title: How to dump YUV from OMXCodec decoding output
body: <p>I'd like to dump <code>YUV</code> data from <code>OMXCodec</code> decoding output.
  It's <code>MediaBuffer</code> type. It's impossible to access data() pointer.</p>
  
  <p>If I try to access data, crash happens due to the check code below.</p>
  
  <pre><code>frameworks/av/media/libstagefright/MediaBuffer.cpp:119 CHECK(mGraphicBuffer == NULL) failed.
  </code></pre>
  
  <p>Please let me know the solution to extract <code>YUV</code> data from this <code>MediaBuffer</code>.</p>