title: How to stream images with correct number of pixels using camera app?
body: <p>When I stream Images using <a href="https://pub.dartlang.org/packages/camera" rel="nofollow noreferrer">camera app</a>  . 
  I con't convert YUV_420 to BGR. I hope lenU &amp; lenV in below code should be 230400, if not, can you suggest me best way to convert <a href="https://developer.android.com/reference/android/graphics/ImageFormat#YUV_420_888" rel="nofollow noreferrer">YUV_420</a> to BGR.</p>
  
  <pre><code>controller.startImageStream((CameraImage availableImage){
  var framesY = availableImage.planes[0].bytes;
  var framesU = availableImage.planes[1].bytes;
  var framesV = availableImage.planes[2].bytes;
  var lenU = framesU.length;
  var lenV = framesV.length;
  var lenY = framesY.length;
  print('$lenU'+' '+'$lenV'+' '+'$lenY');
  });
  </code></pre>
  
  <p>where, lenU = 460799 (I expect it should be 230400)</p>
  
  <p>lenV = 460799 (I expect it should be 230400)</p>
  
  <p>lenY = 921600</p>