Add callback in VideoDecoder and AudioDecoder to return decoded frames.

media/filters/gpu_video_decoder.h

Index: media/filters/gpu_video_decoder.h
diff --git a/media/filters/gpu_video_decoder.h b/media/filters/gpu_video_decoder.h
index 290dec85c332bd75c98b7cc50daff9e748b9eb3e..d21911a96eb3a252a40158c15b1dc49800ae1fc4 100644
--- a/media/filters/gpu_video_decoder.h
+++ b/media/filters/gpu_video_decoder.h
@@ -44,13 +44,15 @@ class MEDIA_EXPORT GpuVideoDecoder
   // VideoDecoder implementation.
   virtual void Initialize(const VideoDecoderConfig& config,
                           bool live_mode,
-                          const PipelineStatusCB& status_cb) OVERRIDE;
+                          const PipelineStatusCB& status_cb,
+                          const OutputCB& output_cb) OVERRIDE;
   virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
                       const DecodeCB& decode_cb) OVERRIDE;
   virtual void Reset(const base::Closure& closure) OVERRIDE;
   virtual void Stop() OVERRIDE;
   virtual bool NeedsBitstreamConversion() const OVERRIDE;
   virtual bool CanReadWithoutStalling() const OVERRIDE;
+  virtual int GetMaxDecodeRequests() const OVERRIDE;
 
   // VideoDecodeAccelerator::Client implementation.
   virtual void ProvidePictureBuffers(uint32 count,
@@ -83,25 +85,19 @@ class MEDIA_EXPORT GpuVideoDecoder
   };
 
   // A SHMBuffer and the DecoderBuffer its data came from.
-  struct BufferPair {
-    BufferPair(SHMBuffer* s, const scoped_refptr<DecoderBuffer>& b);
-    ~BufferPair();
+  struct PendingDecodeBuffer {

[xhwang, 2014/05/29 22:15:14]

Shall this be PendingDecode-r-Buffer?

[Sergey Ulanov, 2014/06/03 00:08:11]

Yes

+    PendingDecodeBuffer(SHMBuffer* s,
+                        const scoped_refptr<DecoderBuffer>& b,
+                        const DecodeCB& done_cb);
+    ~PendingDecodeBuffer();
     SHMBuffer* shm_buffer;
     scoped_refptr<DecoderBuffer> buffer;
+    DecodeCB done_cb;
   };
 
   typedef std::map<int32, PictureBuffer> PictureBufferMap;
 
-  // Return true if more decode work can be piled on to the VDA.
-  bool CanMoreDecodeWorkBeDone();
-
-  // Enqueue a frame for later delivery (or drop it on the floor if a
-  // vda->Reset() is in progress) and trigger out-of-line delivery of the oldest
-  // ready frame to the client if there is a pending read.  A NULL |frame|
-  // merely triggers delivery, and requires the ready_video_frames_ queue not be
-  // empty.
-  void EnqueueFrameAndTriggerFrameDelivery(
-      const scoped_refptr<VideoFrame>& frame);
+  void DeliverFrame( const scoped_refptr<VideoFrame>& frame);

[xhwang, 2014/05/29 22:15:14]

nit: drop extra space before "const"

[Sergey Ulanov, 2014/06/03 00:08:11]

Done.

 
   // Static method is to allow it to run even after GVD is deleted.
   static void ReleaseMailbox(
@@ -141,9 +137,11 @@ class MEDIA_EXPORT GpuVideoDecoder
   // occurs.
   scoped_ptr<VideoDecodeAccelerator> vda_;
 
-  // Callbacks that are !is_null() only during their respective operation being
-  // asynchronously executed.
-  DecodeCB pending_decode_cb_;
+  OutputCB output_cb_;
+
+  DecodeCB flush_cb_;

[xhwang, 2014/05/29 22:15:14]

Usually people associate "flush" with "Reset". So it's a bit confusing to have
"flush_cb_" and "pending_reset_cb_|. Can we just name it decode_cb_?

[Sergey Ulanov, 2014/06/03 00:08:11]

I think Flush and Reset are distinct operations. VideoDecodeAccelerator does
have Flush() and Reset(). There is no explicit Flush() for VideoDecoder, but as
I mentioned before it might be better to add it - we already have it implicitly
as Decode(EOS). Anyway I renamed this to |eos_decode_cb_| for now..

+
+  // Not null only during reset.
   base::Closure pending_reset_cb_;
 
   State state_;
@@ -157,7 +155,7 @@ class MEDIA_EXPORT GpuVideoDecoder
 
   scoped_refptr<MediaLog> media_log_;
 
-  std::map<int32, BufferPair> bitstream_buffers_in_decoder_;
+  std::map<int32, PendingDecodeBuffer> bitstream_buffers_in_decoder_;
   PictureBufferMap assigned_picture_buffers_;
   // PictureBuffers given to us by VDA via PictureReady, which we sent forward
   // as VideoFrames to be rendered via decode_cb_, and which will be returned
@@ -182,7 +180,6 @@ class MEDIA_EXPORT GpuVideoDecoder
 
   // picture_buffer_id and the frame wrapping the corresponding Picture, for
   // frames that have been decoded but haven't been requested by a Decode() yet.
-  std::list<scoped_refptr<VideoFrame> > ready_video_frames_;
   int32 next_picture_buffer_id_;
   int32 next_bitstream_buffer_id_;