title: resize using ffmpeg in python syntax error
body: <p>I'm trying to resize a video using ffmpeg in python but am having an error with the syntax.  I would expect it to be as easy as this (which is my code)</p>
  
  <pre><code>import ffmpeg
  
  ffmpeg -i video.mov -vf "scale=250:150" newmovie.mp4
  </code></pre>
  
  <p>this gives an invalid syntax of this:</p>
  
  <pre><code>    ffmpeg -i video.mov -vf "scale=250:150" newmovie.mp4
                    ^
  SyntaxError: invalid syntax
  </code></pre>
  
  <p>I tried this:</p>
  
  <pre><code>ffmpeg -i video.mov -vf scale=250:150 newmovie.mp4
  </code></pre>
  
  <p>and also putting everything file in quotations.  No luck.</p>