title: How to get the Y component from CMSampleBuffer resulted from the AVCaptureSession?
body: <p>Hey there, I am trying to access raw data from iphone camera using AVCaptureSession. I follow the guide provided by Apple (<a href="http://developer.apple.com/library/ios/#qa/qa2010/qa1702.html" rel="noreferrer">link here</a>).</p>
  
  <p>The raw data from the samplebuffer is in YUV format ( Am I correct here about the raw video frame format?? ), how to directly obtain the data for Y component out of the raw data stored in the samplebuffer. </p>