title: Fluent-ffmpeg "not a suitable output format"
body: <p>I'm using the fluent-ffmpeg module for Node.js to convert audio files. I have a .mp3 file that I'd like to convert to .wma</p>
  
  <p>Here's what that looks like:</p>
  
  <pre><code>var proc = new ffmpeg({
     source: 'file.mp3',
     nolog: false
  }).toFormat('wma')                                                
    .saveToFile('file.wma', function(stdout, stderr)
  {                                                 
      console.log(stderr);
  });
  </code></pre>
  
  <p>Unfortunately, I get the error:</p>
  
  <blockquote>
  <pre><code>Requested output format 'wma' is not a suitable output format
  </code></pre>
  </blockquote>
  
  <p>This is the entire error log:</p>
  
  <pre><code>ffmpeg version 0.8.9-4:0.8.9-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav developers
    built on Nov  9 2013 19:25:10 with gcc 4.6.3
  *** THIS PROGRAM IS DEPRECATED ***
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
  Input #0, mp3, from 'song_downloads/You Suffer.mp3':
    Metadata:
      title           : You Suffer
      artist          : Napalm Death
      album           : Scum
      genre           : Death Metal
      track           : 12
      date            : 1987
    Duration: 00:00:04.98, start: 0.000000, bitrate: 381 kb/s
      Stream #0.0: Audio: mp3, 44100 Hz, stereo, s16, 193 kb/s
  Requested output format 'wma' is not a suitable output format
  </code></pre>
  
  <p>I know this isn't an ffmpeg issue because</p>
  
  <pre><code>ffmpeg -i file.mp3 file.wma
  </code></pre>
  
  <p>Works fine. Any ideas?</p>