Move BWE period calculation from ProbingIntervalEstimator to AimdRateControl.

webrtc/modules/remote_bitrate_estimator/aimd_rate_control.h

 /*
  *  Copyright (c) 2014 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_AIMD_RATE_CONTROL_H_
 #define WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/bwe_defines.h"
 
 namespace webrtc {
 
 // A rate control implementation based on additive increases of
 // bitrate when no over-use is detected and multiplicative decreases when
 // over-uses are detected. When we think the available bandwidth has changes or
 // is unknown, we will switch to a "slow-start mode" where we increase
 // multiplicatively.
 class AimdRateControl {
  public:
   AimdRateControl();
-  virtual ~AimdRateControl();
+  ~AimdRateControl();
 
   // Returns true if there is a valid estimate of the incoming bitrate, false
   // otherwise.
   bool ValidEstimate() const;
   void SetStartBitrate(int start_bitrate_bps);
   void SetMinBitrate(int min_bitrate_bps);
   int64_t GetFeedbackInterval() const;
   // Returns true if the bitrate estimate hasn't been changed for more than
   // an RTT, or if the incoming_bitrate is less than half of the current
   // estimate. Should be used to decide if we should reduce the rate further
   // when over-using.
   bool TimeToReduceFurther(int64_t time_now,
                            uint32_t incoming_bitrate_bps) const;
   uint32_t LatestEstimate() const;
   void SetRtt(int64_t rtt);
   uint32_t Update(const RateControlInput* input, int64_t now_ms);
   void SetEstimate(int bitrate_bps, int64_t now_ms);
 
-  // Returns the increase rate which is used when used bandwidth is near the

[michaelt, 2017/04/05 07:06:02]

Was the comment to obvious ?

[terelius, 2017/04/05 10:58:03]

Initially I tried to remove the entire function and I forgot to reinsert the
comment when I changed my mind. Fixed.

-  // maximal available bandwidth.
-  virtual int GetNearMaxIncreaseRateBps() const;
-
-  virtual rtc::Optional<int> GetLastBitrateDecreaseBps() const;
+  int GetNearMaxIncreaseRateBps() const;

[michaelt, 2017/04/05 07:06:02]

This function could be made private, but I'm not sure about it since we would
not be able to test it then.

[stefan-webrtc, 2017/04/05 07:20:42]

I prefer making it private. There should be other ways of testing what we want
to test.

[terelius, 2017/04/05 10:58:03]

In principle I agree, but as I don't see a clean way to test the functionality,
I'd prefer to keep it for now.

+  // Returns the expected time until the next overuse (assuming steady state).
+  int GetExpectedBandwidthPeriodMs() const;
 
  private:
   // Update the target bitrate according based on, among other things,
   // the current rate control state, the current target bitrate and the incoming
   // bitrate. When in the "increase" state the bitrate will be increased either
   // additively or multiplicatively depending on the rate control region. When
   // in the "decrease" state the bitrate will be decreased to slightly below the
   // incoming bitrate. When in the "hold" state the bitrate will be kept
   // constant to allow built up queues to drain.
   uint32_t ChangeBitrate(uint32_t current_bitrate,
@@ skipping 23 matching lines @@
   int64_t time_first_incoming_estimate_;
   bool bitrate_is_initialized_;
   float beta_;
   int64_t rtt_;
   bool in_experiment_;
   rtc::Optional<int> last_decrease_;
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_