Does gmb able to display standard multi-value tags ?
I think it is, but may be I make confusion beetween gmb-multi-genre and standard-multi-value-tag.
An user, here (fr), pretends it can't.

It should. Looking at the thread, it seems he's talking about a "style" tag, the "style" optional field in gmb is not read/written to tags (no standard that I know of). But maybe he's talking about the mood tag (TMOO) which is a standard id3v2.4 frame, which gmb use for the optional mood field. And a quick look shows that I forgot to declare the TMOO frame as a multi-value tag for id3v2.4. So it could be the problem.

Anyway, I'd be happy to look at a file and make sure it is read properly.

i'm using multi-genre id3 v2.4 (TCON) with gmusicbrowser with no problem, both foobar and gmb, and mpd read them fine.
and it's ok with vorbis comment, musepack (apeV2),

with m4a it's a little different :

foobar and mp3tag read multiple"©gen"  atom, but write multiple Atom [com.apple.iTunes;GENRE]  field (and convert multiple atom "©gen" to Atom [com.apple.iTunes;GENRE])

and gmusic browser only read/write multiple "©gen" field
i think it 's perhaps  the specs doesn' t allow multiple atom "©gen" ?
(source "Coverart is the only atom that permits more than 1 data child atom" from http://atomicparsley.sourceforge.net/mpeg-4files.html)
does gmb could do the same ?

at the moment the only two audio player on gnu/linux that support multiple genre tag for vorbis_comment, apev2, m4a, id3v2.4 are gmusicbrowser and MPD






Thanks, I didn't know about the atom [com.apple.iTunes;GENRE].
Yes it's possible that the official spec doesn't allow multiple atom "©gen" (though finding the official spec is rather hard, it's a mess of documents, some I think are not public, damn apple). I generally ignore this only one tag by that name requirement, because usually it won't hurt, the worst case is only one of the values is read rather than none or one value that is made of multiple values.

I'll see what I should do, the easy options are read/write both, or read both but write only one ("@gen" or "com.apple.iTunes;GENRE"). Writing only one value to "@gen" and multiple values to "com.apple.iTunes;GENRE" would be a bit harder.
Comments are welcome, especially on what other players do/support.

ok,


reading both could be fine

for writing, i don't know what is the best solution

I committed a change that makes gmb use both "@gen" and "com.apple.iTunes;GENRE" for reading and writing genres. Let me know if it causes problem for some software.