Make the BWE threshold adaptive.

webrtc/modules/remote_bitrate_estimator/overuse_detector.h

 /*
  *  Copyright (c) 2012 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_REMOTE_BITRATE_ESTIMATOR_OVERUSE_DETECTOR_H_
 #define WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_OVERUSE_DETECTOR_H_
 
 #include <list>
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/interface/module_common_types.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/bwe_defines.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 enum RateControlRegion;
 
+bool AdaptiveThresholdExperimentIsEnabled();
+
 class OveruseDetector {
  public:
   explicit OveruseDetector(const OverUseDetectorOptions& options);
-  ~OveruseDetector();
+  virtual ~OveruseDetector();
 
   // Update the detection state based on the estimated inter-arrival time delta
   // offset. |timestamp_delta| is the delta between the last timestamp which the
   // estimated offset is based on and the last timestamp on which the last
   // offset was based on, representing the time between detector updates.
   // |num_of_deltas| is the number of deltas the offset estimate is based on.
   // Returns the state after the detection update.
   BandwidthUsage Detect(double offset,
                         double timestamp_delta,
                         int num_of_deltas,
                         int64_t now_ms);
 
   // Returns the current detector state.
   BandwidthUsage State() const;
 
-  // Sets the current rate-control region as decided by RemoteRateControl. This
-  // affects the sensitivity of the detector.
-  void SetRateControlRegion(webrtc::RateControlRegion region);
+  virtual void InitializeExperiment();

[pbos-webrtc, 2015/07/06 10:01:40]

Don't like this being virtual, pref. checking in_experiment_ in subclasses and
applying experiment magic, then everything should be ready-to-rock after
construction.

[stefan-webrtc, 2015/07/06 10:54:26]

Done.

[pbos-webrtc, 2015/07/06 11:13:26]

This is still virtual, does it even have to be externally visible or can it go
under private:? or protected:?

[stefan-webrtc, 2015/07/06 12:16:13]

Done.

+
+ protected:
+  double threshold_;
+  double k_up_;
+  double k_down_;
+  bool experiment_set_;
+  bool in_experiment_;
 
  private:
+  void UpdateThreshold(double modified_offset, int64_t now_ms);
+  bool AdaptiveThresholdExperimentIsEnabled();
+  bool ReadExperimentConstants(double* k_up, double* k_down) const;
+
   // Must be first member variable. Cannot be const because we need to be
   // copyable.
   webrtc::OverUseDetectorOptions options_;
-  double threshold_;
+  int64_t last_update_ms_;
   double prev_offset_;
   double time_over_using_;
   int overuse_counter_;
   BandwidthUsage hypothesis_;
 
   DISALLOW_COPY_AND_ASSIGN(OveruseDetector);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_OVERUSE_DETECTOR_H_