read it. Removes the decrypt-time
+  ciphertext restore, the mux NULL-TS conceal loop, and the per-unit key-server
+  refetch, plus the dead `aacs_unit_still_ciphertext` predicate.
+
+- **Decrypt and TS-structure are now separate primitives.** AACS has no MAC;
+  the only "did it decrypt?" signal is whether plaintext looks like MPEG-TS —
+  a data-quality / key-selection question, not a decrypt verdict. The old
+  `decrypt_unit(...) -> bool` is split into `decrypt_unit_raw` (pure crypto) and
+  `is_clean_ts` (structural check), composed explicitly only where needed. The
+  mux calls only `decrypt_unit_raw`.
+
+- **Key-proof floor replaces the 75% supermajority.** The old proportion
+  (≥75% of content packets synced) conflated *the key worked* with *the content
+  is well-encoded*. `is_clean_ts` now requires `synced >= min(E, 4)` on
+  **encrypted** packets (skipping packet 0 whose `0x47` is in the clear seed):
+  four synced packets ≈ 1-in-4-billion false-positive; `min(E, 4)` scales to
+  short fragment tails so they're never false-rejected. A unit is "opened" when
+  a handful of packets prove the key — bad-encoded packets are the muxer's job.
+
+## [1.4.1] — 2026-07-14
+
+### Fixed
+
+- **Mux no longer discards good video over a single defective packet.** AACS
+  decryption required **every** content packet to be conformant MPEG-TS: one
+  authored-bad packet (encoding defect, AACS 2.1 forensic-variant frame) made
+  the mux conceal the **whole** 6144-byte aligned unit as NULL TS (up to 31/32
+  good packets discarded, tallied as loss). On affected discs this produced
+  false "corruption" over otherwise-perfect video (~466 MB concealed across two
+  UHD titles). The gate is now a padding-aware **≥75% supermajority** of content
+  packets restoring their `0x47` sync — no wrong key reaches this threshold
+  (uniform-AES noise floor ≈ 256⁻ⁿ), but a minority of authored-bad packets
+  still passes. Opened units flow through verbatim; the demuxer drops
+  non-conforming packets on sync-loss. TS-sync conformance is a muxer concern,
+  never a decrypt verdict. (The supermajority threshold is tightened in 1.4.2.)
+- **MVC (Blu-ray 3D) track signals unified and hardened.** The `mvcC`
+  `CodecPrivate` extension, the `BlockAdditionMapping`, and each frame's
+  `BlockAdditional` now all derive from a single `MVCDecoderConfigurationRecord`
+  built once per track, so they can no longer diverge. A track is flagged 3D
+  only when that record actually builds — a malformed dependent-view parameter
+  set no longer emits a mapping with no matching record (previously the flag was
+  taken from `mvc_params.is_some()`, which could orphan a `BlockAddID`). The base
+  track's `CodecPrivate` now carries the `mvcC` extension block
+  (`avcC ‖ u32be(size) ‖ "mvcC" ‖ record`, Matroska-spec size = block − 4) so
+  players and mediainfo detect MVC at the track level.
+
+## [1.4.0] — 2026-07-13
+
+### Added
+
+- **Blu-ray 3D (MVC) support.** A 3D disc now rips to an MKV that preserves
+  **both eyes** as a single MVC video track — the AVC base (left) view in each
+  Block, and the MVC dependent (right-eye) view as a per-frame `BlockAdditional`
+  under an `mvcC` `BlockAdditionMapping` (`MVCDecoderConfigurationRecord` per
+  ISO/IEC 14496-15 §7.6.2), paired to the base by PTS. Remux only — no
+  transcode, no side-by-side conversion. The Blu-ray scan reads the interleaved
+  `STREAM/SSIF/<clip>.ssif`, enumerates the dependent view (stream_type `0x20`)
+  by the BD-3D PID convention, and parses it in a parameter-set-passthrough mode
+  so every dependent frame is a self-contained access unit. Verified on
+  *300: Rise of an Empire*: one MVC track, ~8.7 GB dependent payload carried in
+  per-frame BlockAdditionals, base view byte-identical to the 2D rip.
+
+## [1.3.2] — 2026-07-10
+
+### Added
+
+- **AACS 2.1 (FMTS) variant-decode foundation.** `UnitKey` gains a
+  `variant_number` field (`0` = ordinary content, `1..=32` = a forensic
+  variant) with `UnitKey::new` / `UnitKey::variant` constructors, and a new
+  `aacs::variant_select` module resolves a disc's single forensic variant and
+  classifies each aligned unit — decrypt with the default key, decrypt with the
+  variant key, drop a foreign variant, or conceal a keyless forensic unit. This
+  is the groundwork for selecting one variant's segments and dropping the other
+  31; the decrypt-pipeline wiring lands with the variant key source.
+
+### Fixed
+
+- **`IndividualSegment.tbl`: the per-record field is the variant, not a segment
+  number.** `Segment.number` → `Segment.variant`. Verified against a retail 2.1
+  disc, the field cycles `1..=32` across the table (a per-variant tag) rather
+  than counting up, so variant selection routes on the correct value.
+
 ## [1.3.1] — 2026-07-10
 
 ### Licensing
 
 - **Relicensed to the MIT License, from 1.3.1 onwards** (releases up to and
-  including 1.3.0 remain under AGPL-3.0). All code is an independent Rust
-  implementation of the public/standard disc formats and cryptographic
-  algorithms; comments that cross-referenced GPL/LGPL C projects (libdvdcss,
-  libaacs, libbluray, libdvdread, libdvdnav) were dropped, and the CSS content
-  cipher and the Stevenson title-key attack are attributed to their published
-  cryptanalysis rather than any particular software.
+  including 1.3.0 remain under AGPL-3.0).
 
 ### Added
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libfreemkv"
-version = "1.3.1"
+version = "1.4.5"
 edition = "2024"
 rust-version = "1.86"
 license = "MIT"
@@ -28,7 +28,7 @@ cbc = "0.1"
 # Interim path dep for local cross-repo dev; the release script re-pins this to
 # `{ git = ".../freemkv-unlock", tag = "vX.Y.Z" }` before tagging libfreemkv (so
 # the released tag resolves freemkv-unlock from git, not a sibling path).
-freemkv-unlock = { git = "https://github.com/freemkv/freemkv-unlock", tag = "v1.3.1" }
+freemkv-unlock = { git = "https://github.com/freemkv/freemkv-unlock", tag = "v1.4.5" }
 num-bigint = "0.4"
 num-traits = "0.2"
 num-integer = "0.1"

src/aacs/derive.rs

@@ -463,9 +463,9 @@ pub enum KeyCandidate {
 /// PURE DERIVATION — no unit sampling, no validation. `unit_keys` holds every
 /// CPS-unit key the disc's `Unit_Key_RO.inf` yields from the VUK (paired with
 /// its declared CPS-unit number); the caller runs
-/// [`super::content::unit_key_validates`] to find which one actually opens the
+/// `decrypt_unit` + `is_clean_ts` to find which one actually opens the
 /// disc. Rungs above the candidate are `None`.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct ResolvedChain {
     pub unit_keys: Vec<(u32, [u8; 16])>,
     pub vuk: Option<Vuk>,
@@ -475,6 +475,21 @@ pub struct ResolvedChain {
     pub dk: Option<DeviceKey>,
 }
 
+// Redacting `Debug`: `unit_keys` holds raw title-key bytes, never printed. The
+// other rungs are `types` newtypes that self-redact. Guarded by
+// `resolved_chain_debug_is_redacted`.
+impl std::fmt::Debug for ResolvedChain {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ResolvedChain")
+            .field("unit_keys_len", &self.unit_keys.len())
+            .field("vuk", &self.vuk)
+            .field("mk", &self.mk)
+            .field("pk", &self.pk)
+            .field("dk", &self.dk)
+            .finish()
+    }
+}
+
 /// Derive the full AACS key chain from a candidate key of ANY ladder rung.
 ///
 /// Runs the deterministic derivation DOWNWARD to the disc's terminal unit keys:
@@ -487,7 +502,7 @@ pub struct ResolvedChain {
 ///
 /// PURE DERIVATION: no sampling, no validation, no position recovery. Validate
 /// `unit_keys` against a real encrypted unit with
-/// [`super::content::unit_key_validates`] to prove the candidate opens the disc.
+/// `decrypt_unit` + `is_clean_ts` to prove the candidate opens the disc.
 ///
 /// Returns `None` only when derivation itself cannot proceed: a PK its MKB
 /// rejects, a `Dk` the MKB can't process, a missing VID on a path that needs
@@ -505,7 +520,8 @@ pub fn resolve_candidate(
         let version = mkb_type(mkb)
             .map(|t| t.generation())
             .unwrap_or(AacsVersion::V10);
-        let ukf = parse_unit_key_ro(unit_key_ro, version)?;
+        // BD/UHD Unit_Key_RO.inf or HD DVD VTKF000.AACS — dispatched by magic.
+        let ukf = parse_title_keys(unit_key_ro, version)?;
         if ukf.encrypted_keys.is_empty() {
             return None;
         }
@@ -567,6 +583,28 @@ mod resolve_candidate_tests {
     use super::*;
     use crate::aacs::crypto::aes_ecb_encrypt;
 
+    /// `ResolvedChain.unit_keys` holds raw title-key bytes (the other rungs are
+    /// self-redacting `types` newtypes). `Debug` must not leak the title keys.
+    #[test]
+    fn resolved_chain_debug_is_redacted() {
+        let c = ResolvedChain {
+            unit_keys: vec![(1, [0xD5; 16])],
+            vuk: None,
+            mk: None,
+            pk: None,
+            dk: None,
+        };
+        let dbg = format!("{c:?}");
+        assert!(
+            !dbg.contains("213"),
+            "ResolvedChain leaked unit keys: {dbg}"
+        );
+        assert!(
+            dbg.contains("unit_keys_len"),
+            "ResolvedChain missing redaction: {dbg}"
+        );
+    }
+
     /// Minimal AACS-1.0 (48-byte stride) `Unit_Key_RO.inf` with `n` encrypted
     /// unit keys — `parse_unit_key_ro` numbers CPS units 1..=n.
     fn synth_inf(encs: &[[u8; 16]]) -> Vec<u8> {
@@ -612,10 +650,7 @@ mod resolve_candidate_tests {
     /// A bare UK candidate is terminal — it returns itself keyed by its own idx.
     #[test]
     fn resolve_candidate_uk_is_itself() {
-        let uk = UnitKey {
-            idx: 2,
-            key: [0x9u8; 16],
-        };
+        let uk = UnitKey::new(2, [0x9u8; 16]);
         let r = resolve_candidate(&KeyCandidate::Uk(uk), &[], &[], None).expect("uk is terminal");
         assert_eq!(r.unit_keys, vec![(2, uk.key)]);
         assert!(r.vuk.is_none() && r.mk.is_none());

src/aacs/index_select.rs

@@ -0,0 +1,178 @@
+//! FMTS index selection — the pure decode-time decision for a 2.1 disc.
+//!
+//! A 2.1 disc resolves to exactly one forensic index (1..=32) for a given
+//! rip. `IndividualSegment.tbl` tags each forensic segment with an index (see
+//! [`super::segment`]); the decode keeps the segments matching our index,
+//! drops the other 31, and treats everything outside a segment as ordinary
+//! (index-0) content. This module owns that classification and nothing else —
+//! no I/O, no keys, no cipher — so it is fully testable in isolation. The
+//! decrypt pipeline consumes the [`UnitDisposition`] it returns.
+//!
+//! Where the resolved index comes from is a separate concern
+//! ([`resolve_disc_index`]): today it is read off the index keys the key
+//! source handed us; when Processing Keys are available it will come from the
+//! VK derivation instead. Either way the disposition logic below is identical.
+
+use super::segment::{Segment, segment_for_unit};
+use super::types::UnitKey;
+
+/// What the decode should do with one AACS aligned unit.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum UnitDisposition {
+    /// Outside every forensic segment: ordinary content, decrypt with the
+    /// default (index-0) unit key.
+    Default,
+    /// Inside a forensic segment tagged with OUR resolved index: decrypt with
+    /// that index's key.
+    Index(u8),
+    /// Inside a forensic segment tagged with a DIFFERENT index: not our
+    /// watermark, so it is not part of our output — drop it.
+    DropForeignIndex(u8),
+    /// Inside a forensic segment but no index key is held (the disc's index
+    /// was never resolved): the segment cannot be decoded, so it is concealed
+    /// as loss. Carries the segment's index for diagnostics.
+    ForensicNoKey(u8),
+}
+
+/// Resolve the disc's single forensic index from the keys we hold.
+///
+/// Scans for an index key (`index_number` in `1..=32`) and returns its
+/// index. `None` when only default (index-0) keys are held — i.e. no
+/// index source answered, so forensic segments are not decodable. A disc has
+/// exactly one index, so the first non-zero key decides; if several distinct
+/// index keys were somehow supplied the lowest wins (deterministic), which is
+/// only a defensive tiebreak — the probe/derivation yields one.
+pub fn resolve_disc_index(unit_keys: &[UnitKey]) -> Option<u8> {
+    unit_keys
+        .iter()
+        .map(|k| k.index_number)
+        .filter(|&v| v != 0)
+        .min()
+}
+
+/// Classify the AACS aligned unit at `unit_offset` (clip-relative bytes) given
+/// the forensic segment map and the disc's resolved index (`None` if no
+/// index key is held).
+pub fn unit_disposition(
+    unit_offset: u64,
+    segments: &[Segment],
+    disc_index: Option<u8>,
+) -> UnitDisposition {
+    match segment_for_unit(segments, unit_offset) {
+        // Not in any forensic segment → ordinary content.
+        None => UnitDisposition::Default,
+        // In a forensic segment → decide by whether it is our index.
+        Some(seg) => {
+            let seg_index = seg.index as u8;
+            match disc_index {
+                Some(v) if v == seg_index => UnitDisposition::Index(v),
+                Some(_) => UnitDisposition::DropForeignIndex(seg_index),
+                None => UnitDisposition::ForensicNoKey(seg_index),
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::aacs::content::ALIGNED_UNIT_LEN;
+    use crate::aacs::segment::{SOURCE_PACKET_LEN, parse_individual_segments};
+
+    /// Build a one-record segment table (index, start_spn, end_spn).
+    fn tbl(recs: &[(u16, u32, u32)]) -> Vec<Segment> {
+        let mut v = Vec::new();
+        v.extend_from_slice(&0x0100_0000u32.to_be_bytes());
+        v.extend_from_slice(&(recs.len() as u16).to_be_bytes());
+        v.extend_from_slice(&16u16.to_be_bytes());
+        for &(n, s, e) in recs {
+            v.extend_from_slice(&0x0100_0000u32.to_be_bytes());
+            v.extend_from_slice(&n.to_be_bytes());
+            v.extend_from_slice(&1u16.to_be_bytes());
+            v.extend_from_slice(&s.to_be_bytes());
+            v.extend_from_slice(&e.to_be_bytes());
+        }
+        parse_individual_segments(&v).expect("parse")
+    }
+
+    fn uk(idx: u32, index: u8) -> UnitKey {
+        if index == 0 {
+            UnitKey::new(idx, [0u8; 16])
+        } else {
+            UnitKey::forensic(idx, [index; 16], index)
+        }
+    }
+
+    #[test]
+    fn resolve_picks_the_single_index_key() {
+        // Default keys only → no index resolved.
+        assert_eq!(resolve_disc_index(&[uk(0, 0)]), None);
+        assert_eq!(resolve_disc_index(&[]), None);
+        // One index key among defaults → that index.
+        assert_eq!(resolve_disc_index(&[uk(0, 0), uk(1, 7)]), Some(7));
+        // Defensive: lowest of several distinct indexes (deterministic).
+        assert_eq!(resolve_disc_index(&[uk(0, 9), uk(1, 3)]), Some(3));
+    }
+
+    #[test]
+    fn unit_outside_segments_is_default() {
+        let segs = tbl(&[(1, 343680, 346239)]);
+        let off = 1000u64 * SOURCE_PACKET_LEN; // well before the segment
+        assert_eq!(
+            unit_disposition(off, &segs, Some(1)),
+            UnitDisposition::Default
+        );
+        // With no segments at all (1.0 / 2.0), everything is Default.
+        assert_eq!(
+            unit_disposition(off, &[], Some(1)),
+            UnitDisposition::Default
+        );
+    }
+
+    #[test]
+    fn unit_in_our_index_decrypts() {
+        let segs = tbl(&[(7, 100, 200)]);
+        let off = 120u64 * SOURCE_PACKET_LEN;
+        assert_eq!(
+            unit_disposition(off, &segs, Some(7)),
+            UnitDisposition::Index(7)
+        );
+    }
+
+    #[test]
+    fn unit_in_foreign_index_drops() {
+        // Segment tagged index 7, but our disc index is 3 → drop it.
+        let segs = tbl(&[(7, 100, 200)]);
+        let off = 120u64 * SOURCE_PACKET_LEN;
+        assert_eq!(
+            unit_disposition(off, &segs, Some(3)),
+            UnitDisposition::DropForeignIndex(7)
+        );
+    }
+
+    #[test]
+    fn forensic_unit_with_no_key_is_concealed() {
+        // A forensic segment but we never resolved an index → conceal as loss.
+        let segs = tbl(&[(7, 100, 200)]);
+        let off = 120u64 * SOURCE_PACKET_LEN;
+        assert_eq!(
+            unit_disposition(off, &segs, None),
+            UnitDisposition::ForensicNoKey(7)
+        );
+    }
+
+    #[test]
+    fn straddling_unit_still_classified_as_its_segment() {
+        // A unit whose 32-packet span only tails into the segment still routes
+        // to the segment (matches segment_for_unit's span test).
+        let segs = tbl(&[(5, 100, 200)]);
+        let unit_packets = (ALIGNED_UNIT_LEN as u64 / SOURCE_PACKET_LEN) as u32; // 32
+        // Start so the unit covers [80, 80+31] = [80, 111]: overlaps at 100.
+        let off = 80u64 * SOURCE_PACKET_LEN;
+        assert!(80 + unit_packets - 1 >= 100, "sanity: unit tails into seg");
+        assert_eq!(
+            unit_disposition(off, &segs, Some(5)),
+            UnitDisposition::Index(5)
+        );
+    }
+}

src/aacs/inf.rs

@@ -161,6 +161,87 @@ pub fn parse_unit_key_ro(data: &[u8], version: AacsVersion) -> Option<UnitKeyFil
     })
 }
 
+/// HD DVD Video Title Key File (`VTKF000.AACS`) magic — "DVD HD Video TKF".
+pub const VTKF_MAGIC: &[u8; 12] = b"DVD_HD_V_TKF";
+/// Fixed header length before the first title-key entry.
+const VTKF_HEADER_LEN: usize = 0x80;
+/// Each title-key entry: BE32 flag + 16-byte encrypted key + 12-byte 0xFF pad.
+const VTKF_ENTRY_LEN: usize = 0x20;
+
+/// Parse an HD DVD `VTKF000.AACS` into the SAME [`UnitKeyFile`] a BD/UHD
+/// `Unit_Key_RO.inf` yields — so the shared AACS crypto (`derive_unit_keys` →
+/// `decrypt_unit_key(vuk, …)`) unwraps HD DVD title keys with no change. Only
+/// the on-disc CONTAINER differs between BD and HD DVD; the title-key unwrap is
+/// the identical AES-128 VUK step (`Kt = AES-128D(Kvu, Kte)`).
+///
+/// Layout (grounded in real discs — Shaun of the Dead, Anchorman, Harry Potter):
+/// ```text
+///   [0x00..0x0C] magic "DVD_HD_V_TKF"
+///   [0x0C..0x10] BE32 total file length
+///   [0x10..0x1C] associated playlist name ("VPLST000.XPL")
+///   [0x1C..0x80] reserved (zero)
+///   [0x80..]     32-byte entries: BE32 flag | 16-byte ENCRYPTED title key | 12-byte 0xFF pad
+///                flag bit 31 (0x8000_0000) set = present; a cleared flag ends the table
+///   [tail]       16-byte signature/MAC (never a key — the cleared-flag stop guards it)
+/// ```
+/// Entries number 1..=N as CPS units, matching `Unit_Key_RO`'s 1-based CPS
+/// numbering, so a title's CPS unit indexes this list identically. The
+/// title→CPS mapping itself is playlist-driven (`VPLST000.XPL`) and owned by the
+/// HD DVD enumerator, so `title_cps_unit` is left empty here.
+pub fn parse_vtkf(data: &[u8]) -> Option<UnitKeyFile> {
+    if data.len() < VTKF_HEADER_LEN || &data[..12] != VTKF_MAGIC {
+        return None;
+    }
+    // SHA1 of the WHOLE file — the KEYDB lookup key. BackupHDDVD-family key
+    // databases index an HD DVD disc by SHA1(VTKF000.AACS), the same role the
+    // BD disc_hash plays for `Unit_Key_RO.inf`.
+    let hash = disc_hash(data);
+
+    let mut encrypted_keys = Vec::new();
+    let mut pos = VTKF_HEADER_LEN;
+    let mut cps: u32 = 1;
+    while pos + VTKF_ENTRY_LEN <= data.len() {
+        let flag = u32::from_be_bytes([data[pos], data[pos + 1], data[pos + 2], data[pos + 3]]);
+        // A cleared present-bit terminates the key table. The file's trailing
+        // 16-byte signature then follows and must NOT be read as a key.
+        if flag & 0x8000_0000 == 0 {
+            break;
+        }
+        let mut key = [0u8; 16];
+        key.copy_from_slice(&data[pos + 4..pos + 20]);
+        encrypted_keys.push((cps, key));
+        cps += 1;
+        pos += VTKF_ENTRY_LEN;
+    }
+    if encrypted_keys.is_empty() {
+        return None;
+    }
+
+    Some(UnitKeyFile {
+        disc_hash: hash,
+        app_type: 0,     // HD DVD VTKF carries no BD-ROM app_type
+        num_bdmv_dir: 0, // BD-only concept
+        use_skb_mkb: false,
+        version: AacsVersion::V10, // HD DVD is always AACS 1.0
+        encrypted_keys,
+        title_cps_unit: Vec::new(),
+    })
+}
+
+/// Parse a disc's title-key file, dispatching on the self-describing magic:
+/// an HD DVD `VTKF000.AACS` (`DVD_HD_V_TKF`) → [`parse_vtkf`]; anything else is a
+/// BD/UHD `Unit_Key_RO.inf` → [`parse_unit_key_ro`]. Both return the same
+/// [`UnitKeyFile`], so every downstream AACS derivation stays container-agnostic
+/// — the single seam where BD-vs-HD-DVD key layout is resolved (mirrors the key
+/// service, which classifies HD DVD by the very same magic).
+pub fn parse_title_keys(data: &[u8], version: AacsVersion) -> Option<UnitKeyFile> {
+    if data.len() >= 12 && &data[..12] == VTKF_MAGIC {
+        parse_vtkf(data)
+    } else {
+        parse_unit_key_ro(data, version)
+    }
+}
+
 /// MKB disc structure format code.
 const MKB_DISC_STRUCTURE_FORMAT: u8 = 0x83;
 
@@ -283,3 +364,94 @@ pub fn parse_content_cert(data: &[u8]) -> Option<ContentCert> {
         version,
     })
 }
+
+#[cfg(test)]
+mod vtkf_tests {
+    use super::*;
+
+    /// Build a synthetic `VTKF000.AACS` matching the real on-disc layout
+    /// (Shaun of the Dead / Anchorman): magic, BE32 size, playlist name,
+    /// reserved to 0x80, then 32-byte present-flagged entries, a cleared-flag
+    /// terminator, and a 16-byte trailer.
+    fn synth_vtkf(keys: &[[u8; 16]]) -> Vec<u8> {
+        let mut v = Vec::new();
+        v.extend_from_slice(VTKF_MAGIC); // 0x00
+        v.extend_from_slice(&0u32.to_be_bytes()); // 0x0C size (patched below)
+        v.extend_from_slice(b"VPLST000.XPL"); // 0x10
+        v.resize(0x80, 0); // reserve to first entry
+        for k in keys {
+            v.extend_from_slice(&0x8000_0000u32.to_be_bytes()); // present flag
+            v.extend_from_slice(k); // 16-byte encrypted title key
+            v.extend_from_slice(&[0xFFu8; 12]); // 0xFF pad → 32-byte entry
+        }
+        // Cleared-flag terminator entry (must NOT be read as a key).
+        v.extend_from_slice(&[0u8; VTKF_ENTRY_LEN]);
+        // 16-byte trailing signature (must NOT be read as a key).
+        v.extend_from_slice(&[0xABu8; 16]);
+        let len = v.len() as u32;
+        v[0x0C..0x10].copy_from_slice(&len.to_be_bytes());
+        v
+    }
+
+    #[test]
+    fn parse_vtkf_extracts_present_entries_and_stops_at_terminator() {
+        let k1 = [0x11u8; 16];
+        let k2 = [0x22u8; 16];
+        let k3 = [0x33u8; 16];
+        let data = synth_vtkf(&[k1, k2, k3]);
+
+        let ukf = parse_vtkf(&data).expect("valid VTKF must parse");
+        // Exactly the three present entries — the cleared-flag terminator and
+        // the 16-byte trailer are NOT mistaken for keys.
+        assert_eq!(ukf.encrypted_keys.len(), 3, "must stop at the cleared flag");
+        assert_eq!(ukf.encrypted_keys[0], (1, k1), "CPS units number 1..=N");
+        assert_eq!(ukf.encrypted_keys[1], (2, k2));
+        assert_eq!(ukf.encrypted_keys[2], (3, k3));
+        assert_eq!(ukf.version, AacsVersion::V10, "HD DVD is AACS 1.0");
+        // disc_hash is SHA1 of the whole file (the KEYDB lookup key).
+        assert_eq!(ukf.disc_hash, disc_hash(&data));
+    }
+
+    #[test]
+    fn parse_vtkf_rejects_non_magic() {
+        let mut data = synth_vtkf(&[[0x11u8; 16]]);
+        data[0] = b'X'; // corrupt magic
+        assert!(
+            parse_vtkf(&data).is_none(),
+            "non-VTKF magic must be rejected"
+        );
+        assert!(
+            parse_vtkf(&[0u8; 4]).is_none(),
+            "too short must be rejected"
+        );
+    }
+
+    #[test]
+    fn parse_title_keys_dispatches_by_magic() {
+        // VTKF magic → parse_vtkf.
+        let data = synth_vtkf(&[[0x44u8; 16], [0x55u8; 16]]);
+        let ukf = parse_title_keys(&data, AacsVersion::V10).expect("VTKF dispatch");
+        assert_eq!(ukf.encrypted_keys.len(), 2);
+
+        // Non-VTKF → parse_unit_key_ro (a 2-byte buffer is not a valid inf, so
+        // this proves it ROUTED to the BD parser rather than parse_vtkf).
+        assert!(
+            parse_title_keys(&[0x00, 0x00], AacsVersion::V10).is_none(),
+            "non-magic input must route to parse_unit_key_ro"
+        );
+    }
+
+    /// The whole point of the seam: a parsed VTKF feeds the SHARED VUK→title-key
+    /// crypto (`decrypt_unit_key`) exactly like a BD `Unit_Key_RO.inf` would —
+    /// no HD-DVD-specific crypto path.
+    #[test]
+    fn vtkf_encrypted_keys_feed_shared_vuk_unwrap() {
+        let enc = [0x9Au8; 16];
+        let data = synth_vtkf(&[enc]);
+        let ukf = parse_vtkf(&data).unwrap();
+        let vuk = [0x5Cu8; 16];
+        let derived = super::super::derive::decrypt_unit_key(&vuk, &ukf.encrypted_keys[0].1);
+        // Same as applying the shared unwrap directly to the stored enc key.
+        assert_eq!(derived, super::super::derive::decrypt_unit_key(&vuk, &enc));
+    }
+}

src/aacs/mod.rs

@@ -29,6 +29,7 @@ pub mod content;
 pub mod crypto;
 pub mod derive;
 pub mod host_certs;
+pub mod index_select;
 pub mod inf;
 pub mod mkb;
 pub mod provider;
@@ -39,10 +40,18 @@ pub mod trace;
 pub mod types;
 pub mod variant;
 
-/// On-disc UDF paths to the AACS key-input files (with their fallbacks).
-/// Centralised so every reader (`resolve_vid_only`, `read_aacs_inputs`,
-/// `read_mkb_content`, `read_aacs_version`) walks the exact same files — adding
-/// or changing a fallback in one place can then never silently diverge the
+/// On-disc UDF paths to the AACS key-input files.
+///
+/// BD and UHD keep their key material under `/AACS/…`; HD DVD keeps the
+/// equivalents under `/ANY!/…` with different names (`VTKF000.AACS` is the
+/// title-key file — magic `DVD_HD_V_TKF`; `MKBROM.AACS` is the MKB). The
+/// container difference is expressed here purely as DATA: each ROLE
+/// ([`UNIT_KEY_RO_PATHS`], [`MKB_PATHS`], [`CONTENT_CERT_PATHS`]) is an ordered
+/// candidate list, and every reader walks it with [`read_first`] taking the
+/// first that reads. No reader ever branches on disc type — a BD/UHD disc has
+/// the `/AACS/` files so those win; an HD DVD has neither, so it falls through
+/// to the `/ANY!/` entry. Centralised so `resolve_vid_only`, `read_aacs_inputs`,
+/// `read_mkb_content`, and `read_aacs_version` can never silently diverge the
 /// disc_hash / MKB / VID that another reader feeds a key service.
 pub const PATH_UNIT_KEY_RO: &str = "/AACS/Unit_Key_RO.inf";
 pub const PATH_UNIT_KEY_RO_DUPLICATE: &str = "/AACS/DUPLICATE/Unit_Key_RO.inf";
@@ -50,6 +59,46 @@ pub const PATH_MKB_RO: &str = "/AACS/MKB_RO.inf";
 pub const PATH_MKB_RW: &str = "/AACS/MKB_RW.inf";
 pub const PATH_CONTENT_CERT: &str = "/AACS/Content000.cer";
 pub const PATH_CONTENT_CERT_ALT: &str = "/AACS/Content001.cer";
+/// HD DVD title-key file (`/ANY!/`), forwarded as `inf_b64`; the key service
+/// recognises it by its `DVD_HD_V_TKF` magic.
+pub const PATH_VTKF_HDDVD: &str = "/ANY!/VTKF000.AACS";
+/// HD DVD Media Key Block (`/ANY!/`), forwarded as `mkb_b64`.
+pub const PATH_MKBROM_HDDVD: &str = "/ANY!/MKBROM.AACS";
+/// HD DVD content certificate (`/ANY!/`); byte 0 gives the AACS major (0x00 → V10).
+pub const PATH_CONTENT_CERT_HDDVD: &str = "/ANY!/CONTENT_CERT.AACS";
+
+/// Title-key / `Unit_Key_RO.inf` role, in resolution order (BD/UHD, then HD DVD).
+pub const UNIT_KEY_RO_PATHS: &[&str] = &[
+    PATH_UNIT_KEY_RO,
+    PATH_UNIT_KEY_RO_DUPLICATE,
+    PATH_VTKF_HDDVD,
+];
+/// MKB role, in resolution order (BD/UHD RO then RW, then HD DVD).
+pub const MKB_PATHS: &[&str] = &[PATH_MKB_RO, PATH_MKB_RW, PATH_MKBROM_HDDVD];
+/// Content-certificate role, in resolution order (BD/UHD, then HD DVD).
+pub const CONTENT_CERT_PATHS: &[&str] = &[
+    PATH_CONTENT_CERT,
+    PATH_CONTENT_CERT_ALT,
+    PATH_CONTENT_CERT_HDDVD,
+];
+
+/// Walk an AACS role's candidate paths and return the first that reads.
+///
+/// `read` performs the actual per-path read (full file or bounded prefix), so
+/// callers share the same first-present walk regardless of read style. Returns
+/// [`Error::AacsNoKeys`] if no candidate is present. This is the single place
+/// the `/AACS/` (BD/UHD) vs `/ANY!/` (HD DVD) layout difference is resolved.
+pub(crate) fn read_first<F>(candidates: &[&str], mut read: F) -> crate::error::Result<Vec<u8>>
+where
+    F: FnMut(&str) -> crate::error::Result<Vec<u8>>,
+{
+    for path in candidates {
+        if let Ok(buf) = read(path) {
+            return Ok(buf);
+        }
+    }
+    Err(crate::error::Error::AacsNoKeys)
+}
 
 // The module structure IS the public API — consumers import from the owning
 // module directly (e.g. `aacs::content::decrypt_unit`, `aacs::mkb::MkbType`,
@@ -60,7 +109,7 @@ pub const PATH_CONTENT_CERT_ALT: &str = "/AACS/Content001.cer";
 // content-decrypt entry points that downstream key-source crates import through
 // the `aacs::` path. These are the stable, load-bearing names; keeping them here
 // lets those crates track the module refactor without a lockstep re-pin.
-pub use content::{ALIGNED_UNIT_LEN, decrypt_unit_try_keys};
+pub use content::ALIGNED_UNIT_LEN;
 pub use derive::derive_vuk;
 pub use types::{DeviceKey, HostCert, MediaKey, ProcessingKey, UnitKey, Vid, Vuk};
 
@@ -70,7 +119,7 @@ mod tests {
     //! Touching one representative item per module keeps these as a
     //! compile-time contract that the module paths stay stable.
 
-    use super::content::{ALIGNED_UNIT_LEN, ts_sync_destroyed};
+    use super::content::ALIGNED_UNIT_LEN;
     use super::inf::{disc_hash, disc_hash_hex};
     use super::mkb::{AacsVersion, mkb_content_len, walk_mkb};
     use super::variant::is_variant_mkb;
@@ -98,15 +147,15 @@ mod tests {
     fn public_helpers_are_callable_by_module_path() {
         // Touch a representative function from each module so a dropped/renamed
         // item fails to compile. Smoke calls, not behavioural assertions.
-        let _ = ts_sync_destroyed(&[0u8; ALIGNED_UNIT_LEN]);
+        let _ = !crate::aacs::content::is_clean(
+            &[0u8; ALIGNED_UNIT_LEN],
+            crate::disc::ContentFormat::BdTs,
+        );
         let _ = mkb_content_len(&[]);
         let _ = is_variant_mkb(&walk_mkb(&[]));
         let _ = disc_hash_hex(&disc_hash(b"x"));
         let _ = super::derive::resolve_candidate(
-            &super::derive::KeyCandidate::Uk(super::types::UnitKey {
-                idx: 0,
-                key: [0u8; 16],
-            }),
+            &super::derive::KeyCandidate::Uk(super::types::UnitKey::new(0, [0u8; 16])),
             &[],
             &[],
             None,

src/aacs/resolve.rs

@@ -13,7 +13,6 @@ use super::mkb::*;
 // ── Full VUK resolution chain ───────────────────────────────────────────────
 
 /// Result of resolving a disc's VUK.
-#[derive(Debug)]
 pub struct ResolvedKeys {
     /// Disc hash (SHA1 of Unit_Key_RO.inf)
     pub disc_hash: [u8; 20],
@@ -34,6 +33,23 @@ pub struct ResolvedKeys {
     pub key_source: u8,
 }
 
+// Redacting `Debug`: `vuk` and `unit_keys` are raw key bytes, never printed.
+// `disc_hash` is the public per-disc identifier (SHA-1 of the .inf), not secret.
+// Guarded by `resolved_keys_debug_is_redacted`.
+impl std::fmt::Debug for ResolvedKeys {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ResolvedKeys")
+            .field("disc_hash", &self.disc_hash)
+            .field("vuk", &self.vuk.map(|_| "<redacted>"))
+            .field("unit_keys_len", &self.unit_keys.len())
+            .field("title_cps_unit", &self.title_cps_unit)
+            .field("version", &self.version)
+            .field("bus_encryption", &self.bus_encryption)
+            .field("key_source", &self.key_source)
+            .finish()
+    }
+}
+
 /// Inputs shared by every classical-path resolver. References only —
 /// callers retain ownership of all buffers.
 pub struct ResolveContext<'a> {
@@ -156,7 +172,7 @@ pub fn resolve_keys_v2(ctx: &ResolveContext<'_>) -> Option<ResolvedKeys> {
 /// equivalent of path 2 — there's no host-side PK derivation against a
 /// Variant MKB.)
 pub fn resolve_keys_v21(ctx: &ResolveContext<'_>) -> Option<ResolvedKeys> {
-    let uk_file = parse_unit_key_ro(ctx.unit_key_ro, AacsVersion::V20)?;
+    let uk_file = parse_title_keys(ctx.unit_key_ro, AacsVersion::V20)?;
     let hash_hex = disc_hash_hex(&uk_file.disc_hash);
     let bus_encryption = ctx
         .content_cert
@@ -280,8 +296,9 @@ fn resolve_keys_classical(ctx: &ResolveContext<'_>, version: AacsVersion) -> Opt
         .map(|cc| cc.bus_encryption)
         .unwrap_or(false);
 
-    // Parse Unit_Key_RO.inf at the version-appropriate stride.
-    let uk_file = parse_unit_key_ro(ctx.unit_key_ro, version)?;
+    // Parse the disc's title-key file (BD/UHD Unit_Key_RO.inf at the
+    // version-appropriate stride, or HD DVD VTKF000.AACS) → common UnitKeyFile.
+    let uk_file = parse_title_keys(ctx.unit_key_ro, version)?;
 
     let hash_hex = disc_hash_hex(&uk_file.disc_hash);
     let has_vid = *ctx.volume_id != [0u8; 16];
@@ -466,6 +483,27 @@ mod tests {
     use super::super::types::*;
     use super::*;
 
+    /// `ResolvedKeys` carries the disc's VUK and unit keys raw; `Debug` must not
+    /// leak them. Sentinel 213 (0xD5); non-secret fields are not 213.
+    #[test]
+    fn resolved_keys_debug_is_redacted() {
+        let rk = ResolvedKeys {
+            disc_hash: [0u8; 20],
+            vuk: Some([0xD5; 16]),
+            unit_keys: vec![(1, [0xD5; 16])],
+            title_cps_unit: vec![0],
+            version: AacsVersion::V21,
+            bus_encryption: true,
+            key_source: 1,
+        };
+        let dbg = format!("{rk:?}");
+        assert!(!dbg.contains("213"), "ResolvedKeys leaked keys: {dbg}");
+        assert!(
+            dbg.contains("redacted"),
+            "ResolvedKeys missing marker: {dbg}"
+        );
+    }
+
     /// Audit #5: the `major` / `from_major` mapping is load-bearing for the
     /// Unit_Key_RO stride, so pin it as a table. V10 ↔ BD; V20/V21 → UHD; any
     /// non-BD major selects the V20/V21 64-byte stride (V10 is the only 48-byte).

src/aacs/segment.rs

@@ -1,55 +1,55 @@
 //! AACS 2.1 FMTS forensic segment map — `AACS/IndividualSegment.tbl`.
 //!
-//! An FMTS main feature interleaves N "variant" segments — the sequence-key /
-//! forensic-watermark mechanism. The same frames are authored as several
-//! slightly different variants; each variant is encrypted under its own SEGMENT
-//! key (from `SegmentKeyNNNNN.tbl`), NOT the CPS Unit Key. A player with the
-//! right device keys can decrypt exactly one variant per segment, and which one
-//! silently identifies the player (traitor tracing). Decrypting a variant
-//! segment with the Unit Key yields garbage — broken HEVC reference frames
-//! (empirically: `Could not find ref with POC …` on a plain unit-key rip).
+//! An FMTS main feature interleaves short forensic **segments** — the sequence-key
+//! / forensic-watermark mechanism. Each segment carries an **index** (1..32): a
+//! tag in `IndividualSegment.tbl` that selects which of the 32 forensic **index
+//! keys** decrypts that segment's units, in place of the ordinary CPS Unit Key.
 //!
-//! This table says WHERE the variant segments live so a decoder can decrypt
-//! them with segment keys and select one coherent variant instead of muxing
+//! Terminology (see the project AACS reference): the **index** here is NOT the
+//! AACS 2.1 *Media Key Variant* — that is the 65536-value device selector in the
+//! MKB that decides *which set* of index keys a device receives, a layer this
+//! module does not deal with. All the index keys belong to one variant, whose
+//! number is unknown and irrelevant to the segment map. Decrypting a segment with
+//! the Unit Key yields garbage — broken HEVC reference frames (empirically:
+//! `Could not find ref with POC …` on a plain unit-key rip).
+//!
+//! This table says WHERE the segments live and which index each carries, so a
+//! decoder can decrypt them with the matching index key instead of muxing
 //! unit-key garbage.
 //!
 //! Format (validated against a retail AACS 2.1 disc):
 //! ```text
 //!   header (8 bytes):  u32 type | u16 count | u16 record_size (= 16)
 //!   record[count] (16 bytes each):
-//!     u32 marker (= 0x01000000) | u16 segment_number | u16 flag (= 1)
+//!     u32 marker (= 0x01000000) | u16 index | u16 flag (= 1)
 //!     u32 start_spn | u32 end_spn        (source-packet numbers, inclusive)
 //! ```
-//! Source-packet numbers are the 192-byte BDAV packet index: byte offset =
-//! `spn * 192`. Observed on one disc: 792 segments, each ~2560 packets
-//! (~480 KB), spread across the entire 54 GB feature (one roughly every 67 MB).
+//! `index` is the 1..32 forensic index tag, NOT a sequential segment id: measured
+//! on a retail 2.1 disc (Zombieland) it cycles 1,2,…,32,1,2,… across records in
+//! file order — 24 full cycles of 32 plus a final partial cycle of 24 = 792
+//! records. Source-packet numbers are the 192-byte BDAV packet index: byte offset
+//! = `spn * 192`. Each segment is ~2560 packets (~480 KB) = 80 aligned units,
+//! spread across the entire 54 GB feature (one roughly every 67 MB). Inside a
+//! segment the 80 units interleave in two stride-2 halves: applying the segment's
+//! index key decrypts ~40 of them to clean TS and garbles the other ~40 (a second
+//! interleaved half, unidentified), which the demux then drops — leaving one
+//! coherent stream. Confirmed by decoding a retail disc with a full set of 32
+//! index keys.
 
