Matthew Jackson
a32373ff40
All 21 findings held up under verification; 15 fixed here, 6 deferred to files another agent held this round, 0 rejected. **A defect in my own round-2 probe fix.** CHUNK_SECTORS was 1024, and 1024 % 3 == 1 — verified — so every chunk after the first was misaligned against the 6144-byte AACS aligned unit and would be REJECTED by DecryptingSectorSource's alignment gate. On an encrypted disc the forced-subtitle probe I added last round would have read almost nothing past its first chunk. Now 1023 sectors (341 aligned units) with a const assertion that fails the build if it stops dividing, plus set_unit_base per extent so the source's gate is anchored where the extent actually starts. **The same probe skipped sectors on a short read**, advancing by the REQUESTED count rather than the bytes actually returned, so a partial read silently left a gap in the middle of the evidence. It now advances by n/SECTOR_BYTES and clamps n to the buffer. **Its cache key omitted the PGS PID set**, so a playlist declaring an extra subtitle PID got another playlist's verdict for a track that had never been probed. And the key was the whole extent list, so partial clip sharing missed entirely. Both fixed by keying (start_lba, sector_count, pid) — and per-extent keying was shown SOUND rather than assumed: ForcedTracker is two monotone booleans, so per-extent evidence composes by field-wise OR, order- and grouping-independently. Making that honest required per-extent demux state, so an extent's evidence comes only from its own bytes, and memoising only extents whose read reached a designed stop. **A reachable panic in the timeline.** mkvstream::parse_block accepts a TimestampScale up to i64::MAX, so a video frame can set high_ns = i64::MAX and the next passive frame panicked adding the backstep. In release it wrapped negative instead, firing the straggler clamp for essentially every passive frame — audio and subtitles rewritten onto the wrong point of the output timeline. All four sites saturate. **A public constructor divided by zero**: PrefetchedSectorSource::new_with_events with unit_align == 0. Now InvalidInput, matching its batch_sectors sibling. **Two Debug impls printed key material.** DiscInputs (volume_id, mkb, unit_key_ro, samples) and UnitKeyFile both derived Debug. Nothing logs them today — fixed as prevention, because the next tracing::debug! someone adds is the leak. A doc claim that DiscInputs "contains no secrets" was false and is corrected. **An env-var multiply could overflow** in file_sector_source; now bounded at 64 GiB like its writeback sibling, with the parse split out so the bound is testable without touching process env. **The mp4 demuxer allowed one sample per file byte** — ~64x RAM amplification. Now file_len/16, since only vide/soun tracks are indexed and the shortest legal AC-3 frame is 128 bytes. **Two pipeline concurrency defects**: a consumer apply() error was invisible to the producer, and abandon/finalise had a TOCTOU where a caller could report an unfinalised output. Both fixed with compare-exchange state rather than a bool. **Two per-frame copies removed**, both MEASURED rather than reasoned: the AU assembler now hands its allocation to the frame (same pointer, unchanged capacity, proven by asserting the pointer) and tsmux reuses one Annex-B buffer across frames. Both keep capacity deliberately — a naive split_off would have cost more than it saved. **A comment pointed at the wrong file** for a mirrored constant; the mirror is now compiler-enforced with a const assertion converting 90 kHz ticks to ns, so drift fails the build. Deferred to another agent's files, all confirmed: detect_rate's fractional-twin snap, the mp4 reserve's u32 truncation, round_up_grain's overflow, the quadratic base-key gap fill, and MkvStream's frame cap counting frames rather than bytes. Every fix verified red by reverting it. Also noted for later: DecodeSampleSet still derives Debug over multi-MB of on-disc ciphertext.
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.
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