Add media::VideoEncodeAccelerator with WebRTC integration

content/renderer/media/rtc_video_encoder.h

+// Copyright 2013 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_RENDERER_MEDIA_RTC_VIDEO_ENCODER_H_
+#define CONTENT_RENDERER_MEDIA_RTC_VIDEO_ENCODER_H_
+
+#include <vector>
+
+#include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "content/common/content_export.h"
+#include "media/base/video_decoder_config.h"
+#include "third_party/webrtc/modules/video_coding/codecs/interface/video_codec_interface.h"
+#include "ui/gfx/size.h"
+
+namespace base {
+
+class MessageLoopProxy;
+
+}  // namespace base
+
+namespace media {
+
+class GpuVideoAcceleratorFactories;
+
+}  // namespace media
+
+namespace content {
+
+// This class uses a media::VideoEncodeAccelerator to implement a
+// webrtc::VideoEncoder class for WebRTC.  Internally, VEA methods are
+// trampolined to a private RTCVideoEncoder::Impl instance.  The class runs on
+// the |impl_message_loop_proxy_|, which is queried from the |gpu_factories_|
+// and is presently the media thread.  VEA::Client callbacks are posted back to
+// the thread that the RTCVideoEncoder constructor is called on.
+class CONTENT_EXPORT RTCVideoEncoder
+    : NON_EXPORTED_BASE(public webrtc::VideoEncoder) {
+ public:
+  RTCVideoEncoder(
+      media::VideoCodecProfile profile,
+      const scoped_refptr<media::GpuVideoAcceleratorFactories>& gpu_factories);
+  virtual ~RTCVideoEncoder();
+
+  // webrtc::VideoEncoder implementation.  Tasks are posted to |impl_| using the
+  // appropriate VEA methods.
+  virtual int32_t InitEncode(const webrtc::VideoCodec* codec_settings,
+                             int32_t number_of_cores,
+                             uint32_t max_payload_size) OVERRIDE;
+  virtual int32_t Encode(
+      const webrtc::I420VideoFrame& input_image,
+      const webrtc::CodecSpecificInfo* codec_specific_info,
+      const std::vector<webrtc::VideoFrameType>* frame_types) OVERRIDE;
+  virtual int32_t RegisterEncodeCompleteCallback(
+      webrtc::EncodedImageCallback* callback) OVERRIDE;
+  virtual int32_t Release() OVERRIDE;
+  virtual int32_t SetChannelParameters(uint32_t packet_loss, int rtt) OVERRIDE;
+  virtual int32_t SetRates(uint32_t new_bit_rate, uint32_t frame_rate) OVERRIDE;
+
+ private:
+  class Impl;
+  friend class RTCVideoEncoder::Impl;
+
+  enum {
+    kInputBufferExtraCount = 1,  // The number of input buffers allocated, more
+                                 // than what is requested by
+                                 // VEA::RequireBitstreamBuffers().
+    kOutputBufferCount = 3,
+  };
+
+  // Handlers for VEA::Client methods, which translate back to the
+  // WebRTC::VideoEncoder methods.
+  void RequireBitstreamBuffers(int input_count,
+                               const gfx::Size& input_dimensions,
+                               size_t output_size);
+  void NotifyInputDone(int32 bitstream_buffer_id);
+  void BitstreamBufferReady(int32 bitstream_buffer_id,
+                            size_t size,
+                            bool key_frame);
+  void NotifyError(int32_t error);
+
+  base::ThreadChecker thread_checker_;
+
+  // The video codec profile we were created with.
+  media::VideoCodecProfile video_codec_profile_;
+
+  // Factory for creating VEAs, shared memory buffers, etc.
+  const scoped_refptr<media::GpuVideoAcceleratorFactories> gpu_factories_;
+
+  // Message loop that |impl_| runs on; queried from |gpu_factories_|.
+  const scoped_refptr<base::MessageLoopProxy> impl_message_loop_proxy_;
+
+  // Weak pointer and factory for posting back VEA::Client notifications to
+  // RTCVideoEncoder.
+  base::WeakPtrFactory<RTCVideoEncoder> weak_this_factory_;
+  base::WeakPtr<RTCVideoEncoder> weak_this_;
+
+  // webrtc::VideoEncoder encode complete callback.
+  webrtc::EncodedImageCallback* encoded_image_callback_;
+
+  // The RTCVideoEncoder::Impl that does all the work.
+  scoped_ptr<Impl> impl_;
+
+  // We cannot immediately return error conditions to the WebRTC user of this
+  // class, as there is no error callback in the webrtc::VideoEncoder interface.
+  // Instead, we cache an error status here and return it the next time an
+  // interface entry point is called.
+  int32_t impl_status_;
+
+  // Frame parameters.
+  gfx::Size input_frame_dimensions_;
+  gfx::Size output_frame_dimensions_;
+
+  // Required output buffer size.
+  size_t output_buffer_size_;
+
+  // Shared memory buffers for input/output with the VEA.
+  ScopedVector<base::SharedMemory> input_buffers_;
+  ScopedVector<base::SharedMemory> output_buffers_;
+
+  // Input buffers ready to be filled with input from Encode().
+  std::vector<int> input_buffers_free_;
+
+  DISALLOW_COPY_AND_ASSIGN(RTCVideoEncoder);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_RTC_VIDEO_ENCODER_H_