bitrate_estimator.h

Enable keyboard shortcuts

/*

 *  Copyright (c) 2017 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 MODULES_CONGESTION_CONTROLLER_GOOG_CC_BITRATE_ESTIMATOR_H_

#define MODULES_CONGESTION_CONTROLLER_GOOG_CC_BITRATE_ESTIMATOR_H_

#include <stdint.h>

#include "absl/types/optional.h"

#include "api/field_trials_view.h"

#include "api/units/data_rate.h"

#include "api/units/data_size.h"

#include "api/units/timestamp.h"

#include "rtc_base/experiments/field_trial_parser.h"

namespace webrtc {

// 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:

  explicit BitrateEstimator(const FieldTrialsView* key_value_config);

  virtual ~BitrateEstimator();

  virtual void Update(Timestamp at_time, DataSize amount, bool in_alr);

  virtual absl::optional<DataRate> bitrate() const;

  absl::optional<DataRate> PeekRate() const;

  virtual void ExpectFastRateChange();

 private:

  float UpdateWindow(int64_t now_ms,

                     int bytes,

                     int rate_window_ms,

                     bool* is_small_sample);

  int sum_;

  FieldTrialConstrained<int> initial_window_ms_;

  FieldTrialConstrained<int> noninitial_window_ms_;

  FieldTrialParameter<double> uncertainty_scale_;

  FieldTrialParameter<double> uncertainty_scale_in_alr_;

  FieldTrialParameter<double> small_sample_uncertainty_scale_;

  FieldTrialParameter<DataSize> small_sample_threshold_;

  FieldTrialParameter<DataRate> uncertainty_symmetry_cap_;

  FieldTrialParameter<DataRate> estimate_floor_;

  int64_t current_window_ms_;

  int64_t prev_time_ms_;

  float bitrate_estimate_kbps_;

  float bitrate_estimate_var_;

};

}  // namespace webrtc

#endif  // MODULES_CONGESTION_CONTROLLER_GOOG_CC_BITRATE_ESTIMATOR_H_