What metadata can an m4a file hold and how do I get at it?
Metadata for .m4a apple lossless (ALAC) files
My new music library is all nicely ripped Apple Lossless files in .m4a containers. These contain metadata, but it’s not id3v2 and the universe of mp3 tools mostly don’t work. ffmpeg’s ffprobe sort of works but doesn’t show all tags.
What does work for displaying m4a metadta is mp4v2, installable via Homebrew. Docs here. It seems pretty stable but still gets some updates.
(imac) = mp4file --list test.m4a BRAND COMPAT SIZING FILE ---------------------------------------------------------------------- M4A M4A,isom,mp42 32-bit test.m4a (imac) = mp4info test.m4a mp4info version 1.9.1 test.m4a: Track Type Info 1 audio alac, 260.806 secs, 562 kbps, 44100 Hz Name: Pastourelle (E passo de dossai: Ah! viens pres de moi), folksong for voice & orchestra (Chants d'Auvergne, Series 2, No. 1) Artist: Dawn Upshaw Composer: Joseph Canteloube Release Date: 1994 Album: Canteloube: Songs of the Auvergne Track: 1 of 15 Disk: 1 of 1 Genre: Vocal Music BPM: 0 Part of Compilation: no Cover Art pieces: 1 Album Artist: Kent Nagano Media Type: Movie TV Episode: 0 TV Season: 0