title: GPUImageMovie not playing video file when initWithPlayerItem
body: <p>I am using GPUImageMovie with initWithPlayerItem and its not starting the movie file on startProcessing. It was working fine with initWithUrl but I need playback controls for the player as told in <a href="https://stackoverflow.com/questions/23799836/gpuimagemovie-pause-while-applying-filter">this</a> thread. I am using the following code</p>
  
  <pre><code>-(void)loadVideo
  {
      _playerItem = [[AVPlayerItem alloc]initWithURL:movieURL];
      _player = [AVPlayer playerWithPlayerItem:_playerItem];
      movieFile = [[GPUImageMovie alloc] initWithPlayerItem:_playerItem];
  
      movieFile.runBenchmark = YES;
      movieFile.playAtActualSpeed = YES;
  
      filter = [[TSFilter alloc] init];
      _movieView = [[GPUImageView alloc] initWithFrame:self.view.bounds];
  
      [self.view addSubview:_movieView];
      [self.view sendSubviewToBack:_movieView];
  
      [movieFile addTarget:filter];
      [filter addTarget:_movieView];
  
      _player.rate = 1.0;
  
      [movieFile startProcessing];
  
      [_player play];
  
  }
  </code></pre>