title: Can use AVCaptureVideoDataOutput and AVCaptureMovieFileOutput at the same time?
body: <p>I want to record video and grab frames at the same time with my code. </p>
  
  <p>I am using <code>AVCaptureVideoDataOutput</code> for grab frames and <code>AVCaptureMovieFileOutput</code> for video recording. But can't work and get the error code -12780 while working at the same time but individual.</p>
  
  <p>I searched this problem but get no answer. Did anyone have the same experience or explain? 
  It's really bother me for a while time. </p>
  
  <p>thanks.</p>