Matthew Jackson c3e82f28b5 Enforce the no-rewind invariant instead of guessing at clip crossings
Round 7 enumerated the state space of SeamPlan::place and found three more
holes in the mark heuristics — the third consecutive round to find a defect
here, each time in the guard the previous round added:

- a clip file opening ON its own IN mark, after a tail frame past the previous
  clip OUT had already advanced the cursor, read as another crossing and jumped
  a clip too far: 28 minutes of clip 6 dropped;
- the last clip was unguarded entirely (`clip + 1 < len` skipped the check), so
  the 9->10 seam rewound 75.6s with dropped_total() at 0 — the exact round-5
  signature, reachable without any corrupt input;
- a glitch mid-clip satisfies "inside the current clip", so the round-6
  stranding survived for the rest of that clip.

Three patches to the same heuristic, three wrong in a new way. So stop patching
it. Everything above the placement is still heuristics over marks, but the
property they exist to serve is now checked DIRECTLY: a track output must not
run backwards. A placement that would rewind by more than
DISCONTINUITY_BACKSTEP_NS is refused; the scan then looks for a LATER clip
containing the frame that does not rewind, which is exactly what a genuine
overlap crossing looks like; and if none exists the frame is dropped and
counted, because emitting it anywhere moves the track backwards.

The tolerance is the backstep constant because B-frame reorder legitimately
emits out of order by a fraction of a second, while a rewind that matters is
orders of magnitude larger.

The cursor moves ONLY when a later clip actually accepts the frame. My first
version of this advanced on a failed search, which strands a track exactly as
before — caught immediately by the round-6 regression test.

All 29 previous timeline tests still pass, including
continuity_preserves_forward_gap. The three round-7 scenarios now have a test
each, with the real 00801.mpls numbers.
2026-08-06 12:31:23 -07:00
2026-08-05 16:44:23 -07:00
2026-04-16 17:51:45 +00:00

License: MIT

libfreemkv

Rust library for 4K UHD / Blu-ray / DVD optical drives. Drive access, disc scanning, stream labels, AACS decryption, CSS decryption, KEYDB updates, and content reading in one crate. Drive-level unlocking is handled internally; consumers work with disc access and decryption only.

DVDs (CSS) decrypt out of the box. Blu-ray and UHD (AACS) require a keydb.cfg (default ~/.config/freemkv/keydb.cfg) supplying disc-specific volume unique keys; no AACS key material is compiled in.

12+ MB/s sustained read speeds on BD. Drive prep (init()) handles unlocking internally via the freemkv-unlock crate — clients never see it; when no drive unlock applies, the library rips via the host-certificate AACS handshake.

Multi-lingual by design — the library outputs structured data and numeric error codes, never English text. Build any UI or localization on top.

Source & API · Technical Docs

Part of the freemkv project.

Install

Consumed by git tag (not published to crates.io):

[dependencies]
libfreemkv = { git = "https://github.com/freemkv/libfreemkv", tag = "vX.Y.Z" }

Quick Start

use libfreemkv::{Drive, Disc, ScanOptions};
use std::path::Path;

// Open drive — identified via INQUIRY
let mut drive = Drive::open(Path::new("/dev/sg4"))?;
drive.wait_ready()?;              // wait for disc
drive.init()?;                     // unlock + prep (handled internally)
drive.probe_disc()?;               // probe disc surface for optimal speeds

// Scan disc — UDF, playlists, streams, AACS (all automatic)
let disc = Disc::scan(&mut drive, &ScanOptions::default())?;

for title in &disc.titles {
    println!("{}{} streams", title.duration_display(), title.streams.len());
}

// Stream pipeline — read PES frames from any source, write to any output
let opts = libfreemkv::InputOptions::default();
let mut input = libfreemkv::input("iso://Disc.iso", &opts)?;
let title = input.info().clone();
let mut output = libfreemkv::output("mkv://Movie.mkv", &title)?;
while let Ok(Some(frame)) = input.read() {
    output.write(&frame)?;
}
output.finish()?;

Multi-pass recovery rip

Recovery moved OUT of this crate in 1.6.0. The sweep/patch strategy, the ddrescue mapfile, damage classification and the multipass loop now live in the freemkv-engine crate as freemkv_engine::recovery::{copy, sweep, patch}.

libfreemkv keeps the layers underneath: the raw single-shot read (Drive::read) and the SCSI-fact translation (SenseFamily) that the engine's strategy is built on. The dependency runs engine → libfreemkv, so this crate cannot call into it; front-ends get recovery from the engine directly. See docs/rip-recovery.md for what stayed here.

