title: Simple example of using ffmpeg as a Python subprocess, and "checking in" on the conversion
body: <p>I'm looking to convert a large directory of movies from one format to another, and to check in on the status of the conversion. I'm programming in Python.</p>
  
  <p>Something like this:</p>
  
  <pre><code>&gt;&gt; m = MovieGenerator()
  &gt;&gt; m.convertMovie('/path/to/movie/movie1.avi')
  &gt;&gt; print m.status
  &gt;&gt; 35 frames completed
  </code></pre>
  
  <p>Is this possible (or recommended)? Does anyone have a working example of how to use ffmpeg as a subprocess?</p>
  
  <p>Once the conversion is happening, is there any way to "check in" on the status of the conversion (for example, how many frames have been completed?)</p>