sezanzeb
commented
1 year ago Alternative:
def load(self, atoms: Atoms, fileobj):
try:
self._load_from_path(atoms.path(b"moov", b"udta", b"meta", b"ilst"), fileobj)
except KeyError as key:
raise MP4MetadataError(key)
try:
# for reading m4a files written by gstreamer
self._load_from_path(atoms.path(b"moov", b"trak", b"udta", b"meta", b"ilst"), fileobj)
except KeyError:
pass
def _load_from_path(self, path: List[Atom], fileobj):
free = _find_padding(path)
self._padding = free.datalength if free is not None else 0
ilst = path[-1]
for atom in ilst.children:
ok, data = atom.read(fileobj)
if not ok:
raise MP4MetadataError("Not enough data")
try:
if atom.name in self.__atoms:
info = self.__atoms[atom.name]
info[0](self, atom, data)
else:
# unknown atom, try as text
self.__parse_text(atom, data, implicit=False)
except MP4MetadataError:
# parsing failed, save them so we can write them back
self._failed_atoms.setdefault(_name2key(atom.name), []).append(data)
This makes it possible to read m4a files written by gstreamer, which might store tags incorrectly: https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/issues/759#note_2041293
closes https://github.com/quodlibet/mutagen/issues/480
An alternative to recursion could be to specify multiple possible paths.
I don't know if there could be ilst atoms that mutagen shouldn't read in mp4/m4a containers, so I don't know if this is really ok.
Assuming that gstreamer is really doing something wrong there, I hope that they fix it instead eventually. Still, adding a change to mutagen would help reading old m4a files.