unflac

unflac

A command line tool for fast frame accurate audio image + cue sheet splitting.

This project is started mostly out of frustration over supporting split2flac with all the external dependencies and their quirks.

Manual installation

You need Go and ffmpeg installed.

go install git.sr.ht/~ft/unflac@latest
~/go/bin/unflac -h

Some useful options

• Set a specific sample format and rate for output files:

  unflac -F -sample_fmt -F s16 -F -ar -F 192000 ...

  See ffmpeg -sample_fmts. man ffmpeg contains a lot more.

Output file naming

To set a custom output file naming use -n option (run unflac -h to see the default value). The format of the argument is described here.

Elem - a function that replaces invalid file path characters with ones that look (almost) the same but valid

.Input.TrackNumberFmt - track number printf format (it's either "%02d" or "%03d" depending on the number of tracks)
.Input.Composer       - composer (can be empty)
.Input.Performer      - performer (can be empty)
.Input.SongWriter     - song writer (can be empty)
.Input.Title          - title, that's album name in general (can be empty)
.Input.Genre          - genre
.Input.Date           - date
.Input.TotalTracks    - total number of tracks
.Input.TotalDisks     - total number of disks, 0 if there is only one disk
.Input.Artist         - a special handy field that is selected based on Composer/Performer/SongWriter; is never empty

.Track.Number         - track number
.Track.DiskNumber     - disk number, 0 if there is only one disk
.Track.Composer       - composer (can be empty)
.Track.Performer      - performer (can be empty)
.Track.SongWriter     - song writer (can be empty)
.Track.Title          - track title
.Track.Artist         - a special handy field that is selected based on Composer/Performer/SongWriter; is never empty

TODO

• copying cue, log, images over to the destination
• clean up on errors
• replay gain
• support multiple artist/performer/composer?

DONE

• basic splitting
• tagging
• split to other formats (ogg/vorbis, mp3)
• parallel extraction
• support more input formats (wavpack, wave, mac)
• get the artist/performer/composer right
• multi-disk cue sheets support
• detect cue sheet encoding and convert to utf8
• an option to format the output path in a specific way

NOTES

• using id3 v2.3 tags because it seems basically no software reads id3 v2.4