 /// Fixed size of one `IndividualSegment.tbl` record.
 pub const SEGMENT_RECORD_LEN: usize = 16;
 /// Bytes per BDAV source packet (188-byte TS + 4-byte arrival-time header).
 pub const SOURCE_PACKET_LEN: u64 = 192;
 
-/// Whether a 2.1 (FMTS) disc may rip WITHOUT segment (variant) keys.
-///
-/// `true` (today): the forensic variant segments are skipped as expected loss
-/// and the bulk of the title decodes with the unit key, so a 2.1 disc rips
-/// mostly-complete. A unit key (VUK) is still required, exactly as for any AACS
-/// disc. `false`: the absence of a segment-key source is a hard, UPFRONT failure
-/// ([`Error::FmtsKeyMissing`]) — the same policy as a missing unit key, so a
-/// forensic-holed rip is refused rather than produced. No segment-key source
-/// exists yet, so `true` is the only value under which a 2.1 disc rips at all;
-/// flip to `false` once segment keys can be sourced and a partial rip should be
-/// refused. Hardcoded on purpose — not a user setting.
-///
-/// [`Error::FmtsKeyMissing`]: crate::error::Error::FmtsKeyMissing
-pub const BYPASS_FMTS_KEY: bool = true;
-
-/// One forensic variant segment: the inclusive source-packet range it occupies
-/// in the FMTS clip.
+/// One forensic segment: the inclusive source-packet range it occupies in the
+/// FMTS clip.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct Segment {
-    /// 1-based segment number (table order).
-    pub number: u16,
+    /// Forensic index tag, 1..=32 (field@4 of the record). Cycles across the
+    /// table rather than counting up — it selects WHICH of the 32 index keys
+    /// decrypts this range. (`0` is not used here; the default/non-forensic
+    /// content carries no segment record at all.)
+    pub index: u16,
     /// First source packet of the segment (inclusive).
     pub start_spn: u32,
     /// Last source packet of the segment (inclusive).
@@ -103,8 +103,8 @@ pub fn lba_byte_offset(lba: u32) -> u64 {
 /// unit's clip-relative byte offset.
 ///
 /// This is the routing decision behind a 2.1 decrypt-miss: a unit that
-/// overlaps a forensic segment must be opened with that segment's **variant
-/// key** (from `SegmentKeyNNNNN.tbl`), not the CPS Unit Key. Opening it with
+/// overlaps a forensic segment must be opened with that segment's **index key**
+/// (selected by the segment's `index`), not the CPS Unit Key. Opening it with
 /// the Unit Key is exactly what yields the broken-reference-frame garbage a
 /// plain unit-key rip produces. A unit outside every segment is ordinary
 /// content and a miss on it is a Unit-Key miss, so this returns `None` and the
@@ -112,16 +112,16 @@ pub fn lba_byte_offset(lba: u32) -> u64 {
 ///
 /// The unit is tested as a packet *span* (`[off/192, (off+6144-1)/192]`) so a
 /// unit that only partly overlaps a segment edge is still classified as
-/// variant; on the observed disc segments are unit-aligned, but the span test
+/// forensic; on the observed disc segments are unit-aligned, but the span test
 /// does not rely on that.
-pub fn variant_segment_for_unit(segments: &[Segment], unit_offset: u64) -> Option<&Segment> {
+pub fn segment_for_unit(segments: &[Segment], unit_offset: u64) -> Option<&Segment> {
     let unit_len = crate::aacs::content::ALIGNED_UNIT_LEN as u64;
     let first = (unit_offset / SOURCE_PACKET_LEN) as u32;
     let last = ((unit_offset + unit_len - 1) / SOURCE_PACKET_LEN) as u32;
     segments.iter().find(|s| s.overlaps_spn(first, last))
 }
 
-/// Parse `IndividualSegment.tbl` into its forensic variant segments, in table
+/// Parse `IndividualSegment.tbl` into its forensic segments, in table
 /// order. Returns `None` when the header is malformed, the record size is not
 /// [`SEGMENT_RECORD_LEN`], or the declared record count overruns the buffer —
 /// so a truncated / foreign table degrades to "no segment map" rather than
@@ -141,12 +141,12 @@ pub fn parse_individual_segments(tbl: &[u8]) -> Option<Vec<Segment>> {
     let mut segments = Vec::with_capacity(count);
     for i in 0..count {
         let o = 8 + i * record_size;
-        // o+4..o+8 = segment_number (u16) + flag (u16); o+8..o+16 = start/end SPN.
-        let number = u16::from_be_bytes([tbl[o + 4], tbl[o + 5]]);
+        // o+4..o+8 = index (u16, 1..32) + flag (u16); o+8..o+16 = start/end SPN.
+        let index = u16::from_be_bytes([tbl[o + 4], tbl[o + 5]]);
         let start_spn = u32::from_be_bytes([tbl[o + 8], tbl[o + 9], tbl[o + 10], tbl[o + 11]]);
         let end_spn = u32::from_be_bytes([tbl[o + 12], tbl[o + 13], tbl[o + 14], tbl[o + 15]]);
         segments.push(Segment {
-            number,
+            index,
             start_spn,
             end_spn,
         });
@@ -154,12 +154,74 @@ pub fn parse_individual_segments(tbl: &[u8]) -> Option<Vec<Segment>> {
     Some(segments)
 }
 
+/// Map a clip-relative byte offset to the absolute LBA that holds it, by walking
+/// the title's extents (the `.fmts` clip's sectors in file order). Segment
+/// offsets in [`Segment`] are clip-relative source-packet numbers, so this is how
+/// a segment's `spn` range becomes disc LBAs. `None` if the offset is past the
+/// clip.
+pub fn clip_byte_to_lba(extents: &[crate::disc::Extent], clip_byte: u64) -> Option<u32> {
+    let mut cum = 0u64;
+    for e in extents {
+        let len = e.sector_count as u64 * crate::consts::SECTOR_BYTES as u64;
+        if clip_byte < cum + len {
+            let sector_in_ext = ((clip_byte - cum) / crate::consts::SECTOR_BYTES as u64) as u32;
+            return Some(e.start_lba.saturating_add(sector_in_ext));
+        }
+        cum += len;
+    }
+    None
+}
+
+/// Build the `[start_lba, end_lba) → key_idx` ranges for an FMTS forensic key map.
+///
+/// Each forensic segment's clip-relative source-packet span becomes an absolute
+/// LBA range tagged with the key its `index` selects (via `index_to_key_idx`,
+/// e.g. `|i| i as usize` when the pool is `[base, idx1, idx2, …]`). Applying that
+/// one key across the whole segment decodes the ~40 units of its interleave half
+/// to clean TS and garbles the other ~40 (the second interleaved half), which the
+/// demux then drops — yielding one coherent stream. Ranges outside every segment
+/// are left for the map's default (the ordinary Unit Key). A segment that straddles
+/// a UDF extent boundary is emitted as one range per whole-sector slice it covers.
+///
+/// The result feeds [`AacsKeyMap::from_ranges`](crate::decrypt::AacsKeyMap::from_ranges)
+/// with the Unit-Key index as the default — the same structure the CPS map uses,
+/// only finer-grained.
+pub fn fmts_key_ranges(
+    segments: &[Segment],
+    extents: &[crate::disc::Extent],
+    index_to_key_idx: &dyn Fn(u16) -> usize,
+) -> Vec<(u32, u32, usize)> {
+    let mut ranges = Vec::new();
+    for s in segments {
+        let start_byte = s.start_spn as u64 * SOURCE_PACKET_LEN;
+        let end_byte = (s.end_spn as u64 + 1) * SOURCE_PACKET_LEN; // exclusive
+        // A segment is unit-aligned and contiguous in clip bytes; map its first
+        // and last sector to LBAs. Segments are ~480 KB and extents are GB-sized,
+        // so a segment almost never crosses an extent boundary — but if the two
+        // ends land in different extents (non-contiguous LBAs), skip rather than
+        // emit a wrong span; the units there fall to the Unit Key (garble+drop),
+        // never a mis-decrypt.
+        let (Some(a), Some(b)) = (
+            clip_byte_to_lba(extents, start_byte),
+            clip_byte_to_lba(extents, end_byte - 1),
+        ) else {
+            continue;
+        };
+        if b >= a
+            && (b - a) as u64 == (end_byte - 1 - start_byte) / crate::consts::SECTOR_BYTES as u64
+        {
+            ranges.push((a, b + 1, index_to_key_idx(s.index)));
+        }
+    }
+    ranges
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
     /// Build a table with the real on-disc layout: 8-byte header + N 16-byte
-    /// records. `recs` are `(segment_number, start_spn, end_spn)`.
+    /// records. `recs` are `(index, start_spn, end_spn)`.
     fn build_tbl(recs: &[(u16, u32, u32)]) -> Vec<u8> {
         let mut v = Vec::new();
         v.extend_from_slice(&0x0100_0000u32.to_be_bytes()); // type
@@ -175,9 +237,75 @@ mod tests {
         v
     }
 
+    #[test]
+    fn fmts_key_ranges_maps_segments_to_lba_by_index() {
+        use crate::disc::Extent;
+        // One big clip extent starting at LBA 1000. Clip byte B lives at
+        // LBA 1000 + B/2048.
+        let extents = vec![Extent {
+            start_lba: 1000,
+            sector_count: 1_000_000,
+        }];
+        // Two segments, indexes 5 and 7 (spn ranges as on a real disc).
+        let segs = vec![
+            Segment {
+                index: 5,
+                start_spn: 100,
+                end_spn: 199,
+            },
+            Segment {
+                index: 7,
+                start_spn: 10_000,
+                end_spn: 10_099,
+            },
+        ];
+        // Pool layout [base, idx1, idx2, …] → index N uses key slot N.
+        let ranges = fmts_key_ranges(&segs, &extents, &|v| v as usize);
+        assert_eq!(ranges.len(), 2, "one LBA range per segment");
+        // Segment 0: spn 100..=199 → clip bytes [19200, 38400) → sectors 9..=18
+        // → LBA 1009..1019, key index 5.
+        assert_eq!(ranges[0], (1009, 1019, 5));
+        // Segment 1: spn 10000..=10099 → bytes [1_920_000, 1_939_200) →
+        // sectors 937..=946 → LBA 1937..1947, key index 7.
+        assert_eq!(ranges[1], (1937, 1947, 7));
+
+        // The ranges drive an AacsKeyMap with the Unit Key (index 0) as default.
+        let map = crate::decrypt::AacsKeyMap::from_ranges(ranges, 0);
+        assert_eq!(map.key_idx_for(500), 0, "outside any segment → Unit Key");
+        assert_eq!(map.key_idx_for(1012), 5, "inside index-5 segment → key 5");
+        assert_eq!(map.key_idx_for(1940), 7, "inside index-7 segment → key 7");
+        assert_eq!(
+            map.key_idx_for(1019),
+            0,
+            "segment end is exclusive → Unit Key"
+        );
+    }
+
+    #[test]
+    fn clip_byte_to_lba_walks_extents() {
+        use crate::disc::Extent;
+        let extents = vec![
+            Extent {
+                start_lba: 100,
+                sector_count: 10,
+            }, // clip bytes [0, 20480)
+            Extent {
+                start_lba: 500,
+                sector_count: 10,
+            }, // clip bytes [20480, 40960)
+        ];
+        assert_eq!(clip_byte_to_lba(&extents, 0), Some(100));
+        assert_eq!(clip_byte_to_lba(&extents, 2048), Some(101));
+        assert_eq!(clip_byte_to_lba(&extents, 20480), Some(500)); // second extent
+        assert_eq!(clip_byte_to_lba(&extents, 22528), Some(501));
+        assert_eq!(clip_byte_to_lba(&extents, 40960), None); // past the clip
+    }
+
     #[test]
     fn parses_real_disc_layout() {
-        // First three records observed on a retail 2.1 disc: 2560-packet segments.
+        // First three records observed on retail 2.1 (Zombieland): the variant
+        // field counts 1,2,3,… (it wraps at 32 further into the table — see
+        // `index_field_cycles_one_to_thirty_two`), segments are 2560 packets.
         let tbl = build_tbl(&[
             (1, 343680, 346239),
             (2, 695616, 698175),
@@ -185,7 +313,9 @@ mod tests {
         ]);
         let segs = parse_individual_segments(&tbl).expect("parse");
         assert_eq!(segs.len(), 3);
-        assert_eq!(segs[0].number, 1);
+        assert_eq!(segs[0].index, 1);
+        assert_eq!(segs[1].index, 2);
+        assert_eq!(segs[2].index, 3);
         assert_eq!(segs[0].start_spn, 343680);
         assert_eq!(segs[0].end_spn, 346239);
         assert_eq!(segs[0].packet_count(), 2560);
@@ -224,13 +354,33 @@ mod tests {
     }
 
     #[test]
-    fn unit_inside_segment_routes_to_variant() {
+    fn unit_inside_segment_routes_to_index() {
         // A real first-record segment: packets [343680, 346239].
         let segs = parse_individual_segments(&build_tbl(&[(1, 343680, 346239)])).unwrap();
         // A unit sitting squarely inside: start at packet 344000 → byte 344000*192.
         let off = 344000u64 * SOURCE_PACKET_LEN;
-        let hit = variant_segment_for_unit(&segs, off).expect("inside the segment");
-        assert_eq!(hit.number, 1);
+        let hit = segment_for_unit(&segs, off).expect("inside the segment");
+        assert_eq!(hit.index, 1);
+    }
+
+    #[test]
+    fn index_field_cycles_one_to_thirty_two() {
+        // Reality on Zombieland: field@4 is the index, cycling 1..=32 in file
+        // order (NOT a sequential segment id). Reproduce one-and-a-bit cycles.
+        let mut recs = Vec::new();
+        let mut spn = 1000u32;
+        for row in 0..2 {
+            for v in 1..=32u16 {
+                recs.push((v, spn, spn + 2559));
+                spn += 50_000; // ~one segment every ~67 MB
+            }
+            let _ = row;
+        }
+        let segs = parse_individual_segments(&build_tbl(&recs)).unwrap();
+        assert_eq!(segs.len(), 64);
+        assert_eq!(segs[31].index, 32); // end of first cycle
+        assert_eq!(segs[32].index, 1); // wraps, does not become 33
+        assert!(segs.iter().all(|s| (1..=32).contains(&s.index)));
     }
 
     #[test]
@@ -238,29 +388,29 @@ mod tests {
         let segs = parse_individual_segments(&build_tbl(&[(1, 343680, 346239)])).unwrap();
         // A unit well before the segment is ordinary content → None (unit-key path).
         let off = 1000u64 * SOURCE_PACKET_LEN;
-        assert!(variant_segment_for_unit(&segs, off).is_none());
+        assert!(segment_for_unit(&segs, off).is_none());
     }
 
     #[test]
-    fn unit_straddling_a_segment_edge_counts_as_variant() {
+    fn unit_straddling_a_segment_edge_counts_as_forensic() {
         // Segment starts at packet 100. A unit that ENDS just inside it (its 32
-        // packets straddle the boundary) must still route to the variant key,
-        // because part of its ciphertext is variant-encrypted.
+        // packets straddle the boundary) must still route to the index key,
+        // because part of its ciphertext is forensic-encrypted.
         let segs = parse_individual_segments(&build_tbl(&[(7, 100, 200)])).unwrap();
         // Unit covering packets [80, 111]: overlaps [100,200] at the tail.
         let off = 80u64 * SOURCE_PACKET_LEN;
-        let hit = variant_segment_for_unit(&segs, off).expect("straddles the start edge");
-        assert_eq!(hit.number, 7);
+        let hit = segment_for_unit(&segs, off).expect("straddles the start edge");
+        assert_eq!(hit.index, 7);
         // A unit ending exactly at packet 99 (offset s.t. last = 99) does NOT overlap.
         let before = 68u64 * SOURCE_PACKET_LEN; // [68, 99]
-        assert!(variant_segment_for_unit(&segs, before).is_none());
+        assert!(segment_for_unit(&segs, before).is_none());
     }
 
     #[test]
-    fn no_segments_never_routes_to_variant() {
+    fn no_segments_never_routes_to_index() {
         // The 1.0 / 2.0 case: no forensic map, so every miss is a unit-key miss.
-        assert!(variant_segment_for_unit(&[], lba_byte_offset(0)).is_none());
-        assert!(variant_segment_for_unit(&[], lba_byte_offset(9_999_999)).is_none());
+        assert!(segment_for_unit(&[], lba_byte_offset(0)).is_none());
+        assert!(segment_for_unit(&[], lba_byte_offset(9_999_999)).is_none());
     }
 
     #[test]

src/aacs/types.rs

@@ -6,7 +6,7 @@
 //! owns only the crypto and these value types that flow through it.
 
 /// A device key for MKB subset-difference tree processing.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct DeviceKey {
     pub key: [u8; 16],
     pub node: u16,
@@ -15,7 +15,7 @@ pub struct DeviceKey {
 }
 
 /// Host certificate + private key for AACS SCSI authentication.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct HostCert {
     /// AACS 1.0: 20 bytes. AACS 2.0: 32 bytes.
     pub private_key: [u8; 20],
@@ -28,22 +28,22 @@ pub struct HostCert {
 }
 
 /// Volume ID (16 bytes) — read from the disc via the SCSI handshake / OEM path.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub struct Vid(pub [u8; 16]);
 
 /// Media Key (Km, 16 bytes) — the MKB-scoped key derived from device keys.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub struct MediaKey(pub [u8; 16]);
 
 /// Volume Unique Key (VUK / Kvu, 16 bytes) — derived from `MediaKey` + `Vid`,
 /// decrypts the per-disc encrypted title keys in `Unit_Key_RO.inf`.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub struct Vuk(pub [u8; 16]);
 
 /// Processing Key (Kp, 16 bytes) — an MKB Subset-Difference key that yields the
 /// Media Key. A leaked/precomputed PK in the keydb, or the intermediate PK a
 /// device-key walk derives at its matching SD node.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub struct ProcessingKey(pub [u8; 16]);
 
 /// One decrypted per-CPS-unit AACS title key.
@@ -53,14 +53,49 @@ pub struct ProcessingKey(pub [u8; 16]);
 /// area). The CPS-unit *number* association is a higher-level concern owned by
 /// [`super::inf::parse_unit_key_ro`], which pairs each positional key with its
 /// declared CPS unit; this primitive only does the AES, so it surfaces position.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub struct UnitKey {
     pub idx: u32,
     pub key: [u8; 16],
+    /// AACS 2.1 (FMTS) forensic **index** tag (see [`crate::aacs::segment`]).
+    ///
+    /// `0` = ordinary (non-forensic) content — the value for every 1.0 / 2.0
+    /// key and for the bulk of a 2.1 title. `1..=32` = a forensic index key that
+    /// decrypts the `IndividualSegment.tbl` segments tagged with that same index.
+    /// This is the per-segment index (1..32), NOT the AACS 2.1 Media Key Variant
+    /// (the 65536-value device selector), which is a separate MKB-layer concern.
+    pub index_number: u8,
+}
+
+impl UnitKey {
+    /// An ordinary (non-forensic) unit key: `index_number == 0`. The value
+    /// for every AACS 1.0 / 2.0 key and the bulk of a 2.1 title.
+    pub const fn new(idx: u32, key: [u8; 16]) -> Self {
+        Self {
+            idx,
+            key,
+            index_number: 0,
+        }
+    }
+
+    /// A forensic index key: `index_number` in `1..=32`, decrypting the
+    /// `IndividualSegment.tbl` segments tagged with that index.
+    pub const fn forensic(idx: u32, key: [u8; 16], index_number: u8) -> Self {
+        Self {
+            idx,
+            key,
+            index_number,
+        }
+    }
+
+    /// Whether this key decrypts ordinary (non-forensic) content (index 0).
+    pub const fn is_default_index(&self) -> bool {
+        self.index_number == 0
+    }
 }
 
 /// A per-disc entry from the key database.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct DiscEntry {
     /// Disc hash (20 bytes, hex)
     pub disc_hash: String,
@@ -75,3 +110,158 @@ pub struct DiscEntry {
     /// Unit keys (title keys) indexed by CPS unit number
     pub unit_keys: Vec<(u32, [u8; 16])>,
 }
+
+// ── Redacting `Debug` impls ──────────────────────────────────────────────────
+//
+// Every type above carries AACS secret material (device keys, host PRIVATE keys,
+// media/volume/processing/unit keys). `#[derive(Debug)]` would print those bytes
+// verbatim, so a stray `debug!("{:?}", …)` or a panic message would leak the
+// keys. These hand-written impls print only NON-secret shape (presence, lengths,
+// tree coordinates, indices) — never key bytes. `decrypt::DecryptKeys` follows
+// the same policy by omitting `Debug` entirely; here we keep `Debug` because
+// these are `PartialEq`/`Eq` value types used in `assert_eq!` and nested inside
+// other `#[derive(Debug)]` structs, so the trait must exist — just not leak.
+// Guarded by `redaction_tests` below.
+
+impl std::fmt::Debug for DeviceKey {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("DeviceKey")
+            .field("key", &"<redacted>")
+            .field("node", &self.node)
+            .field("uv", &self.uv)
+            .field("u_mask_shift", &self.u_mask_shift)
+            .finish()
+    }
+}
+
+impl std::fmt::Debug for HostCert {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("HostCert")
+            .field("private_key", &"<redacted>")
+            .field("certificate_len", &self.certificate.len())
+            .field("private_key_v2", &self.private_key_v2.map(|_| "<redacted>"))
+            .field(
+                "certificate_v2_len",
+                &self.certificate_v2.as_ref().map(|c| c.len()),
+            )
+            .finish()
+    }
+}
+
+impl std::fmt::Debug for Vid {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("Vid(<redacted>)")
+    }
+}
+
+impl std::fmt::Debug for MediaKey {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("MediaKey(<redacted>)")
+    }
+}
+
+impl std::fmt::Debug for Vuk {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("Vuk(<redacted>)")
+    }
+}
+
+impl std::fmt::Debug for ProcessingKey {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("ProcessingKey(<redacted>)")
+    }
+}
+
+impl std::fmt::Debug for UnitKey {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("UnitKey")
+            .field("idx", &self.idx)
+            .field("key", &"<redacted>")
+            .field("index_number", &self.index_number)
+            .finish()
+    }
+}
+
+impl std::fmt::Debug for DiscEntry {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("DiscEntry")
+            .field("disc_hash", &self.disc_hash)
+            .field("title", &self.title)
+            .field("media_key", &self.media_key.map(|_| "<redacted>"))
+            .field("disc_id", &self.disc_id.map(|_| "<redacted>"))
+            .field("vuk", &self.vuk.map(|_| "<redacted>"))
+            .field("unit_keys_len", &self.unit_keys.len())
+            .finish()
+    }
+}
+
+#[cfg(test)]
+mod redaction_tests {
+    use super::*;
+
+    // Sentinel key byte 0xD5 = decimal 213. A derived `Debug` prints `[u8;N]`
+    // as decimal, so a leaked key surfaces the substring "213"; the redacting
+    // impls must not. No non-secret field below is 213, so "213" appearing means
+    // key bytes leaked. Each type must also carry a "redacted" marker (or omit
+    // the secret entirely) so re-adding `#[derive(Debug)]` fails this test.
+    const S: u8 = 0xD5;
+
+    fn assert_redacted(what: &str, dbg: &str) {
+        assert!(
+            !dbg.contains("213"),
+            "{what}: Debug leaked key bytes (found decimal 213): {dbg}"
+        );
+        assert!(
+            dbg.contains("redacted"),
+            "{what}: Debug missing redaction marker: {dbg}"
+        );
+    }
+
+    #[test]
+    fn device_key_debug_is_redacted() {
+        let d = DeviceKey {
+            key: [S; 16],
+            node: 1,
+            uv: 2,
+            u_mask_shift: 3,
+        };
+        assert_redacted("DeviceKey", &format!("{d:?}"));
+    }
+
+    #[test]
+    fn host_cert_debug_is_redacted() {
+        let h = HostCert {
+            private_key: [S; 20],
+            certificate: vec![0u8; 92],
+            private_key_v2: Some([S; 32]),
+            certificate_v2: None,
+        };
+        assert_redacted("HostCert", &format!("{h:?}"));
+    }
+
+    #[test]
+    fn newtype_keys_debug_is_redacted() {
+        assert_redacted("Vid", &format!("{:?}", Vid([S; 16])));
+        assert_redacted("MediaKey", &format!("{:?}", MediaKey([S; 16])));
+        assert_redacted("Vuk", &format!("{:?}", Vuk([S; 16])));
+        assert_redacted("ProcessingKey", &format!("{:?}", ProcessingKey([S; 16])));
+    }
+
+    #[test]
+    fn unit_key_debug_is_redacted() {
+        assert_redacted("UnitKey", &format!("{:?}", UnitKey::new(0, [S; 16])));
+    }
+
+    #[test]
+    fn disc_entry_debug_is_redacted() {
+        let e = DiscEntry {
+            disc_hash: "0xAA".into(),
+            title: "T".into(),
+            media_key: Some([S; 16]),
+            disc_id: Some([S; 16]),
+            vuk: Some([S; 16]),
+            unit_keys: vec![(1, [S; 16])],
+        };
+        assert_redacted("DiscEntry", &format!("{e:?}"));
+    }
+}

src/aacs/variant.rs

@@ -146,7 +146,7 @@ use super::derive::{calc_pk_from_dk, calc_v_mask};
 /// 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)]
+#[derive(Clone, Copy)]
 pub struct ProcessingKeyMatch {
     /// Processing Key.
     pub kp: [u8; 16],
@@ -158,6 +158,20 @@ pub struct ProcessingKeyMatch {
     pub cvalue_index: usize,
 }
 
+// Redacting `Debug`: `kp` (a Processing Key) and `cvalue` are secret, never
+// printed. `uv` / `cvalue_index` are non-secret coordinates. Guarded by
+// `processing_key_match_debug_is_redacted`.
+impl std::fmt::Debug for ProcessingKeyMatch {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ProcessingKeyMatch")
+            .field("kp", &"<redacted>")
+            .field("uv", &self.uv)
+            .field("cvalue", &"<redacted>")
+            .field("cvalue_index", &self.cvalue_index)
+            .finish()
+    }
+}
+
 fn mkb_find_mk_dv(records: &[MkbRecord]) -> Option<[u8; 16]> {
     let r = records.iter().find(|r| {
         (r.rec_type == REC_VERIFY_MEDIA_KEY_V1 || r.rec_type == REC_VERIFY_MEDIA_KEY_V2)
@@ -635,6 +649,27 @@ mod tests {
     use super::super::crypto::aesg3;
     use super::super::derive::calc_pk_from_dk;
 
+    /// `ProcessingKeyMatch` carries the Processing Key (`kp`) and `cvalue` raw;
+    /// `Debug` must redact both. Non-secret `uv`/`cvalue_index` are not 213.
+    #[test]
+    fn processing_key_match_debug_is_redacted() {
+        let m = ProcessingKeyMatch {
+            kp: [0xD5; 16],
+            uv: 1,
+            cvalue: [0xD5; 16],
+            cvalue_index: 2,
+        };
+        let dbg = format!("{m:?}");
+        assert!(
+            !dbg.contains("213"),
+            "ProcessingKeyMatch leaked kp/cvalue: {dbg}"
+        );
+        assert!(
+            dbg.contains("redacted"),
+            "ProcessingKeyMatch missing marker: {dbg}"
+        );
+    }
+
     #[test]
     fn calc_pk_from_dk_terminates_on_nonconvergent_mask() {
         // Regression for the unbounded-loop hang: pick a (dev_key_v_mask,

src/consts.rs

@@ -66,6 +66,10 @@ pub mod coding_type {
     pub const MPEG2_VIDEO: u8 = 0x02;
     /// H.264 / AVC video (ISO/IEC 13818-1 Table 2-34).
     pub const H264: u8 = 0x1B;
+    /// H.264 / MVC dependent view (Blu-ray 3D right-eye substream). Carried in
+    /// the SSIF interleaved stream under its own PID; the base view is [`H264`].
+    /// ISO/IEC 13818-1 stream_type 0x20 (MVC video sub-bitstream).
+    pub const H264_MVC: u8 = 0x20;
     /// HEVC / H.265 video (ISO/IEC 13818-1 Table 2-34, 2015 amendment).
     pub const HEVC: u8 = 0x24;
     /// SMPTE VC-1 video (BD-ROM convention, ISO user-private range).

src/css/mod.rs

@@ -29,7 +29,7 @@ use crate::sector::SectorSource;
 const CSS_LOCKED_BAIL: u32 = 64;
 
 /// CSS decryption state for a DVD title.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct CssState {
     /// 5-byte CSS title key (from SCSI auth or the crack fallback).
     pub title_key: [u8; 5],
@@ -43,6 +43,18 @@ pub struct CssState {
     pub crack_span: Option<(u32, u32)>,
 }
 
+// Redacting `Debug`: `CssState` is reachable via the public `Disc.css` field, so
+// a `{:?}` on a `Disc` would otherwise print the raw CSS title key. Print only
+// the (non-secret) crack span. Guarded by `css_state_debug_is_redacted`.
+impl std::fmt::Debug for CssState {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("CssState")
+            .field("title_key", &"<redacted>")
+            .field("crack_span", &self.crack_span)
+            .finish()
+    }
+}
+
 /// Recover the CSS title key with no keys, by scanning scrambled sectors and
 /// running the Stevenson known-plaintext attack (see the [`stevenson`] module).
 ///
@@ -54,12 +66,16 @@ pub struct CssState {
 /// extents and return the first sector that yields a key — no player keys, no
 /// disc-key crack. Works on a live drive (after bus-auth unlocks reads) and on
 /// disc images alike.
+/// This convenience form runs to completion (no cancellation) and returns just
+/// the key; callers needing an operator-Stop / watchdog cancel, or the three-way
+/// [`CrackOutcome`] (to distinguish "unencrypted" from "encrypted-but-uncracked"),
+/// use [`crack_key_outcome`], which takes a `halt` token.
 pub fn crack_key(
     reader: &mut dyn SectorSource,
     extents: &[Extent],
     batch_sectors: u16,
 ) -> Option<CssState> {
-    crack_key_halt(reader, extents, batch_sectors, None)
+    crack_key_scan(reader, extents, batch_sectors, None, false).into_state()
 }
 
 /// Outcome of a CSS crack scan that distinguishes the THREE cases the bare
@@ -105,6 +121,12 @@ impl CrackOutcome {
 /// ScrambledUncracked) so callers can distinguish "genuinely unencrypted" from
 /// "encrypted but uncrackable" — the latter must become a hard error, never a
 /// silent fall-through to plaintext.
+///
+/// Takes an optional cooperative-cancellation token. "No silent hangs": the
+/// crack scans up to 50_000 sectors, which on a live drive hitting bad sectors
+/// can take a long time, so it polls `halt` once per batch (the same cadence
+/// sweep/patch use) and emits a `freemkv::heartbeat` beat ("css_crack") each
+/// batch so a stuck scan is visible in the log.
 pub fn crack_key_outcome(
     reader: &mut dyn SectorSource,
     extents: &[Extent],
@@ -114,27 +136,10 @@ pub fn crack_key_outcome(
     crack_key_scan(reader, extents, batch_sectors, halt, true)
 }
 
-/// [`crack_key`] with an optional cooperative-cancellation token.
-///
-/// "No silent hangs": the crack scans up to 50_000 sectors, which on a live
-/// drive hitting bad sectors can take a long time. This variant polls `halt`
-/// once per batch (the same cadence sweep/patch use) so an operator Stop or a
-/// scan-level watchdog can interrupt the scan, and emits a
-/// `freemkv::heartbeat` beat ("css_crack") each batch so a stuck scan is
-/// visible in the log.
-pub fn crack_key_halt(
-    reader: &mut dyn SectorSource,
-    extents: &[Extent],
-    batch_sectors: u16,
-    halt: Option<&crate::halt::Halt>,
-) -> Option<CssState> {
-    crack_key_scan(reader, extents, batch_sectors, halt, false).into_state()
-}
-
 /// The crack scan, returning the full [`CrackOutcome`]. Tracks a
 /// `saw_scrambled` flag so a scrambled-but-uncracked disc is distinguished
-/// from a genuinely-unencrypted one (the [`crack_key`] / [`crack_key_halt`]
-/// `Option` wrappers collapse both to `None`).
+/// from a genuinely-unencrypted one (the [`crack_key`] `Option` wrapper
+/// collapses both to `None` via [`CrackOutcome::into_state`]).
 fn crack_key_scan(
     reader: &mut dyn SectorSource,
     extents: &[Extent],
@@ -364,6 +369,26 @@ mod tests {
     use super::*;
     use crate::error::{Error, Result};
 
+    /// `CssState` is reachable via the public `Disc.css` field, so a `{:?}` on a
+    /// `Disc` must not print the raw CSS title key. Sentinel byte 213 (0xD5);
+    /// `crack_span` is non-secret and none of its values are 213.
+    #[test]
+    fn css_state_debug_is_redacted() {
+        let s = CssState {
+            title_key: [0xD5; 5],
+            crack_span: Some((10, 20)),
+        };
+        let dbg = format!("{s:?}");
+        assert!(
+            !dbg.contains("213"),
+            "CssState Debug leaked the title key: {dbg}"
+        );
+        assert!(
+            dbg.contains("redacted"),
+            "CssState Debug missing marker: {dbg}"
+        );
+    }
+
     // ── is_scrambled ───────────────────────────────────────────────────────
 
     /// is_scrambled returns false for any buffer shorter than one sector,

src/diag.rs

@@ -336,7 +336,7 @@ fn frame_record(track_idx: usize, pts_ns: i64, keyframe: bool, data: &[u8]) -> V
 /// `track_number` is the 1-based MKV track number; `track` is the built
 /// [`crate::mux::mkv::MkvTrack`] whose fields map one-to-one onto the emitted
 /// elements (see `MkvMuxer::new`). No-op unless the diag target is on.
-pub fn dump_mkv_track(track_number: u64, track: &crate::mux::mkv::MkvTrack) {
+pub(crate) fn dump_mkv_track(track_number: u64, track: &crate::mux::mkv::MkvTrack) {
     if !diag_enabled() {
         return;
     }
@@ -530,7 +530,7 @@ fn dump_aacs(disc: &Disc) {
         a.bus_encryption,
         a.mkb_version,
         a.disc_hash,
-        a.key_source.name(),
+        a.key_source,
         a.vuk.is_some(),
         a.unit_keys.len(),
         a.uk_ro.len(),

src/disc/bluray.rs

@@ -72,6 +72,11 @@ impl Disc {
         // Parse each clip for size, duration, and sector extents
         let mut extents = Vec::new();
         let mut total_size: u64 = 0;
+        // Set when any clip resolves to a STREAM/SSIF/<clip>.ssif — a Blu-ray 3D
+        // interleaved stream carrying both the base (left) and MVC dependent
+        // (right) views. Drives reading the SSIF for both eyes and adding the
+        // dependent-view stream below.
+        let mut is_3d = false;
         let mut clips = Vec::with_capacity(parsed.play_items.len());
         // BD playlists legally reference the same .m2ts clip_id from
         // multiple PlayItems (multi-angle, seamless splits, looped
@@ -110,10 +115,23 @@ impl Disc {
                         // use `.ssif` (see [`CLIP_STREAM_EXTS`]). A normal `.m2ts`
                         // clip is unchanged — the fallback only runs when `.m2ts`
                         // is absent, which is exactly when `file_extents` errors.
-                        let file_exts = CLIP_STREAM_EXTS.iter().find_map(|ext| {
-                            let path = format!("/BDMV/STREAM/{}.{}", play_item.clip_id, ext);
-                            udf_fs.file_extents(reader, &path).ok()
-                        });
+                        // 3D discs interleave the left (base) and right (MVC
+                        // dependent) views in STREAM/SSIF/<clip>.ssif — note the
+                        // SSIF/ subdir. Prefer it when present: the SSIF is one
+                        // transport stream carrying BOTH eyes on distinct PIDs,
+                        // so muxing it captures the full 3D. 2D clips fall back to
+                        // the base .m2ts / .fmts as before.
+                        let ssif = format!("/BDMV/STREAM/SSIF/{}.ssif", play_item.clip_id);
+                        let file_exts = match udf_fs.file_extents(reader, &ssif) {
+                            Ok(exts) => {
+                                is_3d = true;
+                                Some(exts)
+                            }
+                            Err(_) => CLIP_STREAM_EXTS.iter().find_map(|ext| {
+                                let path = format!("/BDMV/STREAM/{}.{}", play_item.clip_id, ext);
+                                udf_fs.file_extents(reader, &path).ok()
+                            }),
+                        };
                         if let Some(file_exts) = file_exts {
                             for (lba, sectors) in file_exts {
                                 if sectors > 0 && lba > 0 {
@@ -138,7 +156,7 @@ impl Disc {
         }
 
         // Build streams from STN table
-        let streams: Vec<Stream> = parsed
+        let mut streams: Vec<Stream> = parsed
             .streams
             .iter()
             .filter_map(|s| {
@@ -232,6 +250,42 @@ impl Disc {
             })
             .collect();
 
+        // 3D: add the MVC dependent (right-eye) video stream. The base STN table
+        // lists only the left-eye video; the dependent view is a second video
+        // PID (stream_type 0x20) carried in the SSIF. The on-disc PAT/PMT are
+        // AACS-encrypted (unreadable pre-key) and the base STN omits the
+        // dependent view (it lives in the MPLS STN_table_SS), so we use the
+        // BD-3D PID convention: dependent = base-view video PID + 1
+        // (e.g. 0x1011 -> 0x1012). Reading the SSIF (above) provides its packets.
+        //
+        // Limitation: `is_3d` latches per PLAYLIST, not per clip. A playlist that
+        // mixed a 3D clip (has an SSIF) with a 2D clip (no SSIF) would tag the
+        // whole title 3D; the 2D clip's frames then mux as plain Blocks (no
+        // dependent PID → no BlockAdditional) under a track that still advertises
+        // the mvcC mapping. That output is valid (per-frame BlockAdditional is
+        // optional) but over-claims 3D for those frames. Real 3D main-feature
+        // playlists are single-clip or uniformly 3D, so this is not exercised;
+        // per-clip 3D would need per-clip stream sets (a larger change).
+        if is_3d {
+            if let Some(base) = streams.iter().find_map(|s| match s {
+                Stream::Video(v) => Some(v.clone()),
+                _ => None,
+            }) {
+                let dep_pid = base.pid.wrapping_add(1);
+                let have_dep = streams
+                    .iter()
+                    .any(|s| matches!(s, Stream::Video(v) if v.pid == dep_pid));
+                if !have_dep {
+                    streams.push(Stream::Video(VideoStream {
+                        pid: dep_pid,
+                        secondary: true,
+                        label: crate::disc::MVC_DEPENDENT_LABEL.to_string(),
+                        ..base
+                    }));
+                }
+            }
+        }
+
         // Convert marks to chapters. mark_type == 1 is an entry-mark
         // (chapter); type 2 is a link point and type 0 is reserved, so
         // neither is a chapter.

src/disc/encrypt.rs

@@ -7,7 +7,6 @@ use crate::udf;
 
 /// Result of SCSI AACS handshake (ECDH authentication).
 /// Only available when scanning from a real drive, not ISO images.
-#[derive(Debug)]
 pub(super) struct HandshakeResult {
     pub volume_id: [u8; 16],
     pub read_data_key: Option<[u8; 16]>,
@@ -29,6 +28,19 @@ pub(super) struct HandshakeResult {
     pub drive_unlocked: bool,
 }
 
+// Redacting `Debug`: `volume_id` and `read_data_key` (the AACS 2.0 bus key) are
+// secret; print only shape. Guarded by `handshake_result_debug_is_redacted`.
+impl std::fmt::Debug for HandshakeResult {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("HandshakeResult")
+            .field("volume_id", &"<redacted>")
+            .field("read_data_key", &self.read_data_key.map(|_| "<redacted>"))
+            .field("read_data_key_err", &self.read_data_key_err)
+            .field("drive_unlocked", &self.drive_unlocked)
+            .finish()
+    }
+}
+
 /// Single source of truth for "is AACS bus encryption gone for this scan?". The
 /// gate asks ONLY this — `if !removed { error }` — never enumerating cases. Bus
 /// encryption is gone when ANY of these holds:
@@ -311,15 +323,11 @@ impl Disc {
     ) -> Result<AacsState> {
         use crate::aacs;
 
-        let uk_ro_data = udf_fs
-            .read_file(reader, crate::aacs::PATH_UNIT_KEY_RO)
-            .or_else(|_| udf_fs.read_file(reader, crate::aacs::PATH_UNIT_KEY_RO_DUPLICATE))
-            .map_err(|_| Error::AacsNoKeys)?;
+        let uk_ro_data =
+            aacs::read_first(aacs::UNIT_KEY_RO_PATHS, |p| udf_fs.read_file(reader, p))?;
         let dh = aacs::inf::disc_hash(&uk_ro_data);
 
-        let cc = udf_fs
-            .read_file(reader, crate::aacs::PATH_CONTENT_CERT)
-            .or_else(|_| udf_fs.read_file(reader, crate::aacs::PATH_CONTENT_CERT_ALT))
+        let cc = aacs::read_first(aacs::CONTENT_CERT_PATHS, |p| udf_fs.read_file(reader, p))
             .ok()
             .as_deref()
             .and_then(aacs::inf::parse_content_cert);
@@ -432,6 +440,27 @@ mod tests {
     use crate::sector::SectorSource;
     use std::collections::HashMap;
 
+    /// `HandshakeResult` carries the Volume ID and the AACS 2.0 bus (read-data)
+    /// key; `Debug` must redact both. Sentinel 213 (0xD5).
+    #[test]
+    fn handshake_result_debug_is_redacted() {
+        let hs = HandshakeResult {
+            volume_id: [0xD5; 16],
+            read_data_key: Some([0xD5; 16]),
+            read_data_key_err: None,
+            drive_unlocked: false,
+        };
+        let d = format!("{hs:?}");
+        assert!(
+            !d.contains("213"),
+            "HandshakeResult leaked VID/bus key: {d}"
+        );
+        assert!(
+            d.contains("redacted"),
+            "HandshakeResult missing marker: {d}"
+        );
+    }
+
     // ---------------------------------------------------------------
     // In-memory disc + minimal UDF image with a single physical
     // partition (metadata_start == partition_start). Offsets cited
@@ -980,7 +1009,7 @@ mod tests {
     /// A minimal in-test KeySource that yields no keys but a fixed cert list.
     struct CertSource(Vec<aacs::types::HostCert>);
     impl crate::KeySource for CertSource {
-        fn get_uk(
+        fn get_unit_keys(
             &self,
             _ctx: &dyn crate::keysource::ResolveCtx,
         ) -> Result<Vec<crate::aacs::types::UnitKey>> {

src/disc/extract.rs

@@ -288,63 +288,6 @@ impl Disc {
     }
 }
 
-/// True for the AACS-encrypted stream files (`.m2ts`, `.ssif`). Every other UDF
-/// file is clear (nav / playlists / filesystem) and needs no decrypt verify.
-fn is_aacs_clip(name: &str) -> bool {
-    let lower = name.to_ascii_lowercase();
-    lower.ends_with(".m2ts") || lower.ends_with(".ssif")
-}
-
-/// Enumerate the disc's AACS clip (`.m2ts`/`.ssif`) files as
-/// [`crate::disc::verify::ClipLayout`]s for the post-read verify gate: each
-/// clip's declared size plus its absolute disc extents in FILE order. Reads the
-/// UDF tree through `reader`.
-///
-/// FAIL-SAFE: any enumeration error (bad UDF read, name collision, …) yields an
-/// EMPTY list — the verify gate then covers nothing and the sweep behaves as
-/// today. Enumeration must never break a rip, so the error is logged, not
-/// propagated.
-pub(crate) fn clip_layouts(reader: &mut dyn SectorSource) -> Vec<crate::disc::verify::ClipLayout> {
-    let result = (|| -> Result<Vec<crate::disc::verify::ClipLayout>> {
-        let fs = udf::read_filesystem(reader)?;
-        let mut planned: Vec<PlannedFile> = Vec::new();
-        let mut dirs: Vec<PathBuf> = Vec::new();
-        let mut seen_hosts: std::collections::HashMap<PathBuf, String> =
-            std::collections::HashMap::new();
-        plan_tree(
-            reader,
-            &fs,
-            &fs.root,
-            Path::new(""),
-            "",
-            true,
-            &mut planned,
-            &mut dirs,
-            &mut seen_hosts,
-        )?;
-        Ok(planned
-            .into_iter()
-            .filter(|pf| pf.inline.is_none() && is_aacs_clip(&pf.disc_name))
-            .map(|pf| crate::disc::verify::ClipLayout {
-                size: pf.size,
-                extents: pf.extents,
-                // Every AACS clip we enumerate today is BD-TS (`.m2ts`/`.ssif`).
-                // HD-DVD `.evo` (program stream) maps to `ContainerKind::Ps` here
-                // once `is_aacs_clip` recognises it — the one-line HD-DVD hook.
-                container: crate::disc::verify::ContainerKind::Ts,
-            })
-            .collect())
-    })();
-    result.unwrap_or_else(|e| {
-        tracing::warn!(
-            target: "freemkv::verify",
-            error = %e,
-            "clip enumeration failed; post-read verify disabled for this pass"
-        );
-        Vec::new()
-    })
-}
-
 /// A borrowing `SectorSource` wrapper. Lets the decrypting decorator "own" an
 /// inner source for its lifetime while the caller keeps the underlying
 /// `&mut dyn SectorSource` (the decorator is a `DecryptingSectorSource<S>`

src/disc/hddvd.rs

@@ -522,8 +522,10 @@ fn compose_xpl_titles(
             })
             .collect();
         titles.push(DiscTitle {
+            // Language-neutral identifier (no user-facing English in the library):
+            // matches the UDF `TITLE_*` volume-label style. Apps localize display.
             playlist: if t.name.is_empty() {
-                format!("Title {}", t.number)
+                format!("TITLE_{}", t.number)
             } else {
                 t.name.clone()
             },

src/disc/mapfile.rs

@@ -77,7 +77,7 @@ impl SectorStatus {
 
 /// One contiguous range of bytes with a status.
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct MapEntry {
+pub(crate) struct MapEntry {
     pub pos: u64,
     pub size: u64,
     pub status: SectorStatus,
@@ -498,7 +498,7 @@ impl Mapfile {
 
     /// All map entries, sorted ascending by `pos` and (after load)
     /// guaranteed disjoint and non-overflowing.
-    pub fn entries(&self) -> &[MapEntry] {
+    pub(crate) fn entries(&self) -> &[MapEntry] {
         &self.entries
     }
 

src/disc/mod.rs

@@ -10,7 +10,7 @@
 
 mod bluray;
 mod dvd;
-pub mod dvd_audio_probe;
+pub(crate) mod dvd_audio_probe;
 mod encrypt;
 mod extract;
 mod hddvd;
@@ -19,7 +19,6 @@ mod patch;
 pub mod read_error;
 mod section_recover;
 mod sweep;
-pub mod verify;
 
 use crate::drive::{Drive, extract_scsi_context};
 use crate::error::{Error, Result};
@@ -85,7 +84,8 @@ pub struct Disc {
 pub enum ContentFormat {
     /// Blu-ray BD Transport Stream (192-byte packets)
     BdTs,
-    /// DVD MPEG-2 Program Stream (VOB)
+    /// MPEG-2 Program Stream — DVD (`.vob`) and HD-DVD (`.evo`). For AACS content
+    /// this selects the PS-aware encrypted-flag / structural checks.
     MpegPs,
 }
 
@@ -216,6 +216,22 @@ pub struct VideoStream {
     pub measured_cicp: Option<MeasuredCicp>,
 }
 
+/// Label marking a video stream as the Blu-ray 3D **MVC dependent (right-eye)
+/// view** — the paired substream of the AVC base view. Set by the BD scan
+/// (`bluray.rs`) and recognised by the mux path (`resolve.rs` builds its parser
+/// in param-set-preserving mode; `mkvstream.rs` folds it into the base track as
+/// per-frame `BlockAdditional`). Single source of truth for the contract.
+pub const MVC_DEPENDENT_LABEL: &str = "MVC dependent view (3D right eye)";
+
+impl VideoStream {
+    /// Whether this video stream is the MVC dependent (right-eye) view — the
+    /// 3D substream that the muxer merges into the base track as a per-frame
+    /// `BlockAdditional` rather than emitting as an independent track.
+    pub fn is_mvc_dependent(&self) -> bool {
+        self.label == MVC_DEPENDENT_LABEL
+    }
+}
+
 /// Measured CICP colour signalling read directly from a video elementary stream
 /// (ITU-T H.273). Preferred over the coarse [`ColorSpace`] enum when present.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -441,7 +457,7 @@ pub(crate) fn chapter_name(i: usize) -> String {
 }
 
 /// A contiguous range of sectors on disc.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct Extent {
     pub start_lba: u32,
     pub sector_count: u32,
@@ -667,7 +683,10 @@ fn range_chapter(lba: u32, title: &DiscTitle) -> (Option<u32>, Option<f64>) {
 /// This is the single place range→chapter/time annotation happens; autorip used
 /// to own it and read the mapfile to do so. Now the library computes it from
 /// its in-memory mapfile + title, and the client renders the result verbatim.
-pub fn locate_ranges(raw: &[(u64, u64)], title: &DiscTitle) -> crate::progress::LocatedProgress {
+pub(crate) fn locate_ranges(
+    raw: &[(u64, u64)],
+    title: &DiscTitle,
+) -> crate::progress::LocatedProgress {
     use crate::consts::{MILLIS_PER_SEC, SECTOR_BYTES_U64};
     use crate::progress::{LocatedProgress, LocatedRange};
     const MAX_LOCATED: usize = 50;
@@ -811,7 +830,11 @@ impl Codec {
         use crate::consts::coding_type as c;
         match ct {
             c::HEVC => Codec::Hevc,
-            c::H264 => Codec::H264,
+            // 0x1B base-view AVC and 0x20 MVC dependent-view (Blu-ray 3D right
+            // eye) are both H.264. Mapping 0x20 to video is what makes the PMT
+            // scan enumerate the dependent view as a second H.264 stream (its
+            // own PID in the SSIF) instead of dropping it — the basis of 3D.
+            c::H264 | c::H264_MVC => Codec::H264,
             c::VC1 => Codec::Vc1,
             c::MPEG2_VIDEO => Codec::Mpeg2,
             c::TRUEHD => Codec::TrueHd,
@@ -1343,7 +1366,6 @@ impl DiscTitle {
 // ─── Encryption ─────────────────────────────────────────────────────────────
 
 /// AACS decryption state for a disc.
-#[derive(Debug)]
 pub struct AacsState {
     /// AACS version (1 or 2)
     pub version: u8,
@@ -1374,6 +1396,28 @@ pub struct AacsState {
     pub mkb: Vec<u8>,
 }
 
+// Redacting `Debug`: `AacsState` is crate-root re-exported and reachable via the
+// public `Disc.aacs` field; it carries VUK / unit keys / read-data (bus) key /
+// volume id / raw .inf + MKB. Print only non-secret shape; redact every
+// key/secret field. Guarded by `aacs_state_and_key_debug_are_redacted`.
+impl std::fmt::Debug for AacsState {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("AacsState")
+            .field("version", &self.version)
+            .field("bus_encryption", &self.bus_encryption)
+            .field("mkb_version", &self.mkb_version)
+            .field("disc_hash", &self.disc_hash)
+            .field("key_source", &self.key_source)
+            .field("vuk", &self.vuk.map(|_| "<redacted>"))
+            .field("unit_keys_len", &self.unit_keys.len())
+            .field("read_data_key", &self.read_data_key.map(|_| "<redacted>"))
+            .field("volume_id", &"<redacted>")
+            .field("uk_ro_len", &self.uk_ro.len())
+            .field("mkb_len", &self.mkb.len())
+            .finish()
+    }
+}
+
 /// 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
@@ -1396,18 +1440,9 @@ pub enum KeyOrigin {
     ExternalUk,
 }
 
-impl KeyOrigin {
-    pub fn name(&self) -> &'static str {
-        match self {
-            KeyOrigin::DeviceKey => "MKB + device key",
-            KeyOrigin::ProcessingKey => "MKB + processing key",
-            KeyOrigin::KeyDbDerived => "KEYDB (derived)",
-            KeyOrigin::KeyDb => "KEYDB",
-            KeyOrigin::KeyDbUnitKeys => "KEYDB (unit keys)",
-            KeyOrigin::ExternalUk => "external UK",
-        }
-    }
-}
+// No `KeyOrigin::name()`: the library holds ZERO user-facing English (CLAUDE.md).
+// `KeyOrigin` is a typed enum; applications map its variants to display text
+// (see freemkv's `disc_info::key_origin_label`).
 
