I have an irritating problem with mp3tag (tested with 2.39k but also occured some months ago with previous beta).
My library is in AAC format (*.m4a) and was tagged with foobar2000.
The problem comes from %composer% and %writer% confusion. I have both on my m4a files (plus artist field).
Each time I edit a file with mp3tag the %composer% tag is erased and its content is put into the %writer% field.
• composer=Bach, Johann Sebastian (1685-1750)
after any mp3tag operation:
• writer=Bach, Johann Sebastian (1685-1750);Goebel
I don't know if it's a bug or an intended feature (cf. here). But I can edit my m4a files with foobar2000 and iTunes (embedded coverart) without changing anything to both composer and writer fields. So I suppose that both can coexist without conflict with the MP4 tagging specification.
Any comment about this? Thanks.