Adapt encoder behavior to target bitrate

remoting/protocol/webrtc_frame_scheduler.h

Index: remoting/protocol/webrtc_frame_scheduler.h
diff --git a/remoting/protocol/webrtc_frame_scheduler.h b/remoting/protocol/webrtc_frame_scheduler.h
index 0e9f3fce026fa22da3a288f7c79164fa724a0f07..72568c260d9ae746723cf875ab4ddb3bc36ad69e 100644
--- a/remoting/protocol/webrtc_frame_scheduler.h
+++ b/remoting/protocol/webrtc_frame_scheduler.h
@@ -14,6 +14,7 @@
 #include "base/task/cancelable_task_tracker.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
+#include "media/capture/content/feedback_signal_accumulator.h"
 #include "remoting/codec/video_encoder.h"
 #include "remoting/protocol/video_stream.h"
 #include "remoting/protocol/webrtc_transport.h"
@@ -23,6 +24,16 @@
 namespace remoting {
 namespace protocol {
 
+namespace {
+
+// Max Quantizer value.
+const int kMaxQuantizer = 63;
+
+// Default target bitrate in kbps
+const int kDefaultTargetBitrateKbps = 1000;
+
+}  // namespace
+
 // Class responsible for scheduling frames for encode and hand-over to
 // WebRtc transport for sending across the network.
 class WebRtcFrameScheduler : public webrtc::DesktopCapturer::Callback {
@@ -55,19 +66,31 @@ class WebRtcFrameScheduler : public webrtc::DesktopCapturer::Callback {
   static std::unique_ptr<VideoPacket> EncodeFrame(
       VideoEncoder* encoder,
       std::unique_ptr<webrtc::DesktopFrame> frame,
+      uint32_t target_bitrate,
+      int64_t frame_duration_us,
       bool key_frame_request);
   void OnFrameEncoded(std::unique_ptr<VideoPacket> packet);
 
   void SetKeyFrameRequest();
   bool ClearAndGetKeyFrameRequest();
+  void SetTargetBitrate(uint32_t bitrate);
 
-  // Protects |key_frame_request_|.
+  // Protects |key_frame_request_| and |target_bitrate_kbps_|.
   base::Lock lock_;
   bool key_frame_request_ = false;
+  uint32_t target_bitrate_kbps_ = kDefaultTargetBitrateKbps;
+  int last_quantizer_ = kMaxQuantizer;
 
   bool capture_pending_ = false;
   bool encode_pending_ = false;
 
+  // Accumulated frame duration.
+  media::FeedbackSignalAccumulator<base::TimeTicks> acc_frame_duration_;
+  // Last time capture was completed.
+  base::TimeTicks last_capture_completed_ticks_;
+  // Last time capture was started.
+  base::TimeTicks last_capture_started_ticks_;
+
   webrtc::DesktopSize frame_size_;
   webrtc::DesktopVector frame_dpi_;
   VideoStream::SizeCallback size_callback_;
@@ -88,7 +111,6 @@ class WebRtcFrameScheduler : public webrtc::DesktopCapturer::Callback {
   std::unique_ptr<VideoEncoder> encoder_;
 
   base::ThreadChecker thread_checker_;
-  base::TimeTicks last_capture_ticks_;
 
   base::WeakPtrFactory<WebRtcFrameScheduler> weak_factory_;