Support configuration changes in VTVideoDecodeAccelerator.

content/common/gpu/media/vt_video_decode_accelerator.h

 // Copyright 2014 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 CONTENT_COMMON_GPU_MEDIA_VT_VIDEO_DECODE_ACCELERATOR_H_
 #define CONTENT_COMMON_GPU_MEDIA_VT_VIDEO_DECODE_ACCELERATOR_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 74 matching lines @@
   // Methods for interacting with VideoToolbox. Run on |decoder_thread_|.
   bool ConfigureDecoder(
       const std::vector<const uint8_t*>& nalu_data_ptrs,
       const std::vector<size_t>& nalu_data_sizes);
   void DecodeTask(const media::BitstreamBuffer&);
   void FlushTask();
   void DropBitstream(int32_t bitstream_id);
 
   // Methods for interacting with |client_|. Run on |gpu_task_runner_|.
   void OutputTask(DecodedFrame frame);
-  void SizeChangedTask(gfx::Size coded_size);
   void NotifyError(Error error);
 
   // Send decoded frames up to and including |up_to_bitstream_id|, and return
   // the last sent |bitstream_id|.
   int32_t SendPictures(int32_t up_to_bitstream_id);
 
+  // Internal helper for SendPictures(): Drop frames with no image data up to
+  // a particular bitstream ID, so that if there is still a frame in the queue
+  // when this function returns, it is guaranteed to have image data, and thus
+  // it is time to set up the GPU context. Returns the last bitstream ID that
+  // was dropped, or |last_sent_bitstream_id| if no frames were dropped.
+  int32_t ProcessDroppedFrames(
+      int32_t last_sent_bitstream_id,
+      int32_t up_to_bitstream_id);
+
+  // Internal helper for SendPictures(): Check if the next frame has a size
+  // different from the current picture buffers, and request new ones if so.
+  void ProcessSizeChangeIfNeeded();
+
   // Since VideoToolbox has no reset feature (only flush), and the VDA API
   // allows Decode() and Flush() calls during a reset operation, it's possible
   // to have multiple pending actions at once. We handle the fully general case
   // of an arbitrary sequence of pending actions (in reality, there should
   // probably be at most one reset and one flush at a time).
   void QueueAction(Action action);
 
   // Process queued decoded frames, usually by sending them (unless there
   // is a pending ACTION_RESET or ACTION_DESTROY, in which case they are
   // dropped), completing queued actions along the way.
   void ProcessDecodedFrames();
 
   // Complete a particular action, by eg. calling NotifyFlushDone().
   // Warning: Deletes |this| if |action| is ACTION_DESTROY.
   void CompleteAction(Action action);
 
   // Complete all actions pending for a particular |bitstream_id|.
   // Warning: Do not call if there is a pending ACTION_DESTROY.
   void CompleteActions(int32_t bitstream_id);
 
   //
   // GPU thread state.
   //
   CGLContextObj cgl_context_;
   base::Callback<bool(void)> make_context_current_;
   media::VideoDecodeAccelerator::Client* client_;
-  bool has_error_;  // client_->NotifyError() called.
-  gfx::Size texture_size_;
+
+  // client_->NotifyError() called.
+  bool has_error_;
+
+  // Size of assigned picture buffers.
+  gfx::Size picture_size_;
+
+  // Queue of actions so that we can quickly discover what the next action will
+  // be; this is useful because we are dropping all frames when the next action
+  // is ACTION_RESET or ACTION_DESTROY.
   std::queue<PendingAction> pending_actions_;
+
+  // Queue of bitstreams that have not yet been decoded. This is mostly needed
+  // to be sure we free them all in Destroy().
   std::queue<int32_t> pending_bitstream_ids_;
 
-  // Texture IDs of pictures.
-  // TODO(sandersd): A single map of structs holding picture data.
+  // All picture buffers assigned to us. Used to check if reused picture buffers
+  // should be added back to the available list or released. (They are not
+  // released immediately because we need the reuse event to free the binding.)
+  std::set<int32_t> assigned_picture_ids_;
+
+  // Texture IDs of assigned pictures.
   std::map<int32_t, uint32_t> texture_ids_;
 
   // Pictures ready to be rendered to.
-  std::queue<int32_t> available_picture_ids_;
+  std::vector<int32_t> available_picture_ids_;
 
   // Decoded frames ready to render.
   std::queue<DecodedFrame> decoded_frames_;
 
   // Image buffers kept alive while they are bound to pictures.
   std::map<int32_t, base::ScopedCFTypeRef<CVImageBufferRef>> picture_bindings_;
 
   //
   // Decoder thread state.
   //
   VTDecompressionOutputCallbackRecord callback_;
   base::ScopedCFTypeRef<CMFormatDescriptionRef> format_;
   base::ScopedCFTypeRef<VTDecompressionSessionRef> session_;
   media::H264Parser parser_;
-  gfx::Size coded_size_;
+
+  std::vector<uint8_t> last_sps_;
+  std::vector<uint8_t> last_spsext_;
+  std::vector<uint8_t> last_pps_;
 
   //
   // Shared state (set up and torn down on GPU thread).
   //
   scoped_refptr<base::SingleThreadTaskRunner> gpu_task_runner_;
 
   // This WeakPtrFactory does not need to be last as its pointers are bound to
   // the same thread it is destructed on (the GPU thread).
   base::WeakPtrFactory<VTVideoDecodeAccelerator> weak_this_factory_;
 
   // Declared last to ensure that all decoder thread tasks complete before any
   // state is destructed.
   base::Thread decoder_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(VTVideoDecodeAccelerator);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_MEDIA_VT_VIDEO_DECODE_ACCELERATOR_H_