[Remoting Host] Supporting WebRTC VP9 streaming

remoting/protocol/webrtc_dummy_video_encoder.h

 // Copyright 2016 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 REMOTING_PROTOCOL_WEBRTC_DUMMY_VIDEO_ENCODER_H_
 #define REMOTING_PROTOCOL_WEBRTC_DUMMY_VIDEO_ENCODER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 17 matching lines @@
 // in WebrtcDummyVideoEncoderFactory. Video frames are captured and encoded
 // outside of this dummy encoder (in WebrtcVideoEncoder called from
 // WebrtcVideoStream). They are passed to SendEncodedFrame() to be delivered to
 // the network layer.
 class WebrtcDummyVideoEncoder : public webrtc::VideoEncoder {
  public:
   enum State { kUninitialized = 0, kInitialized };
 
   WebrtcDummyVideoEncoder(
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
-      base::WeakPtr<VideoChannelStateObserver> video_channel_state_observer);
+      base::WeakPtr<VideoChannelStateObserver> video_channel_state_observer,
+      webrtc::VideoCodecType type);
   ~WebrtcDummyVideoEncoder() override;
 
   // webrtc::VideoEncoder overrides.
   int32_t InitEncode(const webrtc::VideoCodec* codec_settings,
                      int32_t number_of_cores,
                      size_t max_payload_size) override;
   int32_t RegisterEncodeCompleteCallback(
       webrtc::EncodedImageCallback* callback) override;
   int32_t Release() override;
   int32_t Encode(const webrtc::VideoFrame& frame,
                  const webrtc::CodecSpecificInfo* codec_specific_info,
                  const std::vector<webrtc::FrameType>* frame_types) override;
   int32_t SetChannelParameters(uint32_t packet_loss, int64_t rtt) override;
   int32_t SetRates(uint32_t bitrate, uint32_t framerate) override;
 
   webrtc::EncodedImageCallback::Result SendEncodedFrame(
       const WebrtcVideoEncoder::EncodedFrame& frame,
       base::TimeTicks capture_time);
 
  private:
   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 
   // Protects |encoded_callback_| and |state_|.
   base::Lock lock_;
   State state_;
   webrtc::EncodedImageCallback* encoded_callback_ = nullptr;
+  webrtc::VideoCodecType codec_type_;
 
   base::WeakPtr<VideoChannelStateObserver> video_channel_state_observer_;
 };
 
 // This is the external encoder factory implementation that is passed to
 // WebRTC at the time of creation of peer connection. The external encoder
 // factory primarily manages creation and destruction of encoder.
 class WebrtcDummyVideoEncoderFactory
     : public cricket::WebRtcVideoEncoderFactory {
  public:
   WebrtcDummyVideoEncoderFactory();
   ~WebrtcDummyVideoEncoderFactory() override;
 
   // cricket::WebRtcVideoEncoderFactory interface.
   webrtc::VideoEncoder* CreateVideoEncoder(
       webrtc::VideoCodecType type) override;
   const std::vector<cricket::WebRtcVideoEncoderFactory::VideoCodec>& codecs()
       const override;
   bool EncoderTypeHasInternalSource(webrtc::VideoCodecType type) const override;
   void DestroyVideoEncoder(webrtc::VideoEncoder* encoder) override;
 
   webrtc::EncodedImageCallback::Result SendEncodedFrame(
       const WebrtcVideoEncoder::EncodedFrame& packet,
       base::TimeTicks capture_time);
 
+  // Callback will be called once the dummy encoder has been created on
+  // |main_task_runner_|.
+  void SetEncoderCreatedCallback(

[Yuwei, 2017/03/29 01:08:33]

Alternatively we can make the factory own the VPX encoder and make the video
stream directly post the frame into something like Factory::EncodeFrame().

+      const base::Callback<void(webrtc::VideoCodecType)>& callback);
+
   void SetVideoChannelStateObserver(
       base::WeakPtr<VideoChannelStateObserver> video_channel_state_observer);
   base::WeakPtr<VideoChannelStateObserver>
   get_video_channel_state_observer_for_tests() {
     return video_channel_state_observer_;
   }
 
  private:
   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 
   std::vector<cricket::WebRtcVideoEncoderFactory::VideoCodec> codecs_;
 
   // Protects |video_channel_state_observer_| and |encoders_|.
   base::Lock lock_;
   base::WeakPtr<VideoChannelStateObserver> video_channel_state_observer_;
   std::vector<std::unique_ptr<WebrtcDummyVideoEncoder>> encoders_;
+  base::Callback<void(webrtc::VideoCodecType)> encoder_created_callback_;
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_WEBRTC_DUMMY_VIDEO_ENCODER_H_