Use bayesian estimate of acked bitrate.

webrtc/modules/congestion_controller/delay_based_bwe.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_CONGESTION_CONTROLLER_DELAY_BASED_BWE_H_
 #define WEBRTC_MODULES_CONGESTION_CONTROLLER_DELAY_BASED_BWE_H_
 
-#include <list>
-#include <map>
 #include <memory>
+#include <utility>
 #include <vector>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/rate_statistics.h"
 #include "webrtc/base/thread_checker.h"
 #include "webrtc/modules/congestion_controller/probe_bitrate_estimator.h"
 #include "webrtc/modules/remote_bitrate_estimator/aimd_rate_control.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
 #include "webrtc/modules/remote_bitrate_estimator/inter_arrival.h"
@@ skipping 19 matching lines @@
   virtual ~DelayBasedBwe() {}
 
   Result IncomingPacketFeedbackVector(
       const std::vector<PacketInfo>& packet_feedback_vector);
   void OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms);
   bool LatestEstimate(std::vector<uint32_t>* ssrcs,
                       uint32_t* bitrate_bps) const;
   void SetMinBitrate(int min_bitrate_bps);
 
  private:
+  // Computes a bayesian estimate of the throughput given acks containing
+  // the arrival time and payload size. Samples which are far from the current
+  // estimate or are based on few packets are given a smaller weight, as they
+  // are considered to be more likely to have been caused by, e.g., delay spikes
+  // unrelated to congestion.
+  class BitrateEstimator {
+   public:
+    BitrateEstimator();
+    void Update(int64_t now_ms, int bytes);
+    rtc::Optional<uint32_t> bitrate_bps() const;
+
+   private:
+    float UpdateWindow(int64_t now_ms, int bytes, int rate_window_ms);
+    int sum_;
+    int64_t current_win_ms_;
+    int64_t prev_time_ms_;
+    float bitrate_estimate_;
+    float bitrate_estimate_var_;
+    RateStatistics old_estimator_;
+    const bool in_experiment_;
+  };
+
   Result IncomingPacketInfo(const PacketInfo& info);
   // Updates the current remote rate estimate and returns true if a valid
   // estimate exists.
   bool UpdateEstimate(int64_t packet_arrival_time_ms,
                       int64_t now_ms,
+                      rtc::Optional<uint32_t> acked_bitrate_bps,
                       uint32_t* target_bitrate_bps);
 
   rtc::ThreadChecker network_thread_;
   Clock* const clock_;
   std::unique_ptr<InterArrival> inter_arrival_;
   std::unique_ptr<OveruseEstimator> estimator_;
   OveruseDetector detector_;
-  RateStatistics receiver_incoming_bitrate_;
+  BitrateEstimator receiver_incoming_bitrate_;
   int64_t last_update_ms_;
   int64_t last_seen_packet_ms_;
   bool uma_recorded_;
   AimdRateControl rate_control_;
   ProbeBitrateEstimator probe_bitrate_estimator_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(DelayBasedBwe);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_DELAY_BASED_BWE_H_