sacd_extract

Project repository: github.com/dev-zetta/sacd_extract2

sacd_extract is a command-line tool for inspecting readable SACD images and extracting their audio and metadata on Linux, macOS, and Windows. It can write stereo or multichannel tracks as DSF, DSDIFF, or playback-ready PCM FLAC, decode DST during extraction, export an Edit Master file, and generate CUE/XML metadata.

An adopted Tauri 2 desktop interface is included under gui/. Tagged releases provide Linux AppImage, Apple Silicon macOS DMG, and Windows installer packages containing the matching extractor executable.

This repository contains the host-native extractor. It does not authenticate or decrypt physical SACD media, so local input must already be available as a readable SACD ISO image. A compatible network source can also be supplied as host:port.

Features

• Stereo and multichannel extraction
• DSF, DSDIFF, 24-bit PCM FLAC, DSDIFF Edit Master, and raw ISO output
• DST-to-DSD conversion
• Per-track selection and consecutive-track concatenation
• CUE and XML metadata export
• Bounded recovery from damaged sectors and malformed DSD/DST frames
• Timestamped per-session extraction logs with severity and subsystem fields
• Configurable ID3v2.3 and ID3v2.4 tagging
• Optional output directories, performer naming, pause handling, and DSF padding control
• Cross-platform desktop GUI for the most common extraction settings

Desktop GUI

The GUI selects a local SACD ISO and destination directory, then drives this extractor with its current position-independent long options. It supports DSF, DSDIFF, or FLAC output, stereo, multichannel, or both areas, optional DST decoding, selectable FLAC sample rates, and CUE export.

Release GUI packages contain the exact host-platform extractor tested in the same Actions job. Linux is distributed as a single AppImage, Apple Silicon macOS as an ad-hoc-signed DMG, and Windows as a compact installer using the WebView2 runtime included with current Windows installations.

Set SACD_EXTRACT_PATH=/absolute/path/to/sacd_extract if the executable is not under build/linux, build/macos, build/windows, the legacy build directories, the GUI directory, or PATH. See the GUI documentation for packaging details and retained upstream provenance.

Build and test

Linux, macOS, and Windows use the same dependency-checking build entry point:

scripts/build.sh

See the building guide for platform dependencies, build options, and packaging. See the testing guide for CTest, GUI, sanitizer, optional SACD ISO integration, and CI details.

Usage

Print disc and track metadata without extracting audio:

sacd_extract "Album.iso" --info

Extract all stereo tracks as DSF:

sacd_extract --stereo --dsf "Album.iso"

Extract all multichannel tracks as DSF:

sacd_extract "Album.iso" --dsf --multichannel

Extract selected stereo tracks and convert DST to DSDIFF:

sacd_extract --tracks 1,5,13 "Album.iso" --stereo --dsdiff --convert-dst

Create 24-bit/88.2 kHz PCM FLAC files for playback:

sacd_extract "Album.iso" --stereo --flac --track-output-dir ./output

Use --flac-rate 176400 or --flac-rate 352800 for a higher PCM sample rate. FLAC compression is lossless, but conversion from the SACD's 1-bit DSD signal to PCM is irreversible. Keep the ISO, DSF, or DFF files if the goal is an archival DSD copy.

Options and the positional input may appear in any order, including when the POSIXLY_CORRECT environment variable is set. The explicit -i INPUT and --input INPUT forms remain supported.

Use -y DIR to choose the DSF/DSDIFF/FLAC output directory and -o DIR for raw ISO or DSDIFF Edit Master output.

