title: How to convert m4v and wmv videos to mp4 format using ffmpeg?
body: <p>I am using ffmpeg to convert videos to mp4 in my PHPMotion project. I am not able to convert wmv and m4v video to mp4 format. I've pasted the command that I used to convert wmv and m4v:</p>
  
  <pre><code>ffmpeg -i 1.wmv -ab 128 -b 1200 test.mp4
  ffmpeg -i 1.m4v -ab 128 -b 1200 test.mp4
  </code></pre>
  
  <p>When I use this codes, i got an error message:</p>
  
  <pre><code>Output #0, mp4, to 'test.mp4':
      Stream #0.0: Video: mpeg4, yuv420p, 640x360, q=2-31, 1 kb/s, 90k tbn, 24 tbc
      Stream #0.1: Audio: 0x0000, 44100 Hz, stereo, s16, 0 kb/s
  Stream mapping:
    Stream #0.0 -&gt; #0.0
    Stream #0.1 -&gt; #0.1
  Unsupported codec for output stream #0.1
  </code></pre>
  
  <p>How can I solve this issue?</p>