 // ─── Disc scanning ──────────────────────────────────────────────────────────
 
@@ -1603,12 +1638,11 @@ impl Disc {
         // detection needs the read, the read needs auth, auth needs detection.
         // The handshake is itself the detector: on a non-CSS (unencrypted) DVD
         // the disc-key read fails, `resolve` returns None, and the disc is left
-        // in the clear. This block is DVD-only (MPEG-PS); BD/UHD (MPEG-TS) goes
-        // through the AACS handshake above and never reaches here.
-        if disc.css.is_none()
-            && disc.content_format == ContentFormat::MpegPs
-            && !disc.titles.is_empty()
-        {
+        // in the clear. This block is DVD-only: gate on `DiscFormat::Dvd`, NOT
+        // `content_format == MpegPs` — HD-DVD `.evo` is ALSO MPEG-PS but is AACS,
+        // not CSS, so it must never enter the CSS/REPORT-KEY handshake (it goes
+        // through the AACS path above). BD/UHD are MPEG-TS and never reach here.
+        if disc.css.is_none() && disc.format == DiscFormat::Dvd && !disc.titles.is_empty() {
             // CSS title keys are per-VTS, and ONLY the scrambled movie content
             // carries a non-zero key. Menu / VMG / logo cells (often the
             // low-LBA first extent) return a ZERO title key over REPORT KEY —
@@ -1724,10 +1758,13 @@ impl Disc {
         // pre-decrypted one. A pre-decrypted image has its scramble flags clear,
         // so `crack_key` finds no crackable sector and the disc stays in the
         // clear. AACS images go through KEYDB VUK lookup, not here.
-        if disc.css.is_none()
-            && disc.content_format == ContentFormat::MpegPs
-            && !disc.titles.is_empty()
-        {
+        //
+        // Gate on `DiscFormat::Dvd`, NOT `content_format == MpegPs`: HD-DVD
+        // `.evo` images are ALSO MPEG-PS but are AACS, not CSS — they must not
+        // enter the CSS crack path. A CSS DVD's IFO (which defines the titles
+        // this branch reads) is unscrambled, so `detect_format` reliably sets
+        // `Dvd` from the SD-resolution titles even on a still-scrambled image.
+        if disc.css.is_none() && disc.format == DiscFormat::Dvd && !disc.titles.is_empty() {
             let main_extents = match disc
                 .titles
                 .iter()
@@ -1779,10 +1816,9 @@ impl Disc {
         reader: &mut dyn SectorSource,
         udf_fs: &udf::UdfFs,
     ) -> Result<(Vec<u8>, Vec<u8>, u8)> {
-        let inf = udf_fs
-            .read_file(reader, crate::aacs::PATH_UNIT_KEY_RO)
-            .or_else(|_| udf_fs.read_file(reader, crate::aacs::PATH_UNIT_KEY_RO_DUPLICATE))
-            .map_err(|_| Error::AacsNoKeys)?;
+        let inf = crate::aacs::read_first(crate::aacs::UNIT_KEY_RO_PATHS, |p| {
+            udf_fs.read_file(reader, p)
+        })?;
         let mkb = Self::read_mkb_content(reader, udf_fs)?;
         let version = Self::read_aacs_version(reader, udf_fs);
         Ok((inf, mkb, version))
@@ -1800,12 +1836,12 @@ impl Disc {
     /// mis-strided title keys (silent wrong unit keys), so a missing cert must
     /// not quietly pick the V10 stride for a UHD disc.
     fn read_aacs_version(reader: &mut dyn SectorSource, udf_fs: &udf::UdfFs) -> u8 {
-        match udf_fs
-            .read_file(reader, crate::aacs::PATH_CONTENT_CERT)
-            .or_else(|_| udf_fs.read_file(reader, crate::aacs::PATH_CONTENT_CERT_ALT))
-            .ok()
-            .as_deref()
-            .and_then(crate::aacs::inf::parse_content_cert)
+        match crate::aacs::read_first(crate::aacs::CONTENT_CERT_PATHS, |p| {
+            udf_fs.read_file(reader, p)
+        })
+        .ok()
+        .as_deref()
+        .and_then(crate::aacs::inf::parse_content_cert)
         {
             Some(c) => c.version.major(),
             None => {
@@ -1836,10 +1872,9 @@ impl Disc {
         const MAX_BYTES: usize = 64 * 1024 * 1024;
         let mut want = START_BYTES;
         loop {
-            let buf = udf_fs
-                .read_file_prefix(reader, crate::aacs::PATH_MKB_RO, want)
-                .or_else(|_| udf_fs.read_file_prefix(reader, crate::aacs::PATH_MKB_RW, want))
-                .map_err(|_| Error::AacsNoKeys)?;
+            let buf = crate::aacs::read_first(crate::aacs::MKB_PATHS, |p| {
+                udf_fs.read_file_prefix(reader, p, want)
+            })?;
             let n = crate::aacs::mkb::mkb_content_len(&buf);
             // `n` strictly inside `buf` => the record walk reached the padding
             // boundary (full content captured). `buf` shorter than `want` =>
@@ -2224,7 +2259,7 @@ impl Disc {
 /// point at one level of that chain; [`Disc::decrypt_with`] derives down from
 /// it to the per-CPS unit keys. New levels can be added without breaking
 /// callers.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 #[non_exhaustive]
 pub enum Key {
     /// Device key(s) (AACS DK, positioned). libfreemkv walks the MKB
@@ -2253,6 +2288,22 @@ pub enum Key {
     Unit(Vec<(u32, [u8; 16])>),
 }
 
+// Redacting `Debug`: `Key` is crate-root re-exported and is the key-transport
+// type crossing `Disc::decrypt_with`; every variant carries raw key material.
+// Print only the variant name and count — never bytes. Guarded by
+// `aacs_state_and_key_debug_are_redacted`.
+impl std::fmt::Debug for Key {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Key::Device(v) => write!(f, "Key::Device(<{} redacted>)", v.len()),
+            Key::Processing(v) => write!(f, "Key::Processing(<{} redacted>)", v.len()),
+            Key::Media(v) => write!(f, "Key::Media(<{} redacted>)", v.len()),
+            Key::Volume(_) => f.write_str("Key::Volume(<redacted>)"),
+            Key::Unit(v) => write!(f, "Key::Unit(<{} redacted>)", v.len()),
+        }
+    }
+}
+
 /// True if `unit_keys` covers EVERY supplied scrambled content `sample` — the
 /// validation gate for [`Disc::decrypt_with`]. Conservative: a sample that is
 /// not AACS-scrambled proves nothing, and with no scrambled sample at all there
@@ -2277,12 +2328,15 @@ fn aligned_unit_keys_validate(
     unit_keys: &[(u32, [u8; 16])],
     read_data_key: Option<&[u8; 16]>,
     samples: &[Vec<u8>],
+    format: ContentFormat,
 ) -> bool {
-    use crate::aacs::content::{ALIGNED_UNIT_LEN, aacs_unit_needs_decrypt, decrypt_unit_full};
+    use crate::aacs::content::{
+        ALIGNED_UNIT_LEN, aacs_unit_needs_decrypt, decrypt_bus, decrypt_unit, is_clean,
+    };
     let scrambled: Vec<&[u8]> = samples
         .iter()
         .map(|s| s.as_slice())
-        .filter(|s| aacs_unit_needs_decrypt(s))
+        .filter(|s| aacs_unit_needs_decrypt(s, format))
         .collect();
     if scrambled.is_empty() {
         return true; // nothing to disprove against — accept
@@ -2304,7 +2358,13 @@ fn aligned_unit_keys_validate(
             hb.tick_cpu(tried, total);
             tried += 1;
             probe.copy_from_slice(&sample[..ALIGNED_UNIT_LEN]);
-            if decrypt_unit_full(&mut probe, k, read_data_key) {
+            // bus layer (AACS 2.0) first, then the CPS unit key, then the structural
+            // proof — the composed form of the old `decrypt_unit_full`.
+            if let Some(rdk) = read_data_key {
+                decrypt_bus(&mut probe, rdk);
+            }
+            decrypt_unit(&mut probe, k);
+            if is_clean(&probe, format) {
                 covered = true;
                 break;
             }
@@ -2331,6 +2391,7 @@ impl Disc {
             crate::decrypt::DecryptKeys::Aacs {
                 unit_keys: aacs.unit_keys.clone(),
                 read_data_key: aacs.read_data_key,
+                format: self.content_format,
             }
         } else if let Some(ref css) = self.css {
             crate::decrypt::DecryptKeys::Css {
@@ -2357,7 +2418,7 @@ impl Disc {
     ///
     /// Empty when the disc has no parsed titles (CSS / unencrypted / unscanned);
     /// callers treat an empty map as "no content gate" and fall back accordingly.
-    pub fn encrypted_content_ranges(&self) -> Vec<(u32, u32)> {
+    pub(crate) fn encrypted_content_ranges(&self) -> Vec<(u32, u32)> {
         merged_extents(self.titles.iter().flat_map(|t| &t.extents))
     }
 
@@ -2365,10 +2426,10 @@ impl Disc {
     /// empty when this disc has no captured AACS state. Used to name the disc in
     /// a [`Error::NoDiscKey`] so the application can tell the user which disc to
     /// add to the keydb.
-    pub fn aacs_disc_hash(&self) -> String {
+    pub(crate) fn aacs_disc_hash(&self) -> String {
         self.aacs
             .as_ref()
-            .map(|a| a.disc_hash.trim_start_matches("0x").to_string())
+            .map(|a| crate::hex::strip_hex_prefix(&a.disc_hash).to_string())
             .unwrap_or_default()
     }
 
@@ -2505,35 +2566,25 @@ impl Disc {
     ///
     /// `batch_sectors` sizes the crack's batched reads (file-safe value for
     /// an ISO; `detect_max_batch_sectors` for a live drive).
-    pub fn decrypt_keys_for_title(
-        &self,
-        idx: usize,
-        reader: &mut dyn SectorSource,
-        batch_sectors: u16,
-    ) -> crate::decrypt::DecryptKeys {
-        self.decrypt_keys_for_title_checked(idx, reader, batch_sectors)
-            .0
-    }
-
-    /// [`Self::decrypt_keys_for_title`] plus the per-title encryption verdict the
-    /// gate needs to AVOID A FALSE ERROR on a genuinely-clear extra title.
+    /// Also returns the per-title encryption verdict the gate needs to AVOID A
+    /// FALSE ERROR on a genuinely-clear extra title.
     ///
     /// On a multi-VTS CSS DVD that ALSO carries a clear, unencrypted stub title
     /// (a 0.5 s menu loop, an FBI-warning nav title) living in its own VTS, the
     /// re-crack over that stub's extents finds NO scrambled sector and recovers
-    /// no key. The bare `decrypt_keys_for_title` collapses that to
+    /// no key. Returning ONLY the keys would collapse that to
     /// `DecryptKeys::None`, indistinguishable from "scrambled but uncrackable",
     /// so [`Self::ensure_decryptable_keys`] (which fails whenever `css.is_some()`
-    /// and the key is `None`) wrongly raised `E7023` for a title that needs no
-    /// key at all. That is the false error the multi-title mux must never emit.
+    /// and the key is `None`) would wrongly raise `E7023` for a title that needs
+    /// no key at all — the false error the multi-title mux must never emit.
     ///
-    /// This variant runs the re-crack via [`crate::css::crack_key_outcome`] and
+    /// So the re-crack runs via [`crate::css::crack_key_outcome`] and ALSO
     /// returns `title_is_clear == true` when the title's own extents showed NO
     /// scrambling (`CrackOutcome::Unencrypted`) — the gate then treats that title
     /// as needing no key and passes it cleanly. A title that genuinely IS
     /// scrambled but uncrackable returns `(None, false)` and still hard-fails.
     /// The returned bool pairs with [`Self::ensure_title_decryptable`].
-    pub fn decrypt_keys_for_title_checked(
+    pub fn decrypt_keys_for_title(
         &self,
         idx: usize,
         reader: &mut dyn SectorSource,
@@ -2597,7 +2648,7 @@ impl Disc {
     }
 
     /// Per-title decrypt gate that honours the `title_is_clear` verdict from
-    /// [`Self::decrypt_keys_for_title_checked`].
+    /// [`Self::decrypt_keys_for_title`].
     ///
     /// Identical to [`Self::ensure_decryptable_keys`] EXCEPT it does not raise
     /// `E7023` when the chosen title proved genuinely clear (`title_is_clear`):
@@ -2625,28 +2676,6 @@ impl Disc {
         self.ensure_decryptable_keys(raw, keys)
     }
 
-    /// Upfront FMTS (AACS 2.1) key gate, parallel to
-    /// [`ensure_title_decryptable`](Self::ensure_title_decryptable). A 2.1 disc
-    /// carries forensic variant segments that need segment (variant) keys the
-    /// unit-key path cannot provide. When
-    /// [`BYPASS_FMTS_KEY`](crate::aacs::segment::BYPASS_FMTS_KEY) is `false`,
-    /// their absence is a hard upfront failure ([`Error::FmtsKeyMissing`]) — the
-    /// same policy as a missing unit key, so a forensic-holed rip is refused, not
-    /// produced. When `true` (the default today) the segments are skipped as
-    /// expected loss and this passes. `raw` mode and non-FMTS discs always pass.
-    pub fn ensure_forensic_segments_decryptable(&self, raw: bool) -> Result<()> {
-        if raw || crate::aacs::segment::BYPASS_FMTS_KEY {
-            return Ok(());
-        }
-        // A 2.1 (FMTS) disc carries forensic variant segments with no segment-key
-        // source (none exists yet), so its variant segments cannot be opened.
-        // Refuse upfront rather than emit a forensic-holed rip.
-        if self.format == DiscFormat::Fmts {
-            return Err(Error::FmtsKeyMissing);
-        }
-        Ok(())
-    }
-
     /// Inject pre-resolved AACS unit keys into a scanned disc — the deferred-mux
     /// / resume path. The keys come from the mapfile's `# freemkv-uk:` header
     /// (persisted at sweep time when the disc was keyed), so the mux decrypts
@@ -2664,7 +2693,7 @@ impl Disc {
     /// file-backed mux. Without this, a keyed disc swept without a keydb would
     /// recover its UK yet still report E8005 (no usable `decrypt_keys`) at
     /// remux. No-op for an unencrypted or CSS (DVD) disc.
-    pub fn inject_unit_keys(&mut self, keys: Vec<(u32, [u8; 16])>) {
+    pub(crate) fn inject_unit_keys(&mut self, keys: Vec<(u32, [u8; 16])>) {
         if let Some(aacs) = self.aacs.as_mut() {
             aacs.unit_keys = keys;
             aacs.key_source = KeyOrigin::ExternalUk;
@@ -2820,7 +2849,12 @@ impl Disc {
         // de-scramble it. With no samples (or only clear ones) there is nothing
         // to disprove against, so the key is accepted as-is — keeping the
         // sample-less paths (resume / mapfile cache) byte-for-byte unchanged.
-        if !aligned_unit_keys_validate(&candidate_unit_keys, read_data_key.as_ref(), samples) {
+        if !aligned_unit_keys_validate(
+            &candidate_unit_keys,
+            read_data_key.as_ref(),
+            samples,
+            self.content_format,
+        ) {
             return Err(crate::error::Error::AacsKeyRejected);
         }
 
@@ -3053,10 +3087,6 @@ impl Disc {
             progress: opts.progress,
             halt: opts.halt.clone(),
             key_fetch: opts.key_fetch.clone(),
-            // Disc::copy's internal patch grinds each range fully (it's a
-            // single-call recovery); the breadth-first fast-capture ordering is
-            // an autorip multi-pass concern.
-            fast_capture: false,
         };
         let pr = self.patch(reader, path, &patch_opts)?;
         tracing::info!(
@@ -3111,27 +3141,15 @@ impl Disc {
         // A decrypting sweep (`opts.decrypt`, e.g. `disc:// → iso://` without
         // `--raw`) decrypts each unit IN PLACE → the ISO holds plaintext.
         //
-        // A NON-decrypting MULTIPASS sweep (`!opts.decrypt && skip_on_error`, the
-        // autorip / `--multipass` path) writes the ISO as CIPHERTEXT, but we
-        // still resolve the keys and VERIFY each unit on a scratch copy: a unit
-        // that won't decrypt fails the read (`DECRYPT_VERIFY_READ`) exactly like
-        // a SCSI error, and flows into the SAME read-error recovery (skip /
-        // NonTrimmed / patch). This is the one spot that makes "a read succeeded"
-        // mean "read AND decrypts" — everything downstream is unchanged. With no
-        // usable AACS keys (no keydb) it degrades to a plain pass-through.
-        //
-        // A plain `--raw` single-pass (no `skip_on_error`) stays a pass-through:
-        // the user asked for the raw image, untouched and unchecked.
-        // The sweep COPIES ciphertext (multipass / `--raw`) or decrypts IN PLACE
-        // (`opts.decrypt`, the rare disc→decrypted-ISO). It deliberately does NOT
-        // decrypt-VERIFY: a whole-disc sweep reads disc-absolute, but AACS aligned
-        // units are anchored to each clip's FILE start and clips can be non-6144-
-        // aligned OR fragmented across UDF extents — so a disc-absolute verify
-        // mis-aligns the unit grid and false-fails good clips (it skipped the
-        // ~990 MB orphan-CPS clip on Dunkirk). Verification moved to the
-        // clip-anchored [`Disc::verify_clips`] pass that runs AFTER the sweep,
-        // reading each clip file-order-anchored from the ISO. The read here stays
-        // a fail-safe copy; alignment is never assumed.
+        // Every other sweep (`!opts.decrypt`: the autorip / `--multipass` path and
+        // plain `--raw`) writes the ISO as CIPHERTEXT verbatim — keys = `None`, a
+        // pure pass-through. Bad sectors are found by PHYSICAL read success (a SCSI
+        // read error → skip / NonTrimmed → patch re-read), NOT by decrypt structure.
+        // (The old decrypt-VERIFY read gate — which mis-aligned the disc-absolute
+        // unit grid against clip-file-anchored AACS units and false-failed good
+        // clips like Dunkirk's orphan-CPS clip — was removed. There is no scratch
+        // verify and no post-sweep clip-anchored pass; decryptability is proven at
+        // mux time, not at capture time.)
         let keys = if opts.decrypt {
             self.decrypt_keys()
         } else {
@@ -3157,22 +3175,6 @@ impl Disc {
         };
         let reader = &mut reader;
 
-        // Post-read verify gate (universal `read -> verify -> sign-off`). Built
-        // ONLY for the ciphertext sweep (`!opts.decrypt`, the multipass rip
-        // path) so `observe` always sees on-disc ciphertext and never
-        // double-decrypts already-plaintext bytes. `UnitVerifier::new` is itself
-        // fail-safe: it returns `None` (verify disabled, behavior unchanged) for
-        // a non-AACS disc, no keys, the kill-switch off, or an empty clip
-        // enumeration. We resolve the REAL AACS keys here even though the sweep
-        // copies ciphertext, and reuse the application's key-fetch seam.
-        let mut verifier = if opts.decrypt {
-            None
-        } else {
-            let verify_keys = self.decrypt_keys();
-            let layouts = extract::clip_layouts(&mut *reader);
-            crate::disc::verify::UnitVerifier::new(&layouts, &verify_keys, opts.key_fetch.clone())
-        };
-
         // Mapfile: load if resuming, else wipe + recreate.
         let mapfile_path = self.mapfile_for(path);
         // covers_disc reconciliation. A resume against a mapfile whose total
@@ -3463,18 +3465,6 @@ impl Disc {
                         // The consumer thread sees decrypted bytes; the
                         // pre-0.18 inline decrypt_sectors call lived here.
 
-                        // Post-read verify: observe the just-read ciphertext
-                        // BEFORE it is moved into the channel, collecting the
-                        // clip units this batch completes that are confidently
-                        // undecryptable. Sent as `MarkBad` AFTER the `Good`
-                        // below so the FIFO pipe records `Finished` first and the
-                        // downgrade to `NonTrimmed` last. No-op when the gate is
-                        // disabled (`verifier` is `None`).
-                        let verify_bad = verifier
-                            .as_mut()
-                            .map(|v| v.observe(block_lba, &buf[..block_bytes as usize]))
-                            .unwrap_or_default();
-
                         // Move the batch into the channel via fresh
                         // owned Vec. The producer's `buf` is reused
                         // for the next read.
@@ -3483,26 +3473,6 @@ impl Disc {
                             producer_err = Some(consumer_gone());
                             break 'outer;
                         }
-                        // Downgrade any unit that failed verify (decrypt-fail ==
-                        // bad read). decrypt-fail is NOT physical damage, so it
-                        // deliberately does not touch the damage-jump window.
-                        let mut send_failed = false;
-                        for (bad_lba, bad_cnt) in verify_bad {
-                            if pipe
-                                .send(WorkItem::MarkBad {
-                                    pos: bad_lba as u64 * 2048,
-                                    len: bad_cnt as u64 * 2048,
-                                })
-                                .is_err()
-                            {
-                                producer_err = Some(consumer_gone());
-                                send_failed = true;
-                                break;
-                            }
-                        }
-                        if send_failed {
-                            break 'outer;
-                        }
                         bytes_done = bytes_done.saturating_add(block_bytes);
                         pos += block_bytes;
                     }
@@ -3989,18 +3959,6 @@ pub struct PatchOptions<'a> {
     /// On-decrypt-miss key fetch (see [`CopyOptions::key_fetch`]). Lets Pass N
     /// recover an orphan CPS unit's key when re-reading its bad range.
     pub key_fetch: Option<crate::sector::KeyFetch>,
-    /// Fast-capture pass: read each bad range ONCE at the full batch and leave
-    /// every failed block `NonTrimmed` for a later pass — WITHOUT bisecting,
-    /// re-reading, or grinding it here. This lets a first retry pass grab the
-    /// readable blocks (the sweep's good skip-ahead overshoot) of EVERY range
-    /// quickly, before any single range's slow per-sector recovery — so
-    /// recovered data surfaces across the whole disc first instead of grinding
-    /// section 1 to exhaustion before even touching section 2. A later pass
-    /// (`fast_capture = false`) does the granular bisect/retry on what's left.
-    /// No data is dropped: a failed block stays `NonTrimmed` until a granular
-    /// pass recovers it or finally gives up. A transport fault (bridge crash)
-    /// still aborts — it isn't a recoverable bad sector.
-    pub fast_capture: bool,
 }
 
 /// Result returned by [`Disc::patch`].
@@ -4251,6 +4209,40 @@ pub fn detect_max_batch_sectors(device_path: &str) -> u16 {
 mod tests {
     use super::*;
 
+    /// `AacsState` (public via `Disc.aacs`) and `Key` (the key-transport enum)
+    /// must never print raw key bytes on `{:?}`. Sentinel 213 (0xD5); non-secret
+    /// fields below are not 213.
+    #[test]
+    fn aacs_state_and_key_debug_are_redacted() {
+        let st = AacsState {
+            version: 2,
+            bus_encryption: true,
+            mkb_version: Some(77),
+            disc_hash: "0xAA".into(),
+            key_source: KeyOrigin::ExternalUk,
+            vuk: Some([0xD5; 16]),
+            unit_keys: vec![(1, [0xD5; 16])],
+            read_data_key: Some([0xD5; 16]),
+            volume_id: [0xD5; 16],
+            uk_ro: vec![1, 2, 3],
+            mkb: vec![4, 5, 6],
+        };
+        let d = format!("{st:?}");
+        assert!(!d.contains("213"), "AacsState leaked key bytes: {d}");
+        assert!(d.contains("redacted"), "AacsState missing marker: {d}");
+
+        for k in [
+            Key::Unit(vec![(1, [0xD5; 16])]),
+            Key::Volume([0xD5; 16]),
+            Key::Processing(vec![[0xD5; 16]]),
+            Key::Media(vec![[0xD5; 16]]),
+        ] {
+            let d = format!("{k:?}");
+            assert!(!d.contains("213"), "Key leaked bytes: {d}");
+            assert!(d.contains("redacted"), "Key missing marker: {d}");
+        }
+    }
+
     // ── encrypted-content map (`merged_extents` core) ────────────────────────
 
     fn ext(start_lba: u32, sector_count: u32) -> Extent {
@@ -4847,6 +4839,7 @@ mod tests {
             crate::decrypt::DecryptKeys::Aacs {
                 unit_keys,
                 read_data_key,
+                ..
             } => {
                 assert_eq!(unit_keys, uk, "injected UK must be the decrypt key");
                 assert_eq!(read_data_key, None, "ISO mux needs no bus key");
@@ -5125,8 +5118,8 @@ mod tests {
     // ── Fix 2/3: a genuinely-clear extra title on a CSS disc never E7023s ──────
 
     /// Reader that serves clear (unscrambled) sectors for one extent range and
-    /// CSS-locked errors elsewhere — enough to drive `decrypt_keys_for_title_
-    /// checked`'s per-title re-crack to `Unencrypted` for a clear stub.
+    /// CSS-locked errors elsewhere — enough to drive `decrypt_keys_for_title`'s
+    /// per-title re-crack to `Unencrypted` for a clear stub.
     struct ClearStubReader {
         clear_range: (u32, u32),
     }
@@ -5186,7 +5179,7 @@ mod tests {
         let mut reader = ClearStubReader {
             clear_range: (0, 100_000),
         };
-        let (keys, title_is_clear) = disc.decrypt_keys_for_title_checked(stub_idx, &mut reader, 8);
+        let (keys, title_is_clear) = disc.decrypt_keys_for_title(stub_idx, &mut reader, 8);
         assert!(
             !keys.is_encrypted(),
             "a clear stub needs no key (got encrypted keys)"
@@ -5366,14 +5359,15 @@ mod tests {
 
     #[test]
     fn unit_key_validation_gates_on_real_ciphertext() {
-        use crate::aacs::content::{ALIGNED_UNIT_LEN, ts_sync_destroyed};
+        use crate::aacs::content::ALIGNED_UNIT_LEN;
 
         // No samples -> nothing to disprove against -> accept (sample-less paths
         // like resume / mapfile must be unaffected).
         assert!(super::aligned_unit_keys_validate(
             &[(0, [0x11u8; 16])],
             None,
-            &[]
+            &[],
+            ContentFormat::BdTs
         ));
 
         // A clear unit (TS syncs intact) is not scrambled -> proves nothing ->
@@ -5384,18 +5378,22 @@ mod tests {
             clear[off] = 0x47;
             off += 192;
         }
-        assert!(!ts_sync_destroyed(&clear));
+        assert!(crate::aacs::content::is_clean(
+            &clear,
+            crate::disc::ContentFormat::BdTs
+        ));
         assert!(super::aligned_unit_keys_validate(
             &[(0, [0x11u8; 16])],
             None,
-            &[clear.clone()]
+            &[clear.clone()],
+            ContentFormat::BdTs
         ));
 
         // A genuinely scrambled unit the RIGHT key restores to clear TS.
         let uk = [0x5au8; 16];
         let enc = encrypt_unit_for_test(&clear, &uk);
         assert!(
-            ts_sync_destroyed(&enc),
+            !crate::aacs::content::is_clean(&enc, crate::disc::ContentFormat::BdTs),
             "encrypted unit must read scrambled"
         );
 
@@ -5403,16 +5401,23 @@ mod tests {
         assert!(super::aligned_unit_keys_validate(
             &[(7, uk)],
             None,
-            &[enc.clone()]
+            &[enc.clone()],
+            ContentFormat::BdTs
         ));
         // Wrong key -> cannot de-scramble a scrambled sample -> reject.
         assert!(!super::aligned_unit_keys_validate(
             &[(7, [0x00u8; 16])],
             None,
-            &[enc.clone()]
+            &[enc.clone()],
+            ContentFormat::BdTs
         ));
         // Empty key set against a scrambled sample -> reject.
-        assert!(!super::aligned_unit_keys_validate(&[], None, &[enc]));
+        assert!(!super::aligned_unit_keys_validate(
+            &[],
+            None,
+            &[enc],
+            ContentFormat::BdTs
+        ));
     }
 
     #[test]
@@ -5424,7 +5429,7 @@ mod tests {
         // CPS-unit-1 sectors then passed through as raw encrypted bytes into the
         // ISO/MKV with no error surfaced. The gate must now reject a key set
         // that leaves any scrambled sample uncovered.
-        use crate::aacs::content::{ALIGNED_UNIT_LEN, ts_sync_destroyed};
+        use crate::aacs::content::ALIGNED_UNIT_LEN;
 
         let mut clear = vec![0u8; ALIGNED_UNIT_LEN];
         let mut off = 4;
@@ -5437,8 +5442,14 @@ mod tests {
         let uk1 = [0x22u8; 16];
         let sample0 = encrypt_unit_for_test(&clear, &uk0); // CPS unit 0 body
         let sample1 = encrypt_unit_for_test(&clear, &uk1); // CPS unit 1 body
-        assert!(ts_sync_destroyed(&sample0));
-        assert!(ts_sync_destroyed(&sample1));
+        assert!(!crate::aacs::content::is_clean(
+            &sample0,
+            crate::disc::ContentFormat::BdTs
+        ));
+        assert!(!crate::aacs::content::is_clean(
+            &sample1,
+            crate::disc::ContentFormat::BdTs
+        ));
 
         let samples = vec![sample0.clone(), sample1.clone()];
 
@@ -5447,21 +5458,24 @@ mod tests {
         assert!(!super::aligned_unit_keys_validate(
             &[(0, uk0)],
             None,
-            &samples
+            &samples,
+            ContentFormat::BdTs
         ));
 
         // Complete key set (both CPS units) -> accept.
         assert!(super::aligned_unit_keys_validate(
             &[(0, uk0), (1, uk1)],
             None,
-            &samples
+            &samples,
+            ContentFormat::BdTs
         ));
 
         // Order-independent: covering key present anywhere in the set is fine.
         assert!(super::aligned_unit_keys_validate(
             &[(1, uk1), (0, uk0)],
             None,
-            &samples
+            &samples,
+            ContentFormat::BdTs
         ));
     }
 
@@ -5587,7 +5601,7 @@ mod tests {
         let mut src = RecordingSource {
             reads: std::cell::RefCell::new(Vec::new()),
         };
-        match disc.decrypt_keys_for_title(0, &mut src, 16) {
+        match disc.decrypt_keys_for_title(0, &mut src, 16).0 {
             crate::decrypt::DecryptKeys::Css { title_key } => {
                 assert_eq!(title_key, [0xAB; 5], "same-VTS title reuses cracked key");
             }
@@ -5612,7 +5626,7 @@ mod tests {
         let mut src = RecordingSource {
             reads: std::cell::RefCell::new(Vec::new()),
         };
-        let keys = disc.decrypt_keys_for_title(1, &mut src, 16);
+        let keys = disc.decrypt_keys_for_title(1, &mut src, 16).0;
         assert!(
             matches!(keys, crate::decrypt::DecryptKeys::None),
             "a re-crack miss in a provably-different VTS must be a hard failure (None), \

src/disc/patch.rs

@@ -405,9 +405,15 @@ pub(super) fn compute_initial_state(
         bad_ranges.reverse();
     }
     let work_total: u64 = bad_ranges.iter().map(|(_, sz)| *sz).sum();
+    // Fail SAFE when metadata is indeterminate: assume a regular file so a
+    // real `sync_all` failure is surfaced, not swallowed. `/dev/null` and pipes
+    // report success-with-non-file here (so they still correctly map to
+    // `false`); only a genuine metadata error (e.g. transient NFS ESTALE) hits
+    // the default, and for a data-integrity guard "surface the error" is the
+    // right side to err on.
     let is_regular = std::fs::metadata(path)
         .map(|m| m.file_type().is_file())
-        .unwrap_or(false);
+        .unwrap_or(true);
     Ok((
         map,
         initial_stats,
@@ -1247,7 +1253,24 @@ impl Disc {
     pub fn bytes_bad_in_title(&self, mapfile_path: &std::path::Path, title: &DiscTitle) -> u64 {
         let map = match mapfile::Mapfile::load(mapfile_path) {
             Ok(m) => m,
-            Err(_) => return 0,
+            // A MISSING mapfile is legitimate (no damage was ever tracked — e.g. a
+            // clean single-pass rip): 0 bad bytes is correct. Any OTHER load error
+            // (corrupt / unreadable mapfile) means we CANNOT know the damage — and
+            // a returned 0 reads to the caller as "clean." Logging alone is not
+            // fail-safe: the RETURN VALUE drives the loss/abort accounting, not the
+            // log. So fail safe by reporting the ENTIRE title as bad (its full
+            // in-extent byte count) — a corrupt damage record must surface as
+            // maximal loss, never as a clean rip.
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => return 0,
+            Err(e) => {
+                tracing::warn!(
+                    target: "freemkv::disc",
+                    path = %mapfile_path.display(),
+                    error = %e,
+                    "bytes_bad_in_title: mapfile load failed; reporting whole title bad (fail-safe: cannot confirm clean)"
+                );
+                return bytes_bad_in_title(title, &[(0, u64::MAX)]);
+            }
         };
         let bad_ranges = map.ranges_with(&[
             mapfile::SectorStatus::NonTrimmed,
@@ -1299,33 +1322,13 @@ impl Disc {
         let bytes_good_before = initial_stats.bytes_good;
         let bytes_good_start = bytes_good_before;
 
-        // Post-read verify gate for the patch pass (ciphertext multipass only,
-        // `!opts.decrypt`). Built here from the raw reader's UDF enumeration;
-        // reused AFTER the recovery loop (`reverify_iso`) to re-check the units
-        // this pass touched by reading them WHOLE back from the patched ISO —
-        // patch re-reads only the bad sectors of a unit, so per-unit verify
-        // can't run live. Fail-safe `None` when disabled / non-AACS / no keys.
-        let mut verifier = if opts.decrypt {
-            None
-        } else {
-            let verify_keys = self.decrypt_keys();
-            let layouts = crate::disc::extract::clip_layouts(&mut *reader);
-            crate::disc::verify::UnitVerifier::new(&layouts, &verify_keys, opts.key_fetch.clone())
-        };
         // Decrypt-aware read — symmetric with `Disc::sweep`. A decrypting patch
-        // (`opts.decrypt`) decrypts in place (plaintext ISO). A NON-decrypting
-        // patch (the multipass / `--raw --multipass` path) resolves the keys and
-        // VERIFIES each unit on a scratch copy: a re-read that STILL won't decrypt
-        // fails the read (`DECRYPT_VERIFY_READ`) and stays NonTrimmed, so the
-        // retry loop keeps re-reading it "until it decrypts or retries exhaust"
-        // exactly as for a SCSI read error — and a unit that DOES decrypt on a
-        // fresh read (the drive returned different bytes) is recovered for free.
-        // With no usable AACS keys this degrades to a plain pass-through.
-        // Symmetric with `Disc::sweep`: the patch COPIES ciphertext (multipass /
-        // `--raw`) or decrypts IN PLACE (`opts.decrypt`). It does NOT decrypt-
-        // VERIFY — the disc-absolute read can't anchor to a clip's file-relative
-        // unit grid (see `Disc::sweep` + `Disc::verify_clips`). Re-reads recover
-        // bad sectors; the clip-anchored verify pass re-checks them afterward.
+        // (`opts.decrypt`) decrypts in place (plaintext ISO); a NON-decrypting
+        // patch (the multipass / `--raw --multipass` path) copies ciphertext
+        // verbatim (keys = `None` → pass-through). Bad sectors are found by
+        // PHYSICAL read success, not by decrypt structure: a re-read that returns
+        // good bytes recovers the range; a read that errors leaves it NonTrimmed
+        // for the next pass. (The old decrypt-VERIFY read gate was removed.)
         let keys = if opts.decrypt {
             self.decrypt_keys()
         } else {
@@ -1435,64 +1438,7 @@ impl Disc {
         // sink's summary. `close` failing on a regular-file sync_all is
         // surfaced here as `Error::IoError`, matching pre-split
         // behaviour.
-        let mut summary = pipe.finish()?;
-
-        // Scoped post-read re-verify (decrypt-fail == bad read). The consumer
-        // has flushed the ISO + mapfile; re-read each clip unit this pass touched
-        // WHOLE from the patched ISO and downgrade any that still won't decrypt
-        // to NonTrimmed, so the orchestrator's end-of-recovery promotion
-        // terminalizes it. Reuses the same verifier as the sweep. Fail-safe:
-        // disabled gate / unreadable ISO / load failure all leave the pass as-is.
-        if let Some(mut v) = verifier.take() {
-            if let Ok(mut m) = mapfile::Mapfile::load(&mapfile_path) {
-                // Only units whose every backing sector was actually READ
-                // (Finished) may be re-verified — we can't verify what wasn't read
-                // (a non-Finished sector is zero-filled because the read failed),
-                // and must not waste a key lookup on a known-bad block.
-                let finished = m.ranges_with(&[mapfile::SectorStatus::Finished]);
-                let is_finished = |lba: u32| -> bool {
-                    let p = lba as u64 * 2048;
-                    finished.iter().any(|&(s, sz)| p >= s && p < s + sz)
-                };
-                if let Ok(mut iso) = crate::io::file_sector_source::FileSectorSource::open(path) {
-                    let bad = v.reverify_iso(&mut iso, &bad_ranges, &is_finished);
-                    if !bad.is_empty() {
-                        let n: usize = bad.len();
-                        for (lba, cnt) in bad {
-                            if let Err(e) = m.record(
-                                lba as u64 * 2048,
-                                cnt as u64 * 2048,
-                                mapfile::SectorStatus::NonTrimmed,
-                            ) {
-                                tracing::warn!(
-                                    lba,
-                                    "reverify downgrade: mapfile record failed ({e}) — unit may stay mismarked as good"
-                                );
-                            }
-                        }
-                        if let Err(e) = m.flush() {
-                            tracing::warn!(
-                                "reverify downgrade: mapfile flush failed ({e}) — downgrade not persisted; a resume could mismark it good"
-                            );
-                        }
-                        // The re-verify ran AFTER `pipe.finish()` snapshotted
-                        // `summary.stats`, so those stats still count the just-
-                        // downgraded units as good. Refresh from the mapfile so
-                        // `build_outcome` reports the true post-downgrade picture
-                        // (bytes_good ↓, bytes_pending ↑) — otherwise the caller
-                        // over-reports recovery and can call an imperfect rip
-                        // "complete".
-                        summary.stats = m.stats();
-                        tracing::info!(
-                            target: "freemkv::verify",
-                            phase = "patch.reverify",
-                            downgraded_ranges = n,
-                            "post-read re-verify downgraded undecryptable units to NonTrimmed"
-                        );
-                    }
-                }
-            }
-        }
+        let summary = pipe.finish()?;
 
         let outcome = build_outcome(
             &state,

src/disc/sweep.rs

@@ -66,14 +66,6 @@ pub(super) enum WorkItem {
     /// tell them apart without parsing a flag.
     GapFill { pos: u64, len: u64 },
 
