title: MusicBrainz Picard error tagging video files
body: <p><a href="https://picard.musicbrainz.org" rel="nofollow noreferrer">MusicBrainz Picard</a> is an <strong>excellent</strong> music tagging tool, able to fingerprint audio, even in video files… in theory! It's just not being able to write the tags onto the video files, spewing this error instead (line numbers may vary): </p>
  
  <pre><code>E: 11:16:58 Traceback (most recent call last):
    File "picard/util/thread.pyo", line 46, in run
    File "picard/file.pyo", line 210, in _save_and_rename
    File "picard/formats/mp4.pyo", line 179, in _save
    TypeError: 'NoneType' object does not support item assignment
  </code></pre>
  
  <p>This has been ticketed on <a href="https://tickets.metabrainz.org/browse/PICARD-987" rel="nofollow noreferrer">MusicBrainz's issue tracking system</a> over a year ago, so I thought I'd see if anyone here might have a clue…</p>