Taglib-ruby does not allow GIF images to be stored as cover art of M4A files, so if that happens, id3_tags simply does not store the cover art.
An improvement would be to do what iTunes does: implicitly convert the GIF into a PNG image, and store that into the ID3 metadata.
Taglib-ruby does not allow GIF images to be stored as cover art of M4A files, so if that happens, id3_tags simply does not store the cover art.
An improvement would be to do what iTunes does: implicitly convert the GIF into a PNG image, and store that into the ID3 metadata.