I have created a fix for this problem in a branch, by just using the general mutagen importer instead of the mp3-specific one: https://github.com/barbeque-squared/ponytone/tree/import-ogg
However, I literally cannot tests if this actually works in browsers, otherwise I'd have created a pull request instead.
$ docker exec ponytone_web_1 python importmlk.py https://www.mylittlekaraoke.com/store/beta/dotmlk/Community/4EverfreeBrony%20-%20A%20Final%20Twilight%20%28Cover%29.tar.mlk postgres://postgres:postgres@db:5432/postgres
Traceback (most recent call last):
File "importmlk.py", line 155, in <module>
info = song_info(tar, filename)
File "importmlk.py", line 82, in song_info
duration = mutagen.mp3.MP3(tar.extractfile(mp3_path)).info.length
File "/usr/local/lib/python3.6/site-packages/mutagen/_file.py", line 49, in __init__
self.load(*args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/mutagen/_util.py", line 129, in wrapper
return func(self, h, *args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/mutagen/id3/_file.py", line 406, in load
self.info = self._Info(fileobj, offset)
File "/usr/local/lib/python3.6/site-packages/mutagen/_util.py", line 158, in wrapper
return func(*args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/mutagen/mp3/__init__.py", line 396, in __init__
raise HeaderNotFoundError("can't sync to MPEG frame")
mutagen.mp3.HeaderNotFoundError: can't sync to MPEG frame