By default, Picard writes MP3 tags that don’t have great compatibility with a mixed format library (e.g., mix of MP3 files and FLAC files), or play nicely with foobar2000. This script moves Picard fields so that they look the same as FLAC files in foobar2000.
$if($eq($upper(%_extension%),MP3),
$noop(Move UFID:http://musicbrainz.org to TXXX)
$set(MUSICBRAINZ_TRACKID,%musicbrainz_recordingid%)
$unset(musicbrainz_recordingid)
$noop(foobar2000 can't read INVOLVED PEOPLE / TIPL v2.4 / IPLS v2.3)
$set(ARRANGER,%arranger%)
$unset(arranger)
$set(DJMIXER,%djmixer%)
$unset(djmixer)
$setmulti(ENGINEER,%engineer%)
$unset(engineer)
$setmulti(MIXER,%mixer%)
$unset(mixer)
$set(PRODUCER,%producer%)
$unset(producer)
$set(MEDIA,%media%)
$unset(media)
$noop(Use TXXX rather than PUBLISHER)
$set(LABEL,%label%)
$unset(label)
$noop(Move single-value <MUSICBRAINZ ALBUM ID> to MUSICBRAINZ_ALBUMID)
$set(MUSICBRAINZ_ALBUMID,%musicbrainz_albumid%)
$unset(musicbrainz_albumid)
$noop(Move single-value <MUSICBRAINZ RELEASE GROUP ID> to MUSICBRAINZ_RELEASEGROUPID)
$set(MUSICBRAINZ_RELEASEGROUPID,%musicbrainz_releasegroupid%)
$unset(musicbrainz_releasegroupid)
$noop(Move <MUSICBRAINZ ALBUM ARTIST ID> to MUSICBRAINZ_ALBUMARTISTID)
$setmulti(MUSICBRAINZ_ALBUMARTISTID,%musicbrainz_albumartistid%)
$unset(musicbrainz_albumartistid)
$noop(Move <MUSICBRAINZ ARTIST ID> to MUSICBRAINZ_ARTISTID)
$setmulti(MUSICBRAINZ_ARTISTID,%musicbrainz_artistid%)
$unset(musicbrainz_artistid)
$noop(Move <MUSICBRAINZ WORK ID> to MUSICBRAINZ_WORKID)
$setmulti(MUSICBRAINZ_WORKID,%musicbrainz_workid%)
$unset(musicbrainz_workid)
$noop(Move <MUSICBRAINZ ALBUM TYPE> to RELEASETYPE)
$setmulti(RELEASETYPE,%releasetype%)
$unset(releasetype)
$noop(Move <MUSICBRAINZ ALBUM RELEASE COUNTRY> to RELEASECOUNTRY)
$set(RELEASECOUNTRY,%releasecountry%)
$unset(releasecountry)
$set(ORIGINALDATE,%originaldate%)
$unset(originaldate)
)