matthew d7f186283e disc: Pass 1 wedge-skip instead of abort-on-first-wedge
Pre-fix: when the drive returned HARDWARE_ERROR or ILLEGAL_REQUEST
during Pass 1 sweep, libfreemkv immediately returned ReadAction::
AbortPass. Autorip surfaced this as a fatal error and stopped the
rip at whatever progress percentage Pass 1 had reached — typically
40-50%. On a disc with one physical-damage cluster, the user would
see Pass 1 die at ~48% with the cryptic message 'E6000: <lba>
0x02/0x04/0x3e' and have no rip output to work with.

Root cause analysis: BU40N firmware transitions into a fast-fail
state when it hits cumulative read failures in a small LBA range —
returns HARDWARE_ERROR for every subsequent read near that LBA, even
sectors that aren't physically damaged. Per CLAUDE.md 'Bad-sector
handling' rule #2, 'Recovery requires eject+reload OR significant
cool-down.' Aborting on first wedge throws away the rest of the
disc; the right response is to SKIP the wedged region (mark as
NonTrimmed for Pass N), pause for drive cooldown, and continue.

Fix: in handle_read_error, the HARDWARE_ERROR / ILLEGAL_REQUEST arm
now branches on bisect_on_marginal:

  Pass 1 (bisect_on_marginal=false): JumpAhead with WEDGE_JUMP_SECTORS
    (1 GB at 2048 bytes/sector) and WEDGE_PAUSE_SECS (30 s cooldown).
    Tracks wedge_count in ReadCtx; resets on any successful read.
    Truly aborts only after WEDGE_ABORT_THRESHOLD (16) consecutive
    wedges with no good read in between — generous enough to clear
    most physical-damage clusters, bounded enough to not loop forever
    on a permanently bricked drive.

  Pass N (bisect_on_marginal=true): unchanged AbortPass. Pass N's
    job is single-sector recovery; if the drive won't talk near a
    specific LBA, skipping doesn't help. Pass N exits and lets the
    outer layer decide retry/eject/surface.

5 unit tests cover the new policy:
  pass_1_hardware_error_jumps_ahead_not_aborts — JumpAhead emitted
    with correct sectors+pause, wedge_count incremented.
  pass_1_hardware_error_aborts_after_threshold — AbortPass kicks in
    on the WEDGE_ABORT_THRESHOLD-th consecutive wedge.
  pass_1_good_read_resets_wedge_count — on_success clears
    wedge_count; subsequent wedge gets fresh skip budget.
  pass_n_hardware_error_still_aborts — Pass N's AbortPass behavior
    intact.
  pass_1_illegal_request_also_routes_to_wedge_skip — both wedge
    sense families get the skip treatment.

Impact: on the Dune Pt 2 disc that consistently wedged at 48%
(physical damage at LBA ~19.9M), Pass 1 will now jump ahead 1 GB
on the wedge, give the drive 30 s cooldown, and continue scanning
the rest of the disc. The damaged region becomes Pass N's job to
revisit. Worst case if the drive stays wedged: 16 GB of NonTrimmed
disc area before honest AbortPass.

Precommit (cargo +1.86 fmt + clippy + test) green; 430 passing.
2026-05-10 16:37:59 -07:00
2026-04-16 17:51:45 +00:00

Crates.io docs.rs License: AGPL-3.0

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. Bundled drive profiles — no external files needed.

12+ MB/s sustained read speeds on BD. Full init: unlock, firmware upload, speed calibration — all from pure Rust.

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

API Documentation · Technical Docs

Part of the freemkv project.

Install

[dependencies]
libfreemkv = "0.18"

Quick Start

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

// Open drive — profiles are bundled, auto-identified
let mut drive = Drive::open(Path::new("/dev/sg4"))?;
drive.wait_ready()?;              // wait for disc
drive.init()?;                     // unlock + firmware upload
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

For damaged discs the library exposes two flat verbs — Disc::sweep for the forward Pass 1 and Disc::patch for retrying bad ranges. The library never loops; the multipass policy is the caller's job. See docs/rip-recovery.md and the design notes in freemkv-private/memory/0_18_redesign.md.

use libfreemkv::{SweepOptions, PatchOptions};
use libfreemkv::disc::{mapfile, mapfile_path_for};
use std::path::Path;

let iso = Path::new("disc.iso");

// Pass 1: disc → ISO. Skip-on-error, zero-fill, write the sidecar mapfile.
disc.sweep(&mut drive, iso, &SweepOptions {
    decrypt: true,
    resume: false,
    batch_sectors: None,
    skip_on_error: true,
    progress: None,
    halt: None,
})?;

// Pass 2..N: retry every non-finished range. Idempotent.
loop {
    let map = mapfile::Mapfile::load(&mapfile_path_for(iso))?;
    let stats = map.stats();
    if stats.bytes_pending + stats.bytes_unreadable == 0 { break; }

    let outcome = disc.patch(&mut drive, iso, &PatchOptions {
        decrypt: true,
        block_sectors: None,
        full_recovery: true,
        reverse: true,
        wedged_threshold: 50,
        progress: None,
        halt: None,
    })?;
    if outcome.bytes_recovered_this_pass == 0 { break; }
}

// Mux from the ISO via the normal stream pipeline (no drive involvement).

What It Does

  • Drive access — open, identify, unlock, firmware upload, speed calibration, 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 via Disc::sweep())
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 FrameSource (read) and/or FrameSink (write); direction is type-checked. input() / output() resolve URL strings to PES stream instances. All URLs use the scheme://path format — bare paths are rejected.

AACS decryption requires a KEYDB.cfg file. If available at ~/.config/aacs/KEYDB.cfg or passed via ScanOptions, the library handles everything — handshake, key derivation, and per-sector decryption — without the application needing to know anything about encryption.

Architecture

Drive                  — open, identify, init, unlock, single-shot read
  ├── ScsiTransport    — SG_IO (Linux), IOKit (macOS), SPTI (Windows)
  ├── DriveProfile     — per-drive unlock parameters (bundled)
  └── PlatformDriver   — MediaTek (supported), Renesas (planned)

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 cipher (table-driven, no keys needed)
  └── KEYDB            — download + verify + save

Streams                — unified PES pipeline
  ├── FrameSource      — read() PES frames (direction-typed)
  ├── FrameSink        — write() PES frames (direction-typed)
  ├── 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

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 contribute your drive's profile.

License

AGPL-3.0-only

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