1 /*
2  *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef MODULES_CONGESTION_CONTROLLER_BITRATE_ESTIMATOR_H_
12 #define MODULES_CONGESTION_CONTROLLER_BITRATE_ESTIMATOR_H_
13 
14 #include <vector>
15 
16 #include "api/optional.h"
17 
18 namespace webrtc {
19 
20 // Computes a bayesian estimate of the throughput given acks containing
21 // the arrival time and payload size. Samples which are far from the current
22 // estimate or are based on few packets are given a smaller weight, as they
23 // are considered to be more likely to have been caused by, e.g., delay spikes
24 // unrelated to congestion.
25 class BitrateEstimator {
26  public:
27   BitrateEstimator();
28   virtual ~BitrateEstimator();
29   virtual void Update(int64_t now_ms, int bytes);
30 
31   virtual rtc::Optional<uint32_t> bitrate_bps() const;
32 
33   virtual void ExpectFastRateChange();
34 
35  private:
36   float UpdateWindow(int64_t now_ms, int bytes, int rate_window_ms);
37   int sum_;
38   int64_t current_win_ms_;
39   int64_t prev_time_ms_;
40   float bitrate_estimate_;
41   float bitrate_estimate_var_;
42 };
43 
44 }  // namespace webrtc
45 
46 #endif  // MODULES_CONGESTION_CONTROLLER_BITRATE_ESTIMATOR_H_
47