1 /*
2  *  Copyright (c) 2013 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 #ifndef MODULES_REMOTE_BITRATE_ESTIMATOR_OVERUSE_ESTIMATOR_H_
11 #define MODULES_REMOTE_BITRATE_ESTIMATOR_OVERUSE_ESTIMATOR_H_
12 
13 #include <stdint.h>
14 
15 #include <deque>
16 
17 #include "modules/remote_bitrate_estimator/include/bwe_defines.h"
18 #include "rtc_base/constructor_magic.h"
19 
20 namespace webrtc {
21 
22 // Bandwidth over-use detector options.  These are used to drive
23 // experimentation with bandwidth estimation parameters.
24 // TODO(terelius): This is only used in overuse_estimator.cc, and only in the
25 // default constructed state. Can we move the relevant variables into that
26 // class and delete this?
27 struct OverUseDetectorOptions {
28   OverUseDetectorOptions() = default;
29   double initial_slope = 8.0 / 512.0;
30   double initial_offset = 0;
31   double initial_e[2][2] = {{100.0, 0.0}, {0.0, 1e-1}};
32   double initial_process_noise[2] = {1e-13, 1e-3};
33   double initial_avg_noise = 0.0;
34   double initial_var_noise = 50.0;
35 };
36 
37 class OveruseEstimator {
38  public:
39   explicit OveruseEstimator(const OverUseDetectorOptions& options);
40   ~OveruseEstimator();
41 
42   // Update the estimator with a new sample. The deltas should represent deltas
43   // between timestamp groups as defined by the InterArrival class.
44   // |current_hypothesis| should be the hypothesis of the over-use detector at
45   // this time.
46   void Update(int64_t t_delta,
47               double ts_delta,
48               int size_delta,
49               BandwidthUsage current_hypothesis,
50               int64_t now_ms);
51 
52   // Returns the estimated noise/jitter variance in ms^2.
var_noise()53   double var_noise() const { return var_noise_; }
54 
55   // Returns the estimated inter-arrival time delta offset in ms.
offset()56   double offset() const { return offset_; }
57 
58   // Returns the number of deltas which the current over-use estimator state is
59   // based on.
num_of_deltas()60   unsigned int num_of_deltas() const { return num_of_deltas_; }
61 
62  private:
63   double UpdateMinFramePeriod(double ts_delta);
64   void UpdateNoiseEstimate(double residual, double ts_delta, bool stable_state);
65 
66   // Must be first member variable. Cannot be const because we need to be
67   // copyable.
68   OverUseDetectorOptions options_;
69   uint16_t num_of_deltas_;
70   double slope_;
71   double offset_;
72   double prev_offset_;
73   double E_[2][2];
74   double process_noise_[2];
75   double avg_noise_;
76   double var_noise_;
77   std::deque<double> ts_delta_hist_;
78 
79   RTC_DISALLOW_COPY_AND_ASSIGN(OveruseEstimator);
80 };
81 }  // namespace webrtc
82 
83 #endif  // MODULES_REMOTE_BITRATE_ESTIMATOR_OVERUSE_ESTIMATOR_H_
84