Hmm, interesting. If you rename the file to remove the ".mp4" extension,
and then run the "file" command, what does it report?
Technically, you may not even need to remove the .mp4 extension.
I wonder whether the file is:
- not actually an mp4, but just close enough to one to fool mplayer into
thinking it is (probably unlikely);
- or more likely, corrupted.
Can you re-download the video and check whether it is the same?
(Running diff on the old copy and the new will tell you if there are any
differences.)
If you have a URL for the original, I'm willing to download it myself
and see if I can get it to play.
--
Steve