-    /// Post-read verify downgrade. The producer's `UnitVerifier` found that the
-    /// just-`Finished` clip unit at `[pos, pos+len)` is confidently undecryptable
-    /// (a silent bad read). The consumer re-records the range as `NonTrimmed` so
-    /// the patch pass re-reads it — the ISO bytes (ciphertext) already written by
-    /// the preceding `Good` are left in place for the patch to overwrite. FIFO
-    /// pipe ordering guarantees this arrives AFTER the `Good` that wrote them.
-    MarkBad { pos: u64, len: u64 },
-
     /// Producer wants the latest mapfile stats for the progress
     /// callback. Consumer responds on `prog_tx` with a fresh
     /// [`ProgressSnapshot`]. Best-effort: if the producer hasn't
@@ -182,12 +174,6 @@ impl Sink<WorkItem> for SweepSink {
                 }
                 self.map.record(pos, len, SectorStatus::NonTrimmed)?;
             }
-            WorkItem::MarkBad { pos, len } => {
-                // Verify downgrade: the ISO bytes are already written by the
-                // preceding Good; only the mapfile status changes so patch
-                // re-reads this range. No file write.
-                self.map.record(pos, len, SectorStatus::NonTrimmed)?;
-            }
             WorkItem::StatsRequest => {
                 let stats = self.map.stats();
                 // DAMAGE only — NOT NonTried. NonTried is the unread remainder

src/hex.rs

@@ -16,7 +16,7 @@
 /// (case-insensitive), then requires an even run of ASCII hex digits. Any
 /// non-hex byte, or an odd length, yields `None`.
 pub fn parse_hex_bytes(s: &str) -> Option<Vec<u8>> {
-    let body = strip_prefix(s.trim());
+    let body = strip_hex_prefix(s.trim());
     let bytes = body.as_bytes();
     // Empty → empty Vec (a legitimately-empty variable-length field); odd length
     // is malformed. (`parse_hex_fixed` enforces a concrete length separately.)
@@ -34,7 +34,7 @@ pub fn parse_hex_bytes(s: &str) -> Option<Vec<u8>> {
 /// prefix; requires EXACTLY `2*N` ASCII hex digits after it. `None` on any
 /// non-hex byte or a length mismatch.
 pub fn parse_hex_fixed<const N: usize>(s: &str) -> Option<[u8; N]> {
-    let body = strip_prefix(s.trim());
+    let body = strip_hex_prefix(s.trim());
     let bytes = body.as_bytes();
     if bytes.len() != 2 * N {
         return None;
@@ -46,8 +46,33 @@ pub fn parse_hex_fixed<const N: usize>(s: &str) -> Option<[u8; N]> {
     Some(out)
 }
 
-/// Strip a single leading `0x` / `0X` if present (case-insensitive).
-fn strip_prefix(s: &str) -> &str {
+/// Parse a hex string into a `u16`. Accepts an optional `0x`/`0X` prefix
+/// (case-insensitive) via the same [`strip_hex_prefix`] the byte parsers use.
+/// `None` on any non-hex content or overflow.
+///
+/// Exists so callers never hand-roll `from_str_radix(s.trim_start_matches("0x"), 16)`
+/// — a **case-sensitive** strip that silently dropped an uppercase-`0X` value.
+/// (That reintroduced-in-keydb bug is exactly what this module was built to kill;
+/// the integer fields now share the one prefix rule.)
+pub fn parse_hex_u16(s: &str) -> Option<u16> {
+    u16::from_str_radix(strip_hex_prefix(s.trim()), 16).ok()
+}
+
+/// Parse a hex string into a `u32`. See [`parse_hex_u16`].
+pub fn parse_hex_u32(s: &str) -> Option<u32> {
+    u32::from_str_radix(strip_hex_prefix(s.trim()), 16).ok()
+}
+
+/// Parse a hex string into a `u8`. See [`parse_hex_u16`].
+pub fn parse_hex_u8(s: &str) -> Option<u8> {
+    u8::from_str_radix(strip_hex_prefix(s.trim()), 16).ok()
+}
+
+/// Strip a single leading `0x` / `0X` if present (case-insensitive). Public so
+/// callers that only need the prefix rule (e.g. normalizing a disc hash) reuse
+/// the one definition instead of hand-rolling a case-sensitive
+/// `trim_start_matches("0x")`.
+pub fn strip_hex_prefix(s: &str) -> &str {
     s.strip_prefix("0x")
         .or_else(|| s.strip_prefix("0X"))
         .unwrap_or(s)
@@ -95,6 +120,23 @@ mod tests {
         assert_eq!(parse_hex_fixed::<16>(&s), None);
     }
 
+    #[test]
+    fn hex_ints_accept_both_prefix_cases_and_bare() {
+        // The regression the keydb device-key bug hit: uppercase `0X` must parse
+        // identically to `0x` and to a bare value.
+        assert_eq!(parse_hex_u16("0x0001"), Some(1));
+        assert_eq!(parse_hex_u16("0X0001"), Some(1));
+        assert_eq!(parse_hex_u16("0001"), Some(1));
+        assert_eq!(parse_hex_u16(" 0XABCD "), Some(0xABCD));
+        assert_eq!(parse_hex_u32("0X00000002"), Some(2));
+        assert_eq!(parse_hex_u32("deadbeef"), Some(0xDEAD_BEEF));
+        assert_eq!(parse_hex_u8("0X03"), Some(3));
+        assert_eq!(parse_hex_u8("ff"), Some(0xFF));
+        // Overflow / non-hex → None.
+        assert_eq!(parse_hex_u8("0x1FF"), None);
+        assert_eq!(parse_hex_u16("0xzz"), None);
+    }
+
     #[test]
     fn bytes_variable_length_and_odd_rejected() {
         assert_eq!(parse_hex_bytes("0xAABBCC"), Some(vec![0xAA, 0xBB, 0xCC]));

src/io/file_sector_source/mod.rs

@@ -78,8 +78,8 @@ use crate::consts::{SECTOR_BYTES, SECTOR_BYTES_U64};
 /// read side. Mirrors `WRITEBACK_CHUNK_BYTES` so the read-side page
 /// cache stays bounded the same way the write side does.
 ///
-/// 32 MiB is the empirically tuned value on the rip1 test bed (single
-/// 7200rpm HDD via SATA): smaller windows (8 / 16 MiB) shorten the
+/// 32 MiB is the empirically tuned value on a 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`.

src/keysource.rs

@@ -23,6 +23,64 @@ use crate::aacs::types::{UnitKey, Vid};
 use crate::disc::Key;
 use crate::error::Error;
 
+/// Minimum encrypted-content unit samples a single online key request must carry.
+///
+/// The key service identifies a key by which of the submitted units it decrypts,
+/// so too few samples — especially on FMTS, where a segment interleaves several
+/// variants at the unit level — can return a key that matches an incidental unit
+/// rather than the one asked about (a false positive). This many distinct units
+/// make the request unambiguous.
+///
+/// Canonical here (the base crate) so BOTH consumers agree on one value: the
+/// online source in `freemkv-keysources` (which refuses to send an under-sampled
+/// request) re-exports it, and libfreemkv's own FMTS forensic query
+/// ([`crate::mux`]) sizes its per-segment batch by it. Layering forbids the
+/// reverse import (keysources depends on libfreemkv, not vice versa), so the
+/// value lives at the lower layer both share.
+pub const MIN_SAMPLE_UNITS: usize = 8;
+
+/// A set of encrypted content-unit samples PROVEN to carry at least
+/// [`MIN_SAMPLE_UNITS`] units — the online `/decode` request's proof-of-ownership.
+///
+/// "Parse, don't validate": the only constructor, [`DecodeSampleSet::new`], returns
+/// `None` for an under-sized slice, so an online key request simply *cannot be built*
+/// from too few samples. The runtime `len() < MIN_SAMPLE_UNITS` check that used to
+/// live at the request site (and was silently forgotten by an under-sampling caller,
+/// reading as "key service down") becomes a compile-time obligation: a request builder
+/// that takes `&DecodeSampleSet` can never receive an unchecked `Vec`.
+///
+/// The *count* enforced here is a runtime property of the disc (how many encrypted
+/// units it yields); the *requested* count is a caller-side compile-time constant that
+/// callers pin to `MIN_SAMPLE_UNITS` (see e.g. autorip's `SAMPLE_UNITS`). Together the
+/// two make under-sampling unrepresentable at the request boundary.
+#[derive(Debug, Clone)]
+pub struct DecodeSampleSet(Vec<Vec<u8>>);
+
+impl DecodeSampleSet {
+    /// Wrap `units` iff it carries at least [`MIN_SAMPLE_UNITS`] samples; `None`
+    /// otherwise (the caller then skips the online source rather than sending an
+    /// ambiguous request). This is the sole way to obtain a `DecodeSampleSet`.
+    pub fn new(units: Vec<Vec<u8>>) -> Option<Self> {
+        (units.len() >= MIN_SAMPLE_UNITS).then_some(Self(units))
+    }
+
+    /// The proven-sufficient samples. Guaranteed `>= MIN_SAMPLE_UNITS` in length.
+    pub fn units(&self) -> &[Vec<u8>] {
+        &self.0
+    }
+
+    /// Number of samples — always `>= MIN_SAMPLE_UNITS`.
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    /// Always `false` (a `DecodeSampleSet` never holds fewer than `MIN_SAMPLE_UNITS`);
+    /// provided so the type satisfies the usual `len`/`is_empty` pairing.
+    pub fn is_empty(&self) -> bool {
+        false
+    }
+}
+
 /// The public AACS inputs a key source needs to look a disc up. Captured at
 /// scan; contains no secrets — only the disc identity and the on-disc AACS
 /// structures a source or key server may key on.
@@ -57,7 +115,7 @@ pub struct DiscInputs {
     pub volume_label: Option<String>,
 }
 
-/// A lazy view of a disc's AACS material, handed to [`KeySource::get_uk`] so a
+/// A lazy view of a disc's AACS material, handed to [`KeySource::get_unit_keys`] so a
 /// source can drive the derivation chain without holding the disc reader.
 ///
 /// "Lazy" by contract: each accessor returns only what the source asks for, so a
@@ -175,10 +233,34 @@ impl ResolveCtx for DiscInputsCtx<'_> {
 /// ([`resolve_and_apply`]) tries each source in order and validates the returned
 /// keys against real ciphertext before committing them, so a wrong key from one
 /// source transparently falls through to the next.
+///
+/// Two explicit resolve operations, one per key kind — never one overloaded call
+/// whose meaning depends on how many keys came back:
+/// * [`get_unit_keys`](Self::get_unit_keys) — the disc's base per-CPS-unit Unit
+///   Keys (index space = CPS-unit number). The common path for every disc.
+/// * [`get_fmts_indexes`](Self::get_fmts_indexes) — the AACS 2.1 forensic index
+///   keys (index space = forensic index 1..N). Defaults to empty: a source with
+///   no forensic material opts out, and only an FMTS disc ever asks.
+///
+/// What each source must do to answer is the source's own business: a keydb keys
+/// on `disc_hash` and reads no samples; the online source submits the ctx's
+/// content samples (a base batch for `get_unit_keys`, an index-1 anchor batch for
+/// `get_fmts_indexes`) to the key service.
 pub trait KeySource {
-    /// Resolve this disc's terminal Unit Keys from this source. An empty `Vec`
-    /// is a genuine "no key here"; `Err` is a source failure.
-    fn get_uk(&self, ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error>;
+    /// Resolve this disc's base per-CPS-unit Unit Keys from this source. An empty
+    /// `Vec` is a genuine "no key here"; `Err` is a source failure.
+    fn get_unit_keys(&self, ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error>;
+
+    /// Resolve this disc's AACS 2.1 forensic index keys — the per-index keys the
+    /// base Unit Key cannot open (see [`crate::aacs::segment`]) — ordered by
+    /// forensic index (element `i` carries `UnitKey.idx == i`, forensic index
+    /// `i + 1`). The source hands back the COMPLETE set it holds; the caller
+    /// trusts any non-empty result as all of them and never assumes a fixed count.
+    /// Defaults to empty: a source with no forensic material (a plain keydb, the
+    /// mapfile) opts out, and only an FMTS disc's mux ever calls this.
+    fn get_fmts_indexes(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+        Ok(Vec::new())
+    }
 
     /// The AACS host certificate(s) this source can supply for the live-drive
     /// SCSI mutual-auth handshake (the OEM/AACS baseline route). `mkb` is the
@@ -215,7 +297,7 @@ pub fn resolve_and_apply(
 /// [`crate::aacs::trace::ResolutionTrace`] recording, per source, what happened — for
 /// applications to render. ZERO English; the trace is typed enums only.
 ///
-/// One-shot per source: each source's [`KeySource::get_uk`] is called exactly
+/// One-shot per source: each source's [`KeySource::get_unit_keys`] is called exactly
 /// once with a [`DiscInputsCtx`] over `inputs`. Non-empty Unit Keys are mapped
 /// to terminal [`Key::Unit`]s and applied via [`crate::Disc::decrypt_with`],
 /// which validates them against `inputs.samples` and only mutates the disc on
@@ -243,7 +325,7 @@ pub fn resolve_and_apply_traced(
     for source in sources {
         // `who` is the source's own stable identifier — no enum to map back to.
         let who = source.label().to_string();
-        match source.get_uk(&ctx) {
+        match source.get_unit_keys(&ctx) {
             Ok(uks) if !uks.is_empty() => {
                 // Positional index → canonical CPS-unit number (position + 1).
                 let unit_keys: Vec<(u32, [u8; 16])> = uks
@@ -294,7 +376,7 @@ pub fn resolve_and_apply_traced(
 /// decorator re-decrypts with the returned keys, which is the validation.
 pub fn fetch_unit_keys(sources: &[Box<dyn KeySource>], ctx: &dyn ResolveCtx) -> Vec<UnitKey> {
     for source in sources {
-        if let Ok(uks) = source.get_uk(ctx) {
+        if let Ok(uks) = source.get_unit_keys(ctx) {
             if !uks.is_empty() {
                 return uks;
             }
@@ -303,35 +385,92 @@ pub fn fetch_unit_keys(sources: &[Box<dyn KeySource>], ctx: &dyn ResolveCtx) ->
     Vec::new()
 }
 
-/// Build the read-time key-fetch closure from the disc's public AACS inputs and
-/// a way to (re)build the application's key sources. The decorator calls it with
-/// the still-scrambled unit ciphertext when no held key opens that unit; it runs
-/// [`fetch_unit_keys`] with those bytes as `samples` and returns any keys.
+/// The forensic counterpart to [`fetch_unit_keys`]: drive `sources` in order and
+/// return the first source's non-empty AACS 2.1 forensic index set. `ctx` carries
+/// the index-1 anchor batch (the mux, which owns disc geometry, gathers it and
+/// injects it as the ctx's samples); a source that needs no samples (a keydb
+/// keying on `disc_hash`) ignores them. Whatever the winning source returns —
+/// ≥ 1 key — is trusted as the COMPLETE ordered set; no fixed count is assumed.
+pub fn fetch_fmts_indexes(sources: &[Box<dyn KeySource>], ctx: &dyn ResolveCtx) -> Vec<UnitKey> {
+    for source in sources {
+        if let Ok(uks) = source.get_fmts_indexes(ctx) {
+            if !uks.is_empty() {
+                return uks;
+            }
+        }
+    }
+    Vec::new()
+}
+
+/// Build the read-time [`crate::sector::KeyFetch`] from the disc's public AACS
+/// inputs and a way to (re)build the application's key sources. The returned
+/// resolver has the two explicit operations the mux and recovery decorator call:
+/// [`unit_keys`](crate::sector::KeyFetch::unit_keys) drives [`fetch_unit_keys`]
+/// (base per-CPS-unit keys), [`fmts_indexes`](crate::sector::KeyFetch::fmts_indexes)
+/// drives [`fetch_fmts_indexes`] (the AACS 2.1 forensic set). Each is handed the
+/// caller's sample batch as the ctx's `samples`, so a source pulls whatever
+/// material it needs.
 ///
-/// One builder, used by every read path (sweep / patch / mux) and by every
-/// consumer (CLI, autorip) — neither application contains the fetch logic, only
-/// its key-source config. Returns a **shared, stateless** [`crate::sector::KeyFetch`]
-/// (`Arc<Fn>`): build it once, clone it into each read path. `make_sources` is
-/// invoked per fetch (the cold path, ~once per CPS unit) so the closure stays
+/// One builder, used by every read path (sweep / patch / mux) and every consumer
+/// (CLI, autorip) — neither application contains the fetch logic, only its
+/// key-source config. Cheap to clone; build once, clone into each read path.
+/// `make_sources` is invoked per fetch (the cold path) so the resolver stays
 /// `Send + Sync` without requiring `KeySource: Send`.
 pub fn key_fetch(
     inputs: DiscInputs,
     make_sources: std::sync::Arc<dyn Fn() -> Vec<Box<dyn KeySource>> + Send + Sync>,
 ) -> crate::sector::KeyFetch {
-    std::sync::Arc::new(move |samples: &[Vec<u8>]| -> Vec<[u8; 16]> {
-        let sources = make_sources();
-        let mut di = inputs.clone();
-        di.samples = samples.to_vec();
-        // Parse Unit_Key_RO.inf at the disc's OWN stride (carried on `inputs`):
-        // an online /decode reply that returns a VUK (not a terminal UK) then
-        // derives unit keys from `enc_title_keys`, which a V10 disc parses at the
-        // 48-byte stride — hardcoding the V20 stride here corrupted them.
-        let ctx = DiscInputsCtx::new(&di);
-        fetch_unit_keys(&sources, &ctx)
-            .into_iter()
-            .map(|u| u.key)
-            .collect()
-    })
+    // One driver behind both operations: rebuild the sources, inject `samples`
+    // as the ctx's content samples, run `drive` (the per-kind fetch), map the
+    // resolved UnitKeys to raw keys. Memoized by the fingerprint of the sample
+    // batch: the resolved keys are disc-level (a clip's index / CPS keys are
+    // identical for every title that references it), so the first batch resolves
+    // over the network and every repeat is answered from the cache with no
+    // request. Empty replies are cached too — a key the service lacks for a batch
+    // won't appear on a re-ask, so re-hitting the network buys nothing. Each
+    // operation gets its OWN cache: a base batch and a forensic anchor never
+    // collide, and the same bytes could legitimately resolve differently per op.
+    // The per-kind driver: `fetch_unit_keys` or `fetch_fmts_indexes`.
+    type FetchDriver = fn(&[Box<dyn KeySource>], &dyn ResolveCtx) -> Vec<UnitKey>;
+    fn make_op(
+        inputs: DiscInputs,
+        make_sources: std::sync::Arc<dyn Fn() -> Vec<Box<dyn KeySource>> + Send + Sync>,
+        drive: FetchDriver,
+    ) -> crate::sector::KeyFetchFn {
+        let cache: std::sync::Arc<std::sync::Mutex<std::collections::HashMap<u64, Vec<[u8; 16]>>>> =
+            std::sync::Arc::new(std::sync::Mutex::new(std::collections::HashMap::new()));
+        std::sync::Arc::new(move |samples: &[Vec<u8>]| -> Vec<[u8; 16]> {
+            let fp = {
+                use std::hash::{Hash, Hasher};
+                let mut h = std::collections::hash_map::DefaultHasher::new();
+                samples.len().hash(&mut h);
+                for s in samples {
+                    s.hash(&mut h);
+                }
+                h.finish()
+            };
+            if let Some(hit) = cache.lock().unwrap_or_else(|e| e.into_inner()).get(&fp) {
+                return hit.clone();
+            }
+            let sources = make_sources();
+            let mut di = inputs.clone();
+            di.samples = samples.to_vec();
+            // Parse Unit_Key_RO.inf at the disc's OWN stride (carried on `inputs`):
+            // an online /decode reply that returns a VUK (not a terminal UK) then
+            // derives unit keys from `enc_title_keys`, which a V10 disc parses at
+            // the 48-byte stride — hardcoding the V20 stride here corrupted them.
+            let ctx = DiscInputsCtx::new(&di);
+            let keys: Vec<[u8; 16]> = drive(&sources, &ctx).into_iter().map(|u| u.key).collect();
+            cache
+                .lock()
+                .unwrap_or_else(|e| e.into_inner())
+                .insert(fp, keys.clone());
+            keys
+        })
+    }
+    let unit = make_op(inputs.clone(), make_sources.clone(), fetch_unit_keys);
+    let fmts = make_op(inputs, make_sources, fetch_fmts_indexes);
+    crate::sector::KeyFetch::new(unit, fmts)
 }
 
 /// Read up to `n` ENCRYPTED 6144-byte aligned units from `title`'s body, raw (no
@@ -407,7 +546,7 @@ pub fn read_encrypted_units(
                     break;
                 }
                 let u = &buf[o..o + ALIGNED_UNIT_LEN];
-                if aacs_unit_encrypted(u) {
+                if aacs_unit_encrypted(u, title.content_format) {
                     out.push(u.to_vec());
                     if out.len() >= n {
                         return out;
@@ -425,6 +564,46 @@ mod tests {
     use crate::aacs::types::UnitKey;
     use std::sync::{Arc, Mutex};
 
+    fn units(n: usize) -> Vec<Vec<u8>> {
+        (0..n).map(|i| vec![i as u8; 4]).collect()
+    }
+
+    // ── DecodeSampleSet: the online request can't be built under-sized ─────────
+
+    /// Fewer than MIN_SAMPLE_UNITS → no set. Mutation: accepting a short slice
+    /// resurrects the exact autorip bug (a 4-sample request silently skipped /
+    /// read as "service down").
+    #[test]
+    fn decode_sample_set_rejects_under_min() {
+        for n in 0..MIN_SAMPLE_UNITS {
+            assert!(
+                DecodeSampleSet::new(units(n)).is_none(),
+                "{n} samples (< {MIN_SAMPLE_UNITS}) must not build a DecodeSampleSet"
+            );
+        }
+    }
+
+    /// Exactly the minimum, and above it, construct — and expose all samples.
+    #[test]
+    fn decode_sample_set_accepts_min_and_above() {
+        let exact = DecodeSampleSet::new(units(MIN_SAMPLE_UNITS)).expect("min builds");
+        assert_eq!(exact.len(), MIN_SAMPLE_UNITS);
+        assert_eq!(exact.units().len(), MIN_SAMPLE_UNITS);
+        assert!(!exact.is_empty());
+
+        let more = DecodeSampleSet::new(units(MIN_SAMPLE_UNITS + 5)).expect("above min builds");
+        assert_eq!(more.len(), MIN_SAMPLE_UNITS + 5);
+    }
+
+    /// The wrapped units round-trip byte-for-byte (the request carries exactly what
+    /// was gathered — no reordering/truncation).
+    #[test]
+    fn decode_sample_set_preserves_units() {
+        let raw = units(MIN_SAMPLE_UNITS);
+        let set = DecodeSampleSet::new(raw.clone()).unwrap();
+        assert_eq!(set.units(), raw.as_slice());
+    }
+
     // ── KeySource default-method behaviour ────────────────────────────────────
 
     /// KeySource::host_certs() defaults to empty regardless of the MKB argument.
@@ -436,7 +615,7 @@ mod tests {
     fn key_source_host_certs_defaults_to_empty() {
         struct MinimalSource;
         impl KeySource for MinimalSource {
-            fn get_uk(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+            fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
                 Ok(Vec::new())
             }
         }
@@ -493,7 +672,7 @@ mod tests {
     fn trace_who_is_the_source_label_verbatim() {
         struct LabeledSource(&'static str);
         impl KeySource for LabeledSource {
-            fn get_uk(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+            fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
                 Ok(Vec::new())
             }
             fn label(&self) -> &'static str {
@@ -550,23 +729,20 @@ mod tests {
 
     struct EmptySource;
     impl KeySource for EmptySource {
-        fn get_uk(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+        fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
             Ok(Vec::new())
         }
     }
     struct ErroringSource;
     impl KeySource for ErroringSource {
-        fn get_uk(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+        fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
             Err(Error::AacsNoKeys)
         }
     }
     struct HasKey([u8; 16]);
     impl KeySource for HasKey {
-        fn get_uk(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
-            Ok(vec![UnitKey {
-                idx: 0,
-                key: self.0,
-            }])
+        fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+            Ok(vec![UnitKey::new(0, self.0)])
         }
     }
 
@@ -608,14 +784,11 @@ mod tests {
             seen: Arc<Mutex<Vec<Vec<u8>>>>,
         }
         impl KeySource for Probe {
-            fn get_uk(&self, ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+            fn get_unit_keys(&self, ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
                 if let Ok(s) = ctx.samples(8) {
                     self.seen.lock().unwrap().extend(s);
                 }
-                Ok(vec![UnitKey {
-                    idx: 0,
-                    key: self.key,
-                }])
+                Ok(vec![UnitKey::new(0, self.key)])
             }
         }
 
@@ -631,7 +804,7 @@ mod tests {
 
         let cb = key_fetch(empty_inputs(), make);
         let samples = vec![vec![0xEEu8; crate::aacs::content::ALIGNED_UNIT_LEN]];
-        let got = cb(&samples);
+        let got = cb.unit_keys(&samples);
         assert_eq!(
             got,
             vec![key],
@@ -645,6 +818,85 @@ mod tests {
         assert_eq!(*builds.lock().unwrap(), 1, "make_sources invoked per fetch");
     }
 
+    /// The two `KeyFetch` operations route to the two DISTINCT trait methods:
+    /// `unit_keys` drives `get_unit_keys`, `fmts_indexes` drives
+    /// `get_fmts_indexes`. A source that returns different keys per method proves
+    /// the seam no longer collapses "1 base key" and "the forensic set" into one
+    /// overloaded call — the operation, not the return length, decides which.
+    #[test]
+    fn key_fetch_routes_unit_and_fmts_to_distinct_source_methods() {
+        const BASE: [u8; 16] = [0xB0; 16];
+        const F1: [u8; 16] = [0xF1; 16];
+        const F2: [u8; 16] = [0xF2; 16];
+
+        struct TwoOp;
+        impl KeySource for TwoOp {
+            fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+                Ok(vec![UnitKey::new(0, BASE)])
+            }
+            fn get_fmts_indexes(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+                Ok(vec![UnitKey::new(0, F1), UnitKey::new(1, F2)])
+            }
+        }
+
+        let make: Arc<dyn Fn() -> Vec<Box<dyn KeySource>> + Send + Sync> =
+            Arc::new(|| vec![Box::new(TwoOp) as Box<dyn KeySource>]);
+        let cb = key_fetch(empty_inputs(), make);
+        let samples = vec![vec![0x01u8; 4]];
+
+        assert_eq!(
+            cb.unit_keys(&samples),
+            vec![BASE],
+            "unit_keys resolves the base Unit Key via get_unit_keys"
+        );
+        assert_eq!(
+            cb.fmts_indexes(&samples),
+            vec![F1, F2],
+            "fmts_indexes resolves the forensic set (any length) via get_fmts_indexes"
+        );
+    }
+
+    /// `KeyFetch::unit_only` serves base keys but NEVER a forensic set — the
+    /// contract the sweep/patch recovery decorator relies on (it resolves CPS
+    /// units only). Its `fmts_indexes` is unconditionally empty.
+    #[test]
+    fn key_fetch_unit_only_never_serves_forensic() {
+        let f = crate::sector::KeyFetch::unit_only(std::sync::Arc::new(|_| vec![[0xAA; 16]]));
+        assert_eq!(f.unit_keys(&[vec![0u8; 4]]), vec![[0xAA; 16]]);
+        assert!(
+            f.fmts_indexes(&[vec![0u8; 4]]).is_empty(),
+            "unit_only resolver yields no forensic keys"
+        );
+    }
+
+    /// `get_fmts_indexes` defaults to empty, so a base-only source (a keydb) opts
+    /// out of the forensic path without implementing it. `fetch_fmts_indexes` then
+    /// falls through to the next source, exactly like the unit-key driver.
+    #[test]
+    fn fetch_fmts_indexes_skips_default_optout_source() {
+        struct BaseOnly; // uses the default (empty) get_fmts_indexes
+        impl KeySource for BaseOnly {
+            fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+                Ok(vec![UnitKey::new(0, [0x11; 16])])
+            }
+        }
+        struct Forensic;
+        impl KeySource for Forensic {
+            fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+                Ok(Vec::new())
+            }
+            fn get_fmts_indexes(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
+                Ok(vec![UnitKey::new(0, [0x77; 16])])
+            }
+        }
+        let inputs = empty_inputs();
+        let ctx = DiscInputsCtx::new(&inputs);
+        let sources: Vec<Box<dyn KeySource>> = vec![Box::new(BaseOnly), Box::new(Forensic)];
+        let got = fetch_fmts_indexes(&sources, &ctx);
+        assert_eq!(got.len(), 1);
+        assert_eq!(got[0].key, [0x77; 16], "the base-only source is skipped");
+    }
+
     /// #4 regression: encrypted content NOT at the extent midpoint (a late-
     /// starting feature, or a midpoint landing in clear nav) must still be
     /// sampled — empty samples make `decrypt_with` skip wrong-key validation.
@@ -723,7 +975,7 @@ mod tests {
         );
         for s in &samples {
             assert!(
-                aacs_unit_encrypted(s),
+                aacs_unit_encrypted(s, crate::disc::ContentFormat::BdTs),
                 "every sample is a CPI-flagged encrypted unit (byte0 & 0xC0 != 0)"
             );
         }
@@ -806,7 +1058,7 @@ mod tests {
         );
         for s in &samples {
             assert!(
-                aacs_unit_encrypted(s),
+                aacs_unit_encrypted(s, crate::disc::ContentFormat::BdTs),
                 "only CPI-flagged units are selected"
             );
             assert_eq!(

src/lib.rs

@@ -98,7 +98,7 @@ pub const VERSION_LABEL: &str = concat!(env!("FREEMKV_VERSION"), env!("GIT_SUFFI
 
 /// The muxing/writing-application string written into MKV output
 /// (`"freemkv <version> (g<hash>)"`).
-pub const MUX_APP: &str = concat!("freemkv ", env!("FREEMKV_VERSION"), env!("GIT_SUFFIX"));
+pub(crate) const MUX_APP: &str = concat!("freemkv ", env!("FREEMKV_VERSION"), env!("GIT_SUFFIX"));
 
 pub mod aacs;
 pub(crate) mod clpi;
@@ -187,7 +187,10 @@ pub use identity::DriveId;
 // 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, decrypt_threads, set_decrypt_threads};
+pub use decrypt::{
+    AacsKeyMap, DecryptKeys, decrypt_sectors, decrypt_sectors_mapped, decrypt_threads,
+    set_decrypt_threads,
+};
 
 // ─── Disc structure ─────────────────────────────────────────────────────────
 //
@@ -248,6 +251,7 @@ pub use mux::{InputOptions, StreamUrl, input, output, parse_url};
 // single decrypt-on-read decorator (AACS / CSS / none) — wrap any
 // `SectorSource` to get plaintext sectors out.
 pub use mux::build_iso_pipeline;
+pub use mux::resolve_mux_key_map;
 pub use scsi::{DriveInfo, ScsiSense, ScsiTransport, drive_has_disc, list_drives};
 pub use sector::{
     DecryptingSectorSource, FileSectorSink, FileSectorSource, KeyFetch, PrefetchedSectorSource,

src/mux/codec/h264.rs

@@ -56,6 +56,13 @@ pub struct H264Parser {
     /// (HD-DVD EVO) path where the source stamps a PTS once per GOP. `None` on
     /// the BD/UHD transport path, which carries a per-frame PTS.
     reorder: Option<super::reorder::SparsePtsReorder>,
+    /// MVC dependent-view (Blu-ray 3D right-eye) passthrough mode. When set, the
+    /// parser does NOT strip SPS/PPS (nor re-assert at keyframes): every NAL —
+    /// subset SPS (type 15), prefix (14), coded-slice-extension (20), PPS (8) —
+    /// is length-prefixed in-band, so each emitted frame is a self-contained
+    /// dependent access unit suitable for a Matroska `BlockAdditional`. The base
+    /// view's avcC/param-set stripping is unchanged (separate parser instance).
+    mvc_passthrough: bool,
 }
 
 impl Default for H264Parser {
@@ -73,6 +80,7 @@ impl H264Parser {
             cur_sps: None,
             cur_pps: None,
             reorder: None,
+            mvc_passthrough: false,
         }
     }
 
@@ -85,6 +93,15 @@ impl H264Parser {
         self
     }
 
+    /// Enable MVC dependent-view passthrough (see the `mvc_passthrough` field):
+    /// keep every parameter set in-band so each frame is a self-contained
+    /// dependent access unit for a Matroska `BlockAdditional`. Used only for the
+    /// Blu-ray 3D dependent (right-eye) stream.
+    pub(crate) fn with_mvc_passthrough(mut self, enabled: bool) -> Self {
+        self.mvc_passthrough = enabled;
+        self
+    }
+
     /// Route a finished frame through the PTS reorderer when enabled, else emit
     /// it directly (unchanged transport-stream behaviour).
     fn finish(&mut self, explicit: Option<i64>, frame: Frame) -> Vec<Frame> {
@@ -192,17 +209,23 @@ impl CodecParser for H264Parser {
         // frame in the mux hot path (mirrors the HEVC parser).
         let mut frame_data = Vec::with_capacity(pes.data.len() + 64);
 
+        // MVC dependent-view passthrough: keep ALL param sets in-band (the frame
+        // is a self-contained BlockAdditional access unit), never strip/re-assert.
+        let mvc = self.mvc_passthrough;
+
         for nal in NalIterator::new(&pes.data) {
             let nal_type = nal[0] & 0x1F;
 
             match nal_type {
                 // Param sets: seed avcC, strip if unchanged vs the active set,
                 // emit in-band on any change (incl. reverting to the avcC copy).
-                NAL_SPS => {
+                // In MVC passthrough these fall through to the default arm so the
+                // subset SPS / PPS stay in-band (self-contained dependent AU).
+                NAL_SPS if !mvc => {
                     emitted_sps |=
                         handle_param_set(&mut self.sps, &mut self.cur_sps, nal, &mut frame_data)
                 }
-                NAL_PPS => {
+                NAL_PPS if !mvc => {
                     emitted_pps |=
                         handle_param_set(&mut self.pps, &mut self.cur_pps, nal, &mut frame_data)
                 }
@@ -250,7 +273,7 @@ impl CodecParser for H264Parser {
         // ahead of the slices (even when unchanged vs codecPrivate) so a decoder
         // that dropped the set at a reset recovers, and a stale avcC re-apply
         // can't revert it. Skipped per-type only when this AU already carried it.
-        if keyframe {
+        if keyframe && !mvc {
             let mut prefix = Vec::new();
             reassert_active(&mut prefix, &self.cur_sps, emitted_sps);
             reassert_active(&mut prefix, &self.cur_pps, emitted_pps);
@@ -651,6 +674,94 @@ mod tests {
         v
     }
 
+    #[test]
+    fn mvc_passthrough_keeps_param_sets_inband() {
+        // A dependent-view access unit: subset SPS (NAL 15) + PPS (NAL 8) +
+        // coded-slice-extension (NAL 20). No IDR (type 5), so keyframe stays
+        // false and there is no keyframe re-assertion.
+        let au = || {
+            let mut d = Vec::new();
+            d.extend_from_slice(&h264_nal(0x6F, &[0x80, 0x00, 0x33, 0xAA])); // subset SPS (15)
+            d.extend_from_slice(&h264_nal(0x68, &[0xCE, 0x01])); // PPS (8)
+            d.extend_from_slice(&h264_nal(0x74, &[0x11, 0x22])); // slice-ext (20)
+            d
+        };
+        let nal_types =
+            |f: &Frame| -> Vec<u8> { h264_nals_in(&f.data).iter().map(|n| n[0] & 0x1F).collect() };
+
+        // Normal parser strips the PPS from a non-keyframe AU (it is captured for
+        // the avcC and, without an IDR, never re-asserted in-band).
+        let mut normal = H264Parser::new();
+        let f = normal.parse(&make_pes(au(), Some(90000)));
+        assert_eq!(f.len(), 1);
+        assert!(
+            !nal_types(&f[0]).contains(&8),
+            "normal parser strips PPS from a non-keyframe AU: {:?}",
+            nal_types(&f[0])
+        );
+
+        // Passthrough keeps EVERY parameter set in-band, so each dependent frame
+        // is a self-contained access unit for a BlockAdditional.
+        let mut pt = H264Parser::new().with_mvc_passthrough(true);
+        let f = pt.parse(&make_pes(au(), Some(90000)));
+        assert_eq!(f.len(), 1);
+        let types = nal_types(&f[0]);
+        assert!(types.contains(&15), "subset SPS kept in-band: {types:?}");
+        assert!(
+            types.contains(&8),
+            "PPS kept in-band under passthrough: {types:?}"
+        );
+        assert!(types.contains(&20), "slice kept: {types:?}");
+    }
+
+    #[test]
+    fn parser_for_mvc_dependent_h264_is_passthrough() {
+        // The dependent-view stream must get a passthrough parser: a PPS in a
+        // non-keyframe AU is kept in-band, not stripped like the base parser.
+        let mut p = crate::mux::codec::parser_for_mvc_dependent(crate::disc::Codec::H264, false);
+        let mut d = Vec::new();
+        d.extend_from_slice(&h264_nal(0x68, &[0xCE, 0x01])); // PPS (8)
+        d.extend_from_slice(&h264_nal(0x74, &[0x11, 0x22])); // slice-ext (20)
+        let f = p.parse(&make_pes(d, Some(90000)));
+        assert_eq!(f.len(), 1);
+        let types: Vec<u8> = h264_nals_in(&f[0].data)
+            .iter()
+            .map(|n| n[0] & 0x1F)
+            .collect();
+        assert!(
+            types.contains(&8),
+            "dependent parser keeps PPS in-band (passthrough): {types:?}"
+        );
+    }
+
+    #[test]
+    fn mvc_passthrough_with_idr_does_not_reassert_param_sets() {
+        // With an IDR present (keyframe=true), passthrough must NOT re-assert the
+        // param sets (the `keyframe && !mvc` guard), so SPS/PPS appear exactly
+        // once — a duplicate would corrupt the dependent BlockAdditional.
+        let mut p = H264Parser::new().with_mvc_passthrough(true);
+        let mut d = Vec::new();
+        d.extend_from_slice(&h264_nal(0x67, &[0x42, 0x00, 0x1E, 0x01])); // SPS (7)
+        d.extend_from_slice(&h264_nal(0x68, &[0xCE, 0x01])); // PPS (8)
+        d.extend_from_slice(&h264_nal(0x65, &[0x88, 0x00])); // IDR slice (5)
+        let f = p.parse(&make_pes(d, Some(90000)));
+        assert_eq!(f.len(), 1);
+        let types: Vec<u8> = h264_nals_in(&f[0].data)
+            .iter()
+            .map(|n| n[0] & 0x1F)
+            .collect();
+        assert_eq!(
+            types.iter().filter(|&&t| t == 7).count(),
+            1,
+            "exactly one SPS, no keyframe re-assert under passthrough: {types:?}"
+        );
+        assert_eq!(
+            types.iter().filter(|&&t| t == 8).count(),
+            1,
+            "exactly one PPS, no keyframe re-assert under passthrough: {types:?}"
+        );
+    }
+
     #[test]
     fn h264_populates_measured_coding_type_and_source() {
         use super::super::coding::CodingType;

src/mux/codec/mod.rs

@@ -207,6 +207,22 @@ pub fn parser_for_codec(
     }
 }
 
+/// Build the codec parser for a Blu-ray 3D **MVC dependent (right-eye)** video
+/// stream. Same codec space as the base view (H.264), but in param-set
+/// passthrough mode so each emitted frame is a self-contained dependent access
+/// unit for a Matroska `BlockAdditional`. Non-H.264 (unexpected) falls back to
+/// the ordinary parser.
+pub fn parser_for_mvc_dependent(codec: Codec, is_dvd_ps: bool) -> Box<dyn CodecParser> {
+    match codec {
+        Codec::H264 => Box::new(
+            h264::H264Parser::new()
+                .with_ps_reorder(is_dvd_ps)
+                .with_mvc_passthrough(true),
+        ),
+        _ => parser_for_codec(codec, None, is_dvd_ps),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/mux/demux_sink.rs

@@ -31,6 +31,10 @@ use std::io::{self, BufWriter, Write};
 use std::path::{Path, PathBuf};
 
 /// Filename-naming strategy for the per-track files.
+// `allow(dead_code)`: the sink honours all variants, but only the `#[default]` is
+// constructed today (`output()` builds `DemuxOptions::default()`). The alternates
+// are a staged option surface awaiting the CLI `--naming` flag (not yet wired).
+#[allow(dead_code)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub enum Naming {
     /// `<base> <track> <lang> <codec> [DELAY <n>ms].<ext>` — human-readable.
@@ -55,6 +59,9 @@ pub enum DelayMode {
 }
 
 /// Chapter export format.
+// `allow(dead_code)`: only the `#[default]` XML variant is constructed today (via
+// `DemuxOptions::default()`); OGM/Both await the CLI `--chapters` flag.
+#[allow(dead_code)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub enum ChaptersFmt {
     /// mkvmerge chapter XML.
@@ -241,11 +248,23 @@ impl EsWriter for AnnexBWriter {
 /// Delegates to the canonical hvcC/avcC → Annex-B converters in
 /// [`crate::mux::hevc`] — the single source of truth across all muxers.
 fn annexb_param_sets(codec: Codec, record: &[u8]) -> Vec<u8> {
-    match codec {
-        Codec::Hevc => hvcc_to_annex_b(record).unwrap_or_default(),
-        Codec::H264 => avcc_to_annex_b(record).unwrap_or_default(),
-        _ => Vec::new(),
-    }
+    let converted = match codec {
+        Codec::Hevc => hvcc_to_annex_b(record),
+        Codec::H264 => avcc_to_annex_b(record),
+        _ => return Vec::new(),
+    };
+    converted.unwrap_or_else(|| {
+        // A malformed hvcC/avcC record yields no parameter sets. Returning empty
+        // means keyframes ship WITHOUT in-band SPS/PPS — playable from the first
+        // keyframe but broken for seek-to-arbitrary-point and hardware decoders.
+        // Surface it rather than silently degrading the output.
+        tracing::warn!(
+            target: "mux",
+            ?codec,
+            "codec-private (hvcC/avcC) parse failed; keyframes will lack in-band SPS/PPS"
+        );
+        Vec::new()
+    })
 }
 
 /// PGS `.sup` writer: rebuilds the HDMV segment framing the parser stripped.

src/mux/demux_thread.rs

@@ -7,7 +7,7 @@
 //! 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
+//! parsers. Profiling 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.
 //!

src/mux/disc.rs

@@ -108,11 +108,6 @@ pub struct DiscStream {
     /// inline `decrypt::decrypt_sectors` step. `DecryptKeys::None`
     /// (raw / unencrypted disc) makes the decorator a pass-through.
     reader: DecryptingSectorSource<Box<dyn SectorSource>>,
-    /// Shared decrypt-loss counter, cloned once at construction from
-    /// `reader.decrypt_loss()`. `lost_bytes()` loads it directly so the
-    /// per-frame hot path performs no per-call `Arc::clone` (matching the
-    /// `PipelinedPesStream` pattern).
-    decrypt_loss: std::sync::Arc<std::sync::atomic::AtomicU64>,
     title: DiscTitle,
     /// Mirror of the keys handed in at construction. The decorator
     /// owns the cryptographic state; this field is kept for
@@ -144,14 +139,14 @@ pub struct DiscStream {
     // Adaptive batch sizer — preferred comes from the caller
     // (detect_max_batch_sectors), shrinks/grows based on read outcomes.
     adaptive: AdaptiveBatch,
-    pub errors: u64,
+    errors: u64,
     /// Cumulative bytes actually skipped (zero-filled) on read error.
     /// Distinct from `errors`, which counts skip *events*: one event can
     /// cover a whole AACS unit (`unit_align` sectors = 6144 bytes), so
     /// `errors * 2048` understates real loss by the alignment factor.
     /// Consumers estimating lost video time must scale by this, not by
     /// the event count.
-    pub lost_bytes: u64,
+    lost_bytes: u64,
     pub skip_errors: bool,
     /// When set and the token is cancelled, fill_extents returns Err(Halted)
     /// at the next retry boundary. Unlike skip_errors, this propagates the
@@ -237,12 +232,12 @@ impl DiscStream {
 
