title: Animations rendered on Videos using AVVideoCompositionCoreAnimationTool behaves differently in Devices
body: <p>I am trying to put some animated layers on top of  videos using the <code>AVVideoCompositionCoreAnimationTool</code>. The speeds of the animations rendered are not consistent across all devices, ie I am forced to use different duration/fps for the
  <code>CABasicAnimation</code> different devices like for iPhone 6 I have a duration of .5 while for iPod Touch 5G I am using .25 ,</p>
  
  <pre><code>composition.animationTool = [AVVideoCompositionCoreAnimationTool
  
                                 videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
  </code></pre>
  
  <p>Anyone faced this issue before?</p>