User's design call after watching the avoidance work prevent a wedge
on the live rip (no wedge events across 6 read errors): "Pass N
and 1 should both be very very similar in recovery. almost identical
just smaller sectors imo in pass n. pause times the same imo as a
failed read is a failed read."
The error-handling code path was already centralized (one
handle_read_error fn, called by both Disc::sweep and Disc::patch).
The TUNING was split — Pass 1 used 5 s inter-error pauses + a
wedge-skip-and-continue policy; Pass N used 1 s pauses + immediate
AbortPass on HARDWARE_ERROR / ILLEGAL_REQUEST. That asymmetry made
Pass N vulnerable to the same wedge that Pass 1's avoidance fixed.
Changes:
1. FAIL_PAUSE_SECS = 5 — single constant, applied uniformly to both
passes. Dropped PASS_1_FAIL_PAUSE_SECS and POST_FAILURE_PAUSE_SECS
in favor of one value. CONSECUTIVE_FAIL_LONG_PAUSE_SECS kept as a
distinct (but currently equal) value for future tuning escalation.
2. HARDWARE_ERROR / ILLEGAL_REQUEST path is now symmetric:
- Pass 1: JumpAhead WEDGE_JUMP_SECTORS (1 GB) + WEDGE_PAUSE_SECS
cooldown, mark skipped region NonTrimmed.
- Pass N: JumpAhead WEDGE_PASS_N_SKIP_SECTORS (64 sectors / 128 KB)
+ WEDGE_PAUSE_SECS cooldown. Pass N's batch=1 means a 1 GB skip
would abandon the entire current NonTrimmed range; small skip
moves past the bricked LBA + buffer, outer patch loop picks up
the next sector.
- Both share WEDGE_ABORT_THRESHOLD — same 16-skip budget before
real AbortPass on a permanently stuck drive.
3. wedge_skip / wedge_abort tracing logs now include `pass=1|N`
so post-mortems can see which pass hit the wedge condition.
Cost analysis:
Pre-reframe worry was "5 s × 5500 NonTrimmed sectors per Pass N
pass × 7 passes = 53 hours." Reality: most NonTrimmed sectors
recover on first or second retry, so most reads are successful and
pay 0 pause. The few that DON'T recover hit the 10-skip budget and
get marked Unreadable — bounded at 10 × 5 s = 50 s per truly-bad
sector. Worst-case Pass N pause overhead on a typical damaged disc
is single-digit minutes, not hours. And it's strictly cheaper than
the alternative (wedge kills the entire multi-pass recovery).
Tests:
- `both_passes_pause_on_failed_read_for_wedge_avoidance` — locks the
unified pause-tuning policy (was pass_1_pauses_briefly).
- `pass_n_hardware_error_also_skips_not_aborts` — was
`pass_n_hardware_error_still_aborts`. New behavior verified:
JumpAhead with WEDGE_PASS_N_SKIP_SECTORS + WEDGE_PAUSE_SECS.
- `pass_n_hardware_error_aborts_after_threshold` — new. Confirms
Pass N respects the same WEDGE_ABORT_THRESHOLD as Pass 1.
- pass_1_does_not_pause_on_skip is gone (it was the old "Pass 1
pause=0" assertion, irrelevant after the avoidance work).
Empirical validation: avoidance was already proven on a live rip
tonight — 6 read errors on a damaged disc, sense_family=Medium
throughout, wedge_count=0, Pass 1 continued cleanly past 40%
where it previously died at 48%. This commit extends the same
discipline to Pass N's recovery loop.
Precommit (cargo +1.86 fmt + clippy + test) green.
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
(internal)/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