         // CSS/unencrypted content needs a decrypting wrapper to yield plaintext
         // VOB bytes before the AC-3 sub-stream probe can read real `acmod`s.
-        // MUX path: tolerate decrypt loss — conceal an undecryptable unit (NULL TS
-        // fill) + tally + log rather than abort the stream (P3). DiscStream is a
-        // decode/mux stream (live-drive single-pass / direct), never the
-        // ciphertext-preserving sweep, so concealment is always correct here.
-        let mut reader =
-            DecryptingSectorSource::new(reader, decrypt_keys.clone()).tolerate_decrypt_loss();
+        // MUX path (read > decrypt > mux): decrypt every unit in place and pass the
+        // bytes to the muxer; a unit that decrypts to broken TS is the muxer's
+        // concern, never conceal / re-fetch / count as loss (fail loud only on a
+        // genuine can't-decrypt). DiscStream is a decode/mux stream (live-drive
+        // single-pass / direct), never the ciphertext-preserving sweep.
+        let mut reader = DecryptingSectorSource::new(reader, decrypt_keys.clone());
 
         // Wrong-substream fix (Silence-of-the-Lambs): re-route the title's
         // declared AC-3 audio onto the physically-correct `0x8x` sub-streams by
@@ -293,9 +288,6 @@ impl DiscStream {
         // the decorator is a pass-through). Reset the unit base the probe read
         // advanced so the first fill_extents read starts cleanly.
         reader.set_unit_base(0);
-        // Clone the shared loss counter once here so `lost_bytes()` never
-        // clones an Arc per frame on the mux hot path.
-        let decrypt_loss = reader.decrypt_loss();
 
         // B1 resync gates: one per stream, video flagged so the gate only
         // drop-to-keyframes video (audio/subtitle always admit). Computed before
@@ -311,7 +303,6 @@ impl DiscStream {
 
         Self {
             reader,
-            decrypt_loss,
             title,
             decrypt_keys,
             unit_align,
@@ -360,6 +351,27 @@ impl DiscStream {
         self
     }
 
+    /// Install a proactive [`AacsKeyMap`](crate::decrypt::AacsKeyMap) on the inline
+    /// live-drive path — the counterpart to what
+    /// [`build_iso_pipeline`](crate::mux::resolve::build_iso_pipeline) does for the
+    /// file-backed highway. The map is the title's read plan: it decides which unit
+    /// each LBA is and, for an FMTS forensic segment, which phase is ours. The
+    /// extent walk is rewritten to the read plan so **only our-phase units are read
+    /// off the drive** (the alternate device-group units are never fetched,
+    /// decrypted, or muxed), and the map is installed so each unit decrypts with its
+    /// mapped key. A non-forensic map returns the extents unchanged, so a plain
+    /// single/multi-CPS disc reads exactly as before.
+    pub fn with_key_map(mut self, map: std::sync::Arc<crate::decrypt::AacsKeyMap>) -> Self {
+        self.extents = map.read_plan(&self.extents, self.unit_align.max(1) as u32);
+        self.bytes_total_extents = self
+            .extents
+            .iter()
+            .map(|e| e.sector_count as u64 * 2048)
+            .sum();
+        self.reader.set_key_map(map);
+        self
+    }
+
     fn is_halted(&self) -> bool {
         self.halt
             .as_ref()
@@ -1003,14 +1015,12 @@ impl crate::pes::Stream for DiscStream {
     }
 
     fn lost_bytes(&self) -> u64 {
-        // Read-error zero-fill loss (counted in fill_extents) PLUS decrypt-time
-        // loss — bytes of scrambled AACS units the decorator could not decrypt
-        // and passed through still encrypted (the TS assembler silently drops
-        // them). Both are real missing content the abort gate must see; without
-        // the decrypt term a partial key failure reports lost_bytes=0 and a rip
-        // missing segments passes even under abort_on_lost_secs=0.
+        // Read-error zero-fill loss (counted in fill_extents) — real missing
+        // content the abort gate must see. There is no decrypt-loss term: the
+        // decrypt path passes bad-encoded/undecryptable units through (a broken-TS
+        // unit is the muxer's concern, and a missing key is indistinguishable from
+        // bad authoring here), so only physical read loss is reported.
         self.lost_bytes
-            .saturating_add(self.decrypt_loss.load(std::sync::atomic::Ordering::Relaxed))
     }
 }
 
@@ -1129,6 +1139,44 @@ mod tests {
         );
     }
 
+    /// `with_key_map` on the inline live-drive path applies the same FMTS read plan
+    /// the file-backed highway uses: within a forensic segment only our-phase units
+    /// survive the extent walk, so the alternate device-group units are never read.
+    #[test]
+    fn with_key_map_reads_only_our_phase_units() {
+        use crate::decrypt::{AacsKeyMap, DecryptKeys, Phase};
+        // AACS keys → unit_align = 3, so a unit is 3 sectors and the phase filter
+        // engages. Key contents are irrelevant to the read plan.
+        let aacs = DecryptKeys::Aacs {
+            unit_keys: vec![(0, [0u8; 16]), (1, [1u8; 16])],
+            read_data_key: None,
+            format: ContentFormat::BdTs,
+        };
+        // 100 units (300 sectors). A 10-unit Even forensic segment at LBA [30,60):
+        // even units (30,36,42,48,54) are ours; odd (33,39,45,51,57) are dropped.
+        let map = AacsKeyMap::from_ranges_phased(vec![(30, 60, 1, Phase::Even)], 0);
+        let stream = DiscStream::new(
+            Box::new(ZeroReader { capacity: 300 }),
+            synthetic_title(300),
+            aacs,
+            8,
+            ContentFormat::BdTs,
+        )
+        .with_key_map(std::sync::Arc::new(map));
+        let total: u32 = stream.extents.iter().map(|e| e.sector_count).sum();
+        assert_eq!(
+            total,
+            300 - 5 * 3,
+            "exactly the 5 alternate-phase units (15 sectors) are dropped from the read walk"
+        );
+        assert!(
+            stream.extents.len() > 1,
+            "the forensic segment split the single extent into our-phase-only runs"
+        );
+        // The progress denominator tracks the reduced read set.
+        assert_eq!(stream.bytes_total_extents, total as u64 * 2048);
+    }
+
     /// Recording `SectorSource`: logs every `(lba, count)` request and
     /// returns `Err` whenever the requested range covers `bad_sector`.
     /// Successful reads return zeroed sectors (which are NOT
@@ -1489,6 +1537,7 @@ mod tests {
         let keys = crate::decrypt::DecryptKeys::Aacs {
             unit_keys: vec![(0, [0u8; 16])],
             read_data_key: None,
+            format: crate::disc::ContentFormat::BdTs,
         };
         let mut stream = DiscStream::new(Box::new(reader), title, keys, 8, ContentFormat::BdTs);
         stream.skip_errors = true;

src/mux/ebml.rs

@@ -94,6 +94,31 @@ pub fn write_uint(w: &mut impl Write, id: u32, val: u64) -> io::Result<()> {
     }
 }
 
+/// Write a complete EBML signed-integer element (two's-complement, big-endian,
+/// minimal width). Used for `ReferenceBlock` (0xFB), whose value is a signed
+/// tick offset relative to the current block's timestamp.
+pub fn write_int(w: &mut impl Write, id: u32, val: i64) -> io::Result<()> {
+    write_id(w, id)?;
+    // Minimal two's-complement width: shrink while the top byte is pure sign
+    // extension of the next byte's MSB.
+    let be = val.to_be_bytes();
+    let mut start = 0usize;
+    while start < 7 {
+        let sign_ext = if be[start + 1] & 0x80 != 0 {
+            0xFF
+        } else {
+            0x00
+        };
+        if be[start] != sign_ext {
+            break;
+        }
+        start += 1;
+    }
+    let bytes = &be[start..];
+    write_size(w, bytes.len() as u64)?;
+    w.write_all(bytes)
+}
+
 /// Write a complete EBML float element (8-byte double).
 pub fn write_float(w: &mut impl Write, id: u32, val: f64) -> io::Result<()> {
     write_id(w, id)?;
@@ -481,6 +506,25 @@ pub const LUMINANCE_MIN: u32 = 0x55DA;
 pub const BLOCK_ADDITION_MAPPING: u32 = 0x41E4;
 pub const BLOCK_ADD_ID_TYPE: u32 = 0x41E7;
 pub const BLOCK_ADD_ID_EXTRA_DATA: u32 = 0x41ED;
+/// BlockAddIDValue (RFC 9559) — the value a per-frame `BlockAddID` references
+/// to select this BlockAdditionMapping. Values ≥ 2 (1 is the default plain
+/// BlockAdditional). Used by the MVC (`mvcC`) mapping for Blu-ray 3D.
+pub const BLOCK_ADD_ID_VALUE: u32 = 0x41F0;
+
+// Block additions carried inside a BlockGroup — per-frame side data. For
+// Blu-ray 3D (MVC) the dependent (right-eye) view NAL units for an access unit
+// ride here as a BlockAdditional under the track's `mvcC` mapping (RFC 9559
+// §5.1.4.1.4; Matroska Codec Specifications §4.1.5).
+pub const BLOCK_ADDITIONS: u32 = 0x75A1;
+pub const BLOCK_MORE: u32 = 0xA6;
+pub const BLOCK_ADDITIONAL: u32 = 0xA5;
+pub const BLOCK_ADD_ID: u32 = 0xEE;
+/// ReferenceBlock (RFC 9559 element 0xFB, child of BlockGroup) — signed
+/// timestamp (in TimestampScale ticks) of a block this one references, relative
+/// to this block's own timestamp. Its PRESENCE marks the Block as non-keyframe
+/// (a keyframe Block in a BlockGroup carries none). Written for non-keyframe
+/// video frames that must live in a BlockGroup to carry an MVC BlockAdditional.
+pub const REFERENCE_BLOCK: u32 = 0xFB;
 
 // Audio
 pub const AUDIO: u32 = 0xE1;
@@ -960,6 +1004,31 @@ mod tests {
         assert_eq!(buf, [0x42, 0x86, 0x81, 0x00]);
     }
 
+    #[test]
+    fn write_int_minimal_two_complement_width() {
+        // ReferenceBlock (0xFB) signed offsets, minimal two's-complement width.
+        let enc = |v: i64| {
+            let mut b = Vec::new();
+            write_int(&mut b, REFERENCE_BLOCK, v).unwrap();
+            b
+        };
+        assert_eq!(enc(0), [0xFB, 0x81, 0x00], "0 -> 1 byte 0x00");
+        assert_eq!(enc(-1), [0xFB, 0x81, 0xFF], "-1 -> 1 byte 0xFF");
+        assert_eq!(enc(127), [0xFB, 0x81, 0x7F], "127 -> 1 byte");
+        assert_eq!(
+            enc(128),
+            [0xFB, 0x82, 0x00, 0x80],
+            "128 needs 2 bytes (0x80 alone is -128)"
+        );
+        assert_eq!(enc(-128), [0xFB, 0x81, 0x80], "-128 -> 1 byte 0x80");
+        assert_eq!(enc(-129), [0xFB, 0x82, 0xFF, 0x7F], "-129 needs 2 bytes");
+        // i64::MIN is the widest: 8 bytes, size 0x88.
+        let mn = enc(i64::MIN);
+        assert_eq!(mn[0], 0xFB);
+        assert_eq!(mn[1], 0x88);
+        assert_eq!(&mn[2..], &i64::MIN.to_be_bytes());
+    }
+
     // ============================================================
     // write_float — EBML floats here are always 8-byte IEEE-754 doubles,
     // big-endian (Matroska SamplingFrequency/Duration). size byte = 0x88.

src/mux/fvi_sink.rs

@@ -157,31 +157,19 @@ impl FviSink {
     ///
     /// `source_path` / `source_title` record where the index was built from
     /// (the input URL path + the 0-based title index); they are carried into the
-    /// header's `source` object. The medium defaults to `file` — callers with a
-    /// known medium / playlist / volume use [`FviSink::create_with_source`].
+    /// header's `source` object. The remaining provenance (medium, playlist,
+    /// volume) takes its `SourceInfo` defaults — no caller needs to override them.
     pub fn create(
         path: &Path,
         title: &DiscTitle,
         source_path: String,
         source_title: usize,
     ) -> io::Result<Self> {
-        Self::create_with_source(
-            path,
-            title,
-            SourceInfo {
-                path: source_path,
-                title: source_title,
-                ..SourceInfo::default()
-            },
-        )
-    }
-
-    /// Create the sink with a fully-specified [`SourceInfo`] provenance root.
-    pub fn create_with_source(
-        path: &Path,
-        title: &DiscTitle,
-        source: SourceInfo,
-    ) -> io::Result<Self> {
+        let source = SourceInfo {
+            path: source_path,
+            title: source_title,
+            ..SourceInfo::default()
+        };
         let file = File::create(path)?;
 
         let video_track = title

src/mux/mkv.rs

@@ -68,6 +68,82 @@ const COLOUR_RANGE_LIMITED: u8 = 1;
 /// Vision configuration record (RFC 9559 + Dolby Vision-in-Matroska spec).
 const BLOCK_ADD_ID_TYPE_DVCC: u64 = 0x6476_6343;
 
+/// BlockAddIDType "mvcC" — the MVCDecoderConfigurationRecord fourcc, big-endian
+/// ASCII 'm''v''c''C'. Matroska BlockAdditionMapping/BlockAddIDType for a
+/// Blu-ray 3D MVC configuration (RFC 9559 + Matroska Codec Specifications
+/// §4.1.5; equals ISO/IEC 14496-15 MVCConfigurationBox('mvcC')). The per-frame
+/// dependent (right-eye) view rides as a BlockAdditional under this mapping.
+const BLOCK_ADD_ID_TYPE_MVCC: u64 = 0x6D76_6343;
+
+/// BlockAddIDValue for the MVC mapping — the value each per-frame `BlockAddID`
+/// references (RFC 9559 requires ≥ 2; 1 is the default plain BlockAdditional).
+const BLOCK_ADD_ID_VALUE_MVC: u64 = 2;
+
+/// Build an `MVCDecoderConfigurationRecord` (ISO/IEC 14496-15:2013 §7.6.2) from
+/// the dependent view's subset-SPS (NAL type 15) and PPS NAL units. This is the
+/// `BlockAddIDExtraData` for the `mvcC` BlockAdditionMapping (and, in the ISO
+/// container, the `MVCConfigurationBox('mvcC')` payload).
+///
+/// Layout mirrors the AVCDecoderConfigurationRecord except byte[4] repurposes
+/// the AVC record's `bit(6) reserved` as
+/// `complete_representation(1) | explicit_au_track(1) | reserved '1111'(4)`.
+/// `profile`/`compat`/`level` describe the WHOLE MVC stream and come from the
+/// subset SPS (bytes 1..=3). `length_size_minus_one` MUST match the base avcC
+/// (freemkv always emits 4-byte length prefixes → 3). SPSs precede subset SPSs
+/// in the array; here the array carries the dependent view's parameter sets.
+///
+/// Returns `None` if either param set is absent, too short, or exceeds the
+/// 16-bit length field (a param set > 65535 bytes is non-conforming and would
+/// mis-frame the record).
+fn mvc_decoder_config_record(subset_sps: &[u8], pps: &[u8]) -> Option<Vec<u8>> {
+    if subset_sps.len() < 4 || subset_sps.len() > 0xFFFF || pps.is_empty() || pps.len() > 0xFFFF {
+        return None;
+    }
+    let mut record = vec![
+        1,             // configurationVersion
+        subset_sps[1], // AVCProfileIndication (whole MVC stream, from subset SPS)
+        subset_sps[2], // profile_compatibility
+        subset_sps[3], // AVCLevelIndication
+        // complete_representation(1)=1 | explicit_au_track(1)=0 |
+        // reserved '1111'(4) | lengthSizeMinusOne(2)=3(11) → 1_0_1111_11 = 0xBF.
+        0xBF,
+        // reserved '0'(1) | numOfSequenceParameterSets(7)=1 → 0_0000001 = 0x01.
+        // NB: distinct from the AVC record's byte[5] (reserved(3)|numSPS(5)).
+        0x01,
+        (subset_sps.len() >> 8) as u8,
+        subset_sps.len() as u8,
+    ];
+    record.extend_from_slice(subset_sps);
+    record.push(1); // numOfPictureParameterSets
+    record.push((pps.len() >> 8) as u8);
+    record.push(pps.len() as u8);
+    record.extend_from_slice(pps);
+    Some(record)
+}
+
+/// Build the `CodecPrivate` for an MVC (Blu-ray 3D) base track: the base view's
+/// `AVCDecoderConfigurationRecord` (`avcc`) followed by an `mvcC` extension
+/// block, per the Matroska Codec Specifications §4.3.9:
+///
+/// ```text
+/// avcC ‖ u32be(extension_block_size − 4) ‖ "mvcC" ‖ MVCDecoderConfigurationRecord
+/// ```
+///
+/// The size field is the extension block length **excluding the 4-byte size
+/// field itself** — i.e. `4 ("mvcC") + record.len()`. This is the track-level
+/// MVC signal that decoders and mediainfo read (the per-frame `BlockAdditional`
+/// under the `mvcC` BlockAdditionMapping carries the dependent view's data). A
+/// plain (2D) track never calls this — it writes its `avcc` verbatim.
+fn mvc_codec_private(avcc: &[u8], record: &[u8]) -> Vec<u8> {
+    let ext_size = (4 + record.len()) as u32; // "mvcC" (4) + record; = block size − 4
+    let mut out = Vec::with_capacity(avcc.len() + 8 + record.len());
+    out.extend_from_slice(avcc);
+    out.extend_from_slice(&ext_size.to_be_bytes());
+    out.extend_from_slice(b"mvcC");
+    out.extend_from_slice(record);
+    out
+}
+
 /// Resolve a video stream's CICP colour code points — `(matrix, transfer,
 /// primaries, range)`, ITU-T H.273 — using a single precedence so EVERY sink
 /// (the MKV muxer here AND the FVI sidecar in `videomap.rs`) agrees and can
@@ -176,6 +252,16 @@ pub struct MkvTrack {
     /// stream is parsed. When `Some`, the serializer emits MasteringMetadata +
     /// MaxCLL/MaxFALL inside Colour; when `None` they are omitted entirely.
     pub hdr10: Option<crate::mux::codec::Hdr10Metadata>,
+    /// Blu-ray 3D (MVC): the dependent (right-eye) view's `(subset_sps, pps)`
+    /// NAL units, from which the serializer builds the `mvcC`
+    /// MVCDecoderConfigurationRecord (ISO/IEC 14496-15 §7.6.2) for the track's
+    /// BlockAdditionMapping. `None` for non-3D tracks. Set at muxer activation
+    /// from the dependent stream's parameter sets — the same deferred path
+    /// `hdr10`/FieldOrder use — never at construction. When `Some`, the per-frame
+    /// dependent view rides as a `BlockAdditional`. (No `StereoMode` is written:
+    /// RFC 9559 assigns no StereoMode value to MVC-in-BlockAdditional; the mvcC
+    /// mapping is the 3D signal.)
+    pub mvc_params: Option<(Vec<u8>, Vec<u8>)>,
 }
 
 /// Build a DOVIDecoderConfigurationRecord (dvcC) — 24 bytes — for the Matroska
@@ -380,6 +466,7 @@ impl MkvTrack {
             // coded picture's PictureInfo before the header is written (the same
             // deferred path FieldOrder uses). `None` here → omitted unless seen.
             hdr10: None,
+            mvc_params: None,
         }
     }
 
@@ -448,6 +535,7 @@ impl MkvTrack {
             bit_depth: 0,
             dv_config: None,
             hdr10: None,
+            mvc_params: None,
         }
     }
 
@@ -485,6 +573,7 @@ impl MkvTrack {
             bit_depth: 0,
             dv_config: None,
             hdr10: None,
+            mvc_params: None,
         }
     }
 }
@@ -530,6 +619,12 @@ pub struct MkvMuxer<W: Write + Seek> {
     /// the primary video. `None` when the title has no video track (no track
     /// drives epochs).
     primary_video_track: Option<usize>,
+    /// Per-track: whether the track declared an `mvcC` BlockAdditionMapping (its
+    /// `mvc_params` was set at activation). A `BlockAdditional` with BlockAddID=2
+    /// is only conforming when the track carries the matching mapping, so
+    /// `write_frame`'s additional is dropped for a track without it (e.g. the
+    /// dependent view's parameter sets were never captured before activation).
+    track_has_mvc_mapping: Vec<bool>,
     /// Cross-clip timeline-continuity corrector (clip-boundary PTS rebasing).
     continuity: TimelineContinuity,
     cues: Vec<CuePoint>,
@@ -565,6 +660,11 @@ pub struct MkvMuxer<W: Write + Seek> {
     /// Highest block timestamp (TimestampScale ticks) written across all tracks —
     /// the muxed runtime, used to back-patch the DURATION placeholder.
     max_block_ticks: i64,
+    /// Timestamp (TimestampScale ticks) of the last video keyframe written on the
+    /// primary video track. A non-keyframe MVC base frame lives in a BlockGroup
+    /// (to carry its dependent-view BlockAdditional) and needs a `ReferenceBlock`
+    /// so players don't mistake it for a keyframe; it references this keyframe.
+    last_video_keyframe_ticks: Option<i64>,
     /// Per-AC-3-audio-track channel-correction state. The DVD IFO audio nibble
     /// is unreliable, so the channel count written in the track header is
     /// corrected from the AC-3 bitstream `acmod` of the first frame on the
@@ -685,23 +785,35 @@ fn block_ts(is_video: bool, prev: Option<i64>, pts_ticks: i64) -> i64 {
 
 /// Encode a Matroska track number as an EBML VINT into a stack buffer,
 /// returning the buffer and the used length. Track numbers are small (1-based,
-/// a handful of tracks), so 1 byte covers `< 0x80` and 2 bytes covers the rest;
-/// no heap allocation, called once per block on the mux hot path.
+/// a handful of tracks), so 1 byte covers `< 0x80`, 2 bytes covers `< 0x4000`,
+/// and 3 bytes covers `< 0x20_0000`; no heap allocation, called once per block
+/// on the mux hot path.
 ///
-/// The 2-byte form holds 14 payload bits (max 0x3FFF). The `debug_assert`
-/// guards the 0x4000 bound: at or above it, `(track_num >> 8)` is >= 0x40 and
-/// OR-ing the 0x40 length marker would clobber it, corrupting the track
-/// number. Not reachable today (track numbers are `i+1` over a few streams),
-/// so this documents the bound rather than handling 3-byte VINTs.
-fn track_vint(track_num: usize) -> ([u8; 2], usize) {
+/// Each width uses a marker bit that must NOT collide with the payload's top
+/// byte: the 1-byte marker is 0x80 (7 payload bits), the 2-byte marker 0x40
+/// (14 payload bits), the 3-byte marker 0x20 (21 payload bits). Handling all
+/// three in RELEASE (not just `debug_assert`) means an out-of-2-byte-range
+/// track number can never silently clobber the marker bit and corrupt the
+/// block. Real discs never approach even the 2-byte range; the 21-bit ceiling
+/// is an absurd upper bound kept as a `debug_assert`.
+fn track_vint(track_num: usize) -> ([u8; 3], usize) {
     if track_num < 0x80 {
-        ([(track_num as u8) | 0x80, 0], 1)
+        ([(track_num as u8) | 0x80, 0, 0], 1)
+    } else if track_num < 0x4000 {
+        ([0x40 | ((track_num >> 8) as u8), track_num as u8, 0], 2)
     } else {
         debug_assert!(
-            track_num < 0x4000,
-            "track number {track_num} exceeds the 14-bit 2-byte EBML VINT range"
+            track_num < 0x20_0000,
+            "track number {track_num} exceeds the 21-bit 3-byte EBML VINT range"
         );
-        ([0x40 | ((track_num >> 8) as u8), track_num as u8], 2)
+        (
+            [
+                0x20 | ((track_num >> 16) as u8),
+                (track_num >> 8) as u8,
+                track_num as u8,
+            ],
+            3,
+        )
     }
 }
 
@@ -805,9 +917,23 @@ impl<W: Write + Seek> MkvMuxer<W> {
         let mut track_uids: Vec<u64> = Vec::with_capacity(tracks.len());
         let mut ac3_channel_fixups: std::collections::HashMap<usize, Ac3ChannelFixup> =
             std::collections::HashMap::new();
+        // Per track: whether it emitted a conforming `mvcC` BlockAdditionMapping.
+        // Filled below from the SAME built record that drives the CodecPrivate
+        // mvcC extension, so the three MVC signals never diverge.
+        let mut track_has_mvc_mapping: Vec<bool> = Vec::with_capacity(tracks.len());
         for (i, track) in tracks.iter().enumerate() {
             let track_uid = (i + 1) as u64 | 0x100_0000;
             track_uids.push(track_uid);
+            // Build the MVC (Blu-ray 3D) MVCDecoderConfigurationRecord ONCE per
+            // track from the dependent view's subset-SPS/PPS. `None` for every
+            // non-3D track (and if the params are malformed) — the single source
+            // of truth for the CodecPrivate mvcC extension, the
+            // BlockAdditionMapping, and whether BlockAdditionals are conforming.
+            let mvc_record = track
+                .mvc_params
+                .as_ref()
+                .and_then(|(sps, pps)| mvc_decoder_config_record(sps, pps));
+            track_has_mvc_mapping.push(mvc_record.is_some());
             let entry_pos = ebml::start_master(&mut writer, ebml::TRACK_ENTRY)?;
             ebml::write_uint(&mut writer, ebml::TRACK_NUMBER, (i + 1) as u64)?;
             ebml::write_uint(&mut writer, ebml::TRACK_UID, track_uid)?;
@@ -827,7 +953,20 @@ impl<W: Write + Seek> MkvMuxer<W> {
             }
 
             if let Some(ref cp) = track.codec_private {
-                ebml::write_binary(&mut writer, ebml::CODEC_PRIVATE, cp)?;
+                match mvc_record.as_ref() {
+                    // MVC (Blu-ray 3D) base track: CodecPrivate = base-view avcC
+                    // followed by the `mvcC` extension block. This is the
+                    // track-level signal decoders/mediainfo read to recognise the
+                    // stereoscopic MVC track (the per-frame dependent view rides
+                    // in BlockAdditional under the mapping below).
+                    Some(record) => {
+                        let cp_mvc = mvc_codec_private(cp, record);
+                        ebml::write_binary(&mut writer, ebml::CODEC_PRIVATE, &cp_mvc)?;
+                    }
+                    // Non-MVC (2D/UHD/audio/…): write the codec_private verbatim —
+                    // the unchanged path, byte-identical to a 2D mux.
+                    None => ebml::write_binary(&mut writer, ebml::CODEC_PRIVATE, cp)?,
+                }
             }
             // Pre-0.13 a deferred codecPrivate path existed for video tracks
             // (placeholder reserve + later seek-back fill via
@@ -923,6 +1062,40 @@ impl<W: Write + Seek> MkvMuxer<W> {
                 ebml::end_master(&mut writer, vid_pos)?;
             }
 
+            // Blu-ray 3D (MVC) signaling — BlockAdditionMapping (sibling of
+            // Video) carries the mvcC MVCDecoderConfigurationRecord so players /
+            // mediainfo recognise the dependent (right-eye) view that rides as a
+            // per-frame BlockAdditional under this mapping (BlockAddIDValue = 2).
+            match mvc_record.as_ref() {
+                Some(record) => {
+                    let map_pos = ebml::start_master(&mut writer, ebml::BLOCK_ADDITION_MAPPING)?;
+                    ebml::write_uint(
+                        &mut writer,
+                        ebml::BLOCK_ADD_ID_VALUE,
+                        BLOCK_ADD_ID_VALUE_MVC,
+                    )?;
+                    ebml::write_uint(&mut writer, ebml::BLOCK_ADD_ID_TYPE, BLOCK_ADD_ID_TYPE_MVCC)?;
+                    ebml::write_binary(&mut writer, ebml::BLOCK_ADD_ID_EXTRA_DATA, record)?;
+                    ebml::end_master(&mut writer, map_pos)?;
+                }
+                // `mvc_params` present but the record failed to build (malformed
+                // parameter sets): no mapping, and `track_has_mvc_mapping` above
+                // is already `false`, so BlockAdditionals are dropped — the file
+                // stays conforming rather than carrying an orphaned BlockAddID.
+                None if track.mvc_params.is_some() => {
+                    let (s, p) = track.mvc_params.as_ref().unwrap();
+                    tracing::warn!(
+                        target: "mux",
+                        "MVC track: could not build MVCDecoderConfigurationRecord from the \
+                         dependent view's parameter sets (subset_sps={} B, pps={} B); \
+                         emitting no mvcC mapping — the 3D pairing will not be signalled.",
+                        s.len(),
+                        p.len(),
+                    );
+                }
+                None => {}
+            }
+
             // Dolby Vision signaling — BlockAdditionMapping is a child of the
             // TrackEntry (sibling of Video). Carries the dvcC so players /
             // mediainfo recognise the track as Dolby Vision.
@@ -1013,6 +1186,7 @@ impl<W: Write + Seek> MkvMuxer<W> {
             primary_video_track: tracks
                 .iter()
                 .position(|t| t.track_type == ebml::TRACK_TYPE_VIDEO),
+            track_has_mvc_mapping,
             continuity: TimelineContinuity::new(),
             cues: Vec::new(),
             frame_count: 0,
@@ -1027,6 +1201,7 @@ impl<W: Write + Seek> MkvMuxer<W> {
             duration_secs,
             duration_patch_pos,
             max_block_ticks: 0,
+            last_video_keyframe_ticks: None,
             ac3_channel_fixups,
             opening_capture: None,
         })
@@ -1058,6 +1233,13 @@ impl<W: Write + Seek> MkvMuxer<W> {
     /// (`None`) leaves the written value untouched: an interlaced track keeps
     /// its guess rather than being cleared via a multi-element change. The byte
     /// width is fixed (FieldOrder is 0..=14), so the in-place rewrite is valid.
+    ///
+    /// `block_additional`, when `Some`, is attached to the frame as a Matroska
+    /// `BlockAdditional` (BlockAddID=2) — Blu-ray 3D (MVC): the base view is the
+    /// Block and the dependent (right-eye) access unit rides as the
+    /// BlockAdditional under the track's `mvcC` mapping. Such a frame is always a
+    /// `BlockGroup` (never a SimpleBlock), with a `ReferenceBlock` when it is not
+    /// a keyframe. `None` for every non-3D frame.
     pub fn write_frame(
         &mut self,
         track_idx: usize,
@@ -1065,6 +1247,7 @@ impl<W: Write + Seek> MkvMuxer<W> {
         keyframe: bool,
         data: &[u8],
         duration_ns: Option<u64>,
+        block_additional: Option<&[u8]>,
     ) -> io::Result<()> {
         // --log-level 3: capture the first ~100 coded frames per track to the
         // side file BEFORE any timeline mangling, with the codec parser's own
@@ -1226,15 +1409,72 @@ impl<W: Write + Seek> MkvMuxer<W> {
         self.max_block_ticks = self.max_block_ticks.max(block_end_ticks);
 
         let relative_ts = (pts_ticks - self.cluster_ts_ticks) as i16;
-        match duration_ns {
-            Some(dur_ns) => {
-                // BlockDuration is in TimestampScale ticks, floored at 1.
-                let duration_ticks = (dur_ns as i64 / TIMESTAMP_SCALE_NS).max(1) as u64;
-                self.write_block_group(track_idx + 1, relative_ts, keyframe, data, duration_ticks)?;
+        let duration_ticks =
+            duration_ns.map(|dur_ns| (dur_ns as i64 / TIMESTAMP_SCALE_NS).max(1) as u64);
+        // A BlockAdditional with BlockAddID=2 is only conforming when the track
+        // declared the matching mvcC BlockAdditionMapping. If it did not (the
+        // dependent view's parameter sets were never captured before the header
+        // was written), drop the additional and emit a plain block rather than a
+        // non-conforming file with an orphaned BlockAddID.
+        let block_additional = match block_additional {
+            Some(a)
+                if self
+                    .track_has_mvc_mapping
+                    .get(track_idx)
+                    .copied()
+                    .unwrap_or(false) =>
+            {
+                Some(a)
             }
-            None => {
-                self.write_simple_block(track_idx + 1, relative_ts, keyframe, data)?;
+            Some(_) => None,
+            None => None,
+        };
+        match block_additional {
+            // MVC: base view Block + dependent-view BlockAdditional, always a
+            // BlockGroup. Non-keyframe base frames get a ReferenceBlock to the
+            // last keyframe (a keyframe carries none), so a player never treats a
+            // P/B frame as a seek point.
+            Some(additional) => {
+                let reference = if keyframe {
+                    None
+                } else {
+                    // Offset (ticks) of the referenced keyframe relative to this
+                    // block. A non-keyframe MUST carry a ReferenceBlock or a reader
+                    // treats it as a seek point; fall back to 0 (self-relative) in
+                    // the pre-first-keyframe corner (unreachable in practice — such
+                    // frames are dropped before a cluster opens) so the marker is
+                    // never absent.
+                    Some(
+                        self.last_video_keyframe_ticks
+                            .map(|kf| kf - pts_ticks)
+                            .unwrap_or(0),
+                    )
+                };
+                self.write_block_group_mvc(
+                    track_idx + 1,
+                    relative_ts,
+                    data,
+                    additional,
+                    reference,
+                    duration_ticks,
+                )?;
             }
+            None => match duration_ticks {
+                // BlockDuration present (PGS subtitles) → BlockGroup.
+                Some(dt) => {
+                    self.write_block_group(track_idx + 1, relative_ts, keyframe, data, dt)?;
+                }
+                None => {
+                    self.write_simple_block(track_idx + 1, relative_ts, keyframe, data)?;
+                }
+            },
+        }
+        // Remember the last PRIMARY-video keyframe's tick so a later non-keyframe
+        // MVC base frame references a keyframe on its OWN track (see the
+        // block_additional path above). Gating to the primary video track avoids a
+        // secondary video track's keyframe becoming a cross-track reference target.
+        if keyframe && Some(track_idx) == self.primary_video_track {
+            self.last_video_keyframe_ticks = Some(pts_ticks);
         }
         self.frame_count += 1;
 
@@ -1519,6 +1759,52 @@ impl<W: Write + Seek> MkvMuxer<W> {
         ebml::end_master(&mut self.writer, bg_pos)?;
         Ok(())
     }
+
+    /// Write a BlockGroup carrying the base view Block plus the MVC dependent
+    /// (right-eye) access unit as a `BlockAdditional` (BlockAddID=2), per the
+    /// track's `mvcC` BlockAdditionMapping. A non-keyframe frame gets a
+    /// `ReferenceBlock` (`reference` = referenced keyframe offset in ticks) so it
+    /// is not mistaken for a seek point; `BlockDuration` is written when known.
+    fn write_block_group_mvc(
+        &mut self,
+        track_num: usize,
+        relative_ts: i16,
+        data: &[u8],
+        additional: &[u8],
+        reference: Option<i64>,
+        duration_ticks: Option<u64>,
+    ) -> io::Result<()> {
+        let (tv, tv_len) = track_vint(track_num);
+        let track_vint = &tv[..tv_len];
+        // The 0x80 Keyframe flag is SimpleBlock-only; inside a BlockGroup Block
+        // it is reserved and MUST be 0 — keyframe-ness is signalled by the
+        // presence/absence of ReferenceBlock.
+        let flags: u8 = 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)?;
+        if let Some(dt) = duration_ticks {
+            ebml::write_uint(&mut self.writer, ebml::BLOCK_DURATION, dt)?;
+        }
+        if let Some(ref_off) = reference {
+            ebml::write_int(&mut self.writer, ebml::REFERENCE_BLOCK, ref_off)?;
+        }
+        // BlockAdditions → BlockMore { BlockAddID=2, BlockAdditional=dependent AU }.
+        let adds_pos = ebml::start_master(&mut self.writer, ebml::BLOCK_ADDITIONS)?;
+        let more_pos = ebml::start_master(&mut self.writer, ebml::BLOCK_MORE)?;
+        ebml::write_uint(&mut self.writer, ebml::BLOCK_ADD_ID, BLOCK_ADD_ID_VALUE_MVC)?;
+        ebml::write_binary(&mut self.writer, ebml::BLOCK_ADDITIONAL, additional)?;
+        ebml::end_master(&mut self.writer, more_pos)?;
+        ebml::end_master(&mut self.writer, adds_pos)?;
+        ebml::end_master(&mut self.writer, bg_pos)?;
+        Ok(())
+    }
 }
 
 // ============================================================
@@ -1702,6 +1988,7 @@ mod tests {
             bit_depth: 0,
             dv_config: None,
             hdr10: None,
+            mvc_params: None,
         }
     }
 
@@ -1731,6 +2018,7 @@ mod tests {
             bit_depth: 0,
             dv_config: None,
             hdr10: None,
+            mvc_params: None,
         }
     }
 
@@ -1814,7 +2102,7 @@ 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], None)
+            .write_frame(0, 0, true, &[0xDE, 0xAD, 0xBE, 0xEF], None, None)
             .unwrap();
         let data = muxer.writer.into_inner();
         assert!(
@@ -1834,7 +2122,7 @@ mod tests {
         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], None)
+            .write_frame(0, 0, true, &[0x01, 0x02, 0x03], None, None)
             .unwrap();
         muxer.finish().unwrap();
 
@@ -1860,7 +2148,7 @@ mod tests {
         let tracks = [make_video_track()];
         let mut muxer = MkvMuxer::new(writer, &tracks, Some("NoCue"), 60.0, &[]).unwrap();
         muxer
-            .write_frame(0, 0, true, &[0x01, 0x02, 0x03], None)
+            .write_frame(0, 0, true, &[0x01, 0x02, 0x03], None, None)
             .unwrap();
         // Force the zero-cue branch: drop every cue before finalizing.
         let cues_entry_pos = muxer.cues_seek_entry_pos.expect("CUES seek entry recorded");
@@ -2111,16 +2399,16 @@ mod tests {
         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], None)
+            .write_frame(0, 0, true, &[0x00, 0x00, 0x01], None, None)
             .unwrap();
         muxer
-            .write_frame(1, 0, false, &[0x0B, 0x77, 0x00], None)
+            .write_frame(1, 0, false, &[0x0B, 0x77, 0x00], None, None)
             .unwrap();
         muxer
-            .write_frame(0, 40_000_000, false, &[0x00, 0x00, 0x01], None)
+            .write_frame(0, 40_000_000, false, &[0x00, 0x00, 0x01], None, None)
             .unwrap();
         muxer
-            .write_frame(1, 32_000_000, false, &[0x0B, 0x77, 0x01], None)
+            .write_frame(1, 32_000_000, false, &[0x0B, 0x77, 0x01], None, None)
             .unwrap();
         // Should not panic
         let data = muxer.writer.into_inner();
@@ -2135,11 +2423,11 @@ mod tests {
 
         // Record position before first frame
         let pos_before_kf = muxer.writer.position();
-        muxer.write_frame(0, 0, true, &[0xAA], None).unwrap();
+        muxer.write_frame(0, 0, true, &[0xAA], None, None).unwrap();
         let pos_after_kf = muxer.writer.position();
 
         muxer
-            .write_frame(0, 1_000_000, false, &[0xBB], None)
+            .write_frame(0, 1_000_000, false, &[0xBB], None, None)
             .unwrap();
         let pos_after_nkf = muxer.writer.position();
 
@@ -2385,7 +2673,7 @@ mod tests {
         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();
+            muxer.write_frame(*t, *pts, *kf, data, None, None).unwrap();
         }
         let frame_count = muxer.frame_count;
         muxer.finish().unwrap();
@@ -2747,7 +3035,7 @@ mod tests {
         let mut muxer = MkvMuxer::new(writer, &tracks, None, 0.0, &[]).unwrap();
         for f in &frames {
             muxer
-                .write_frame(0, f.pts_ns, f.keyframe, &f.data, f.duration_ns)
+                .write_frame(0, f.pts_ns, f.keyframe, &f.data, f.duration_ns, None)
                 .unwrap();
         }
         muxer.finish().unwrap();
@@ -3136,12 +3424,14 @@ mod tests {
         let writer = SharedWriter(shared.clone());
         let mut muxer = MkvMuxer::new(writer, &tracks, None, 0.0, &[]).unwrap();
         // Audio frames (track 1) and non-keyframe video — no track-0 keyframe.
-        muxer.write_frame(1, 0, true, &[0xAA; 8], None).unwrap();
         muxer
-            .write_frame(0, 10_000_000, false, &[0xBB; 8], None)
+            .write_frame(1, 0, true, &[0xAA; 8], None, None)
             .unwrap();
         muxer
-            .write_frame(1, 20_000_000, true, &[0xCC; 8], None)
+            .write_frame(0, 10_000_000, false, &[0xBB; 8], None, None)
+            .unwrap();
+        muxer
+            .write_frame(1, 20_000_000, true, &[0xCC; 8], None, None)
             .unwrap();
         let err = muxer.finish().unwrap_err();
         assert_eq!(err.kind(), io::ErrorKind::InvalidData);
@@ -3216,7 +3506,7 @@ mod tests {
         let writer = SharedWriter(shared.clone());
         let mut muxer = MkvMuxer::new(writer, &tracks, None, 0.0, &[]).unwrap();
         for (t, pts, kf, data) in &frames_in_order {
-            muxer.write_frame(*t, *pts, *kf, data, None).unwrap();
+            muxer.write_frame(*t, *pts, *kf, data, None, None).unwrap();
         }
         muxer.finish().unwrap();
         let data = shared.lock().unwrap().clone().into_inner();
@@ -3229,7 +3519,7 @@ mod tests {
     }
 
     #[test]
-    fn track_vint_encodes_one_and_two_byte_forms() {
+    fn track_vint_encodes_one_two_and_three_byte_forms() {
         // 1-byte form for track numbers < 0x80, high bit set.
         let (b, n) = track_vint(1);
         assert_eq!(&b[..n], &[0x81]);
@@ -3240,6 +3530,12 @@ mod tests {
         assert_eq!(&b[..n], &[0x40, 0x80]);
         let (b, n) = track_vint(0x3FFF);
         assert_eq!(&b[..n], &[0x7F, 0xFF]);
+        // 3-byte form at/above 0x4000, 0x20 length marker in the top byte —
+        // handled in RELEASE (no silent marker-bit clobber), not just debug.
+        let (b, n) = track_vint(0x4000);
+        assert_eq!(&b[..n], &[0x20, 0x40, 0x00]);
+        let (b, n) = track_vint(0x1F_FFFF);
+        assert_eq!(&b[..n], &[0x3F, 0xFF, 0xFF]);
     }
 
     // ============================================================
@@ -3286,7 +3582,7 @@ mod tests {
         let writer = SharedWriter(shared.clone());
         let mut muxer = MkvMuxer::new(writer, tracks, None, 0.0, &[]).unwrap();
         for (t, pts, kf, data, dur) in frames {
-            muxer.write_frame(*t, *pts, *kf, data, *dur).unwrap();
+            muxer.write_frame(*t, *pts, *kf, data, *dur, None).unwrap();
         }
         muxer.finish().unwrap();
         shared.lock().unwrap().clone().into_inner()
@@ -4135,10 +4431,10 @@ mod tests {
         let mut muxer = MkvMuxer::new(writer, &tracks, None, 10.0, &[]).unwrap();
         // Video keyframe 1000 bytes; audio frame 500 bytes.
         muxer
-            .write_frame(0, 0, true, &vec![0xABu8; 1000], None)
+            .write_frame(0, 0, true, &vec![0xABu8; 1000], None, None)
             .unwrap();
         muxer
-            .write_frame(1, 0, false, &vec![0xCDu8; 500], None)
+            .write_frame(1, 0, false, &vec![0xCDu8; 500], None, None)
             .unwrap();
         muxer.finish().unwrap();
         let data = shared.lock().unwrap().clone().into_inner();
@@ -4188,8 +4484,10 @@ mod tests {
         // lfeon(0) = 0b0100_0000 = 0x40. acmod_channels only needs >= 8 bytes.
         let ac3 = vec![0x0B, 0x77, 0x00, 0x00, 0x00, 8 << 3, 0x40, 0x00];
         // Open a cluster with a video keyframe first (cluster invariant).
-        muxer.write_frame(0, 0, true, &[0x01, 0x02], None).unwrap();
-        muxer.write_frame(1, 0, false, &ac3, None).unwrap();
+        muxer
+            .write_frame(0, 0, true, &[0x01, 0x02], None, None)
+            .unwrap();
+        muxer.write_frame(1, 0, false, &ac3, None, None).unwrap();
         muxer.finish().unwrap();
         let data = shared.lock().unwrap().clone().into_inner();
 
@@ -4234,6 +4532,203 @@ mod tests {
         assert!(find_id(&data, ebml::BLOCK_ADDITION_MAPPING).is_none());
     }
 
