title: record video with AVFoundation with custom dimensions?
body: <p>I am recording an MOV file using AVFoundation but im having trouble finding out how to change the dimensions of the video. I have <code>videoGravity</code> property of <code>captureVideoPreviewLayer</code> set to <code>AVLayerVideoGravityResizeAspectFill</code> and the <code>UIView</code> showing the preview layer has custom dimensions (not the same aspect ratio of the screen). </p>
  
  <p>Recording works fine but the dimensions of the recorded video are the same as the aspect ratio of the screen. How can i record with the aspect ratio of the UIView or the preview layer?</p>