Change TWCC send interval to reduce overhead on low BW situations.

webrtc/base/ratetracker.h

 /*
  *  Copyright 2015 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_BASE_RATETRACKER_H_
 #define WEBRTC_BASE_RATETRACKER_H_
 
 #include <stdlib.h>
 #include "webrtc/base/basictypes.h"
 
 namespace rtc {
 
 // Computes units per second over a given interval by tracking the units over
 // each bucket of a given size and calculating the instantaneous rate assuming
 // that over each bucket the rate was constant.
 class RateTracker {
  public:
   RateTracker(int64_t bucket_milliseconds, size_t bucket_count);
   virtual ~RateTracker();
 
   // Computes the average rate over the most recent interval_milliseconds,
   // or if the first sample was added within this period, computes the rate
   // since the first sample was added.
-  double ComputeRateForInterval(int64_t interval_milliseconds) const;
+  virtual double ComputeRateForInterval(int64_t interval_milliseconds) const;
 
   // Computes the average rate over the rate tracker's recording interval
   // of bucket_milliseconds * bucket_count.
-  double ComputeRate() const {
-    return ComputeRateForInterval(bucket_milliseconds_ *
-                                  static_cast<int64_t>(bucket_count_));
-  }
+  virtual double ComputeRate() const;
 
   // Computes the average rate since the first sample was added to the
   // rate tracker.
-  double ComputeTotalRate() const;
+  virtual double ComputeTotalRate() const;
 
   // The total number of samples added.
-  size_t TotalSampleCount() const;
+  virtual size_t TotalSampleCount() const;
 
   // Reads the current time in order to determine the appropriate bucket for
   // these samples, and increments the count for that bucket by sample_count.
-  void AddSamples(size_t sample_count);
+  virtual void AddSamples(size_t sample_count);
 
  protected:
   // overrideable for tests
   virtual int64_t Time() const;
 
  private:
   void EnsureInitialized();
   size_t NextBucketIndex(size_t bucket_index) const;
 
   const int64_t bucket_milliseconds_;
   const size_t bucket_count_;
   size_t* sample_buckets_;
   size_t total_sample_count_;
   size_t current_bucket_;
   int64_t bucket_start_time_milliseconds_;
   int64_t initialization_time_milliseconds_;
 };
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_RATETRACKER_H_