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..b363d8b040fa7a21f8af6b1e86090e64f4be4183 100644
--- a/media/filters/vpx_video_decoder.h
+++ b/media/filters/vpx_video_decoder.h
@@ -9,6 +9,16 @@
 #include "base/memory/ref_counted.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/video_decoder.h"
+#include "media/base/video_frame.h"
+
+// Include libvpx header files.
+// VPX_CODEC_DISABLE_COMPAT excludes parts of the libvpx API that provide
+// backwards compatibility for legacy applications using the library.
+#define VPX_CODEC_DISABLE_COMPAT 1
+extern "C" {
+#include "third_party/libvpx/source/libvpx/vpx/vpx_decoder.h"
+#include "third_party/libvpx/source/libvpx/vpx/vp8dx.h"
+}
 
 struct vpx_codec_ctx;
 struct vpx_image;
@@ -19,6 +29,15 @@ class MessageLoopProxy;
 
 namespace media {
 
+struct VpxDeleter {
+  inline void operator()(vpx_codec_ctx* ptr) const {
+    if (ptr) {
+      vpx_codec_destroy(ptr);
+      delete ptr;
+    }
+  }
+};
+
 class MEDIA_EXPORT VpxVideoDecoder : public VideoDecoder {
  public:
   explicit VpxVideoDecoder(
@@ -47,7 +66,6 @@ class MEDIA_EXPORT VpxVideoDecoder : public VideoDecoder {
   // Returns true when initialization was successful.
   bool ConfigureDecoder();
 
-  void CloseDecoder();
   void ReadFromDemuxerStream();
 
   // Carries out the buffer processing operation scheduled by
@@ -62,7 +80,8 @@ 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,

[scherkus (not reviewing), 2013/04/04 00:36:17]

nit: do we need to have "struct" keyword here?

pretty sure C++ doesn't require it

[vignesh, 2013/04/04 18:17:52]

It doesn't compile without the "struct" keyword. Probably because they are
structures that come from a C include file inside of libvpx.

+                      const struct vpx_image* vpx_image_alpha,
                       scoped_refptr<VideoFrame>* video_frame);
 
   scoped_refptr<base::MessageLoopProxy> message_loop_;
@@ -76,7 +95,8 @@ class MEDIA_EXPORT VpxVideoDecoder : public VideoDecoder {
   // Pointer to the demuxer stream that will feed us compressed buffers.
   scoped_refptr<DemuxerStream> demuxer_stream_;
 
-  vpx_codec_ctx* vpx_codec_;
+  scoped_ptr<vpx_codec_ctx, VpxDeleter> vpx_codec_;
+  scoped_ptr<vpx_codec_ctx, VpxDeleter> vpx_codec_alpha_;
 
   DISALLOW_COPY_AND_ASSIGN(VpxVideoDecoder);
 };