media: Add support for playback of VP8 Alpha video streams

media/base/video_util.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_VIDEO_UTIL_H_
 #define MEDIA_BASE_VIDEO_UTIL_H_
 
 #include "base/basictypes.h"
 #include "media/base/media_export.h"
 #include "ui/gfx/size.h"
@@ skipping 10 matching lines @@
 // Copies a plane of YUV source into a VideoFrame object, taking into account
 // source and destinations dimensions.
 //
 // NOTE: rows is *not* the same as height!
 MEDIA_EXPORT void CopyYPlane(const uint8* source, int stride, int rows,
                              VideoFrame* frame);
 MEDIA_EXPORT void CopyUPlane(const uint8* source, int stride, int rows,
                              VideoFrame* frame);
 MEDIA_EXPORT void CopyVPlane(const uint8* source, int stride, int rows,
                              VideoFrame* frame);
+MEDIA_EXPORT void CopyAPlane(const uint8* source, int stride, int rows,
+                             VideoFrame* frame);
+
+// Sets A Plane values to be completely opaque (all 255's)
+MEDIA_EXPORT void ClearAPlane(int stride, int rows, VideoFrame* frame);

[Tom Finegan, 2013/02/25 22:56:06]

Hmm... 

s/ClearAPlane/x/ ?

Where x is:

OpaqueAPlane
MakeOpaqueAPlane

Per the description, "Clear" seems like the wrong name. I prefer the
MakeOpaqueAPlane (very readable re intent at the call site).

[vignesh, 2013/02/25 23:33:14]

I prefer MakeOpaqueAPlane as it seems consistent with the rest of the file
(starting with a verb, ending with APlane).

 
 // Fills |frame| containing YUV data to the given color values.
 MEDIA_EXPORT void FillYUV(VideoFrame* frame, uint8 y, uint8 u, uint8 v);
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_UTIL_H_