Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2016 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 WEBRTC_VIDEO_QUALITY_THRESHOLD_H_
      12             : #define WEBRTC_VIDEO_QUALITY_THRESHOLD_H_
      13             : 
      14             : #include <memory>
      15             : 
      16             : #include "webrtc/base/optional.h"
      17             : 
      18             : namespace webrtc {
      19             : 
      20           0 : class QualityThreshold {
      21             :  public:
      22             :   // Both thresholds are inclusive, i.e. measurement >= high signifies a high
      23             :   // state, while measurement <= low signifies a low state.
      24             :   QualityThreshold(int low_threshold,
      25             :                    int high_threshold,
      26             :                    float fraction,
      27             :                    int max_measurements);
      28             : 
      29             :   void AddMeasurement(int measurement);
      30             :   rtc::Optional<bool> IsHigh() const;
      31             :   rtc::Optional<double> CalculateVariance() const;
      32             :   rtc::Optional<double> FractionHigh(int min_required_samples) const;
      33             : 
      34             :  private:
      35             :   const std::unique_ptr<int[]> buffer_;
      36             :   const int max_measurements_;
      37             :   const float fraction_;
      38             :   const int low_threshold_;
      39             :   const int high_threshold_;
      40             :   int until_full_;
      41             :   int next_index_;
      42             :   rtc::Optional<bool> is_high_;
      43             :   int sum_;
      44             :   int count_low_;
      45             :   int count_high_;
      46             :   int num_high_states_;
      47             :   int num_certain_states_;
      48             : };
      49             : 
      50             : }  // namespace webrtc
      51             : 
      52             : #endif  // WEBRTC_VIDEO_QUALITY_THRESHOLD_H_