title: MPMoviePlayer streaming video buffer size
body: <p>Is there a way to detect how much data has been buffered while streaming video in <code>MPMoviePlayerController</code>?</p>
  
  <p>I've already checked <code>loadState</code> but that does not give me enough info about buffering.</p>
  
  <p>Youtube's app has exactly what I want...</p>