I was unable to tag an MP4 file that I just downloaded to test. The
first MP4 I found was Lindsey Lohan, so I had to remove it ASAP! :)
** Changed in: amarok (Ubuntu)
Importance: Undecided => Medium
Status: Needs Info => Confirmed
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Amarok Can't Tag AAC/MP4 Files
https://launchpad.net/bugs/83671