Length (duration) calculation for MP4 files

[ohrenkino]

perhaps this is something similar to mp3s with vbr:

[X] VBR Files have a wrong playlength

That's not what I was trying to point out. What I wanted to say is that the playtime issue is not really a bug since other programs (like fb2k) report the same length. More accurate length reports can be delivered when the whole file was scanned (or at least more than one frame). The problem now is that parsing additional frames will take more time. While this might not be noticable when reading two or three files, it is when reading folders with thousands of MP3s.