MusicBrainz tags: MUSICBRAINZ_ALBUMID or MusicBrainz Album Id
I noticed that some of my music collection doesn’t have the correct album art. While investigating, I discovered an unrelated problem with the MusicBrainz tags.
Because I’m old-school, I rip physical CDs to .FLAC files, tag the FLAC files with MusicBrainz
Picard, and then transcode those to .MP3 files using a
generally do this on my Linux box, and then use Syncthing to ensure that the FLAC files are
pushed to my Synology NAS, and the MP3 files are replicated as relevant.
Earlier today, on my Windows laptop, I noticed that some of my MP3 files were missing album artwork – and I’d forgotten
that they were MP3 files – so I opened the
Music folder in Picard and was puzzled that almost none of my music was
correctly grouped into albums.
Using the “Lookup” function on an arbitrary file in Picard correctly identified the music track, but there was a
discrepancy: The track had
MUSICBRAINZ_ALBUMID tags, and Picard was suggesting the addition of
MusicBrainz Album Id
Some quick searching on the internet later, and I found this: https://community.metabrainz.org/t/what-tag-names-are-correct/16998, which pointed me to https://picard-docs.musicbrainz.org/en/appendices/tag_mapping.html, which lays out the cause:
- For MP3 files (i.e. ID3v2 tags), Picard uses
TXXX: MusicBrainz Album Idtags.
- For FLAC files (i.e. Vorbis tags), Picard uses
My transcoding script – which is here – just
ffmpeg to transcode each FLAC file into an MP3 file. It would seem that ffmpeg just converts the Vorbis tags to
TXXX ID3v2 tags. Which makes sense – why would it know that MusicBrainz uses different names?
There doesn’t seem to be a way to fine-tune the behaviour of the
-map_metadata option to
ffmpeg (which is
apparently implied by default, since I don’t use it explicitly), so my options seem to be as follows:
- Accept the situation; my MP3 files won’t be properly grouped by album, etc., as far as MusicBrainz is concerned.
- Use something other than ffmpeg to transcode the files.
- Have the Rakefile make a second pass to fix up the MusicBrainz tags.
For now, I’ll just live with it.