- scsi/linux.rs: full rewrite from async write/poll/read+1.5s timeout+ close-on-timeout to one synchronous ioctl(fd, SG_IO, &hdr). Kernel honors hdr.timeout and runs its own ABORT/RESET escalation. Errors check host_status and driver_status (both 0xFF-synthesised) plus status. Sense-key parser handles descriptor (0x72/0x73) + fixed (0x70/0x71) formats. Deleted fd_recovery, bg close+open thread, fd swap dance. -331/+155 lines. - scsi/macos.rs: try_recover() removed (userspace handle-recovery on task failure was the same anti-pattern stripped from Linux). bsd_name field deleted. Errors bubble up directly. - scsi/windows.rs: try_recover() removed, wide_path field deleted, INVALID_HANDLE guard removed. - scsi/mod.rs: parse_sense_key() helper extracted (used by all three platforms now — single canonical sense-key parse rather than three inlined copies). +10 unit tests covering descriptor format, fixed format, truncated buffers, unknown response codes. - drive/mod.rs: Drive::reset() deleted (escalating eject + STOP/START + reinit recovery — per audit, kernel handles its own escalation; userspace shouldn't). pub fn find_drives() -> Vec<Drive> deleted (opened N drives just to throw most away). find_drive() now uses discover_drives() directly. wait_ready() simplified — drops the reset path on sense_key=5, just keeps polling TUR for 60 iterations. - lib.rs: find_drives re-export removed. - benches/sgio_read.rs: switched to find_drive() (no longer iterates a drive list). Net: 9 files changed, 226 insertions(+), 473 deletions(-). 329 tests pass, clippy -D warnings clean. No consumer breakage (CLI, autorip, bdemu compile + test green). Architecture decision documented in (internal)/docs/audits/2026-04-26-scsi-architecture-research.md (primary-source survey of MakeMKV, sg_dd, ddrescue, and the kernel mid-layer's own scsi_eh.rst escalation ladder).
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 = "0.13"
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