title: AVMutableComposition - Blank/Black frame between videos assets
body: <p>I'm currently trying to put 5 videos back to back using AVMutableComposition like so:</p>
  
  <pre><code>[mixComposition insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset1.duration) ofAsset:asset1 atTime:[mixComposition duration] error:nil];
  [mixComposition insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset2.duration) ofAsset:asset2 atTime:[mixComposition duration] error:nil];
  [mixComposition insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset3.duration) ofAsset:asset3 atTime:[mixComposition duration] error:nil];
  [mixComposition insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset4.duration) ofAsset:asset4 atTime:[mixComposition duration] error:nil];
  [mixComposition insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset5.duration) ofAsset:asset5 atTime:[mixComposition duration] error:nil];
  </code></pre>
  
  <p>I then use an AVAssetExportSession to export the video, which works however between each video I'm getting a blank/black frame which I need to remove. Has anyone had this problem before and if so did you manage to fix it?</p>
  
  <p>Also, the blank frames aren't in the source video files.</p>
  
  <p>Thanks in advance.</p>