Adapt encoder behavior to target bitrate

remoting/protocol/webrtc_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_VIDEO_ENCODER_H_
-#define REMOTING_PROTOCOL_WEBRTC_VIDEO_ENCODER_H_
-
-#include <memory>
-#include <vector>
-
-#include "base/callback.h"
-#include "base/synchronization/lock.h"
-#include "remoting/proto/video.pb.h"
-#include "third_party/webrtc/media/engine/webrtcvideoencoderfactory.h"
-#include "third_party/webrtc/modules/video_coding/include/video_codec_interface.h"
-
-namespace remoting {
-
-// This is the interface between the WebRtc engine and the external encoder
-// provided by remoting. WebRtc provides feedback on network bandwidth, latency
-// & RTT and in turn remoting passes encoded frames as they get encoded
-// through the capture pipeline.
-class WebRtcVideoEncoder : public webrtc::VideoEncoder {
- public:
-  enum State { kUninitialized = 0, kInitialized };
-  explicit WebRtcVideoEncoder(webrtc::VideoCodecType codec);
-  ~WebRtcVideoEncoder() 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;
-
-  int SendEncodedFrame(int64_t capture_timestamp_ms,
-                       std::unique_ptr<VideoPacket> pkt);
-  void SetKeyFrameRequestCallback(const base::Closure& key_frame_request);
-
- private:
-  // Protects |encoded_callback_|, |key_frame_request_| and |state_|.
-  base::Lock lock_;
-  State state_;
-  webrtc::EncodedImageCallback* encoded_callback_;
-
-  base::Closure key_frame_request_;
-  webrtc::VideoCodecType video_codec_type_;
-  uint32_t target_bitrate_;
-};
-
-// 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 WebRtcVideoEncoderFactory : public cricket::WebRtcVideoEncoderFactory {
- public:
-  WebRtcVideoEncoderFactory();
-  ~WebRtcVideoEncoderFactory() override;
-
-  webrtc::VideoEncoder* CreateVideoEncoder(
-      webrtc::VideoCodecType type) override;
-  const std::vector<cricket::WebRtcVideoEncoderFactory::VideoCodec>& codecs()
-      const override;
-
-  // Returns true to directly provide encoded frames to webrtc
-  bool EncoderTypeHasInternalSource(webrtc::VideoCodecType type) const override;
-  void DestroyVideoEncoder(webrtc::VideoEncoder* encoder) override;
-
-  int SendEncodedFrame(int64_t capture_timestamp_ms,
-                       std::unique_ptr<VideoPacket> pkt);
-
-  void SetKeyFrameRequestCallback(const base::Closure& key_frame_request);
-
- private:
-  // Protects |key_frame_request_|.
-  base::Lock lock_;
-  base::Closure key_frame_request_;
-  std::vector<cricket::WebRtcVideoEncoderFactory::VideoCodec> codecs_;
-  std::vector<std::unique_ptr<WebRtcVideoEncoder>> encoders_;
-};
-
-}  // namespace remoting
-
-#endif  // REMOTING_PROTOCOL_WEBRTC_VIDEO_ENCODER_H_