MattJackson e22fc6fd47 io: phase 1 buffering — read-side flatness
Three changes targeting 0.20.9's "muxer never read-stalls on NFS read
latency" invariant:

A. FileSectorSource gets a 32 MiB internal read-ahead buffer
   (READAHEAD_BUF_BYTES). Splits out from src/sector/file.rs into
   src/io/file_sector_source/ with per-OS open hints (Linux
   posix_fadvise(SEQUENTIAL), macOS fcntl(F_RDADVISE) with 64 MiB
   cap, Windows TODO stub, BSD/illumos no-op). Backward seeks
   rebuffer; partial reads at EOF return only the bytes that exist;
   oversize-request bypass for count > BUF_SECTORS.

B. WritebackFile inline #[cfg(target_os = "linux")] blocks split
   into per-OS files under src/io/writeback_file/. Linux unchanged
   (fallocate KEEP_SIZE, fsync via bounded_syscall). macOS gets a
   real F_PREALLOCATE + F_FULLFSYNC impl (was a "skipped (non-linux)"
   debug log before). Windows is a stub (FlushFileBuffers via
   std sync_all; TODO for SetFileValidData). BSDs/illumos fall back
   to std sync_all.

C. New byte_channel module — byte-bounded producer/consumer wrapping
   std sync_channel with Mutex/Condvar byte accounting. Sender blocks
   when used_bytes + item.byte_size() > capacity. HasByteSize impl
   for PesFrame. Default cap BYTE_CHANNEL_DEFAULT_CAPACITY = 64 MiB,
   sized to absorb worst-case NFS read p99 (~2 s × UHD peak compressed
   ~15 MB/s). The mux call site lives in autorip (out of scope here);
   this lands the primitive in libfreemkv for autorip to adopt.

Test counts: byte_channel +6, file_sector_source +5, sector::file
round-trip suite (3) preserved. passn_handler_ab.rs A/B fixture
(8 profiles) still green.

precommit.sh libfreemkv: fmt + clippy + test all green on Rust 1.86.

No version bump; no Cargo.lock changes; no forbidden-file edits
(disc/patch.rs, disc/read_error.rs, io/pipeline.rs,
tests/passn_handler_ab.rs).
2026-05-13 19:48:23 -07:00
2026-05-13 19:15:48 -07:00
2026-05-13 19:18:51 -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 (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

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