title: ffmpeg how do I choose the correct Audio track?
body: <p>I'm converting a few .mkv files and need to choose the right Audio track, but dont know how. </p>
  
  <p>This is the command I use: </p>
  
  <pre><code>ffmpeg -i "movie.mkv" -vcodec h264 -acodec aac -strict -2 output.mp4
  </code></pre>
  
  <p>It is recommended by the webservice where I want to upload the video. </p>
  
  <p>Let's say the Audiotracks look like this:</p>
  
  <pre><code>mkvmerge -i "movie.mkv"
  
  Track ID 0: video (MPEG-4p10/AVC/h.264)
  Track ID 1: audio (AC-3)
  Track ID 2: audio (TrueHD)
  Track ID 3: subtitles (HDMV PGS)
  </code></pre>
  
  <p>How do I select "Track 1" or "Track 2" for Output?
  And which track will be selected, if I leave the Code like that? (and why?)</p>
  
  <p>Thanks for help! </p>