+    #[test]
+    fn mvc_decoder_config_record_matches_iso_14496_15_layout() {
+        // subset SPS (NAL type 15): [nal_hdr, profile, compat, level, ...].
+        let subset_sps = vec![0x6F, 0x80, 0x00, 0x33, 0x11, 0x22];
+        let pps = vec![0x68, 0xEE, 0x3C];
+        let rec = mvc_decoder_config_record(&subset_sps, &pps).expect("record builds");
+
+        // ISO/IEC 14496-15:2013 §7.6.2 byte layout, verbatim:
+        let expected: Vec<u8> = [
+            vec![
+                1,    // configurationVersion
+                0x80, // AVCProfileIndication  = subset_sps[1]
+                0x00, // profile_compatibility = subset_sps[2]
+                0x33, // AVCLevelIndication    = subset_sps[3]
+                0xBF, // complete_rep(1) explicit_au(0) reserved'1111' lengthSizeMinusOne=3
+                0x01, // reserved'0'(1) numOfSequenceParameterSets(7)=1
+                0x00, 0x06, // sequenceParameterSetLength = 6
+            ],
+            subset_sps.clone(),
+            vec![
+                1, // numOfPictureParameterSets
+                0x00, 0x03, // pictureParameterSetLength = 3
+            ],
+            pps.clone(),
+        ]
+        .concat();
+        assert_eq!(rec, expected, "MVCDecoderConfigurationRecord byte layout");
+
+        // Guards: too-short SPS and empty PPS both refuse (no corrupt record).
+        assert!(mvc_decoder_config_record(&[0x6F, 0x80, 0x00], &pps).is_none());
+        assert!(mvc_decoder_config_record(&subset_sps, &[]).is_none());
+        // Over-length param sets (> 65535) would mis-frame the 16-bit length
+        // field; both must refuse rather than emit a truncated record.
+        let huge = vec![0u8; 0x1_0000];
+        assert!(mvc_decoder_config_record(&huge, &pps).is_none());
+        assert!(mvc_decoder_config_record(&subset_sps, &huge).is_none());
+    }
+
+    #[test]
+    fn mvc_frame_emits_blockgroup_additional_and_reference() {
+        // A track declaring an mvcC mapping: a keyframe base frame carrying a
+        // dependent AU emits BlockGroup > BlockAdditions > BlockMore
+        // {BlockAddID=2, BlockAdditional=dep}; a following non-keyframe adds a
+        // ReferenceBlock so it is not mistaken for a seek point.
+        let mut v = make_video_track();
+        v.mvc_params = Some((
+            vec![0x6F, 0x80, 0x00, 0x33, 0x11, 0x22],
+            vec![0x68, 0xEE, 0x3C],
+        ));
+        let mut muxer = MkvMuxer::new(Cursor::new(Vec::new()), &[v], None, 0.0, &[]).unwrap();
+        let dep_kf = [0xDEu8, 0xAD, 0xBE, 0xEF];
+        let dep_p = [0xCAu8, 0xFE];
+        muxer
+            .write_frame(0, 0, true, &[0x65, 0x01, 0x02], None, Some(&dep_kf))
+            .unwrap();
+        muxer
+            .write_frame(0, 40_000_000, false, &[0x41, 0x03], None, Some(&dep_p))
+            .unwrap();
+        let data = muxer.writer.into_inner();
+
+        assert!(
+            find_id(&data, ebml::BLOCK_ADDITIONS).is_some(),
+            "BlockAdditions (0x75A1) present"
+        );
+        // BlockAddID = 2 (uint): element 0xEE, size 0x81, value 0x02.
+        assert!(
+            data.windows(3).any(|w| w == [0xEE, 0x81, 0x02]),
+            "BlockAddID must be 2"
+        );
+        assert!(
+            data.windows(4).any(|w| w == dep_kf),
+            "keyframe dependent AU present as BlockAdditional"
+        );
+        assert!(
+            data.windows(2).any(|w| w == dep_p),
+            "non-keyframe dependent AU present"
+        );
+        assert!(
+            find_id(&data, ebml::REFERENCE_BLOCK).is_some(),
+            "non-keyframe MVC base frame must carry a ReferenceBlock"
+        );
+    }
+
+    #[test]
+    fn additional_dropped_when_track_has_no_mvc_mapping() {
+        // If a track did NOT declare an mvcC mapping (mvc_params None), a stray
+        // block_additional must be dropped (no orphaned BlockAddID=2 / no
+        // BlockAdditions) so the file stays conforming.
+        let mut muxer = MkvMuxer::new(
+            Cursor::new(Vec::new()),
+            &[make_video_track()],
+            None,
+            0.0,
+            &[],
+        )
+        .unwrap();
+        muxer
+            .write_frame(0, 0, true, &[0x65, 0x01], None, Some(&[0xDE, 0xAD]))
+            .unwrap();
+        let data = muxer.writer.into_inner();
+        assert!(
+            find_id(&data, ebml::BLOCK_ADDITIONS).is_none(),
+            "no BlockAdditions without a declared mvcC mapping"
+        );
+    }
+
+    #[test]
+    fn mvc_track_emits_mvcc_block_addition_mapping() {
+        // A track with mvc_params must emit BlockAdditionMapping (0x41E4) with the
+        // mvcC BlockAddIDType (0x6D766343) and a BlockAddIDValue (0x41F0), so
+        // players / mediainfo recognise the Blu-ray 3D dependent view.
+        let mut v = make_video_track();
+        v.mvc_params = Some((
+            vec![0x6F, 0x80, 0x00, 0x33, 0x11, 0x22],
+            vec![0x68, 0xEE, 0x3C],
+        ));
+        let muxer = MkvMuxer::new(Cursor::new(Vec::new()), &[v], None, 0.0, &[]).unwrap();
+        let data = muxer.writer.into_inner();
+        assert!(
+            find_id(&data, ebml::BLOCK_ADDITION_MAPPING).is_some(),
+            "MVC track must emit BlockAdditionMapping"
+        );
+        assert!(
+            find_id(&data, ebml::BLOCK_ADD_ID_VALUE).is_some(),
+            "MVC mapping must carry BlockAddIDValue"
+        );
+        assert!(
+            data.windows(4).any(|w| w == [0x6D, 0x76, 0x63, 0x43]),
+            "mvcC fourcc must be present as the BlockAddIDType value"
+        );
+        // Without mvc_params, no mapping.
+        let muxer = MkvMuxer::new(
+            Cursor::new(Vec::new()),
+            &[make_video_track()],
+            None,
+            0.0,
+            &[],
+        )
+        .unwrap();
+        let data = muxer.writer.into_inner();
+        assert!(find_id(&data, ebml::BLOCK_ADDITION_MAPPING).is_none());
+    }
+
+    #[test]
+    fn mvc_codec_private_appends_mvcc_extension_block() {
+        // avcC ‖ u32be(4 + record.len()) ‖ "mvcC" ‖ record (Matroska Codec Spec §4.3.9).
+        let avcc = vec![0x01, 0x64, 0x00, 0x33, 0xFF, 0xE1, 0xAA];
+        let record = vec![0x01, 0x80, 0x00, 0x33, 0xBF, 0x01, 0xCC]; // 7 bytes
+        let out = mvc_codec_private(&avcc, &record);
+        assert_eq!(&out[..avcc.len()], &avcc[..], "avcC preserved verbatim");
+        // size field = 4 ("mvcC") + 7 (record) = 11 = extension block size minus 4.
+        assert_eq!(&out[avcc.len()..avcc.len() + 4], &11u32.to_be_bytes());
+        assert_eq!(&out[avcc.len() + 4..avcc.len() + 8], b"mvcC");
+        assert_eq!(
+            &out[avcc.len() + 8..],
+            &record[..],
+            "record after the mvcC fourcc"
+        );
+    }
+
+    #[test]
+    fn mvc_track_codec_private_carries_avcc_plus_mvcc() {
+        // An MVC base track's CodecPrivate must be the base avcC followed by the
+        // mvcC extension — the track-level signal mediainfo/decoders read.
+        let avcc = vec![
+            0x01, 0x64, 0x00, 0x33, 0xFF, 0xE1, 0x00, 0x05, 0x67, 0x64, 0x00, 0x33, 0x99,
+        ];
+        let subset_sps = vec![0x6F, 0x80, 0x00, 0x33, 0x11, 0x22];
+        let pps = vec![0x68, 0xEE, 0x3C];
+        let mut v = make_video_track();
+        v.codec_private = Some(avcc.clone());
+        v.mvc_params = Some((subset_sps.clone(), pps.clone()));
+        let data = MkvMuxer::new(Cursor::new(Vec::new()), &[v], None, 0.0, &[])
+            .unwrap()
+            .writer
+            .into_inner();
+        let record = mvc_decoder_config_record(&subset_sps, &pps).unwrap();
+        let expected = mvc_codec_private(&avcc, &record);
+        assert!(
+            data.windows(expected.len())
+                .any(|w| w == expected.as_slice()),
+            "emitted CodecPrivate must be avcC + mvcC extension"
+        );
+
+        // A non-MVC (2D) track writes its avcC VERBATIM — no mvcC appended.
+        let mut v2 = make_video_track();
+        v2.codec_private = Some(avcc.clone());
+        let d2 = MkvMuxer::new(Cursor::new(Vec::new()), &[v2], None, 0.0, &[])
+            .unwrap()
+            .writer
+            .into_inner();
+        assert!(
+            !d2.windows(4).any(|w| w == b"mvcC"),
+            "2D track CodecPrivate must not carry an mvcC extension"
+        );
+    }
+
     // ---- CodecPrivate emission (avcC / hvcC / VC-1 / MPEG-2) -------------
     //
     // `MkvTrack::video` always builds with `codec_private: None`; the PES mux

src/mux/mkvstream.rs

@@ -120,36 +120,253 @@ struct PendingMux {
     video_track: Option<usize>,
     /// `--log-level 3` opening-capture side-file path (if any).
     opening_capture_path: Option<std::path::PathBuf>,
-    /// Frames received before activation, replayed in order once built.
-    buffered: Vec<crate::pes::PesFrame>,
+    /// Frames received before activation, replayed in order once built. Each
+    /// carries an optional MVC dependent-view `BlockAdditional` (present only
+    /// for a 3D base-view frame that was already paired before activation).
+    buffered: Vec<(crate::pes::PesFrame, Option<Vec<u8>>)>,
 }
 
 /// Matroska container stream.
 pub struct MkvStream {
     disc_title: DiscTitle,
     mode: Mode,
+    /// Blu-ray 3D (MVC) merge state — present iff the title carries an MVC
+    /// dependent (right-eye) view. Folds the dependent stream's frames into the
+    /// base video track as per-frame `BlockAdditional`, paired by PTS, so the
+    /// output is a single MVC track instead of two independent H.264 tracks.
+    mvc: Option<MvcMerge>,
+}
+
+/// Largest number of base frames held awaiting their PTS-matching dependent AU
+/// before the oldest is flushed unpaired (a plain Block). The SSIF interleaves
+/// base and dependent access units per unit, so a base's dependent normally
+/// arrives within one or two frames; this window only bounds memory/latency for
+/// a stream where the pairing drifts.
+const MVC_PAIR_WINDOW: usize = 32;
+
+/// A base-view frame (track already remapped to the muxer's base track index)
+/// awaiting — or already carrying — its dependent-view `BlockAdditional`.
+struct PendingBase {
+    frame: crate::pes::PesFrame,
+    additional: Option<Vec<u8>>,
+}
+
+/// State for folding the MVC dependent (right-eye) view into the base track.
+struct MvcMerge {
+    /// `title.streams` index of the base (left-eye) video stream.
+    base_stream_idx: usize,
+    /// `title.streams` index of the dependent (right-eye) video stream.
+    dep_stream_idx: usize,
+    /// Muxer track index of the base view — where the dependent AU is attached
+    /// as a `BlockAdditional` and where `mvc_params` (the `mvcC` mapping) lives.
+    base_track_idx: usize,
+    /// `title.streams` index → muxer track index. The dependent maps to `None`
+    /// (it becomes a BlockAdditional, not a track); every other stream shifts
+    /// down by one if it followed the dependent in stream order.
+    stream_to_track: Vec<Option<usize>>,
+    /// Base frames (decode order) awaiting their dependent or a window flush.
+    pending_base: std::collections::VecDeque<PendingBase>,
+    /// Dependent AU data keyed by PTS, waiting for the matching base.
+    dep_by_pts: std::collections::HashMap<i64, Vec<u8>>,
+    /// `(subset_sps, pps)` from the first dependent AU — builds the `mvcC`
+    /// MVCDecoderConfigurationRecord for the base track's BlockAdditionMapping.
+    captured_params: Option<(Vec<u8>, Vec<u8>)>,
+    /// Count of dependent AUs dropped with no matching base (diagnostic).
+    orphan_deps: u64,
+}
+
+impl MvcMerge {
+    /// Ingest one incoming frame; returns `(frame, additional)` pairs ready to
+    /// hand to the muxer, in emit order. Base frames buffer briefly to pair with
+    /// their dependent by PTS; the dependent stream produces no frames of its own
+    /// (it becomes `BlockAdditional`); all other streams pass straight through
+    /// with their track index remapped.
+    fn ingest(
+        &mut self,
+        frame: &crate::pes::PesFrame,
+    ) -> Vec<(crate::pes::PesFrame, Option<Vec<u8>>)> {
+        let mut out = Vec::new();
+        if frame.track == self.dep_stream_idx {
+            if self.captured_params.is_none() {
+                self.captured_params = extract_mvc_params(&frame.data);
+            }
+            // Attach to a waiting base of the same PTS, else stash by PTS.
+            if let Some(pb) = self
+                .pending_base
+                .iter_mut()
+                .find(|pb| pb.frame.pts == frame.pts && pb.additional.is_none())
+            {
+                pb.additional = Some(frame.data.clone());
+            } else {
+                // Bound the orphan map BEFORE inserting: if dependents pile up
+                // unpaired (pairing badly drifted), drop the drifted buffer so it
+                // stays bounded — but keep THIS just-arrived dependent, whose base
+                // frame commonly arrives next. Clearing after the insert would
+                // discard it and overcount orphans by one.
+                if self.dep_by_pts.len() >= MVC_PAIR_WINDOW * 4 {
+                    self.orphan_deps += self.dep_by_pts.len() as u64;
+                    self.dep_by_pts.clear();
+                }
+                // A duplicate-PTS dependent (e.g. a stale repeat after a stream
+                // discontinuity) displaces the prior one — count it as an orphan
+                // rather than losing it silently.
+                if self
+                    .dep_by_pts
+                    .insert(frame.pts, frame.data.clone())
+                    .is_some()
+                {
+                    self.orphan_deps += 1;
+                }
+            }
+        } else if frame.track == self.base_stream_idx {
+            let additional = self.dep_by_pts.remove(&frame.pts);
+            let mut remapped = frame.clone();
+            remapped.track = self.base_track_idx;
+            self.pending_base.push_back(PendingBase {
+                frame: remapped,
+                additional,
+            });
+        } else {
+            // Audio / subtitle / other video: remap the track index and forward.
+            let mut remapped = frame.clone();
+            if let Some(Some(t)) = self.stream_to_track.get(frame.track) {
+                remapped.track = *t;
+                out.push((remapped, None));
+            }
+        }
+        self.drain_ready(&mut out);
+        out
+    }
+
+    /// Emit base frames from the FIFO front once each has its dependent attached,
+    /// or flush the oldest unpaired base as a plain Block when the window is full.
+    fn drain_ready(&mut self, out: &mut Vec<(crate::pes::PesFrame, Option<Vec<u8>>)>) {
+        loop {
+            let front_ready = self
+                .pending_base
+                .front()
+                .map(|pb| pb.additional.is_some())
+                .unwrap_or(false);
+            if front_ready || self.pending_base.len() > MVC_PAIR_WINDOW {
+                if let Some(pb) = self.pending_base.pop_front() {
+                    out.push((pb.frame, pb.additional));
+                    continue;
+                }
+            }
+            break;
+        }
+    }
+
+    /// Flush every remaining buffered base frame (unpaired → plain Block) at EOF.
+    fn flush(&mut self) -> Vec<(crate::pes::PesFrame, Option<Vec<u8>>)> {
+        let mut out = Vec::new();
+        for pb in self.pending_base.drain(..) {
+            out.push((pb.frame, pb.additional));
+        }
+        self.orphan_deps += self.dep_by_pts.len() as u64;
+        self.dep_by_pts.clear();
+        out
+    }
+}
+
+/// Hand a frame to the muxer, attaching the MVC dependent view as a
+/// `BlockAdditional` when `additional` is `Some` (a 3D base frame), else a
+/// plain block.
+fn emit_to_muxer(
+    m: &mut MkvMuxer<Box<dyn WriteSeek + Send>>,
+    frame: &crate::pes::PesFrame,
+    additional: Option<&[u8]>,
+) -> io::Result<()> {
+    m.write_frame(
+        frame.track,
+        frame.pts,
+        frame.keyframe,
+        &frame.data,
+        frame.duration_ns,
+        additional,
+    )
+}
+
+/// Scan a length-prefixed (4-byte big-endian) H.264 NAL stream for the first
+/// subset SPS (NAL type 15) and first PPS (NAL type 8) — the two parameter sets
+/// that populate the `mvcC` MVCDecoderConfigurationRecord. Returns
+/// `Some((subset_sps, pps))` only when BOTH are found; `None` otherwise (the
+/// serializer then emits no mvcC mapping and logs it).
+fn extract_mvc_params(data: &[u8]) -> Option<(Vec<u8>, Vec<u8>)> {
+    let mut subset_sps: Option<Vec<u8>> = None;
+    let mut pps: Option<Vec<u8>> = None;
+    let mut i = 0usize;
+    while i + 4 <= data.len() {
+        let len = u32::from_be_bytes([data[i], data[i + 1], data[i + 2], data[i + 3]]) as usize;
+        i += 4;
+        // A zero-length NAL (a stray length prefix) is skipped, not fatal — the
+        // subset SPS / PPS may still follow. A length that runs past the buffer
+        // end IS unrecoverable (the NAL can't be read), so stop there.
+        if len == 0 {
+            continue;
+        }
+        if i + len > data.len() {
+            break;
+        }
+        let nal = &data[i..i + len];
+        i += len;
+        match nal[0] & 0x1F {
+            15 if subset_sps.is_none() => subset_sps = Some(nal.to_vec()),
+            8 if pps.is_none() => pps = Some(nal.to_vec()),
+            _ => {}
+        }
+        if subset_sps.is_some() && pps.is_some() {
+            break;
+        }
+    }
+    Some((subset_sps?, pps?))
 }
 
 impl MkvStream {
-    /// Create for writing PES frames → MKV container.
-    /// Codec privates come from title.codec_privates (populated by input stream).
-    pub fn create(writer: Box<dyn WriteSeek + Send>, title: &DiscTitle) -> io::Result<Self> {
-        Self::create_at(writer, title, None)
-    }
-
-    /// As [`create`](Self::create), but `output_path` (when known) enables the
-    /// `--log-level 3` opening-frame capture to `<output>.opening.bin`. A `None`
-    /// path (e.g. an in-memory / stdio sink) silently skips the side-file
-    /// capture; the per-track TrackEntry dump still fires.
-    pub fn create_at(
+    /// Create for writing PES frames → MKV container. Codec privates come from
+    /// `title.codec_privates` (populated by the input stream).
+    ///
+    /// `output_path` (when known) enables the `--log-level 3` opening-frame
+    /// capture to `<output>.opening.bin`; `None` (e.g. an in-memory / stdio sink)
+    /// silently skips the side-file capture — the per-track TrackEntry dump still
+    /// fires either way.
+    pub fn create(
         writer: Box<dyn WriteSeek + Send>,
         title: &DiscTitle,
         output_path: Option<&std::path::Path>,
     ) -> io::Result<Self> {
+        // Blu-ray 3D (MVC): a dependent (right-eye) view stream is NOT emitted as
+        // its own track — it is folded into the base track as per-frame
+        // BlockAdditional. Detect it so we skip building a track for it and set up
+        // the merge. `base_stream_idx` is the first video stream.
+        let dep_stream_idx = title
+            .streams
+            .iter()
+            .position(|s| matches!(s, crate::disc::Stream::Video(v) if v.is_mvc_dependent()));
+        // The base is the first NON-dependent video. Excluding the dependent here
+        // means a (malformed / hand-built) title whose only video IS the dependent
+        // yields `base_stream_idx == None` → no merge (the dependent is muxed as an
+        // ordinary track) instead of `base == dep` and a panic on the skipped slot.
+        let base_stream_idx = title
+            .streams
+            .iter()
+            .position(|s| matches!(s, crate::disc::Stream::Video(v) if !v.is_mvc_dependent()));
+        // The merge is only active when BOTH a dependent and a distinct base exist;
+        // only then is the dependent's track skipped/folded.
+        let mvc_active = dep_stream_idx.is_some() && base_stream_idx.is_some();
+        let skip_stream_idx = if mvc_active { dep_stream_idx } else { None };
+
         let mut tracks = Vec::new();
         let mut has_default_video = false;
         let mut has_default_audio = false;
+        // `title.streams` index → muxer track index (`None` = the dependent view,
+        // which has no track). Streams after the dependent shift down by one.
+        let mut stream_to_track: Vec<Option<usize>> = Vec::with_capacity(title.streams.len());
         for (idx, s) in title.streams.iter().enumerate() {
+            if Some(idx) == skip_stream_idx {
+                stream_to_track.push(None);
+                continue;
+            }
             let mut track = match s {
                 crate::disc::Stream::Video(v) => MkvTrack::video(v),
                 crate::disc::Stream::Audio(a) => MkvTrack::audio(a),
@@ -166,9 +383,31 @@ impl MkvStream {
             if let Some(cp) = title.codec_privates.get(idx).and_then(|c| c.as_ref()) {
                 track.codec_private = Some(cp.clone());
             }
+            stream_to_track.push(Some(tracks.len()));
             tracks.push(track);
         }
 
+        // Assemble the MVC merge only when active — i.e. a dependent AND a
+        // distinct base video both exist (established above). `base_stream_idx`
+        // then always has a built track, so its remap is `Some` (no panic path).
+        let mvc = match (mvc_active, dep_stream_idx, base_stream_idx) {
+            (true, Some(dep_stream_idx), Some(base_stream_idx)) => stream_to_track
+                .get(base_stream_idx)
+                .copied()
+                .flatten()
+                .map(|base_track_idx| MvcMerge {
+                    base_stream_idx,
+                    dep_stream_idx,
+                    base_track_idx,
+                    stream_to_track,
+                    pending_base: std::collections::VecDeque::new(),
+                    dep_by_pts: std::collections::HashMap::new(),
+                    captured_params: None,
+                    orphan_deps: 0,
+                }),
+            _ => None,
+        };
+
         // Defer muxer construction (and the TrackEntry dump) until the first
         // coded picture arrives, so the primary video track's FieldOrder is set
         // from the parser's MEASURED value before the header is written — never
@@ -177,6 +416,7 @@ impl MkvStream {
 
         Ok(Self {
             disc_title: title.clone(),
+            mvc,
             mode: Mode::Write(WriteMode::Pending(Box::new(PendingMux {
                 writer,
                 tracks,
@@ -209,6 +449,24 @@ impl MkvStream {
         if let Some(vt) = pending.video_track {
             apply_coding_to_track(&mut pending.tracks[vt], coding, video_picture_seen);
         }
+        // Blu-ray 3D: set the base video track's `mvc_params` from the dependent
+        // view's captured subset-SPS/PPS BEFORE the header is written, so the
+        // TrackEntry carries the `mvcC` BlockAdditionMapping. Captured from the
+        // first dependent AU (which arrives right after the first base AU in the
+        // SSIF), so it is available by the time the first base frame activates.
+        if let Some(mvc) = &self.mvc {
+            if let Some(params) = &mvc.captured_params {
+                if let Some(t) = pending.tracks.get_mut(mvc.base_track_idx) {
+                    t.mvc_params = Some(params.clone());
+                }
+            } else {
+                tracing::warn!(
+                    target: "mux",
+                    "MVC: no dependent-view subset-SPS/PPS captured before activation; \
+                     the base track will carry no mvcC mapping (3D not signalled)."
+                );
+            }
+        }
         // --log-level 3: dump the FINAL TrackEntry metadata (field order set).
         for (i, track) in pending.tracks.iter().enumerate() {
             crate::diag::dump_mkv_track((i + 1) as u64, track);
@@ -223,18 +481,72 @@ impl MkvStream {
         if let Some(path) = &pending.opening_capture_path {
             muxer.set_opening_capture(crate::diag::OpeningCapture::new(path, pending.tracks.len()));
         }
-        for f in pending.buffered.drain(..) {
-            muxer.write_frame(f.track, f.pts, f.keyframe, &f.data, f.duration_ns)?;
+        for (f, additional) in pending.buffered.drain(..) {
+            muxer.write_frame(
+                f.track,
+                f.pts,
+                f.keyframe,
+                &f.data,
+                f.duration_ns,
+                additional.as_deref(),
+            )?;
         }
         self.mode = Mode::Write(WriteMode::Active(Box::new(muxer)));
         Ok(())
     }
 
+    /// Emit one frame (track index already muxer-relative) with an optional MVC
+    /// dependent-view `BlockAdditional`, honouring the deferred-activation
+    /// machinery: the first video frame triggers muxer construction (its coding
+    /// sets FieldOrder); earlier frames buffer. `additional` is `None` for every
+    /// non-3D frame and for the 3D base frames that had no paired dependent.
+    fn emit(&mut self, frame: &crate::pes::PesFrame, additional: Option<&[u8]>) -> io::Result<()> {
+        match &mut self.mode {
+            Mode::Read(_) => return Err(crate::error::Error::StreamReadOnly.into()),
+            Mode::Write(WriteMode::Active(m)) => {
+                return emit_to_muxer(m, frame, additional);
+            }
+            Mode::Write(WriteMode::Building) => return Ok(()),
+            Mode::Write(WriteMode::Pending(_)) => {}
+        }
+        // Pending: the first video frame (or the safety cap) triggers muxer
+        // construction; that frame's coding sets the field order. Other frames
+        // buffer until then.
+        let (activate_now, use_coding) = match &self.mode {
+            Mode::Write(WriteMode::Pending(p)) => {
+                let is_video = match p.video_track {
+                    Some(vt) => frame.track == vt,
+                    // No video track: nothing to wait for — build on frame one.
+                    None => true,
+                };
+                (is_video || p.buffered.len() >= MAX_PENDING_FRAMES, is_video)
+            }
+            _ => unreachable!("guarded above"),
+        };
+        if activate_now {
+            // Pass the trigger frame's coding only when it IS the video frame; a
+            // cap-triggered build never saw the video frame, so nothing measured
+            // is passed (apply_coding_to_track then logs + leaves UNDETERMINED).
+            self.activate(if use_coding { frame.coding } else { None }, use_coding)?;
+            if let Mode::Write(WriteMode::Active(m)) = &mut self.mode {
+                return emit_to_muxer(m, frame, additional);
+            }
+            Ok(())
+        } else {
+            if let Mode::Write(WriteMode::Pending(p)) = &mut self.mode {
+                p.buffered
+                    .push((frame.clone(), additional.map(|a| a.to_vec())));
+            }
+            Ok(())
+        }
+    }
+
     /// Open an MKV file for reading → PES frames.
     pub fn open(mut reader: impl Read + Send + 'static) -> io::Result<Self> {
         let (disc_title, codec_privates, ts_scale_ns) = parse_mkv_header(&mut reader)?;
         Ok(Self {
             disc_title,
+            mvc: None,
             mode: Mode::Read(ReadState {
                 reader: Box::new(reader),
                 cluster_ts_ticks: 0,
@@ -425,59 +737,40 @@ impl crate::pes::Stream for MkvStream {
     }
 
     fn write(&mut self, frame: &crate::pes::PesFrame) -> io::Result<()> {
-        // Fast paths.
-        match &mut self.mode {
-            Mode::Read(_) => return Err(crate::error::Error::StreamReadOnly.into()),
-            Mode::Write(WriteMode::Active(m)) => {
-                return m.write_frame(
-                    frame.track,
-                    frame.pts,
-                    frame.keyframe,
-                    &frame.data,
-                    frame.duration_ns,
-                );
-            }
-            Mode::Write(WriteMode::Building) => return Ok(()),
-            Mode::Write(WriteMode::Pending(_)) => {}
+        if matches!(self.mode, Mode::Read(_)) {
+            return Err(crate::error::Error::StreamReadOnly.into());
         }
-        // Pending: the first video frame (or the safety cap) triggers muxer
-        // construction; that frame's coding sets the field order. Other frames
-        // buffer until then.
-        let (activate_now, use_coding) = match &self.mode {
-            Mode::Write(WriteMode::Pending(p)) => {
-                let is_video = match p.video_track {
-                    Some(vt) => frame.track == vt,
-                    // No video track: nothing to wait for — build on frame one.
-                    None => true,
-                };
-                (is_video || p.buffered.len() >= MAX_PENDING_FRAMES, is_video)
-            }
-            _ => unreachable!("guarded above"),
-        };
-        if activate_now {
-            // Pass the trigger frame's coding only when it IS the video frame; a
-            // cap-triggered build never saw the video frame, so nothing measured
-            // is passed (apply_coding_to_track then logs + leaves UNDETERMINED).
-            self.activate(if use_coding { frame.coding } else { None }, use_coding)?;
-            if let Mode::Write(WriteMode::Active(m)) = &mut self.mode {
-                return m.write_frame(
-                    frame.track,
-                    frame.pts,
-                    frame.keyframe,
-                    &frame.data,
-                    frame.duration_ns,
-                );
-            }
-            Ok(())
-        } else {
-            if let Mode::Write(WriteMode::Pending(p)) = &mut self.mode {
-                p.buffered.push(frame.clone());
-            }
-            Ok(())
+        // Non-3D fast path: emit the frame directly, no clone, no buffering.
+        if self.mvc.is_none() {
+            return self.emit(frame, None);
         }
+        // Blu-ray 3D: run the frame through the MVC merge, which remaps track
+        // indices, folds the dependent view into the base as BlockAdditional
+        // (paired by PTS), and yields 0+ frames ready to emit. `ingest` returns
+        // owned pairs so the `self.mvc` borrow is released before `emit`.
+        let emits = self.mvc.as_mut().unwrap().ingest(frame);
+        for (f, additional) in emits {
+            self.emit(&f, additional.as_deref())?;
+        }
+        Ok(())
     }
 
     fn finish(&mut self) -> io::Result<()> {
+        // Blu-ray 3D: flush any base frames still awaiting a dependent (emitted
+        // unpaired as plain Blocks) before finalizing.
+        if let Some(mvc) = self.mvc.as_mut() {
+            let tail = mvc.flush();
+            let orphans = mvc.orphan_deps;
+            if orphans > 0 {
+                tracing::debug!(
+                    target: "mux",
+                    "MVC: {orphans} dependent-view access units had no matching base frame (dropped)"
+                );
+            }
+            for (f, additional) in tail {
+                self.emit(&f, additional.as_deref())?;
+            }
+        }
         // A title that produced no frames (or only buffered ones) is still
         // finalized into a valid MKV: activate now with no measured coding.
         if matches!(self.mode, Mode::Write(WriteMode::Pending(_))) {
@@ -720,7 +1013,11 @@ fn parse_track(
                     arem = arem.saturating_sub(ahlen as u64 + as_);
                     match aid {
                         ebml::SAMPLING_FREQUENCY => sr = ebml::read_float_val(r, as_ as usize)?,
-                        ebml::CHANNELS => ch = read_uint_bounded(r, as_)? as u8,
+                        // Clamp instead of `as u8`: a foreign/corrupt MKV with a
+                        // CHANNELS value that is a multiple of 256 would truncate to
+                        // 0 (an invalid channel count) on a bare cast. Saturate to
+                        // u8::MAX so an absurd count degrades to "many", never to 0.
+                        ebml::CHANNELS => ch = read_uint_bounded(r, as_)?.min(u8::MAX as u64) as u8,
                         _ => {
                             skip_bytes(r, as_)?;
                         }
@@ -916,6 +1213,207 @@ mod tests {
     use crate::pes::Stream as _;
     use std::io::Cursor;
 
+    /// Length-prefix (4-byte big-endian) each NAL, as the H.264 parser emits.
+    fn lp(nals: &[&[u8]]) -> Vec<u8> {
+        let mut v = Vec::new();
+        for n in nals {
+            v.extend_from_slice(&(n.len() as u32).to_be_bytes());
+            v.extend_from_slice(n);
+        }
+        v
+    }
+
+    fn mvc_frame(track: usize, pts: i64, keyframe: bool, data: Vec<u8>) -> crate::pes::PesFrame {
+        crate::pes::PesFrame {
+            track,
+            pts,
+            keyframe,
+            data,
+            duration_ns: None,
+            source: None,
+            coding: None,
+        }
+    }
+
+    // A subset SPS (NAL type 15), a PPS (type 8), and a coded-slice-extension
+    // (type 20) — the shape of a dependent-view access unit.
+    const SUBSET_SPS: [u8; 5] = [0x6F, 0x80, 0x00, 0x33, 0xAA]; // 0x6F & 0x1F = 15
+    const DEP_PPS: [u8; 3] = [0x68, 0xEE, 0x3C]; // 0x68 & 0x1F = 8
+    const DEP_SLICE: [u8; 3] = [0x74, 0x11, 0x22]; // 0x74 & 0x1F = 20
+
+    #[test]
+    fn extract_mvc_params_finds_subset_sps_and_pps() {
+        let data = lp(&[&SUBSET_SPS, &DEP_PPS, &DEP_SLICE]);
+        let (s, p) = extract_mvc_params(&data).expect("both param sets present");
+        assert_eq!(s, SUBSET_SPS, "subset SPS (NAL 15) captured verbatim");
+        assert_eq!(p, DEP_PPS, "PPS (NAL 8) captured verbatim");
+        // Missing PPS → None (the serializer then emits no mvcC mapping).
+        assert!(extract_mvc_params(&lp(&[&SUBSET_SPS, &DEP_SLICE])).is_none());
+        // Missing subset SPS → None.
+        assert!(extract_mvc_params(&lp(&[&DEP_PPS, &DEP_SLICE])).is_none());
+    }
+
+    fn empty_merge() -> MvcMerge {
+        MvcMerge {
+            base_stream_idx: 0,
+            dep_stream_idx: 2,
+            base_track_idx: 0,
+            stream_to_track: vec![Some(0), Some(1), None],
+            pending_base: std::collections::VecDeque::new(),
+            dep_by_pts: std::collections::HashMap::new(),
+            captured_params: None,
+            orphan_deps: 0,
+        }
+    }
+
+    #[test]
+    fn mvc_merge_pairs_base_and_dependent_by_pts() {
+        let mut m = empty_merge();
+        let dep = lp(&[&SUBSET_SPS, &DEP_PPS, &DEP_SLICE]);
+
+        // Base arrives first (SSIF order): buffered, nothing emitted yet.
+        let e = m.ingest(&mvc_frame(0, 100, true, lp(&[&[0x65, 1, 2]])));
+        assert!(e.is_empty(), "base held until its dependent arrives");
+
+        // Dependent arrives → base is emitted, remapped to the base track, with
+        // the dependent AU as its BlockAdditional; params are captured.
+        let e = m.ingest(&mvc_frame(2, 100, false, dep.clone()));
+        assert_eq!(e.len(), 1, "the paired base frame is emitted");
+        assert_eq!(e[0].0.track, 0, "remapped to the base muxer track");
+        assert_eq!(
+            e[0].1.as_deref(),
+            Some(dep.as_slice()),
+            "dependent attached"
+        );
+        assert!(m.captured_params.is_some(), "mvcC params captured");
+
+        // Audio passes straight through (remapped, no additional).
+        let e = m.ingest(&mvc_frame(1, 100, true, vec![0xAA]));
+        assert_eq!(e.len(), 1);
+        assert_eq!(e[0].0.track, 1);
+        assert!(e[0].1.is_none());
+
+        // Dependent-before-base (reordered) also pairs.
+        let dep2 = lp(&[&DEP_SLICE]);
+        assert!(m.ingest(&mvc_frame(2, 200, false, dep2.clone())).is_empty());
+        let e = m.ingest(&mvc_frame(0, 200, false, lp(&[&[0x61, 3, 4]])));
+        assert_eq!(e.len(), 1);
+        assert_eq!(e[0].1.as_deref(), Some(dep2.as_slice()));
+    }
+
+    #[test]
+    fn mvc_merge_flushes_unpaired_base_at_eof() {
+        let mut m = empty_merge();
+        // Base with no dependent ever → held, then flushed unpaired at EOF.
+        assert!(
+            m.ingest(&mvc_frame(0, 10, true, vec![0, 0, 0, 1]))
+                .is_empty()
+        );
+        let tail = m.flush();
+        assert_eq!(tail.len(), 1, "unpaired base still emitted");
+        assert!(tail[0].1.is_none(), "no BlockAdditional when unpaired");
+    }
+
+    #[test]
+    fn extract_mvc_params_no_panic_on_truncated_or_empty() {
+        // Empty, sub-header, zero-length NAL, and a length prefix claiming more
+        // than is present must all return None without panicking (untrusted AU).
+        assert!(extract_mvc_params(&[]).is_none());
+        assert!(extract_mvc_params(&[0, 0, 0]).is_none());
+        assert!(
+            extract_mvc_params(&[0, 0, 0, 0]).is_none(),
+            "lone zero-length NAL yields no params"
+        );
+        assert!(
+            extract_mvc_params(&[0, 0, 0, 10, 0x6F]).is_none(),
+            "length prefix past end breaks, no slice panic"
+        );
+        // A zero-length NAL is SKIPPED, not fatal: valid param sets that follow
+        // are still found (a stray length prefix must not abandon the whole AU).
+        let mut d = vec![0, 0, 0, 0];
+        d.extend_from_slice(&lp(&[&SUBSET_SPS, &DEP_PPS]));
+        let (s, p) = extract_mvc_params(&d).expect("params found past the zero-length NAL");
+        assert_eq!(s, SUBSET_SPS);
+        assert_eq!(p, DEP_PPS);
+    }
+
+    #[test]
+    fn mvc_merge_flushes_oldest_base_once_past_window() {
+        let mut m = empty_merge();
+        // Push more unpaired base frames than the window; the excess flush as
+        // plain (unpaired) blocks in FIFO order once len exceeds MVC_PAIR_WINDOW.
+        let n = MVC_PAIR_WINDOW + 8;
+        let mut emitted = 0usize;
+        for pts in 0..n {
+            emitted += m
+                .ingest(&mvc_frame(0, pts as i64, false, vec![0, 0, 0, 1]))
+                .len();
+        }
+        assert_eq!(emitted, 8, "the {n} bases beyond the window flush unpaired");
+        assert_eq!(m.pending_base.len(), MVC_PAIR_WINDOW, "window still held");
+        assert!(m.flush().iter().all(|(_, add)| add.is_none()));
+    }
+
+    #[test]
+    fn mvc_merge_dep_overflow_drops_old_keeps_newest() {
+        let mut m = empty_merge();
+        // Fill dep_by_pts to the bound with unpaired dependents (unique PTS).
+        for pts in 0..(MVC_PAIR_WINDOW * 4) {
+            assert!(
+                m.ingest(&mvc_frame(2, pts as i64, false, lp(&[&DEP_SLICE])))
+                    .is_empty()
+            );
+        }
+        assert_eq!(m.dep_by_pts.len(), MVC_PAIR_WINDOW * 4);
+        // One more overflows: the drifted buffer is cleared BUT the newest survives
+        // so its (soon-to-arrive) base can still pair.
+        let dep_new = lp(&[&DEP_SLICE]);
+        m.ingest(&mvc_frame(2, 9_999, false, dep_new.clone()));
+        assert_eq!(m.dep_by_pts.len(), 1, "old cleared, newest kept");
+        assert!(m.dep_by_pts.contains_key(&9_999));
+        assert_eq!(
+            m.orphan_deps,
+            (MVC_PAIR_WINDOW * 4) as u64,
+            "old buffer counted once"
+        );
+        // The surviving dependent pairs with its base.
+        let e = m.ingest(&mvc_frame(0, 9_999, false, vec![0x61, 1]));
+        assert_eq!(e.len(), 1);
+        assert_eq!(e[0].1.as_deref(), Some(dep_new.as_slice()));
+    }
+
+    #[test]
+    fn create_does_not_panic_when_only_video_is_mvc_dependent() {
+        // A (malformed / hand-built) title whose single video IS the dependent
+        // must NOT panic: base_stream_idx is None, so no merge is set up and the
+        // dependent is muxed as an ordinary track.
+        use crate::disc::{
+            Codec, ColorSpace, DiscTitle, FrameRate, HdrFormat, Resolution, Stream, VideoStream,
+        };
+        let dep = VideoStream {
+            pid: 0x1012,
+            codec: Codec::H264,
+            resolution: Resolution::R1080p,
+            frame_rate: FrameRate::F24,
+            hdr: HdrFormat::Sdr,
+            color_space: ColorSpace::Bt709,
+            display_aspect: None,
+            secondary: true,
+            label: crate::disc::MVC_DEPENDENT_LABEL.to_string(),
+            measured_cicp: None,
+        };
+        let title = DiscTitle {
+            streams: vec![Stream::Video(dep)],
+            ..DiscTitle::empty()
+        };
+        let s = MkvStream::create(Box::new(Cursor::new(Vec::new())), &title, None)
+            .expect("create must succeed, not panic");
+        assert!(
+            s.mvc.is_none(),
+            "no merge when there is no distinct base view"
+        );
+    }
+
     #[test]
     fn apply_coding_to_track_sets_measured_field_order_never_guesses() {
         use crate::disc::{Codec, ColorSpace, FrameRate, HdrFormat, Resolution, VideoStream};

src/mux/mod.rs

@@ -108,15 +108,17 @@ pub(crate) mod tsmux;
 #[allow(dead_code)]
 pub(crate) mod videomap;
 
-pub use demux_sink::{ChaptersFmt, DelayMode, DemuxOptions, DemuxSink, Naming};
+// `demux://` and `fvi://` sinks are constructed internally by `output()` via the
+// direct `super::demux_sink::` / `super::fvi_sink::` paths — no re-export needed,
+// and no consumer names these types, so they are not public API.
 pub use disc::DiscStream;
-pub use fvi_sink::FviSink;
 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::resolve_mux_key_map;
 pub use resolve::{InputOptions, StreamUrl, input, output, parse_url};
 pub use stdio::StdioStream;
 

src/mux/pipelined_stream.rs

@@ -56,14 +56,6 @@ pub struct PipelinedPesStream {
     /// `std::env::var_os` takes a process-wide lock, so the per-batch /
     /// per-poll reads it replaces were needless hot-path overhead.
     skip_parse: bool,
-    /// Cumulative bytes of scrambled AACS units the producer's decrypt step
-    /// could not decrypt — silent decrypt loss the demux drops without a sync.
-    /// Shared with the producer thread's [`DecryptingSectorSource`]
-    /// (`crate::sector::DecryptingSectorSource::decrypt_loss`). Surfaced through
-    /// [`Stream::lost_bytes`] so the file-backed mux abort gate sees a partial
-    /// decrypt failure instead of reporting a perfect rip. `None` for pipelines
-    /// with no AACS decrypt step (e.g. the M2TS byte-stream path).
-    decrypt_loss: Option<std::sync::Arc<std::sync::atomic::AtomicU64>>,
     /// Count of dropped DVD navigation packets (private_stream_2, 0xBF). These
     /// are expected on every disc; instead of a per-packet WARN they're tallied
     /// and summarised once at EOF.
@@ -134,7 +126,6 @@ impl PipelinedPesStream {
             pending_frames: std::collections::VecDeque::new(),
             eof: false,
             skip_parse: std::env::var_os("FREEMKV_SKIP_PARSE").is_some(),
-            decrypt_loss: None,
             dropped_nav_packets: 0,
             resync,
             is_video,
@@ -142,20 +133,6 @@ impl PipelinedPesStream {
         }
     }
 
-    /// Attach the producer's decrypt-loss counter so [`Stream::lost_bytes`]
-    /// reports bytes of scrambled AACS units that could not be decrypted (and
-    /// were therefore silently dropped downstream). Obtained from the
-    /// producer's `DecryptingSectorSource::decrypt_loss()` before it is moved
-    /// into the prefetch thread. The M2TS / no-decrypt pipelines leave this
-    /// unset.
-    pub(crate) fn with_decrypt_loss(
-        mut self,
-        loss: std::sync::Arc<std::sync::atomic::AtomicU64>,
-    ) -> Self {
-        self.decrypt_loss = Some(loss);
-        self
-    }
-
     /// 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
@@ -464,17 +441,9 @@ impl Stream for PipelinedPesStream {
             .and_then(|(_, parser)| parser.codec_private())
     }
 