Common options

Option	Purpose
-2, --stereo	Select the two-channel area (default)
-m, --multichannel	Select the multichannel area
-s, --dsf	Write individual DSF tracks
-p, --dsdiff	Write individual DSDIFF tracks
-f, --flac	Convert DSD64 to 24-bit PCM and write FLAC tracks
--flac-rate HZ	Select 88200 (default), 176400, or 352800 Hz
-e, --edit-master	Write a DSDIFF Edit Master
-I, --iso	Write a raw ISO
-c, --convert-dst	Convert DST-compressed audio to DSD
-t LIST, --tracks LIST	Extract selected tracks, such as 1,5,13
-k, --concatenate	Concatenate consecutive selected tracks
-C, --cue	Export CUE and XML metadata
-P, --info	Print disc information without extracting
-i INPUT, --input INPUT	Read an ISO, device, or compatible host:port source
--max-read-errors N	Allow at most N permanent media defects per output track; default 10, 0 is fail-fast
--log / --no-log	Explicitly enable or disable session logging
--log-file FILE	Write the session log to an explicit path
--log-level LEVEL	Select error, warning, notice, info, or debug

Run sacd_extract --help for the complete option list.

For individual DSF, DSDIFF, or FLAC extraction, each generated CUE FILE entry names the corresponding track file and uses file-relative indices. Edit Master output retains the traditional single-file, disc-relative CUE layout. The WAVE token is retained as the widely supported CUE audio-file convention; strict CDRWIN CUE syntax does not define native DSF, DSDIFF, or FLAC file types.

Configuration

An optional sacd_extract.cfg in the current working directory can set defaults. Command-line naming and pause options are overridden when their matching config entries are present.

artist=0
performer=0
pauses=0
nopad=0
concatenate=0
id3tag=4
# logging=0
max_read_errors=10
log_level=info
# log_file=/path/to/session.log

id3tag accepts 0 (disabled), 1 or 2 (ID3v2.3 UTF-16, full or minimal), 3 (ID3v2.3 ISO-8859-1), and 4 or 5 (ID3v2.4 UTF-8, full or minimal). Boolean settings accept 0/1 or no/yes. Omit logging to use automatic logging for extraction and export commands; set it explicitly to override that default. Command-line logging and error-limit options take precedence over their config counterparts.

Damage recovery and logs

Extraction and metadata-export commands automatically create one session log named sacd_extract-YYYYMMDD-HHMMSS.log in the album output directory. Logs contain local ISO-8601 timestamps, severity, subsystem, selected format/area, retry details, per-track results, and a final summary. Metadata-only (-P), help, and version commands log only when --log or --log-file is supplied.

If a batch read is short or fails, the extractor narrows the failure to individual 2048-byte sectors and retries each sector twice. Unreadable audio sectors reset the incomplete DSD/DST frame and extraction resumes at the next valid sector. Raw ISO output writes a zero-filled sector instead, preserving all subsequent LSN offsets. Malformed sectors, independently incomplete or nonconsecutive frames, and DST decode failures share the per-track error budget.

Outputs are first written as *.inprogress.ext and atomically published when the container has been finalized:

• Track.ext — clean output;
• Track.partial.ext — finalized output containing skipped media;
• Track.failed.ext — an output that could not be written or finalized.

For FLAC, a hole also resets the FIR history so samples are never filtered across missing media. No fabricated PCM is inserted; the finalized FLAC is shorter and is visibly marked .partial.flac.

The master TOC remains mandatory. Stereo and multichannel areas independently fall back to their backup TOC and are omitted if neither copy is usable.

Exit statuses are 0 for clean output, 1 for completed partial/abandoned tracks, 2 for invalid input or another fatal failure, and 130 when the user interrupts extraction.

Output integrity

Extracted files should be decoded or checksummed before the source image is discarded. DSF and DFF preserve the SACD DSD signal; PCM FLAC does not and must not be the only retained copy when DSD-level archival preservation is required. The investigation and fix for the former intermittent 1 MiB DSF corruption issue is documented in docs/dsf-output-corruption-investigation.md.

License

This project is distributed under the GNU General Public License version 2. See COPYING.

The adopted GUI is distributed under the MIT license; see gui/LICENSE and gui/UPSTREAM.md.

FLAC encoding uses the statically bundled libFLAC 1.5.0 reference library under the Xiph BSD license; see licenses/libFLAC-COPYING.Xiph. The streaming DSD decimator and FIR coefficient sets are adapted from GPL-2.0-or-later dsf2flac.

Authors

SACD Ripper was created and maintained by its respective upstream authors. Gabriel Max <dev@zetta.app> is a co-author of the host-native desktop extractor work (2026).