title: How to Merge video with audio?
body: <p><strong>How to Merge video.mp4 with audio.mp4 ?</strong></p>
  
  <p>I download Reddit videos using the Swift App</p>
  
  <p><a href="https://www.reddit.com/r/redditdev/comments/9a16fv/videos_downloading_without_sound/" rel="nofollow noreferrer">Videos downloading without sound</a></p>
  
  <p>I want code Merge video.mp4 with audio.mp4</p>
  
  <p>Or</p>
  
  <p>Convert audio.mp4 to audio.mp3</p>