MattJackson ae2909fe8d v0.17.10: bounded-cache writeback pipeline for big sequential writes
Pass 1 sweep speed on a healthy disc previously dipped from ~15 MB/s
to ~1 MB/s every ~30 s on a host with default Linux dirty-page
settings. Empirical cause: the kernel's vm.dirty_ratio (~20% of RAM)
lets hundreds of MB of dirty pages accumulate, then bursts a flush at
99% disk utilisation that blocks app writes for ~1 s. Confirmed on
the BU40N test bed — dirty pages grew 112 → 563 MB between bursts;
lowering vm.dirty_bytes to 64 MB at the host sysctl level eliminated
the dips. Shipping the equivalent inside libfreemkv so users do not
need to tune the host kernel.

- New crate::io::Writer: drop-in File wrapper (impl Write + Seek).
  Wraps a per-platform WritebackPipeline that on Linux schedules
  sync_file_range(WRITE) + lagging sync_file_range(WAIT_AFTER) +
  posix_fadvise(DONTNEED) in 32 MB chunks, bounding dirty cache at
  ~64 MB. macOS and Windows ship a no-op stub.
- Disc::sweep wraps its output File in Writer. Loop body unchanged.
- Module is purpose-built so any large sequential output (patch,
  mux) can adopt the same wrapper as a one-line change later.
2026-05-08 19:54:25 -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 = "0.17"

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 offers a two-stage rip model: fast sweep with zero-fill and a ddrescue-format mapfile, then targeted retry of bad ranges. See docs/rip-recovery.md for the full architecture.

use libfreemkv::disc::{CopyOptions, PatchOptions};

// Pass 1: disc → ISO. Fast 64 KB reads, skip-forward on failure,
// zero-fill bad blocks, write a sidecar .mapfile.
let mut result = disc.copy(
    &mut drive,
    Path::new("disc.iso"),
    &CopyOptions { skip_on_error: true, skip_forward: true, ..Default::default() },
)?;

// Pass 2..N: retry bad ranges with full drive recovery.
// Idempotent — call as many times as you want.
while result.bytes_unreadable + result.bytes_pending > 0 {
    let pr = disc.patch(&mut drive, Path::new("disc.iso"), &PatchOptions::default())?;
    if pr.bytes_recovered_this_pass == 0 { break; }
}

// Then 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::copy())
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 pes::Stream (frame-level). 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
  ├── pes::Stream      — 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

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