-    fn lost_bytes(&self) -> u64 {
-        // The file-backed highway has no read-error zero-fill term (resolve
-        // tracks read loss separately), but the producer's decrypt step can
-        // pass scrambled units through undecrypted — silent loss the demux
-        // drops. Surface that so the mux abort gate sees a partial AACS/CSS
-        // decrypt failure rather than reporting a perfect rip.
-        self.decrypt_loss
-            .as_ref()
-            .map(|c| c.load(std::sync::atomic::Ordering::Relaxed))
-            .unwrap_or(0)
-    }
+    // `lost_bytes` uses the trait default (0): the file-backed highway has no
+    // read-error zero-fill term (resolve/mapfile tracks physical read loss
+    // separately) and the decrypt path no longer reports a decrypt-loss term.
 }
 
 #[cfg(test)]

src/mux/resolve.rs

@@ -344,9 +344,7 @@ pub fn input(url: &str, opts: &InputOptions) -> io::Result<Box<dyn crate::pes::S
             // unchanged (decrypt_keys_for_title short-circuits to decrypt_keys).
             let (keys, title_is_clear) =
                 match crate::io::file_sector_source::FileSectorSource::open(path) {
-                    Ok(mut crack_reader) => {
-                        disc.decrypt_keys_for_title_checked(idx, &mut crack_reader, 64)
-                    }
+                    Ok(mut crack_reader) => disc.decrypt_keys_for_title(idx, &mut crack_reader, 64),
                     Err(_) => (disc.decrypt_keys(), false),
                 };
             // Per-title decrypt gate (parallel to the disc-wide gate above): on
@@ -358,12 +356,11 @@ pub fn input(url: &str, opts: &InputOptions) -> io::Result<Box<dyn crate::pes::S
             // case must NOT raise a false E7023.
             disc.ensure_title_decryptable(opts.raw, &keys, title_is_clear)
                 .map_err(|e| -> io::Error { e.into() })?;
-            // Upfront FMTS gate, parallel to the unit-key gate above. With
-            // BYPASS_FMTS_KEY this is a no-op and a 2.1 disc's forensic units are
-            // concealed as ordinary decrypt loss below; without it, a 2.1 disc
-            // lacking segment keys fails here rather than emitting a holed mux.
-            disc.ensure_forensic_segments_decryptable(opts.raw)
-                .map_err(|e| -> io::Error { e.into() })?;
+            // FMTS (AACS 2.1) forensic segments are sourced + fail-loud-checked
+            // downstream by `resolve_mux_key_map`/`resolve_fmts_key_map`, which hold
+            // the key-fetch closure and can actually attempt resolution. (An older
+            // upfront blanket-reject gate lived here; it predated the resolver and
+            // rejected every 2.1 disc before a source could be tried.)
             // Correct TrueHD channel counts (MPLS understates 7.1/Atmos as 5.1)
             // by probing the first DECRYPTED access units of the chosen title.
             // A fresh reader avoids disturbing the mux reader below. Skipped in
@@ -391,11 +388,11 @@ pub fn input(url: &str, opts: &InputOptions) -> io::Result<Box<dyn crate::pes::S
             let title = disc.titles[idx].clone();
             let format = disc.content_format;
             // ISO file: 8192-sector batch (16 MiB at 2048 B/sector) —
-            // sequential read from fast storage, no bad sectors. Measured
-            // optimum on the rip1 testbed; bumping to 16384 sectors (32 MiB)
-            // regressed (more cache pressure, longer per-batch latency starves
-            // the consumer between iterations). Physical drives keep smaller
-            // batches for adaptive error handling.
+            // sequential read from fast storage, no bad sectors. Empirically
+            // optimal; bumping to 16384 sectors (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;
 
             // Pass `DecryptKeys::None` to the decrypt decorator when
@@ -480,7 +477,7 @@ pub fn output(
                     IO_BUF_SIZE,
                     crate::io::WritebackFile::create_with_size_hint(path, title.size_bytes)?,
                 ));
-            Ok(Box::new(MkvStream::create_at(writer, title, Some(path))?))
+            Ok(Box::new(MkvStream::create(writer, title, Some(path))?))
         }
         StreamUrl::M2ts { ref path } => {
             validate_file_path(path, "m2ts")?;
@@ -532,8 +529,7 @@ pub fn output(
         // `fvi://` writes the per-picture video index (`docs/FVI_FORMAT.md`).
         // The bare `output()` arm records the resolver path as the provenance
         // `source.path` and defaults the title index to 0 (the resolver carries
-        // no title-index context — the CLI follow-up passes the real medium /
-        // title via `FviSink::create_with_source`).
+        // no title-index context).
         StreamUrl::Fvi { ref path } => {
             validate_file_path(path, "fvi")?;
             Ok(Box::new(super::fvi_sink::FviSink::create(
@@ -575,7 +571,17 @@ fn build_demux_state(title: &DiscTitle, format: ContentFormat) -> DemuxState {
         pids.push(pid);
         pid_to_track.push((pid, idx));
         let is_dvd_ps = matches!(format, ContentFormat::MpegPs);
-        parsers.push((pid, super::codec::parser_for_codec(codec, None, is_dvd_ps)));
+        // The Blu-ray 3D MVC dependent (right-eye) view uses a param-set-
+        // passthrough H.264 parser so each frame is a self-contained dependent
+        // access unit for a BlockAdditional; every other stream uses the
+        // ordinary parser for its codec.
+        let parser = match s {
+            crate::disc::Stream::Video(v) if v.is_mvc_dependent() => {
+                super::codec::parser_for_mvc_dependent(codec, is_dvd_ps)
+            }
+            _ => super::codec::parser_for_codec(codec, None, is_dvd_ps),
+        };
+        parsers.push((pid, parser));
     }
     let (ts, ps) = match format {
         ContentFormat::MpegPs => (None, Some(super::ps::PsDemuxer::new())),
@@ -590,6 +596,391 @@ fn build_demux_state(title: &DiscTitle, format: ContentFormat) -> DemuxState {
     (parsers, pid_to_track, ts, ps)
 }
 
+/// Resolve the proactive [`AacsKeyMap`](crate::decrypt::AacsKeyMap) for a title
+/// before muxing. It decides which held unit key decrypts each of the title's
+/// LBA ranges and secures any key the pool is missing through the app's
+/// configured source (`fetch`) up front, never reactively per unit at mux time.
+///
+/// This is what ends the key-server storm. The old mux decrypted a unit, checked
+/// whether the plaintext looked like clean MPEG-TS, and — because authored-bad
+/// content never reaches that bar — re-asked the key service for a key it already
+/// held. There is no per-unit byte pattern that separates "correctly decrypted
+/// but authored-bad" from "still encrypted", so that check is unanswerable. Here
+/// we answer the answerable question instead: which CPS unit does each LBA range
+/// belong to, decided by the disc's key structure (validated once against real
+/// ciphertext samples, where the `is_clean` proof IS sound). The mux then just
+/// decrypts each unit with its mapped key and trusts it.
+///
+/// Single-CPS (the overwhelming majority, incl. every single-key UHD) is the
+/// trivial map: one key everywhere, no sampling. Multi-CPS assigns each extent to
+/// the key that opens a real sample from it; a bad-content extent no sample can
+/// classify inherits its predecessor's key (contiguity). FMTS segment mapping
+/// layers onto the same structure.
+/// FMTS (AACS 2.1) branch of [`resolve_mux_key_map`]. Returns `Some(map)` when the
+/// disc carries `IndividualSegment.tbl` AND a key source is configured; `None`
+/// otherwise (not FMTS, or no source — the caller's base-Unit-Key path then
+/// applies, and the forensic units garble and are dropped by the demux).
+///
+/// The forensic segments each carry an **index** tag (1..32) selecting one of 32
+/// **index keys** the base Unit Key cannot open (see [`crate::aacs::segment`]).
+/// This resolves those keys up front from the configured source — sending, per
+/// index, a batch of same-index units the service maps to that index's key — adds
+/// them to the pool, and builds a per-segment LBA→key map. Applying a segment's
+/// key over its whole range decodes the ~40 units of that index's interleave half
+/// to clean TS and garbles the other ~40 (the alternate half), which the demux
+/// then drops, yielding one coherent stream. The base Unit Key covers everything
+/// outside a segment.
+fn resolve_fmts_key_map(
+    reader: &mut dyn SectorSource,
+    title: &DiscTitle,
+    keys: &mut crate::decrypt::DecryptKeys,
+    fetch: Option<&crate::sector::KeyFetch>,
+    format: ContentFormat,
+) -> io::Result<Option<crate::decrypt::AacsKeyMap>> {
+    use crate::aacs::content::{ALIGNED_UNIT_LEN, aacs_unit_encrypted, decrypt_unit, is_clean};
+    use crate::aacs::segment::{clip_byte_to_lba, parse_individual_segments};
+
+    // Load the segment map; absent → not an FMTS disc.
+    let Ok(udf) = crate::udf::read_filesystem(reader) else {
+        return Ok(None);
+    };
+    let Ok(tbl) = udf.read_file(reader, "/AACS/IndividualSegment.tbl") else {
+        return Ok(None);
+    };
+    let Some(segments) = parse_individual_segments(&tbl) else {
+        return Ok(None);
+    };
+    if segments.is_empty() {
+        return Ok(None);
+    }
+    // This IS an FMTS disc, so the forensic index keys are REQUIRED — exactly like
+    // a Unit Key. Without a configured key source we cannot obtain them, so we
+    // cannot produce a complete rip: fail loud rather than silently drop the
+    // forensic segments. (The caller may still choose `--raw`, which never reaches
+    // this path.)
+    let Some(fetch) = fetch else {
+        return Err(crate::error::Error::FmtsKeyMissing.into());
+    };
+    tracing::info!(target: "freemkv::keysource", segments = segments.len(), extents = title.extents.len(), "fmts: begin index-key resolution");
+
+    // Read aligned unit `index` of `seg`: clip byte `start_spn*192 + index*6144`.
+    let read_unit =
+        |reader: &mut dyn SectorSource, seg: &crate::aacs::segment::Segment, index: usize| {
+            let clip_byte = seg.start_spn as u64 * 192 + index as u64 * ALIGNED_UNIT_LEN as u64;
+            let lba = clip_byte_to_lba(&title.extents, clip_byte)?;
+            let mut c = vec![0u8; ALIGNED_UNIT_LEN];
+            reader.read_sectors(lba, 3, &mut c, false).ok()?;
+            Some(c)
+        };
+    // ── ANCHOR — fetch the whole 32-key set from ONE index-1 batch. The key
+    //    service returns ALL forensic index keys ordered (element i = index i+1)
+    //    only for a canonical INDEX-1 sample that decrypts under the index-1 key.
+    //    A forensic segment interleaves TWO variants at the aligned-unit level, so
+    //    index-1's real content is one PHASE (even or odd units) and the alternate
+    //    is a different variant that won't decrypt. We don't know the phase a
+    //    priori, so try PHASE A (even) then PHASE B (odd): whichever is index-1's
+    //    content comes back with the full set. Both phases failing (across the
+    //    read-fault fallback over index-1 segments) ⇒ this disc has no FMTS keys.
+    //
+    //    The set's SIZE is whatever the source returns (≥ 1) — never assumed. 32
+    //    is all we have seen, but a disc with a different forensic index count is
+    //    not ruled out, so the map is sized to the returned `len()`, not a const.
+    //    ─────────────────────────────────────────────────────────────────────────
+    // Batch size = the key service's minimum-samples floor (same as the online
+    // source), drawn from ONE phase to land a clean single-variant half.
+    const BATCH_UNITS: usize = crate::keysource::MIN_SAMPLE_UNITS;
+    // Read-fault fallback: how many index-1 segments to attempt if the leading one
+    // is unreadable. The 2 phase requests happen per readable segment.
+    const MAX_ANCHOR_ATTEMPTS: usize = 16;
+    // Even units = p*2; odd units = p*2 + 1.
+    let read_phase_batch = |reader: &mut dyn SectorSource,
+                            seg: &crate::aacs::segment::Segment,
+                            phase_off: usize|
+     -> Option<Vec<Vec<u8>>> {
+        let mut batch: Vec<Vec<u8>> = Vec::with_capacity(BATCH_UNITS);
+        for p in 0..BATCH_UNITS {
+            batch.push(read_unit(reader, seg, p * 2 + phase_off)?);
+        }
+        Some(batch)
+    };
+    let mut index_keys: Vec<[u8; 16]> = Vec::new();
+    'anchor: for seg in segments
+        .iter()
+        .filter(|s| s.index == 1)
+        .take(MAX_ANCHOR_ATTEMPTS)
+    {
+        for phase_off in [0usize, 1usize] {
+            let Some(batch) = read_phase_batch(reader, seg, phase_off) else {
+                continue; // read fault on this phase — try the other / next segment
+            };
+            let fresh = fetch.fmts_indexes(&batch);
+            // Any non-empty reply is the source's COMPLETE ordered forensic set;
+            // trust it and stop. An empty reply = this phase/segment did not anchor.
+            if !fresh.is_empty() {
+                index_keys = fresh;
+                break 'anchor;
+            }
+        }
+    }
+    // The count is whatever the source returned — not a fixed 32. Sized here, used
+    // everywhere below.
+    let n_index = index_keys.len();
+    tracing::info!(target: "freemkv::keysource", held = n_index, "fmts: collection done");
+    // At least one forensic index key is required. None ⇒ no FMTS key for this
+    // disc from any source — fail loud like a missing Unit Key rather than emit
+    // forensic-holed output.
+    if index_keys.is_empty() {
+        return Err(crate::error::Error::FmtsKeyMissing.into());
+    }
+
+    // Map array position → forensic index (element i = index i+1); add each key to
+    // the pool and remember its slot by tag. `base_idx` is the Unit Key (slot 0).
+    let base_idx = 0usize;
+    let mut tag_slot: std::collections::HashMap<u16, usize> = std::collections::HashMap::new();
+    if let crate::decrypt::DecryptKeys::Aacs { unit_keys, .. } = keys {
+        for (i, k) in index_keys.iter().enumerate() {
+            let tag = (i + 1) as u16;
+            let slot = match unit_keys.iter().position(|(_, h)| h == k) {
+                Some(s) => s,
+                None => {
+                    let s = unit_keys.len();
+                    // CPS-unit id is cosmetic for the mapped decrypt (it indexes by
+                    // slot); use a high, distinct number for the forensic keys.
+                    unit_keys.push((1000 + s as u32, *k));
+                    s
+                }
+            };
+            tag_slot.insert(tag, slot);
+        }
+    }
+
+    // ── PROBE each index's phase. A forensic segment interleaves two variants at
+    //    the aligned-unit level; only ONE parity is this index's real content (the
+    //    other is the alternate variant — a different key, garbles under ours). For
+    //    each index, read a representative tagged segment and count clean decrypts
+    //    of its EVEN vs ODD units under that index's key: the clean half is the
+    //    index's phase. This is the ONE place `is_clean` runs — "the map must be
+    //    right", verified here, once — so the mux decrypt can then trust the map.
+    //    Phase is per-index and shared by every segment carrying that index. ──────
+    let mut phase_of_index: std::collections::HashMap<u16, crate::decrypt::Phase> =
+        std::collections::HashMap::new();
+    for (i, k) in index_keys.iter().enumerate() {
+        let tag = (i + 1) as u16;
+        let Some(seg) = segments.iter().find(|s| s.index == tag) else {
+            continue; // no segment carries this index on this feature — skip
+        };
+        let (mut even, mut odd) = (0usize, 0usize);
+        for p in 0..BATCH_UNITS {
+            for (phase_off, counter) in [(0usize, &mut even), (1usize, &mut odd)] {
+                if let Some(mut c) = read_unit(reader, seg, p * 2 + phase_off) {
+                    if aacs_unit_encrypted(&c, format) {
+                        decrypt_unit(&mut c, k);
+                        if is_clean(&c, format) {
+                            *counter += 1;
+                        }
+                    }
+                }
+            }
+        }
+        let phase = match even.cmp(&odd) {
+            std::cmp::Ordering::Greater => crate::decrypt::Phase::Even,
+            std::cmp::Ordering::Less => crate::decrypt::Phase::Odd,
+            std::cmp::Ordering::Equal => {
+                // Neither half decrypts clean under this index's key: the map would
+                // be wrong. Fail loud rather than emit a broken segment map.
+                tracing::warn!(target: "freemkv::keysource", index = tag, even, odd, "fmts: no clean phase under index key — refusing broken map");
+                return Err(crate::error::Error::FmtsKeyMissing.into());
+            }
+        };
+        phase_of_index.insert(tag, phase);
+    }
+
+    // ── Build the per-segment LBA ranges: each forensic segment → its tag's key
+    //    AND its index's phase. The mapped decrypt opens only that half and leaves
+    //    the alternate as ciphertext (the muxer drops untouched ciphertext) —
+    //    clean by construction, no garble. A segment straddling an extent boundary
+    //    is left unmapped and tallied (a hard failure below). ────────────────────
+    let mut ranges: Vec<(u32, u32, usize, crate::decrypt::Phase)> =
+        Vec::with_capacity(segments.len());
+    let mut unresolved = 0usize;
+    for seg in &segments {
+        let Some(&slot) = tag_slot.get(&seg.index) else {
+            unresolved += 1;
+            continue;
+        };
+        let phase = phase_of_index
+            .get(&seg.index)
+            .copied()
+            .unwrap_or(crate::decrypt::Phase::All);
+        let start_byte = seg.start_spn as u64 * 192;
+        let end_byte = (seg.end_spn as u64 + 1) * 192;
+        let (Some(a), Some(b)) = (
+            clip_byte_to_lba(&title.extents, start_byte),
+            clip_byte_to_lba(&title.extents, end_byte - 1),
+        ) else {
+            unresolved += 1;
+            continue;
+        };
+        // Only emit a contiguous within-extent range (segments are ~480 KB; a rare
+        // extent-straddle is left unresolved rather than given a wrong span).
+        if b >= a && (b - a) as u64 == (end_byte - 1 - start_byte) / 2048 {
+            ranges.push((a, b + 1, slot, phase));
+        } else {
+            unresolved += 1;
+        }
+    }
+    // Every forensic segment must map to an index key. Any that did not is a hole
+    // in the rip — with the full 32-key set in hand this should never happen, so
+    // treat it as a hard failure rather than silently emitting a garbled segment.
+    if unresolved != 0 {
+        return Err(crate::error::Error::FmtsKeyMissing.into());
+    }
+
+    Ok(Some(crate::decrypt::AacsKeyMap::from_ranges_phased(
+        ranges, base_idx,
+    )))
+}
+
+pub fn resolve_mux_key_map(
+    reader: &mut dyn SectorSource,
+    title: &DiscTitle,
+    keys: &mut crate::decrypt::DecryptKeys,
+    fetch: Option<&crate::sector::KeyFetch>,
+    format: ContentFormat,
+) -> io::Result<crate::decrypt::AacsKeyMap> {
+    use crate::aacs::content::{
+        ALIGNED_UNIT_LEN, ALIGNED_UNIT_SECTORS, aacs_unit_encrypted, decrypt_unit, is_clean,
+    };
+
+    let pool_len = match keys {
+        crate::decrypt::DecryptKeys::Aacs { unit_keys, .. } => unit_keys.len(),
+        // CSS / clear: no AACS map (the decorator's map path is AACS-only).
+        _ => return Ok(crate::decrypt::AacsKeyMap::single(0)),
+    };
+
+    // Secure the disc's key up front from the configured source when the pool is
+    // empty (a genuine "no key yet" — e.g. keydb miss, online-only disc).
+    if pool_len == 0 {
+        if let Some(f) = fetch {
+            let samples = crate::keysource::read_encrypted_units(reader, title, 8);
+            if !samples.is_empty() {
+                let fresh = f.unit_keys(&samples);
+                if let crate::decrypt::DecryptKeys::Aacs { unit_keys, .. } = keys {
+                    for k in fresh {
+                        if !unit_keys.iter().any(|(_, h)| *h == k) {
+                            let i = unit_keys.len() as u32;
+                            unit_keys.push((i, k));
+                        }
+                    }
+                }
+            }
+        }
+        // If the pool is STILL empty, this AACS-encrypted title needs a Unit Key we
+        // could not obtain from any source. That is the same situation as any known
+        // key we don't hold — fail loud at resolve time rather than deferring an
+        // opaque decrypt error (or, worse, emitting ciphertext) at mux time.
+        let empty = matches!(
+            keys,
+            crate::decrypt::DecryptKeys::Aacs { unit_keys, .. } if unit_keys.is_empty()
+        );
+        if empty {
+            return Err(crate::error::Error::DecryptFailed.into());
+        }
+        return Ok(crate::decrypt::AacsKeyMap::single(0));
+    }
+    // FMTS (AACS 2.1): if the disc carries `IndividualSegment.tbl`, the forensic
+    // segments need per-index keys the base Unit Key can't open. Resolve them up
+    // front from the configured source and build a per-segment map. Returns `None`
+    // when the disc is not FMTS, or no key source is configured (then the base UK
+    // path below applies and the forensic units garble → demux drops them).
+    if let Some(map) = resolve_fmts_key_map(reader, title, keys, fetch, format)? {
+        return Ok(map);
+    }
+    if pool_len == 1 {
+        // One CPS unit → one key everywhere. No structural walk, no sampling.
+        return Ok(crate::decrypt::AacsKeyMap::single(0));
+    }
+
+    // Multi-CPS: read a spread of real encrypted units from each extent and pick
+    // the held key that opens one (the `is_clean` proof is sound HERE — samples
+    // are guaranteed real content, not the authored-bad units that trip the mux).
+    let sample_units = |reader: &mut dyn SectorSource, start: u32, sectors: u32| -> Vec<Vec<u8>> {
+        let total_units = sectors / ALIGNED_UNIT_SECTORS;
+        let mut out = Vec::new();
+        if total_units == 0 {
+            return out;
+        }
+        const PROBES: u32 = 8;
+        for p in 1..=PROBES {
+            let unit = ((total_units as u64 * p as u64) / (PROBES as u64 + 1)) as u32;
+            if unit >= total_units {
+                continue;
+            }
+            let lba = start.saturating_add(unit.saturating_mul(ALIGNED_UNIT_SECTORS));
+            let mut buf = vec![0u8; ALIGNED_UNIT_LEN];
+            if reader
+                .read_sectors(lba, ALIGNED_UNIT_SECTORS as u16, &mut buf, false)
+                .is_ok()
+                && aacs_unit_encrypted(&buf, format)
+            {
+                out.push(buf);
+            }
+        }
+        out
+    };
+    let pick = |samples: &[Vec<u8>], pool: &[(u32, [u8; 16])]| -> Option<usize> {
+        for (i, (_, k)) in pool.iter().enumerate() {
+            if samples.iter().any(|s| {
+                let mut u = s.clone();
+                decrypt_unit(&mut u, k);
+                is_clean(&u, format)
+            }) {
+                return Some(i);
+            }
+        }
+        None
+    };
+
+    let mut ranges: Vec<(u32, u32, usize)> = Vec::with_capacity(title.extents.len());
+    let mut last_idx = 0usize;
+    for ext in &title.extents {
+        let samples = sample_units(reader, ext.start_lba, ext.sector_count);
+        // Snapshot the current pool for the pure `pick` closure.
+        let pool: Vec<(u32, [u8; 16])> = match keys {
+            crate::decrypt::DecryptKeys::Aacs { unit_keys, .. } => unit_keys.clone(),
+            _ => Vec::new(),
+        };
+        let mut idx = pick(&samples, &pool);
+        if idx.is_none() {
+            if let Some(f) = fetch {
+                if !samples.is_empty() {
+                    let fresh = f.unit_keys(&samples);
+                    if let crate::decrypt::DecryptKeys::Aacs { unit_keys, .. } = keys {
+                        for k in fresh {
+                            if !unit_keys.iter().any(|(_, h)| *h == k) {
+                                let i = unit_keys.len() as u32;
+                                unit_keys.push((i, k));
+                            }
+                        }
+                        idx = pick(&samples, unit_keys);
+                    }
+                }
+            }
+        }
+        // A bad-content extent no sample can classify inherits its predecessor's
+        // key (CPS boundaries are contiguous, so the neighbour is almost always
+        // right); this never storms and never mis-fails a decryptable disc.
+        let idx = idx.unwrap_or(last_idx);
+        last_idx = idx;
+        ranges.push((
+            ext.start_lba,
+            ext.start_lba.saturating_add(ext.sector_count),
+            idx,
+        ));
+    }
+    Ok(crate::decrypt::AacsKeyMap::from_ranges(ranges, 0))
+}
+
 /// Assemble the ISO mux pipeline (read+decrypt → demux → parse) for
 /// a `FileSectorSource`-backed reader. Returns the resulting
 /// `PipelinedPesStream`.
@@ -608,17 +999,16 @@ fn build_demux_state(title: &DiscTitle, format: ContentFormat) -> DemuxState {
 /// - `halt`: cooperative cancel token (not a timeout); when cancelled the
 ///   pipeline stops at the next boundary. `None` disables cancellation.
 /// - `event_fn`: optional progress/event callback invoked by the prefetcher.
-/// - `fetch`: optional fresh-key-on-failure callback (see
-///   [`crate::sector::KeyFetch`]). When a unit no held key decrypts, the
-///   decrypt decorator hands that ciphertext to `fetch` and adds any key it
-///   returns. `None` keeps the prior behaviour (the unit is counted as loss).
+/// - `fetch`: optional key source used UP FRONT by [`resolve_mux_key_map`] to
+///   secure any CPS-unit key the pool is missing. Not a per-unit mux-time
+///   callback: the map decides the key for every LBA before the read loop starts.
 // Eight reader/title/keys/tuning/callback params is inherent to the mux entry
 // point; grouping them into a struct would only move the same fields around.
 #[allow(clippy::too_many_arguments)]
 pub fn build_iso_pipeline<S: SectorSource + Send + 'static>(
-    reader: S,
+    mut reader: S,
     title: DiscTitle,
-    keys: crate::decrypt::DecryptKeys,
+    mut keys: crate::decrypt::DecryptKeys,
     batch_sectors: u16,
     format: ContentFormat,
     halt: Option<crate::halt::Halt>,
@@ -635,27 +1025,42 @@ pub fn build_iso_pipeline<S: SectorSource + Send + 'static>(
         crate::decrypt::DecryptKeys::Aacs { .. } => 3,
         _ => 1,
     };
-    // MUX path: tolerate decrypt loss. An undecryptable content unit is concealed
-    // (NULL TS fill) + tallied + logged, never an abort — decrypt-verify is a RIP
-    // gate, not a mux gate (P3). The rip's own read paths keep their fail-loud
-    // decorator; only this mux pipeline opts in.
+    // MUX path: read > decrypt > mux. Resolve the proactive AACS key map UP FRONT
+    // — one key per CPS unit / segment, secured from the configured source and
+    // recorded against the LBA ranges it covers. The mux then decrypts each unit
+    // with its KNOWN key and trusts it: no per-unit `is_clean` verdict, no reactive
+    // key-fetch, no key-server storm. A unit that decrypts to broken TS is the
+    // muxer's problem, exactly as before. AACS-only; CSS self-cracks per region.
+    let key_map =
+        match &keys {
+            crate::decrypt::DecryptKeys::Aacs { .. } => Some(std::sync::Arc::new(
+                resolve_mux_key_map(&mut reader, &title, &mut keys, fetch.as_ref(), format)?,
+            )),
+            _ => None,
+        };
+    // The map IS the title's read plan: it says which CPS unit / forensic segment
+    // each LBA belongs to. Walk ONLY the units it marks as ours — every default /
+    // CPS unit, and inside an FMTS forensic segment only our-phase units. The
+    // alternate-phase units are a different device group's variant; a licensed
+    // player never reads them, and neither do we — they are never fetched,
+    // decrypted, or handed to the demux, so the demux sees one gapless our-variant
+    // stream (no ciphertext to trip a concealed-gap resync). A non-forensic map
+    // returns the extents unchanged, so the common disc reads exactly as before.
+    let extents = match &key_map {
+        Some(map) => map.read_plan(&extents, unit_align as u32),
+        None => extents,
+    };
     let mut decrypting =
-        crate::sector::DecryptingSectorSource::new(Box::new(reader) as Box<dyn SectorSource>, keys)
-            .tolerate_decrypt_loss();
-    // Install the fresh-key-on-failure callback (if any) so a unit no held key
-    // decrypts is re-tried via the application's key source before being counted
-    // as loss. An AACS 2.1 forensic-segment unit that no key opens is just an
-    // undecryptable unit like any other: concealed and counted as decrypt loss —
-    // a loss is a loss, no FMTS special casing.
-    if let Some(cb) = fetch {
-        decrypting = decrypting.with_key_fetch(cb);
+        crate::sector::DecryptingSectorSource::new(Box::new(reader) as Box<dyn SectorSource>, keys);
+    if let Some(map) = key_map {
+        decrypting = decrypting.with_key_map(map);
     }
-    // Grab the loss counters before the decorator is moved into the producer
-    // thread. It tracks bytes of scrambled AACS units no key could decrypt —
-    // silent loss the demux drops; the consuming stream surfaces it through
-    // `lost_bytes()` so the mux abort gate sees a partial decrypt failure rather
-    // than a clean rip. Forensic (2.1) undecryptable units land here too.
-    let decrypt_loss = decrypting.decrypt_loss();
+    // Loss-counter handle. The mux does NOT tally decrypt-quality misses: a
+    // broken-TS unit is the muxer's concern, and a missing key is an up-front
+    // resolve failure — indistinguishable from bad authoring at this seam, so
+    // counting it would false-abort a bad-encoded-but-decryptable disc. A genuine
+    // can't-decrypt surfaces as `Err`; `lost_bytes()` reflects physical read loss
+    // only (there is no decrypt-loss term to fold in).
 
     // Wrong-substream fix (Silence-of-the-Lambs): before the prefetcher takes
     // the reader, probe the feature head through the (plaintext) decrypting
@@ -681,10 +1086,13 @@ pub fn build_iso_pipeline<S: SectorSource + Send + 'static>(
     let (demux_thread, demux_rx) =
         super::demux_thread::DemuxThread::spawn_zero_copy(rx, recycle_tx, shell, halt, ts, ps)
             .map_err(|e| -> io::Error { e.into() })?;
-    Ok(
-        PipelinedPesStream::new(demux_thread, demux_rx, title, parsers, pid_to_track)
-            .with_decrypt_loss(decrypt_loss),
-    )
+    Ok(PipelinedPesStream::new(
+        demux_thread,
+        demux_rx,
+        title,
+        parsers,
+        pid_to_track,
+    ))
 }
 
 /// Assemble the M2TS file mux pipeline (read → demux → parse) for a

src/mux/ts.rs

@@ -12,9 +12,11 @@ use crate::consts::TS_PACKET_BYTES;
 
 /// TS sync byte.
 const SYNC_BYTE: u8 = 0x47;
-/// MPEG-TS null-packet PID (0x1FFF). Carries no elementary stream; the P3
-/// concealment fill emits null packets on this PID, tagged with an
-/// adaptation-field discontinuity_indicator to signal a concealed gap.
+/// MPEG-TS null-packet PID (0x1FFF). Carries no elementary stream. The demuxer
+/// still recognises a `0x1FFF` packet with an adaptation-field
+/// discontinuity_indicator as a concealed-gap loss signal, but the in-tree WRITER
+/// that emitted these (the removed NULL-TS concealment fill) is gone — the mux no
+/// longer conceals; only externally-authored markers reach this path now.
 const NULL_PID: u16 = 0x1FFF;
 
 /// A reassembled PES packet with timestamp info.
@@ -34,8 +36,10 @@ pub struct PesPacket {
     pub source: Option<crate::pes::SourcePos>,
     /// True when one or more packets for this stream were lost before this PES —
     /// a continuity break (CC gap or adaptation-field discontinuity_indicator) on
-    /// a tracked PID, or the CC-independent concealment marker the mux emits when
-    /// it replaces an undecryptable unit with NULL-TS packets (P3/A2). This PES is
+    /// a tracked PID, or a CC-independent NULL-TS concealment marker (P3/B1). NOTE:
+    /// the mux no longer emits such markers (the concealment writer was removed);
+    /// this now flags only real discontinuities and externally-authored markers.
+    /// This PES is
     /// the FIRST whose data is entirely after the gap: a mid-frame loss drops the
     /// truncated partial and flags the next complete PES; a loss landing on a PES
     /// boundary flags the PES STARTING after it (never the one just flushed). So
@@ -200,7 +204,7 @@ impl PesAssembler {
 /// BD Transport Stream demuxer.
 pub struct TsDemuxer {
     assemblers: Vec<PesAssembler>,
-    pid_index: Vec<i16>, // PID → index into assemblers, -1 = not tracked
+    pid_index: Vec<i32>, // PID → index into assemblers, -1 = not tracked
     remainder: Vec<u8>,  // leftover bytes from previous feed() call
     /// Absolute source byte offset of the NEXT byte to be fed — the running
     /// base that turns an in-buffer packet offset into a source position.
@@ -224,20 +228,17 @@ impl TsDemuxer {
     /// limits. Empty `pids` yields max_pid 0; the floor still produces a
     /// valid (wholly-unused) table.
     pub fn new(pids: &[u16]) -> Self {
-        // The PID→assembler index is stored as i16 (-1 = untracked), so a
-        // 32768th+ tracked PID would truncate to a negative value and be
-        // silently treated as untracked. Callers pass a handful of PIDs
-        // (BD-TS has at most ~8192), so this is a programmer-error guard.
-        debug_assert!(
-            pids.len() <= i16::MAX as usize,
-            "TsDemuxer: too many PIDs for an i16 index table"
-        );
+        // The PID→assembler index is stored as i32 (-1 = untracked). PIDs are
+        // u16 (≤ 65535) and the assembler index `i` is bounded by the number of
+        // distinct PIDs (≤ 65536), both far below i32::MAX, so `i as i32` can
+        // never truncate to a negative value and be mis-read as untracked —
+        // unlike an i16 table, this is safe in RELEASE, not just under debug.
         let max_pid = pids.iter().copied().max().unwrap_or(0) as usize;
         let table_size = (max_pid + 1).max(8192);
-        let mut pid_index = vec![-1i16; table_size];
+        let mut pid_index = vec![-1i32; table_size];
         let mut assemblers = Vec::with_capacity(pids.len());
         for (i, &pid) in pids.iter().enumerate() {
-            pid_index[pid as usize] = i as i16;
+            pid_index[pid as usize] = i as i32;
             assemblers.push(PesAssembler::new(pid));
         }
         Self {
@@ -368,10 +369,13 @@ impl TsDemuxer {
         let pusi = ts[1] & 0x40 != 0; // Payload Unit Start Indicator
         let adaptation = (ts[3] >> 4) & 0x03;
 
-        // P3/B1 CONCEALMENT MARKER. The decrypt layer fills an undecryptable
-        // aligned unit with NULL-TS packets (PID 0x1FFF) that carry an
-        // adaptation-field discontinuity_indicator (see `aacs::content::fill_null_ts_unit`).
-        // This is the authoritative loss signal — unlike a tracked PID's 4-bit
+        // P3/B1 CONCEALMENT MARKER: a NULL-TS packet (PID 0x1FFF) carrying an
+        // adaptation-field discontinuity_indicator. NOTE: the in-tree writer that
+        // laid these down on an undecryptable unit was removed with the pure-decrypt
+        // passthrough change (the mux no longer conceals), so this recognition now
+        // only fires on externally-authored markers — a candidate for removal with
+        // the rest of the retired concealment path.
+        // As a loss signal it is CC-INDEPENDENT — unlike a tracked PID's 4-bit
         // continuity_counter it is CC-INDEPENDENT, so it survives a loss that is
         // an exact multiple of 16 packets and a loss at the very start of a PID
         // (no prior CC to diff against). The decrypt layer cannot know which
@@ -1057,7 +1061,7 @@ mod tests {
 
     /// One 192-byte BD source packet that is a B1 concealment marker: a PID-0x1FFF
     /// null packet carrying the adaptation-field discontinuity_indicator (the byte
-    /// shape `fill_null_ts_unit` writes for every packet of a concealed unit).
+    /// shape of a concealed-unit packet).
     fn null_marker_packet() -> Vec<u8> {
         let mut pkt = vec![0u8; BD_SOURCE_PACKET_BYTES];
         pkt[4] = SYNC_BYTE; // 0x47

src/sector/mod.rs

@@ -129,6 +129,10 @@ impl SectorSource for Box<dyn SectorSource> {
     fn set_speed(&mut self, kbs: u16) {
         (**self).set_speed(kbs)
     }
+
+    fn set_unit_base(&mut self, lba: u32) {
+        (**self).set_unit_base(lba)
+    }
 }
 
 impl SectorSource for &mut (dyn SectorSource + '_) {
@@ -160,6 +164,10 @@ impl SectorSource for &mut (dyn SectorSource + '_) {
     fn set_speed(&mut self, kbs: u16) {
         (**self).set_speed(kbs)
     }
+
+    fn set_unit_base(&mut self, lba: u32) {
+        (**self).set_unit_base(lba)
+    }
 }
 
 /// Write 2048-byte sectors to a disc image or composed sink.
@@ -181,7 +189,7 @@ pub trait SectorSink: Send {
 }
 
 pub use crate::io::file_sector_source::FileSectorSource;
-pub use decrypting::{DECRYPT_VERIFY_READ, DecryptingSectorSource, KeyFetch};
+pub use decrypting::{DecryptingSectorSource, KeyFetch, KeyFetchFn};
 pub use file::FileSectorSink;
 pub use prefetched::PrefetchedSectorSource;
 
@@ -198,23 +206,33 @@ mod tests {
         capacity: u32,
         reads: Arc<Mutex<Vec<(u32, u16, bool)>>>,
         speeds: Arc<Mutex<Vec<u16>>>,
+        unit_bases: Arc<Mutex<Vec<u32>>>,
     }
 
-    /// A `Spy` under test plus the handles recording its reads and speed sets.
-    type SpyHarness = (Spy, Arc<Mutex<Vec<(u32, u16, bool)>>>, Arc<Mutex<Vec<u16>>>);
+    /// A `Spy` under test plus the handles recording its reads, speed sets,
+    /// and unit-base sets.
+    type SpyHarness = (
+        Spy,
+        Arc<Mutex<Vec<(u32, u16, bool)>>>,
+        Arc<Mutex<Vec<u16>>>,
+        Arc<Mutex<Vec<u32>>>,
+    );
 
     impl Spy {
         fn new(capacity: u32) -> SpyHarness {
             let reads = Arc::new(Mutex::new(Vec::new()));
             let speeds = Arc::new(Mutex::new(Vec::new()));
+            let unit_bases = Arc::new(Mutex::new(Vec::new()));
             (
                 Self {
                     capacity,
                     reads: reads.clone(),
                     speeds: speeds.clone(),
+                    unit_bases: unit_bases.clone(),
                 },
                 reads,
                 speeds,
+                unit_bases,
             )
         }
     }
@@ -238,6 +256,16 @@ mod tests {
         fn set_speed(&mut self, kbs: u16) {
             self.speeds.lock().unwrap().push(kbs);
         }
+        fn set_unit_base(&mut self, lba: u32) {
+            self.unit_bases.lock().unwrap().push(lba);
+        }
+    }
+
+    /// Call `set_unit_base` through a generic `S: SectorSource` bound — this is
+    /// the path that actually exercises the `Box<dyn>` / `&mut dyn` FORWARDING
+    /// impls (a direct call on a `dyn` value dispatches via the vtable instead).
+    fn set_unit_base_generic<S: SectorSource>(mut s: S, base: u32) {
+        s.set_unit_base(base);
     }
 
     /// The default `capacity_sectors` is 0 (unknown). Grounding: trait
@@ -286,7 +314,7 @@ mod tests {
     /// Box<dyn SectorSource>` forwarding bodies.
     #[test]
     fn boxed_dyn_forwards_all_methods() {
-        let (spy, reads, speeds) = Spy::new(777);
+        let (spy, reads, speeds, unit_bases) = Spy::new(777);
         let mut boxed: Box<dyn SectorSource> = Box::new(spy);
 
         assert_eq!(boxed.capacity_sectors(), 777, "capacity must forward");
@@ -308,24 +336,46 @@ mod tests {
             vec![5400],
             "set_speed must forward"
         );
+
+        // set_unit_base through the generic bound exercises the forwarding impl
+        // (a direct `boxed.set_unit_base()` would vtable-dispatch instead). A
+        // missing forwarding body would silently no-op and record nothing.
+        set_unit_base_generic(boxed, 64);
+        assert_eq!(
+            *unit_bases.lock().unwrap(),
+            vec![64],
+            "set_unit_base must forward through Box<dyn>"
+        );
     }
 
-    /// `&mut dyn SectorSource` must likewise forward all three methods.
+    /// `&mut dyn SectorSource` must likewise forward every method.
     /// Grounding: `impl SectorSource for &mut (dyn SectorSource + '_)`.
     #[test]
     fn mut_ref_dyn_forwards_all_methods() {
-        let (mut spy, reads, speeds) = Spy::new(123);
-        let r: &mut dyn SectorSource = &mut spy;
+        let (mut spy, reads, speeds, unit_bases) = Spy::new(123);
 
-        assert_eq!(r.capacity_sectors(), 123);
+        {
+            let r: &mut dyn SectorSource = &mut spy;
+            assert_eq!(r.capacity_sectors(), 123);
 
-        let mut buf = vec![0u8; 2 * 2048];
-        let n = r.read_sectors(7, 2, &mut buf, false).unwrap();
-        assert_eq!(n, 2 * 2048);
+            let mut buf = vec![0u8; 2 * 2048];
+            let n = r.read_sectors(7, 2, &mut buf, false).unwrap();
+            assert_eq!(n, 2 * 2048);
 
-        r.set_speed(8800);
+            r.set_speed(8800);
+        }
+
+        // Pass `&mut dyn` as a generic S so the forwarding impl's set_unit_base
+        // is the one under test, not the vtable path.
+        let r2: &mut dyn SectorSource = &mut spy;
+        set_unit_base_generic(r2, 128);
 
         assert_eq!(*reads.lock().unwrap(), vec![(7, 2, false)]);
         assert_eq!(*speeds.lock().unwrap(), vec![8800]);
+        assert_eq!(
+            *unit_bases.lock().unwrap(),
+            vec![128],
+            "set_unit_base must forward through &mut dyn"
+        );
     }
 }

src/sector/prefetched.rs

@@ -252,11 +252,14 @@ impl PrefetchedSectorSource {
                         };
                         if bytes <= buf.capacity() {
                             // Re-expose `bytes` without zero-filling pages that
-                            // `read_sectors` is about to overwrite. The enclosing
-                            // capacity guard makes the `set_len` provably sound even
-                            // if a recycled buffer ever comes back smaller than the
-                            // `vec![0u8; batch_bytes]` it was born with.
-                            debug_assert!(bytes <= buf.capacity(), "set_len exceeds capacity");
+                            // `read_sectors` is about to overwrite. Sound because the
+                            // enclosing `bytes <= capacity` guard bounds the length,
+                            // and every byte below `capacity` is physically
+                            // initialised: buffers are born `vec![0u8; batch_bytes]`
+                            // and only ever grown via `resize(_, 0)`, so a recycled
+                            // buffer that came back shorter (consumer `truncate`)
+                            // still has initialised backing storage under `set_len`,
+                            // which `read_sectors` then overwrites before any read.
                             unsafe { buf.set_len(bytes) };
                         } else {
                             buf.resize(bytes, 0);

src/sector/recovery.rs

@@ -103,25 +103,30 @@ pub struct RecoverCtx {
     pub prev_dropped: usize,
 }
 
-/// A recovery: given a read's still-scrambled `buf` and the **generic**
-/// [`DecryptKeys`], make units decrypt (crack or fetch a key into `keys`) and/or
-/// classify the loss (see [`MissOutcome`]). The type names NO encryption scheme
-/// — the installed recovery decides what to do with the generic keys, so any
-/// scheme (an AACS key-fetch, a future CSS re-crack) is just a different
-/// [`Recover`] the input stream installs. `FnMut` so per-recovery
-/// state (the AACS dedup set / call budget) lives in the closure's captures with
-/// no lock; `Send` so it can ride the mux highway's producer thread.
-pub type Recover = Box<dyn FnMut(&mut [u8], &mut DecryptKeys, &RecoverCtx) -> MissOutcome + Send>;
+/// A recovery: given a read's post-decrypt `target` (pure decrypt leaves the
+/// applied-key plaintext), the matching on-disc `ciphertext`, and the **generic**
+/// [`DecryptKeys`], make units decrypt (fetch a key into `keys` and retry) and/or
+/// classify the loss (see [`MissOutcome`]). Decryption itself lives in ONE place
+/// (`decrypt_sectors`); a recovery only supplies the missing KEY and re-runs it.
+/// `ciphertext` is separate from `target` because a pure decrypt overwrites the
+/// target with plaintext — the key server still needs the original on-disc bytes,
+/// and the retry re-decrypts from them. The type names NO encryption scheme; any
+/// scheme is just a different [`Recover`] the input stream installs. `FnMut` so
+/// per-recovery state (dedup set / call budget) lives in the closure's captures;
+/// `Send` so it can ride the mux highway's producer thread.
+pub type Recover =
+    Box<dyn FnMut(&mut [u8], &[u8], &mut DecryptKeys, &RecoverCtx) -> MissOutcome + Send>;
 
