I just started working with some Ogg Vorbis files that were transcoded from Flace using oggenc2.exe. Modifying the tags these files with Mp3tag is several times slower than modifying comparable Flac and mp3 files that I've worked with. According to the oggence2 docs, when the files are transcoded to ogg the tags are being padded with 1k of space.
In a hex editor, before modifying the files with Mp3tag, I can easily see that the vorbis comments are near the beginning of the file and are followed by a very large block of 00 bytes.
All I'm doing is deleting or adding a few fields. Why is Mp3tag so slow in tagging these files?