title: ffmpeg av_register_all() not working?
body: <p>I'm attempting to use ffmpeg on iOS. When I call av_register_all() then attempt to open the file using avformat_open_input() I get the following error:</p>
  
  <pre><code>No URL Protocols are registered. Missing call to av_register_all()?
  </code></pre>
  
  <p>Has anyone seen this before? Any help would be much appreciated</p>