-/// The AACS key-fetch step used by [`key_fetch`]: gather the
-/// still-scrambled units, ask `fetch` for keys, add any new ones to the pool and
-/// re-decrypt. `dry` / `calls` are the caller-owned dedup set and call budget.
-/// Returns the post-retry dropped-byte count.
+/// The AACS key-fetch step used by [`key_fetch`]: gather the units the pool did
+/// NOT open, ask `fetch` for keys, add any new ones to the pool and re-decrypt.
+/// `dry` / `calls` are the caller-owned dedup set and call budget. Returns the
+/// post-retry unverified-byte count.
 fn aacs_fetch_step(
     dry: &mut HashSet<u64>,
     calls: &mut usize,
     fetch: &KeyFetch,
-    buf: &mut [u8],
+    target: &mut [u8],
+    ciphertext: &[u8],
     keys: &mut DecryptKeys,
     ctx: &RecoverCtx,
 ) -> usize {
@@ -130,14 +135,25 @@ fn aacs_fetch_step(
         return prev_dropped;
     }
     let unit_len = crate::aacs::content::ALIGNED_UNIT_LEN;
-    // Gather up to MAX_FETCH_SAMPLES still-scrambled aligned units — the exact
-    // on-disc ciphertext no held key could open. A trailing partial unit
+    // Container of this disc's content — travels with the keys; drives the
+    // encrypted-flag / structure check below (TS vs PS).
+    let format = match &*keys {
+        DecryptKeys::Aacs { format, .. } => *format,
+        _ => crate::disc::ContentFormat::BdTs,
+    };
+    // Gather up to MAX_FETCH_SAMPLES units the current pool did NOT open. Detect
+    // them on the post-decrypt TARGET (a failed unit stays TS-destroyed; an opened
+    // one is now clean TS and is skipped), but SAMPLE the matching on-disc
+    // `ciphertext` — the exact bytes the key server needs. A trailing partial unit
     // (chunks_exact remainder) can't be a whole scrambled unit, so skipping it is
     // correct.
     let mut samples: Vec<Vec<u8>> = Vec::new();
-    for chunk in buf.chunks_exact(unit_len) {
-        if crate::aacs::content::aacs_unit_needs_decrypt(chunk) {
-            samples.push(chunk.to_vec());
+    for (t, c) in target
+        .chunks_exact(unit_len)
+        .zip(ciphertext.chunks_exact(unit_len))
+    {
+        if crate::aacs::content::aacs_unit_needs_decrypt(t, format) {
+            samples.push(c.to_vec());
             if samples.len() >= MAX_FETCH_SAMPLES {
                 break;
             }
@@ -154,7 +170,7 @@ fn aacs_fetch_step(
         return prev_dropped;
     }
     *calls += 1;
-    let fresh = (fetch)(&samples);
+    let fresh = fetch.unit_keys(&samples);
     // Add only keys we don't already hold (dedup by value).
     let mut added = 0usize;
     if let DecryptKeys::Aacs { unit_keys, .. } = keys {
@@ -172,10 +188,13 @@ fn aacs_fetch_step(
         dry.extend(fps);
         return prev_dropped;
     }
-    // Retry now that the pool has grown; a unit that still won't decrypt is
-    // genuine loss. A retry error must not mask the original count.
+    // Retry now that the pool has grown. Reset the target to the on-disc
+    // ciphertext first (a pure decrypt already overwrote it with the failed
+    // plaintext), then re-run the ONE decrypt. A unit that still won't reach clean
+    // TS stays unverified; a retry error must not mask the original count.
+    target.copy_from_slice(ciphertext);
     redecrypt(
-        buf,
+        target,
         keys,
         ctx.unit_key_idx,
         ctx.lba,
@@ -187,7 +206,7 @@ fn aacs_fetch_step(
 /// No recovery: a miss is loss. Equivalent to installing nothing — provided so a
 /// caller that wants an explicit "give up" recovery has one.
 pub fn none() -> Recover {
-    Box::new(|_buf, _keys, ctx| MissOutcome::loss(ctx.prev_dropped))
+    Box::new(|_target, _ciphertext, _keys, ctx| MissOutcome::loss(ctx.prev_dropped))
 }
 
 /// AACS key-fetch recovery (BD / UHD): on a miss, ask the application's key
@@ -195,9 +214,9 @@ pub fn none() -> Recover {
 pub fn key_fetch(fetch: KeyFetch) -> Recover {
     let mut dry: HashSet<u64> = HashSet::new();
     let mut calls: usize = 0;
-    Box::new(move |buf, keys, ctx| {
+    Box::new(move |target, ciphertext, keys, ctx| {
         MissOutcome::loss(aacs_fetch_step(
-            &mut dry, &mut calls, &fetch, buf, keys, ctx,
+            &mut dry, &mut calls, &fetch, target, ciphertext, keys, ctx,
         ))
     })
 }
@@ -243,8 +262,10 @@ mod tests {
         let mut keys = DecryptKeys::Aacs {
             unit_keys: vec![],
             read_data_key: None,
+            format: crate::disc::ContentFormat::BdTs,
         };
-        let out = r(&mut buf, &mut keys, &ctx(0, 6144));
+        let cipher = buf.clone();
+        let out = r(&mut buf, &cipher, &mut keys, &ctx(0, 6144));
         assert_eq!(out.dropped, 6144);
     }
 
@@ -255,18 +276,20 @@ mod tests {
         // decorator's integration tests); here we pin the seam's key-plumbing.
         let calls = Arc::new(AtomicUsize::new(0));
         let c2 = Arc::clone(&calls);
-        let fetch: KeyFetch = Arc::new(move |samples: &[Vec<u8>]| {
+        let fetch: KeyFetch = KeyFetch::unit_only(Arc::new(move |samples: &[Vec<u8>]| {
             c2.fetch_add(1, Ordering::SeqCst);
             assert!(!samples.is_empty(), "failing ciphertext is forwarded");
             vec![[0xAB; 16]]
-        });
+        }));
         let mut r = key_fetch(fetch);
         let mut buf = scrambled_unit(0x33);
         let mut keys = DecryptKeys::Aacs {
             unit_keys: vec![],
             read_data_key: None,
+            format: crate::disc::ContentFormat::BdTs,
         };
-        r(&mut buf, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
+        let cipher = buf.clone();
+        r(&mut buf, &cipher, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
         assert_eq!(calls.load(Ordering::SeqCst), 1, "fetch called once");
         let DecryptKeys::Aacs { unit_keys, .. } = &keys else {
             unreachable!()
@@ -281,19 +304,22 @@ mod tests {
         // the SAME ciphertext must not call the fetch again.
         let calls = Arc::new(AtomicUsize::new(0));
         let c2 = Arc::clone(&calls);
-        let fetch: KeyFetch = Arc::new(move |_: &[Vec<u8>]| {
+        let fetch: KeyFetch = KeyFetch::unit_only(Arc::new(move |_: &[Vec<u8>]| {
             c2.fetch_add(1, Ordering::SeqCst);
             Vec::new() // never helps
-        });
+        }));
         let mut r = key_fetch(fetch);
         let mut keys = DecryptKeys::Aacs {
             unit_keys: vec![],
             read_data_key: None,
+            format: crate::disc::ContentFormat::BdTs,
         };
         let mut buf = scrambled_unit(0x44);
-        r(&mut buf, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
+        let cipher = buf.clone();
+        r(&mut buf, &cipher, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
         let mut buf2 = scrambled_unit(0x44); // identical ciphertext
-        r(&mut buf2, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
+        let cipher2 = buf2.clone();
+        r(&mut buf2, &cipher2, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
         assert_eq!(
             calls.load(Ordering::SeqCst),
             1,
@@ -305,21 +331,23 @@ mod tests {
     fn key_fetch_call_budget_bounds_fetches() {
         let calls = Arc::new(AtomicUsize::new(0));
         let c2 = Arc::clone(&calls);
-        let fetch: KeyFetch = Arc::new(move |_: &[Vec<u8>]| {
+        let fetch: KeyFetch = KeyFetch::unit_only(Arc::new(move |_: &[Vec<u8>]| {
             c2.fetch_add(1, Ordering::SeqCst);
             Vec::new()
-        });
+        }));
         let mut r = key_fetch(fetch);
         let mut keys = DecryptKeys::Aacs {
             unit_keys: vec![],
             read_data_key: None,
+            format: crate::disc::ContentFormat::BdTs,
         };
         // Distinct ciphertext each time so the dry-set never short-circuits; only
         // the internal call budget should stop the fetch. The closure self-limits,
         // so the decorator can call it unconditionally.
         for i in 0..(MAX_FETCH_CALLS as u8 + 5) {
             let mut buf = scrambled_unit(i);
-            r(&mut buf, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
+            let cipher = buf.clone();
+            r(&mut buf, &cipher, &mut keys, &ctx(0, ALIGNED_UNIT_LEN));
         }
         assert_eq!(
             calls.load(Ordering::SeqCst),

src/udf.rs

@@ -593,10 +593,27 @@ impl UdfFs {
             match next_block {
                 Some(cont_lba) => {
                     read_sector(reader, self.meta_to_abs(cont_lba)?, &mut block)?;
-                    // A continuation block is a list of Short ADs from byte 0,
-                    // spanning the whole sector.
-                    ad_start = 0;
-                    ad_bytes = block.len();
+                    // A continuation block does NOT begin with allocation
+                    // descriptors — it begins with a 24-byte Allocation Extent
+                    // Descriptor (ECMA-167 4/14.5, tag id 258): the 16-byte
+                    // descriptor tag, then prev_allocation_extent_location
+                    // (Uint32 @16) and length_of_allocation_descriptors
+                    // (Uint32 @20). The real ADs (same Short/Long/Extended type
+                    // as the file) start at offset 24, and their total byte
+                    // length is that @20 field.
+                    //
+                    // Reading from offset 0 parses the AED's own tag header as
+                    // allocation descriptors → one garbage extent, then an
+                    // unknown extent_type break — silently truncating every
+                    // file whose ADs spill into a continuation block (a heavily
+                    // fragmented file, e.g. a Blu-ray 3D interleaved base-view
+                    // .m2ts with ~1600 fragments). A normal few-extent .m2ts
+                    // fits inline and never reaches here, which is why this
+                    // stayed hidden.
+                    let aed_l_ad =
+                        u32::from_le_bytes([block[20], block[21], block[22], block[23]]) as usize;
+                    ad_start = 24;
+                    ad_bytes = aed_l_ad.min(block.len().saturating_sub(24));
                 }
                 None => break,
             }
@@ -1535,8 +1552,15 @@ mod tests {
 
     /// A continuation block: a bare list of short ADs from byte 0.
     fn build_cont_block(ads: &[(u32, u32, u32)]) -> [u8; 2048] {
+        // A continuation block is an Allocation Extent Descriptor (ECMA-167
+        // 4/14.5): a 16-byte descriptor tag, then prev_allocation_extent_location
+        // (Uint32 @16) and length_of_allocation_descriptors (Uint32 @20). The
+        // actual allocation descriptors begin at offset 24. The parser skips the
+        // 24-byte header and reads `l_ad` bytes of ADs from there.
         let mut s = [0u8; 2048];
-        let mut off = 0usize;
+        let l_ad = (ads.len() * 8) as u32;
+        s[20..24].copy_from_slice(&l_ad.to_le_bytes());
+        let mut off = 24usize;
         for &(etype, dlen, dlba) in ads {
             let raw_len = (etype << 30) | (dlen & 0x3FFF_FFFF);
             s[off..off + 4].copy_from_slice(&raw_len.to_le_bytes());
@@ -1590,6 +1614,35 @@ mod tests {
         assert_eq!(extents, vec![(10, 4096), (20, 2048)]);
     }
 
+    #[test]
+    fn icb_extents_continuation_skips_aed_header_not_read_as_extent() {
+        // Regression (Blu-ray 3D): a continuation block begins with a 24-byte
+        // Allocation Extent Descriptor whose 16-byte descriptor tag holds
+        // NON-zero bytes (tag id 258, CRC, location, ...). Reading allocation
+        // descriptors from offset 0 parses that tag header as an AD → a garbage
+        // extent, then an unknown extent_type break → every fragment past the
+        // first continuation is lost. On a 3D disc that truncated the 25.8 GB
+        // interleaved base-view feature to ~1.8 GB (113 of ~1600 fragments) and
+        // then choked the mux on the bogus, non-unit-aligned extent. The parser
+        // MUST skip the 24-byte AED header and read the real ADs from offset 24.
+        let icb = build_efe(6144, &[(0, 4096, 10), (3, 2048, 50)]);
+        let mut cont = build_cont_block(&[(0, 2048, 20)]);
+        // Stamp a realistic AED descriptor tag (id 258) into the header so a
+        // regression that reads from offset 0 mis-parses it as a bogus extent
+        // instead of finding the real (20, 2048) at offset 24.
+        cont[0..2].copy_from_slice(&258u16.to_le_bytes());
+        let mut reader = MapReader::new();
+        reader.put(5, icb);
+        reader.put(50, cont);
+        let fs = fs_with(0, 0, file_entry("3D", 5, 6144));
+        let extents = fs.read_icb_extents(&mut reader, 5).expect("extents");
+        assert_eq!(
+            extents,
+            vec![(10, 4096), (20, 2048)],
+            "continuation ADs must be read past the 24-byte AED header, not from offset 0"
+        );
+    }
+
     #[test]
     fn icb_extents_long_ad_returns_all_extents_not_just_first() {
         // Regression: BD-ROM large .m2ts files use Long ADs (16-byte
@@ -1737,6 +1790,57 @@ mod tests {
         assert!(inf[2048..].iter().all(|&b| b == 0xBB));
     }
 
+    #[test]
+    fn read_aacs_inputs_falls_through_to_hddvd_any_dir() {
+        // HD DVD keeps its AACS material under /ANY!/ (VTKF000.AACS title-key
+        // file + MKBROM.AACS), NOT /AACS/Unit_Key_RO.inf + /AACS/MKB_RO.inf. The
+        // role-based candidate lists must fall through to the /ANY!/ files with
+        // NO disc-type branch, so the online keyserver POST carries the HD DVD
+        // title-key file (magic "DVD_HD_V_TKF") as inf_b64 + MKBROM as mkb_b64 —
+        // the server then classifies the disc as HD DVD by that magic.
+        let any = DirEntry {
+            name: "ANY!".to_string(),
+            is_dir: true,
+            meta_lba: 0,
+            size: 0,
+            entries: vec![
+                file_entry("VTKF000.AACS", 5, 2048),
+                file_entry("MKBROM.AACS", 7, 2048),
+            ],
+        };
+        let root = DirEntry {
+            name: String::new(),
+            is_dir: true,
+            meta_lba: 0,
+            size: 0,
+            entries: vec![any], // deliberately NO /AACS/ dir
+        };
+        let mut reader = MapReader::new();
+        // VTKF000.AACS: one extent whose content opens with the HD DVD magic.
+        let mut vtkf = [0u8; 2048];
+        vtkf[..12].copy_from_slice(b"DVD_HD_V_TKF");
+        reader.put(5, build_efe_long(2048, &[(0, 2048, 10)]));
+        reader.put(10, vtkf);
+        // MKBROM.AACS: one extent with a type-0x10 AACS-1.0 (HD DVD) version record.
+        let mut mkb = [0u8; 2048];
+        mkb[..12].copy_from_slice(&[
+            0x10, 0x00, 0x00, 0x0C, 0x00, 0x04, 0x10, 0x03, 0x00, 0x00, 0x00, 0x03,
+        ]);
+        reader.put(7, build_efe_long(2048, &[(0, 2048, 50)]));
+        reader.put(50, mkb);
+
+        let fs = fs_with(0, 0, root);
+        let (inf, _mkb, _version) =
+            crate::disc::Disc::read_aacs_inputs_from_reader(&mut reader, &fs)
+                .expect("read_aacs_inputs must source the HD DVD /ANY!/ files");
+        assert_eq!(
+            &inf[..12],
+            b"DVD_HD_V_TKF",
+            "inf must be the HD DVD VTKF (its magic), sourced from /ANY!/ via the \
+             candidate fall-through — not /AACS/Unit_Key_RO.inf"
+        );
+    }
+
     #[test]
     fn merge_ranges_saturates_near_u32_max() {
         // Adjacent ranges near u32::MAX must not panic (debug) or wrap.

tests/crypto_tests.rs

@@ -131,16 +131,15 @@ fn aacs_decrypt_unit_roundtrip() {
     }
 
     // Verify it looks encrypted (body TS syncs scrambled)
-    assert!(aacs::content::ts_sync_destroyed(&plain));
+    assert!(!aacs::content::is_clean(
+        &plain,
+        libfreemkv::disc::ContentFormat::BdTs
+    ));
 
     // Now decrypt
-    let result = aacs::content::decrypt_unit(&mut plain, &unit_key);
+    aacs::content::decrypt_unit(&mut plain, &unit_key);
     assert!(
-        result,
-        "decrypt_unit should return true on valid encrypted unit"
-    );
-    assert!(
-        !aacs::content::ts_sync_destroyed(&plain),
+        aacs::content::is_clean(&plain, libfreemkv::disc::ContentFormat::BdTs),
         "decrypted unit should read as clear (TS syncs restored)"
     );
 
@@ -258,9 +257,9 @@ fn aacs_vuk_derivation_roundtrip() {
     assert_eq!(vuk, vuk2, "derive_vuk not deterministic");
 }
 
-/// Test: aacs_ts_sync_destroyed detects scrambled units via the raw TS syncs.
+/// Test: `is_clean` distinguishes clean vs scrambled units via the TS proof floor.
 #[test]
-fn aacs_ts_sync_destroyed_detection() {
+fn aacs_is_clean_detection() {
     // A clear unit: TS sync (0x47) intact at every 192-byte packet → not
     // scrambled. (Flag bits play no role.)
     let mut clear = vec![0u8; aacs::content::ALIGNED_UNIT_LEN];
@@ -270,7 +269,7 @@ fn aacs_ts_sync_destroyed_detection() {
         off += 192;
     }
     assert!(
-        !aacs::content::ts_sync_destroyed(&clear),
+        aacs::content::is_clean(&clear, libfreemkv::disc::ContentFormat::BdTs),
         "clear unit (syncs intact) must not be scrambled"
     );
 
@@ -279,32 +278,35 @@ fn aacs_ts_sync_destroyed_detection() {
     flagged[0] = 0xC0; // copy-control bits
     flagged[7] = 0xC0; // TSC bits
     assert!(
-        !aacs::content::ts_sync_destroyed(&flagged),
+        aacs::content::is_clean(&flagged, libfreemkv::disc::ContentFormat::BdTs),
         "flag bits must not be read as encryption"
     );
 
     // A scrambled body (syncs destroyed) → scrambled.
     let scrambled = vec![0x99u8; aacs::content::ALIGNED_UNIT_LEN];
     assert!(
-        aacs::content::ts_sync_destroyed(&scrambled),
+        !aacs::content::is_clean(&scrambled, libfreemkv::disc::ContentFormat::BdTs),
         "unit with no intact TS syncs must read as scrambled"
     );
 
     // Too short
     let short = vec![0xFFu8; 100];
     assert!(
-        !aacs::content::ts_sync_destroyed(&short),
+        aacs::content::is_clean(&short, libfreemkv::disc::ContentFormat::BdTs),
         "short buffer should not be detected"
     );
 }
 
-/// Test: aacs_decrypt_unit_unencrypted_passthrough
+/// Test: aacs_clear_unit_reports_not_encrypted
 ///
-/// A clear unit (TS syncs intact) should pass through decrypt_unit unchanged.
+/// `decrypt_unit` is now PURE (applies the key unconditionally). The "leave a
+/// clear unit untouched" policy lives at the caller's gate `aacs_unit_encrypted`:
+/// a CPI-clear unit reports not-encrypted, so the caller never hands it to
+/// decrypt_unit.
 #[test]
-fn aacs_decrypt_unit_unencrypted_passthrough() {
+fn aacs_clear_unit_reports_not_encrypted() {
     let mut unit = vec![0x42u8; aacs::content::ALIGNED_UNIT_LEN];
-    // Intact TS syncs every 192 bytes → not scrambled → passthrough.
+    // Intact TS syncs every 192 bytes → not scrambled.
     let mut off = 4;
     while off < aacs::content::ALIGNED_UNIT_LEN {
         unit[off] = 0x47;
@@ -312,13 +314,15 @@ fn aacs_decrypt_unit_unencrypted_passthrough() {
     }
     // CPI bits (byte 0) CLEAR → the authoritative gate reads this as plaintext.
     unit[0] &= 0x3F;
-    let original = unit.clone();
-    let key = [0xAA; 16];
 
-    assert!(!aacs::content::ts_sync_destroyed(&unit));
-    let result = aacs::content::decrypt_unit(&mut unit, &key);
-    assert!(result, "clear unit should return true");
-    assert_eq!(unit, original, "clear unit should be unchanged");
+    assert!(aacs::content::is_clean(
+        &unit,
+        libfreemkv::disc::ContentFormat::BdTs
+    ));
+    assert!(
+        !aacs::content::aacs_unit_encrypted(&unit, libfreemkv::disc::ContentFormat::BdTs),
+        "CPI-clear unit reports not-encrypted; the caller never decrypts it"
+    );
 }
 
 // ── AACS cross-validation with independent AES implementation ──────────────
@@ -413,11 +417,7 @@ fn aacs_cross_validation_encrypt_then_decrypt() {
     );
 
     // -- Decrypt with the library --
-    let ok = aacs::content::decrypt_unit(&mut plaintext, &unit_key);
-    assert!(
-        ok,
-        "decrypt_unit returned false (TS sync verification failed)"
-    );
+    aacs::content::decrypt_unit(&mut plaintext, &unit_key);
 
     // Decryption clears no flag, so the unit round-trips byte-for-byte.
     assert_eq!(
@@ -458,44 +458,14 @@ fn aacs_cross_validation_alternate_key() {
         &mut plaintext[16..aacs::content::ALIGNED_UNIT_LEN],
     );
 
-    assert!(aacs::content::decrypt_unit(&mut plaintext, &unit_key));
+    aacs::content::decrypt_unit(&mut plaintext, &unit_key);
 
     // Decryption clears no flag, so the unit round-trips byte-for-byte.
     assert_eq!(&plaintext[..], &expected[..]);
 }
 
-/// Verify that `decrypt_bus` correctly reverses AES-CBC encryption applied
-/// per-sector to bytes 16..2048 (bus encryption layer).
-#[test]
-fn aacs_bus_decrypt_cross_validation() {
-    let read_data_key: [u8; 16] = [
-        0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF,
-        0x00,
-    ];
-
-    let mut plaintext = vec![0u8; aacs::content::ALIGNED_UNIT_LEN];
-    #[allow(clippy::needless_range_loop)]
-    for i in 0..aacs::content::ALIGNED_UNIT_LEN {
-        plaintext[i] = ((i * 3 + 17) & 0xFF) as u8;
-    }
-    let expected = plaintext.clone();
-
-    // Encrypt per-sector: AES-CBC encrypt bytes 16..2048 of each 2048-byte sector
-    for sector_start in (0..aacs::content::ALIGNED_UNIT_LEN).step_by(2048) {
-        ref_aes_cbc_encrypt(
-            &read_data_key,
-            &CROSS_AACS_IV,
-            &mut plaintext[sector_start + 16..sector_start + 2048],
-        );
-    }
-    assert_ne!(&plaintext[16..32], &expected[16..32]);
-
-    aacs::content::decrypt_bus(&mut plaintext, &read_data_key);
-    assert_eq!(
-        plaintext, expected,
-        "bus decrypt did not recover original plaintext"
-    );
-}
+// (`decrypt_bus` is a crate-internal layer — its cross-validation lives in-crate
+// in `aacs::content`'s unit tests, not here.)
 
 // ── CSS roundtrip test vectors ─────────────────────────────────────────────
 
@@ -663,6 +633,28 @@ fn css_stevenson_attack_validates_cracked_key() {
              This is expected: synthetic sectors lack the TAB1 output encoding \
              present in real CSS-encrypted DVD sectors."
         );
+        // Never let this test pass vacuously: when the attack can't converge on
+        // synthetic data, still assert always-true properties of the CSS keystream
+        // so a real regression is caught on every run — descramble_sector is
+        // DETERMINISTIC (same key/seed/data → same output) and NON-TRIVIAL (it
+        // actually transforms the payload, not a silent no-op).
+        for (key, seed) in candidates {
+            let mut base = vec![0x00u8; 2048];
+            base[0x14] = 0x30;
+            base[0x54..0x59].copy_from_slice(seed);
+            base[0x80..0x8A]
+                .copy_from_slice(&[0x00, 0x00, 0x01, 0xE0, 0x00, 0x00, 0x80, 0x80, 0x05, 0x21]);
+            let mut a = base.clone();
+            let mut b = base.clone();
+            css::lfsr::descramble_sector(key, &mut a);
+            css::lfsr::descramble_sector(key, &mut b);
+            assert_eq!(a, b, "descramble must be deterministic for key={key:02X?}");
+            assert_ne!(
+                &a[0x80..2048],
+                &base[0x80..2048],
+                "descramble must transform the payload for key={key:02X?}"
+            );
+        }
     }
 }
 
@@ -707,6 +699,20 @@ fn css_recover_title_key_with_exact_plaintext() {
              The LFSR0 recovery phase may not converge for this combination.",
             title_key, seed
         );
+        // Never pass vacuously: when LFSR0 recovery can't converge on this
+        // synthetic sector, still assert always-true properties of the cipher so
+        // a real regression is caught on every run — descramble_sector is
+        // DETERMINISTIC and NON-TRIVIAL (actually transforms the payload).
+        let mut a = original.clone();
+        let mut b = original.clone();
+        css::lfsr::descramble_sector(&title_key, &mut a);
+        css::lfsr::descramble_sector(&title_key, &mut b);
+        assert_eq!(a, b, "descramble must be deterministic");
+        assert_ne!(
+            &a[0x80..2048],
+            &original[0x80..2048],
+            "descramble must transform the payload"
+        );
     }
 }
 

tests/pass_n_patch_fix.rs

@@ -27,21 +27,39 @@ fn decrypt_sectors_with_aacs_keys_works() {
 
     let unit_key: [u8; 16] = [0xAAu8; 16];
 
-    // Encrypt the unit using AACS algorithm
-    aacs::content::decrypt_unit(&mut unit, &unit_key); // decrypt_unit is idempotent on already-encrypted data
+    // Apply the key to the pattern to produce ciphertext-shaped bytes for the
+    // call below. (decrypt_unit is now PURE — it applies the key unconditionally,
+    // so it is NOT idempotent; never call it twice on the same unit.)
+    aacs::content::decrypt_unit(&mut unit, &unit_key);
+    // (byte 0 keeps its CPI bits set from above, so `decrypt_sectors` recognises
+    // this as encrypted content and actually applies the key.)
 
-    // Now we have encrypted data - create DecryptKeys with actual keys
-    let mut keys = DecryptKeys::Aacs {
+    let mut aacs_keys = DecryptKeys::Aacs {
         unit_keys: vec![(0u32, unit_key)],
         read_data_key: None,
+        format: libfreemkv::disc::ContentFormat::BdTs,
     };
+    let mut none_keys = DecryptKeys::None;
 
-    // decrypt_sectors should handle this without error
-    let result = libfreemkv::decrypt::decrypt_sectors(&mut unit, &mut keys, 0);
+    // The regression this guards is passing `DecryptKeys::None` where AACS keys
+    // were meant. Prove the two DIVERGE: AACS applies the key (bytes change), None
+    // leaves the unit byte-for-byte untouched. is_ok alone can't catch that —
+    // both variants return Ok.
+    let mut with_aacs = unit.clone();
+    let mut with_none = unit.clone();
+    libfreemkv::decrypt::decrypt_sectors(&mut with_aacs, &mut aacs_keys, 0)
+        .expect("AACS decrypt must not error");
+    libfreemkv::decrypt::decrypt_sectors(&mut with_none, &mut none_keys, 0)
+        .expect("None decrypt must not error");
 
-    assert!(
-        result.is_ok(),
-        "decrypt_sectors with AACS keys should not error"
+    assert_ne!(
+        with_aacs, unit,
+        "AACS keys must actually transform the unit"
+    );
+    assert_eq!(with_none, unit, "None keys must leave the unit untouched");
+    assert_ne!(
+        with_aacs, with_none,
+        "AACS decrypt must differ from the None no-op (the None-vs-Aacs regression)"
     );
 }
 
@@ -90,16 +108,25 @@ fn aacs_encryption_flag_detection() {
         off += 192;
     }
     // Encryption is the scrambled body (TS syncs destroyed), NOT a flag bit.
-    assert!(!aacs::content::ts_sync_destroyed(&unit));
+    assert!(aacs::content::is_clean(
+        &unit,
+        libfreemkv::disc::ContentFormat::BdTs
+    ));
 
     // Flag bits on a synced unit do not make it look encrypted.
     unit[0] = 0xC0;
     unit[7] = 0xC0;
-    assert!(!aacs::content::ts_sync_destroyed(&unit));
+    assert!(aacs::content::is_clean(
+        &unit,
+        libfreemkv::disc::ContentFormat::BdTs
+    ));
 
     // Scrambled body (syncs gone) → encrypted.
     let scrambled = vec![0x99u8; aacs::content::ALIGNED_UNIT_LEN];
-    assert!(aacs::content::ts_sync_destroyed(&scrambled));
+    assert!(!aacs::content::is_clean(
+        &scrambled,
+        libfreemkv::disc::ContentFormat::BdTs
+    ));
 }
 
 /// Test: DecryptKeys::is_encrypted() correctly identifies encrypted state.
@@ -111,6 +138,7 @@ fn decrypt_keys_is_encrypted_variants() {
     let aacs = DecryptKeys::Aacs {
         unit_keys: vec![],
         read_data_key: None,
+        format: libfreemkv::disc::ContentFormat::BdTs,
     };
     assert!(aacs.is_encrypted());
 

tests/pass_n_size_aware_skip.rs

@@ -275,7 +275,6 @@ fn patch_block_sectors_zero_does_not_busy_spin() {
         progress: None,
         halt: Some(halt.clone()),
         key_fetch: None,
-        fast_capture: false,
     };
 
     let outcome = disc.patch(&mut reader, &iso_path, &opts);

tests/passn_handler_ab.rs

@@ -232,8 +232,6 @@ struct Golden {
     bytes_unreadable: u64,
     /// `bytes_pending` (NonTrimmed) at end.
     bytes_pending: u64,
-    /// Did the pass exit via wedge-detection?
-    wedged_exit: bool,
     /// Sanity bound on trace length — patch makes a finite number of
     /// reads bounded by `MAX_SKIPS_PER_RANGE * range_sectors` plus
     /// retries. Asserted as an UPPER bound only (so any reduction in
@@ -319,7 +317,6 @@ fn profile_01_clean_all_recoverable() {
         bytes_good: capacity_sectors as u64 * 2048,
         bytes_unreadable: 0,
         bytes_pending: 0,
-        wedged_exit: false,
         max_reads: 8, // adaptive batch=32 reads finishes 16 sectors in 1 read; allow up to 8.
     };
     assert_eq!(stats.bytes_good, expected.bytes_good, "01_clean bytes_good");
@@ -796,29 +793,190 @@ fn profile_08_batch_fail_singles_ok() {
 
 // ─────────────────────────────────────────────────────────────────────────
 //
-// Suppressed for now: NOT_READY-then-recover, HARDWARE_ERROR (wedge),
-// ILLEGAL_REQUEST (wedge), and ABORTED_COMMAND profiles. Each would
-// trigger long real-time sleeps inside `handle_read_failure`:
+// Sense-family error paths in `Disc::patch`: NOT_READY-then-recover,
+// HARDWARE_ERROR, ILLEGAL_REQUEST, and ABORTED_COMMAND.
 //
-//   - NOT_READY (sense_key=0x02, asc=0x02/0x03/0x04): 15 s pause per
-//     occurrence (`patch_not_ready_pause`), and retries the same LBA
-//     in-place. Even one NOT_READY costs the test 15 s wall-time.
+// These drive `disc.patch(...)` DIRECTLY rather than through `run_profile`
+// (which drives `Disc::copy`, whose SWEEP path really sleeps on NOT_READY /
+// wedge cooldowns via `sleep_secs_or_halt`). The patch handler chain itself
+// uses an injectable deadline clock (`Instant::now` in production) and never
+// `thread::sleep`s, so these paths run at full speed with no wall-time cost —
+// the earlier "sleeps aren't injectable" suppression only ever applied to the
+// copy/sweep driver, not to patch.
 //
-//   - HARDWARE_ERROR / ILLEGAL_REQUEST: 30 s per occurrence
-//     (`WEDGE_FAMILY_COOLDOWN_SECS`), bounded by
-//     `WEDGE_ABORT_THRESHOLD=16` before wedged-exit. Worst case ~8
-//     minutes per profile.
-//
-// The sleeps are not injectable. Adding them would require either a
-// `now()` / `sleep()` trait injection (out of scope for the unification
-// task) or a "test mode" compile-time flag (architectural smell). The
-// behavioural contracts for those paths are captured in
-// `read_error.rs`'s in-module tests instead — they exercise the
-// classifier without invoking the patch loop's sleep side-effects.
-//
-// If the unification ever proceeds, the next step is to add a clock
-// injection point in `handle_read_failure` and extend this fixture
-// with the wedge/NOT_READY profiles too.
+// The load-bearing invariant asserted across every PERSISTENT failure sense is
+// the recovery contract: a patch pass NEVER promotes a sector to Unreadable
+// (the orchestrator does that only after the final pass) and NEVER silently
+// drops bytes — a still-bad sector stays NonTrimmed (pending), so
+// good + pending always conserves the total. Exact good/pending splits are
+// left loose so wedge-skip tuning can't spuriously fail these.
+
+/// Run a single-always-bad-sector (LBA 130, inside a NonTrimmed [128,192)
+/// range) patch pass with the given failure step and return the final map
+/// stats. 256-sector synthetic disc; everything outside the range is Finished.
+fn single_dead_sector_patch_stats(step: ScriptStep) -> libfreemkv::disc::mapfile::MapStats {
+    let capacity_sectors: u32 = 256;
+    let (mut reader, _trace) = ScriptedSectorReader::new(capacity_sectors);
+    reader.always(130, step);
+
+    let total_bytes = capacity_sectors as u64 * SECTOR_SIZE as u64;
+    let disc = synthetic_disc(capacity_sectors);
+    let tmp = tempfile::NamedTempFile::new().unwrap();
+    let iso_path = tmp.path().to_path_buf();
+    drop(tmp);
+    let nontrimmed = [(128 * 2048, 64 * 2048)];
+    let finished = [
+        (0, 128 * 2048),
+        (192 * 2048, (capacity_sectors as u64 - 192) * 2048),
+    ];
+    prep_iso_and_mapfile(&iso_path, total_bytes, &finished, &nontrimmed);
+
+    let opts = libfreemkv::disc::PatchOptions {
+        decrypt: false,
+        block_sectors: Some(32),
+        full_recovery: true,
+        reverse: true,
+        wedged_threshold: 50,
+        progress: None,
+        halt: None,
+        key_fetch: None,
+    };
+    disc.patch(&mut reader, &iso_path, &opts)
+        .expect("patch must not error on a per-sector failure sense");
+
+    let map_path = libfreemkv::disc::mapfile_path_for(&iso_path);
+    let stats = Mapfile::load(&map_path).unwrap().stats();
+    let _ = std::fs::remove_file(&iso_path);
+    let _ = std::fs::remove_file(&map_path);
+    stats
+}
+
+/// A persistent sense that never clears must obey the pass contract: nothing
+/// Unreadable, nothing lost (good + pending == total), and at least the dead
+/// sector left pending.
+fn assert_persistent_sense_contract(step: ScriptStep, label: &str) {
+    let stats = single_dead_sector_patch_stats(step);
+    let total = 256u64 * 2048;
+    assert_eq!(
+        stats.bytes_unreadable, 0,
+        "{label}: a patch pass must NEVER mark Unreadable"
+    );
+    assert_eq!(
+        stats.bytes_good + stats.bytes_pending,
+        total,
+        "{label}: conservation — no byte may be silently dropped"
+    );
+    assert!(
+        stats.bytes_pending >= 2048,
+        "{label}: the always-dead sector must remain pending (NonTrimmed)"
+    );
+}
+
+#[test]
+fn patch_persistent_hardware_error_conserves_and_never_unreadable() {
+    // HARDWARE_ERROR (sense_key=0x04) — wedge family.
+    assert_persistent_sense_contract(
+        ScriptStep::Err {
+            sense_key: 0x04,
+            asc: 0x11,
+            ascq: 0x00,
+        },
+        "HARDWARE_ERROR",
+    );
+}
+
+#[test]
+fn patch_persistent_illegal_request_conserves_and_never_unreadable() {
+    // ILLEGAL_REQUEST (sense_key=0x05) — wedge family.
+    assert_persistent_sense_contract(
+        ScriptStep::Err {
+            sense_key: 0x05,
+            asc: 0x21,
+            ascq: 0x00,
+        },
+        "ILLEGAL_REQUEST",
+    );
+}
+
+#[test]
+fn patch_persistent_aborted_command_conserves_and_never_unreadable() {
+    // ABORTED_COMMAND (sense_key=0x0B).
+    assert_persistent_sense_contract(
+        ScriptStep::Err {
+            sense_key: 0x0B,
+            asc: 0x00,
+            ascq: 0x00,
+        },
+        "ABORTED_COMMAND",
+    );
+}
+
+#[test]
+fn patch_not_ready_then_recovers_fully() {
+    // NOT_READY (sense_key=0x02, asc=0x04) that clears after two attempts must
+    // recover the sector in-pass — no residual loss, no Unreadable, no hang.
+    let capacity_sectors: u32 = 256;
+    let (mut reader, _trace) = ScriptedSectorReader::new(capacity_sectors);
+    reader.sequence(
+        130,
+        vec![
+            ScriptStep::Err {
+                sense_key: 0x02,
+                asc: 0x04,
+                ascq: 0x00,
+            },
+            ScriptStep::Err {
+                sense_key: 0x02,
+                asc: 0x04,
+                ascq: 0x00,
+            },
+            ScriptStep::Ok,
+        ],
+    );
+
+    let total_bytes = capacity_sectors as u64 * SECTOR_SIZE as u64;
+    let disc = synthetic_disc(capacity_sectors);
+    let tmp = tempfile::NamedTempFile::new().unwrap();
+    let iso_path = tmp.path().to_path_buf();
+    drop(tmp);
+    let nontrimmed = [(128 * 2048, 64 * 2048)];
+    let finished = [
+        (0, 128 * 2048),
+        (192 * 2048, (capacity_sectors as u64 - 192) * 2048),
+    ];
+    prep_iso_and_mapfile(&iso_path, total_bytes, &finished, &nontrimmed);
+
+    let opts = libfreemkv::disc::PatchOptions {
+        decrypt: false,
+        block_sectors: Some(32),
+        full_recovery: true,
+        reverse: true,
+        wedged_threshold: 50,
+        progress: None,
+        halt: None,
+        key_fetch: None,
+    };
+    disc.patch(&mut reader, &iso_path, &opts)
+        .expect("patch must not error on a transient NOT_READY");
+
+    let map_path = libfreemkv::disc::mapfile_path_for(&iso_path);
+    let stats = Mapfile::load(&map_path).unwrap().stats();
+    assert_eq!(
+        stats.bytes_unreadable, 0,
+        "NOT_READY recovery must not mark Unreadable"
+    );
+    assert_eq!(
+        stats.bytes_pending, 0,
+        "a NOT_READY that clears must leave nothing pending"
+    );
+    assert_eq!(
+        stats.bytes_good,
+        capacity_sectors as u64 * 2048,
+        "every sector recovers once NOT_READY clears"
+    );
+    let _ = std::fs::remove_file(&iso_path);
+    let _ = std::fs::remove_file(&map_path);
+}
 
 // ──────── Handler chain recovers re-readable sectors inside a bad block ────────
 //
@@ -826,9 +984,10 @@ fn profile_08_batch_fail_singles_ok() {
 // handler chain's linear pass narrows a failed batch to per-sector reads, so it
 // recovers EVERY re-readable sector and leaves ONLY the dead sector NonTrimmed —
 // strictly better than the old fast-capture path, which left the whole failed
-// 32-block untouched. (`fast_capture` is now inert: the chain supersedes it. The
-// breadth-first "fast on all ranges, then escalate" ORDERING it once provided is
-// a scheduling concern for the handler scheduler, tracked separately.)
+// 32-block untouched. (The old `fast_capture` knob was removed: the handler
+// chain supersedes it. The breadth-first "fast on all ranges, then escalate"
+// ORDERING it once provided is a scheduling concern for the handler scheduler,
+// tracked separately.)
 //
 // The load-bearing invariant is unchanged: NO data is dropped. A still-bad
 // sector becomes NonTrimmed (pending, retried by a later pass), NEVER Unreadable.
@@ -869,10 +1028,9 @@ fn handler_chain_recovers_readable_sectors_leaving_only_dead_pending() {
         progress: None,
         halt: None,
         key_fetch: None,
-        fast_capture: true,
     };
     disc.patch(&mut reader, &iso_path, &opts)
-        .expect("fast-capture patch must not error");
+        .expect("handler-chain patch must not error");
 
     let map_path = libfreemkv::disc::mapfile_path_for(&iso_path);
     let stats = Mapfile::load(&map_path).unwrap().stats();

tests/streams.rs

@@ -591,7 +591,7 @@ fn meta_all_stream_types() {
 fn mkvstream_write_finish() {
     let dt = sample_disc_title();
     let writer: Box<dyn libfreemkv::mux::WriteSeek + Send> = Box::new(Cursor::new(Vec::new()));
-    let mut stream = MkvStream::create(writer, &dt).unwrap();
+    let mut stream = MkvStream::create(writer, &dt, None).unwrap();
 
     // Write some fake PES frames (they won't produce valid MKV content
     // since there is no real codec data, but it should not panic)
@@ -616,7 +616,7 @@ fn mkvstream_write_finish() {
 fn mkvstream_meta_sets_title() {
     let dt = sample_disc_title();
     let writer: Box<dyn libfreemkv::mux::WriteSeek + Send> = Box::new(Cursor::new(Vec::new()));
-    let stream = MkvStream::create(writer, &dt).unwrap();
+    let stream = MkvStream::create(writer, &dt, None).unwrap();
 
     let info = PesStream::info(&stream);
     assert_eq!(info.playlist, "Test Movie");
@@ -656,7 +656,7 @@ fn mkvstream_roundtrip_bdts() {
     };
 
     let writer: Box<dyn libfreemkv::mux::WriteSeek + Send> = Box::new(Cursor::new(Vec::new()));
-    let mut stream = MkvStream::create(writer, &dt).unwrap();
+    let mut stream = MkvStream::create(writer, &dt, None).unwrap();
 
     // Write PES frames targeting the audio track
     for i in 0..10u8 {
@@ -745,7 +745,7 @@ fn mkvstream_meta_preserves_all_streams() {
     };
 
     let writer: Box<dyn libfreemkv::mux::WriteSeek + Send> = Box::new(Cursor::new(Vec::new()));
-    let stream = MkvStream::create(writer, &dt).unwrap();
+    let stream = MkvStream::create(writer, &dt, None).unwrap();
 
     let info = PesStream::info(&stream);
     assert_eq!(info.streams.len(), 5, "all 5 streams should be preserved");
@@ -856,7 +856,7 @@ fn mkvstream_e2e_h264_produces_valid_mkv() {
 
     let writer: Box<dyn libfreemkv::mux::WriteSeek + Send> =
         Box::new(SharedWriter(output2.clone()));
-    let mut stream2 = MkvStream::create(writer, &dt).unwrap();
+    let mut stream2 = MkvStream::create(writer, &dt, None).unwrap();
 
     // Write the ES data (SPS+PPS+IDR) as a keyframe PES frame.
     let frame1 = libfreemkv::pes::PesFrame {