title: How to convert MP4 files to MPEG with avconv?
body: <p>I have some video files in the MP4 format and I want to convert them to MPEG format files.</p>
  
  <p>I try to convert with:</p>
  
  <pre><code>avconv -i 1.mp4 -fmp4 -target mpeg /mpeg/1.mpeg
  </code></pre>
  
  <p>but I get the following error</p>
  
  <pre><code>1.mp4: Invalid data found when processing input
  </code></pre>
  
  <p>What am I missing in my command?</p>