MP4 movie does play in QuickTime but not in iTunes

I have one MP4 movie that plays just fine in QuickTime (I've run it from beginning to end without problem).

However, when I imported it into iTunes, it can load but cannot play. Clicking on the play/pause button does not work. Nevertheless, I can advance the progress bar to any point in the movie, but the screen just shows a still image of that point.

This is really strange since as far as I know, iTunes plays movies with QT.

So, what is the possible cause of this problem and how to fix it? Thanks in advance.

My environmental specs: OS X 10.8.4, iTunes 11.0.4 (4), QuickTime Player 10.2 (603.17).

I suspect that the codec is the issue. You should probably try to re-encode the movie. There are a multitude of encoding apps out there such as Handbrake.

Had a similar problem recently and solved it by using Subler, which is way faster than other alternatives (not as many features though). Just make sure you have the correct settings in Subler and Perian.

I have Audio Output on Multi-Channel in both and AC-3 Audio to AAC is checked in Subler