title: Converting mkv to mp4 vs ogv vs webm
body: <p>I am trying to convert an mkv file to mp4, webm, and ogv using ffmpeg and I am getting really drastic performance results. </p>
  
  <p>The mkv -> mp4 conversion took all of 2 seconds while the webm and ogv conversions took about 5-10minutes. Is there a faster way to convert to these formats?</p>
  
  <p>Commands used:</p>
  
  <p>mkv -> mp4</p>
  
  <pre><code>ffmpeg -i ironman2trailer.mkv -vcodec copy -acodec copy -absf aac_adtstoasc output.mp4
  </code></pre>
  
  <p>mkv -> webm</p>
  
  <pre><code>ffmpeg -i -f webm -vcodec libvpx -acodec libvorbis output.webm
  </code></pre>