title: Why plays Objective-C AVFoundation Video Player a MP4 file format only in Simulator and not on real device?
body: <p>I need to build my own video player with AVFoundation and came way far. But the player only plays the .mp4-file in simulator. No video shows up if I run the app on a device. But if I use a .mov-file all is working fine.
  Also when I play the video file inside an MPMoviePLayer the file shows up and plays well.</p>
  
  <p>the .mp4-file uses</p>
  
  <p>AVC Coding, 2.048 x 1.536
  AAC, 48000 Hz, Stereo (L R)</p>
  
  <p>The audio track is empty.</p>
  
  <p>Does anybody know why? <a href="https://dl.dropbox.com/u/2896178/AVFoundationVideoPLayer.zip" rel="nofollow">Here is some sample code.</a></p>