Allow multiple concurrent Decode() requests in VideoDecoder interface.

media/filters/gpu_video_decoder.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_FILTERS_GPU_VIDEO_DECODER_H_
 #define MEDIA_FILTERS_GPU_VIDEO_DECODER_H_
 
 #include <list>
 #include <map>
 #include <set>
@@ skipping 32 matching lines @@
 
   // VideoDecoder implementation.
   virtual void Initialize(const VideoDecoderConfig& config,
                           const PipelineStatusCB& status_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,
                                      const gfx::Size& size,
                                      uint32 texture_target) OVERRIDE;
   virtual void DismissPictureBuffer(int32 id) OVERRIDE;
   virtual void PictureReady(const media::Picture& picture) OVERRIDE;
   virtual void NotifyEndOfBitstreamBuffer(int32 id) OVERRIDE;
   virtual void NotifyFlushDone() OVERRIDE;
   virtual void NotifyResetDone() OVERRIDE;
@@ skipping 21 matching lines @@
   // A SHMBuffer and the DecoderBuffer its data came from.
   struct BufferPair {
     BufferPair(SHMBuffer* s, const scoped_refptr<DecoderBuffer>& b);
     ~BufferPair();
     SHMBuffer* shm_buffer;
     scoped_refptr<DecoderBuffer> buffer;
   };
 
   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);
 
   // Static method is to allow it to run even after GVD is deleted.
   static void ReleaseMailbox(
       base::WeakPtr<GpuVideoDecoder> decoder,
       const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
       int64 picture_buffer_id,
       uint32 texture_id,
       scoped_ptr<gpu::MailboxHolder> mailbox_holder);
   // Indicate the picture buffer can be reused by the decoder.
   void ReusePictureBuffer(int64 picture_buffer_id);
@@ skipping 19 matching lines @@
   void DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent() const;
 
   bool needs_bitstream_conversion_;
 
   scoped_refptr<GpuVideoAcceleratorFactories> factories_;
 
   // Populated during Initialize() (on success) and unchanged until an error
   // occurs.
   scoped_ptr<VideoDecodeAccelerator> vda_;
 
-  // Callbacks that are !is_null() only during their respective operation being
-  // asynchronously executed.
-  DecodeCB pending_decode_cb_;
+  // Callbacks for the pending Decode requests (not more than
+  // GetMaxDecodeRequests()).
+  std::list<DecodeCB> pending_decode_callbacks_;
+
+  // Not null only during reset.
   base::Closure pending_reset_cb_;
 
   State state_;
 
   VideoDecoderConfig config_;
 
   // Shared-memory buffer pool.  Since allocating SHM segments requires a
   // round-trip to the browser process, we keep allocation out of the
   // steady-state of the decoder.
   std::vector<SHMBuffer*> available_shm_segments_;
@@ skipping 18 matching lines @@
     ~BufferData();
     int32 bitstream_buffer_id;
     base::TimeDelta timestamp;
     gfx::Rect visible_rect;
     gfx::Size natural_size;
   };
   std::list<BufferData> input_buffer_data_;
 
   // 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_;
 
   // Set during ProvidePictureBuffers(), used for checking and implementing
   // HasAvailableOutputFrames().
   int available_pictures_;
 
   // Bound to factories_->GetMessageLoop().
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<GpuVideoDecoder> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuVideoDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_GPU_VIDEO_DECODER_H_