refactoring decoder interface

1. install permanent buffer exchange  callback.
2. render provide buffer in read=>fillthisbuffer.
3. for ffmpeg path, the provided buffer is just dummy. it had no relation to decoded buffer. so as to keep the code almost same.

Review URL: http://codereview.chromium.org/2101022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@48328 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 44 insertions, 10 deletions

diff --git a/media/base/filters.h b/media/base/filters.h
index 980e700..c4da5d9 100644
--- a/media/base/filters.h
+++ b/media/base/filters.h
@@ -265,10 +265,24 @@ class VideoDecoder : public MediaFilter {
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat& media_format() = 0;
 
-  // Schedules a read.  Decoder takes ownership of the callback.
-  //
-  // TODO(scherkus): switch Read() callback to scoped_refptr<>.
-  virtual void Read(Callback1<VideoFrame*>::Type* read_callback) = 0;
+  // |set_fill_buffer_done_callback| install permanent callback from downstream
+  // filter (i.e. Renderer). The callback is used to deliver video frames at
+  // runtime to downstream filter
+  typedef Callback1<scoped_refptr<VideoFrame> >::Type FillBufferDoneCallback;
+  void set_fill_buffer_done_callback(FillBufferDoneCallback* callback) {
+    fill_buffer_done_callback_.reset(callback);
+  }
+  FillBufferDoneCallback* fill_buffer_done_callback() {
+    return fill_buffer_done_callback_.get();
+  }
+
+  // Render provides an output buffer for Decoder to write to. These buffers
+  // will be recycled to renderer by fill_buffer_done_callback_;
+  // We could also pass empty pointer here to let decoder provide buffers pool.
+  virtual void FillThisBuffer(scoped_refptr<VideoFrame> frame) = 0;
+
+ private:
+  scoped_ptr<FillBufferDoneCallback> fill_buffer_done_callback_;
 };
 
 
@@ -289,10 +303,24 @@ class AudioDecoder : public MediaFilter {
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat& media_format() = 0;
 
-  // Schedules a read.  Decoder takes ownership of the callback.
-  //
-  // TODO(scherkus): switch Read() callback to scoped_refptr<>.
-  virtual void Read(Callback1<Buffer*>::Type* read_callback) = 0;
+  // |set_fill_buffer_done_callback| install permanent callback from downstream
+  // filter (i.e. Renderer). The callback is used to deliver buffers at
+  // runtime to downstream filter.
+  typedef Callback1<scoped_refptr<Buffer> >::Type FillBufferDoneCallback;
+  void set_fill_buffer_done_callback(FillBufferDoneCallback* callback) {
+    fill_buffer_done_callback_.reset(callback);
+  }
+  FillBufferDoneCallback* fill_buffer_done_callback() {
+     return fill_buffer_done_callback_.get();
+   }
+
+  // Render provides an output buffer for Decoder to write to. These buffers
+  // will be recycled to renderer by fill_buffer_done_callback_;
+  // We could also pass empty pointer here to let decoder provide buffers pool.
+  virtual void FillThisBuffer(scoped_refptr<Buffer> buffer) = 0;
+
+ private:
+  scoped_ptr<FillBufferDoneCallback> fill_buffer_done_callback_;
 };
 
 
diff --git a/media/base/mock_filters.h b/media/base/mock_filters.h
index 7f49fcf..9aeaeec 100644
--- a/media/base/mock_filters.h
+++ b/media/base/mock_filters.h
@@ -18,6 +18,7 @@
 #include "base/callback.h"
 #include "media/base/factory.h"
 #include "media/base/filters.h"
+#include "media/base/video_frame.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace media {
@@ -170,7 +171,7 @@ class MockVideoDecoder : public VideoDecoder {
   MOCK_METHOD2(Initialize, void(DemuxerStream* stream,
                                 FilterCallback* callback));
   MOCK_METHOD0(media_format, const MediaFormat&());
-  MOCK_METHOD1(Read, void(Callback1<VideoFrame*>::Type* read_callback));
+  MOCK_METHOD1(FillThisBuffer, void(scoped_refptr<VideoFrame>));
 
  protected:
   virtual ~MockVideoDecoder() {}
@@ -193,7 +194,12 @@ class MockAudioDecoder : public AudioDecoder {
   MOCK_METHOD2(Initialize, void(DemuxerStream* stream,
                                 FilterCallback* callback));
   MOCK_METHOD0(media_format, const MediaFormat&());
-  MOCK_METHOD1(Read, void(Callback1<Buffer*>::Type* read_callback));
+  MOCK_METHOD1(FillThisBuffer, void(scoped_refptr<Buffer>));
+
+  // change to public to allow unittest for access;
+  FillBufferDoneCallback* fill_buffer_done_callback() {
+    return AudioDecoder::fill_buffer_done_callback();
+  }
 
  protected:
   virtual ~MockAudioDecoder() {}