media: Add support for playback of VP8 Alpha video streams

media/filters/vpx_video_decoder.h

Index: media/filters/vpx_video_decoder.h
diff --git a/media/filters/vpx_video_decoder.h b/media/filters/vpx_video_decoder.h
index 77578fdc90f7e6c82de90090cadff43857e1a886..1a76ceba62b43b33e44e4ae18a7020ecf9264be2 100644
--- a/media/filters/vpx_video_decoder.h
+++ b/media/filters/vpx_video_decoder.h
@@ -9,6 +9,7 @@
 #include "base/memory/ref_counted.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/video_decoder.h"
+#include "media/base/video_frame.h"
 
 struct vpx_codec_ctx;
 struct vpx_image;
@@ -62,7 +63,8 @@ class MEDIA_EXPORT VpxVideoDecoder : public VideoDecoder {
   // Reset decoder and call |reset_cb_|.
   void DoReset();
 
-  void CopyVpxImageTo(const vpx_image* vpx_image,
+  void CopyVpxImageTo(const struct vpx_image* vpx_image,
+                      const struct vpx_image* vpx_image_alpha,
                       scoped_refptr<VideoFrame>* video_frame);
 
   scoped_refptr<base::MessageLoopProxy> message_loop_;
@@ -77,6 +79,8 @@ class MEDIA_EXPORT VpxVideoDecoder : public VideoDecoder {
   scoped_refptr<DemuxerStream> demuxer_stream_;
 
   vpx_codec_ctx* vpx_codec_;

[scherkus (not reviewing), 2013/02/22 23:18:01]

hmm.. it looks like both of these can use scoped_ptr<T>

[vignesh, 2013/02/25 21:51:42]

To do this, the libvpx includes should be moved from to this file from the .cc
file, thereby exposing the libvpx files in the global namespace (this is needed
because the exact type is required at compile time for template expansion). Will
this be fine?

+  vpx_codec_ctx* vpx_codec_alpha_;
+  VideoFrame::Format format_;
 
   DISALLOW_COPY_AND_ASSIGN(VpxVideoDecoder);
 };