title: ffmpeg how to to execute command from iOS?
body: <p>I was able to successfully compile &amp; import ffmpeg into my existing iOS app. However now I want to ru the following commands to clip and crop a video. How do I interact with the ffmpeg library from iOS?</p>
  
  <p>This command words for me via command line:</p>
  
  <pre><code>./ffmpeg -i input.mp4 -ss 157 -t 10 -vf crop=250:250:200:100 -strict -2 clipped.mp4
  </code></pre>