title: Merge video files with their original audio in iOS
body: <p>I need to merge two video files along with their corresponding audio.
  I tried using :
  <a href="http://www.raywenderlich.com/13418/how-to-play-record-edit-videos-in-ios" rel="nofollow">http://www.raywenderlich.com/13418/how-to-play-record-edit-videos-in-ios</a></p>
  
  <p>The videos gets merged, but their audio is missing. It's like a muted video. I need the audio also to be merged. I also googled on this, couldn't find anything useful. Can someone help me on this please... </p>