title: The color of video is wrong when made from UIImage of the PNG files
body: <p>I am taking a UIImage from Png file and feed it to the videoWriter.</p>
  
  <p>avAdaptor appendPixelBuffer:pixelBuffer</p>
  
  <p>When the end result video comes out, it seems to lacking the one color, missing the yellow color or something.</p>
  
  <p>I take alook of the function that made the pixelbuffer out of the UIImage</p>
  
  <pre><code>CVPixelBufferCreateWithBytes(NULL,
                               myWidth,
                               myHeight,
                               kCVPixelFormatType_32BGRA, 
                               (void*)CFDataGetBytePtr(image), 
                               CGImageGetBytesPerRow(cgImage), 
                               NULL, 
                               0,
                               NULL, 
                               &amp;pixelBuffer);
  </code></pre>
  
  <p>I also try the kCVPixelFormatType_32AGRB and others, it didn't help.</p>
  
  <p>any thoughts?</p>