gistfile1.cs

public virtual void DidOutputSampleBuffer (AVCaptureOutput captureOutput, CMSampleBuffer sampleBuffer, AVCaptureConnection connection)
		{
			CMFormatDescription formatDescription =  sampleBuffer.GetVideoFormatDescription ();

			if (connection == videoConnection) {
				// Get framerate
				CMTime timestamp = sampleBuffer.PresentationTimeStamp;
				CalculateFramerateAtTimestamp (timestamp);			
					
				// Get frame dimensions (for onscreen display)
				if (VideoDimensions.IsEmpty)
					VideoDimensions = formatDescription.GetVideoPresentationDimensions (true, false); 
					
				// Get the buffer type
				if (VideoType == 0)
					VideoType = formatDescription.MediaSubType;

				// Synchronously process the pixel buffer to de-green it.
				using (var pixelBuffer = sampleBuffer.GetImageBuffer ())
					ProcessPixelBuffer (pixelBuffer);