What It Does

  • Drive access — open, identify, internal unlock + prep, speed control, eject
  • 12+ MB/s reads — auto-detects kernel transfer limits, sustained full speed
  • Disc scanning — UDF 2.50 filesystem, MPLS playlists, CLPI clip info
  • Stream labels — 5 BD-J format parsers (Paramount, Criterion, Pixelogic, CTRM, Deluxe)
  • AACS decryption — transparent key resolution and content decrypt (1.0 + 2.0 bus decryption)
  • KEYDB updates — download, verify, save from any HTTP URL (zero deps, raw TCP)
  • Content reading — adaptive batch reads with automatic decryption
  • Stream I/O — unified stream pipeline for reading and writing any format

Streams

Stream Input Output Transport
DiscStream Yes -- Optical drive via SCSI
IsoStream Yes -- Blu-ray ISO image file (read via stream pipeline; written by freemkv_engine::recovery)
MkvStream Yes Yes Matroska container
M2tsStream Yes Yes BD transport stream with FMKV metadata header
NetworkStream Yes (listen) Yes (connect) TCP with FMKV metadata header
StdioStream Yes (stdin) Yes (stdout) Raw byte pipe
NullStream -- Yes Discard sink (byte counter for benchmarks)

Streams implement a single unified pes::Stream trait (re-exported as PesStream) exposing read() and write() on one type. input() / output() resolve URL strings to PES stream instances. All URLs use the scheme://path format — bare paths are rejected.

Keys

DVDs (CSS) decrypt out of the box, with no external key file needed.

Blu-rays and UHD (AACS) require a keydb.cfg at ~/.config/freemkv/keydb.cfg (or passed via ScanOptions). No AACS key material is compiled into the binary.

Architecture

Drive                  — open, identify, init, single-shot read
  ├── ScsiTransport    — SG_IO (Linux), IOKit (macOS), SPTI (Windows)
  └── unlock_bridge    — private seam to the freemkv-unlock crate
                         (firmware / AACS cert / CSS bus-auth unlockers)

Disc                   — scan titles, streams, AACS/CSS state
  ├── UDF reader       — Blu-ray UDF 2.50 with metadata partitions
  ├── MPLS parser      — playlists → titles + clips + streams
  ├── CLPI parser      — clip info → EP map → sector extents
  ├── IFO parser       — DVD title sets, PGC chains, cell addresses
  ├── Labels           — 5 BD-J format parsers (detect + parse)
  ├── AACS             — key resolution + content decryption
  ├── CSS              — DVD CSS (bus auth → player-key disc crack → known-plaintext title-key attack)
  └── KEYDB            — download + verify + save

Streams                — unified PES pipeline
  ├── PesStream        — pes::Stream: one trait, read()/write() PES frames
  ├── DiscStream       — sectors → decrypt → TS demux → PES
  ├── IsoStream        — ISO file → decrypt → TS demux → PES
  ├── MkvStream        — MKV mux/demux
  ├── M2tsStream       — BD transport stream
  ├── NetworkStream    — TCP with FMKV metadata header
  ├── StdioStream      — stdin/stdout pipe
  └── NullStream       — discard sink

See docs/ for detailed technical documentation on each module.

Error Codes

All errors are structured with numeric codes. No user-facing English text — applications format their own messages.

Range Category
E1xxx Device errors (not found, permission)
E2xxx Profile errors (unsupported drive)
E3xxx Unlock errors (failed, signature)
E4xxx SCSI errors (command failed, timeout)
E5xxx I/O errors
E6xxx Disc format errors
E7xxx AACS errors
E8xxx KEYDB update errors
E9xxx Stream / mux errors (URL, PES, ISO, pipeline, demux)

Platform Support

Platform Status Backend
Linux Supported SG_IO ioctl
macOS Supported IOKit SCSITask
Windows Supported SPTI

Contributing

Run freemkv info disc:// --share with the freemkv CLI to capture your drive's identity for contribution. Drive-unlock profiles are maintained in the freemkv-unlock repository.

License

MIT

S
Description
Internal mirror of libfreemkv 1.1-beta HEAD for private kdb builds (tag drops flate2; kdb needs HEAD symbols)
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