title: Create muted video and black screen video with FFmpeg
body: <p>I'm trying to use FFmpeg to generate the following from a local mp4 file:</p>
  
  <ul>
  <li>A copy of the original video with no audio</li>
  <li>A copy of the original video with audio but without visuals (a black screen instead). This file also needs to be in mp4 format. </li>
  </ul>
  
  <p>After reading through the documentation I am struggling to get the terminal commands right. To remove the audio I have tried this command without any success: </p>
  
  <pre><code>ffmpeg -i file.mp4 -map 0:0 -map 0:2 -acodec copy -vcodec copy
  </code></pre>
  
  <p>Could anyone guide me towards how to accomplish this?</p>