title: how to improve the performance of seek when using avplayer
body: <p>I'm using <code>AVPlayer</code> to create a video player, but the <code>seekToTime</code> method is pretty slow. I'm impressed by the seeking performance of Apple's app "Photos". Does anyone have any idea how Apple managed to do such a quick seeking?</p>
  
  <p>Does it has anything to do with threads? I tried to put the <code>seekToTime</code> call in a dispatch queue, it does't help either.</p>