Adds the observability we need to debug wedge incidents from logs
alone — without needing to enable verbose TRACE-level SCSI tracing.
Goal stated by user: "when error occurs we can debug and code
correctly."
Pre-fix the WARN log on each read error showed only sense codes
and consecutive_failures. Missing: timing context (was the failed
read fast or slow?), gap to previous events (cumulative vs.
immediate failure?), and family transitions (did the drive just
flip into wedge mode, or has it been there?).
New fields on ReadCtx (no caller signature change):
last_success_at: Option<Instant>
last_error_at: Option<Instant>
last_error_family: Option<SenseFamily>
total_errors: u64
total_reads_ok: u64
zones_entered: u64
jumps_taken: u64
in_damage_zone: bool
New SenseFamily enum (NotReady / Medium / Hardware / IllegalRequest
/ Other) with is_wedge_family predicate.
handle_read_error WARN log now carries:
consecutive_failures
consecutive_outer_failures
ms_since_last_error NEW gap between this and previous error
ms_since_last_success NEW gap to last good read
total_errors NEW aggregate this pass
total_reads_ok NEW
wedge_count
sense_family NEW typed category, easier to filter
sense_key / asc / ascq (existing)
NEW WARN log "wedge_transition" fires once when the sense family
changes from non-wedge to wedge (Medium to Hardware/IllegalRequest).
That's the moment the drive's firmware flipped into fast-fail
mode. Single timestamped event in the log so post-mortems can
pinpoint the transition without scanning thousands of TRACE lines.
Worked example: if the next wedge incident shows
read_error ms_since_last_success=18234 ms_since_last_error=null
read_error ms_since_last_success=28000 ms_since_last_error=10000
read_error ms_since_last_success=43000 ms_since_last_error=68
(drive returned <100ms = wedge symptom)
wedge_transition errors_in_zone=5 ms_since_last_success=43000
we can immediately tell cumulative damage, 5 errors over 43 s,
drive went into fast-fail mode at the 5th. If instead we see
read_error ms_since_last_success=200 ms_since_last_error=null sense_family=Hardware
wedge_transition errors_in_zone=1
the wedge was triggered by ONE read at a physically-bricked LBA
(immediate fast-fail, no warm-up).
These two patterns demand different tuning responses (longer
pause vs. larger initial jump), and now we can distinguish them
from a single WARN log line each instead of needing TRACE
verbose for the whole rip.
Plus jumps_taken / zones_entered counters that feed an end-of-pass
INFO summary (PassSummary). Caller invokes pass_summary at sweep
end and logs structured stats: "Pass 1 saw N errors / M ok reads
/ K zones / J jumps". Single-line post-mortem for any rip.
No caller signature change (timing is internal to the handler;
end-of-pass summary is a new method callers opt into). Precommit
green; 433+ tests pass. Staged for the 0.18.10 release once we
have user-validation data on 0.18.9's avoidance tuning.
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