Android: Improve handling of RGB texture frames

webrtc/sdk/android/src/java/org/webrtc/TextureBufferImpl.java

 /*
  *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 49 matching lines @@
     return width;
   }
 
   @Override
   public int getHeight() {
     return height;
   }
 
   @Override
   public VideoFrame.I420Buffer toI420() {
+    if (type == Type.RGB) {
+      throw new RuntimeException("toI420 for RGB frames not implemented yet");
+    }
     // SurfaceTextureHelper requires a stride that is divisible by 8.  Round width up.
     // See SurfaceTextureHelper for details on the size and format.
     int stride = ((width + 7) / 8) * 8;
     int uvHeight = (height + 1) / 2;
     // Due to the layout used by SurfaceTextureHelper, vPos + stride * uvHeight would overrun the
     // buffer.  Add one row at the bottom to compensate for this.  There will never be data in the
     // extra row, but now other code does not have to deal with v stride * v height exceeding the
     // buffer's capacity.
     int size = stride * (height + uvHeight + 1);
     ByteBuffer buffer = ByteBuffer.allocateDirect(size);
@@ skipping 47 matching lines @@
 
     return new TextureBufferImpl(
         scaleWidth, scaleHeight, type, id, newMatrix, surfaceTextureHelper, new Runnable() {
           @Override
           public void run() {
             release();
           }
         });
   }
 }