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             : #include "webrtc/modules/video_coding/utility/moving_average.h"
      12             : 
      13             : #include <algorithm>
      14             : 
      15             : namespace webrtc {
      16             : 
      17           0 : MovingAverage::MovingAverage(size_t s) : sum_history_(s + 1, 0) {}
      18             : 
      19           0 : void MovingAverage::AddSample(int sample) {
      20           0 :   count_++;
      21           0 :   sum_ += sample;
      22           0 :   sum_history_[count_ % sum_history_.size()] = sum_;
      23           0 : }
      24             : 
      25           0 : rtc::Optional<int> MovingAverage::GetAverage() const {
      26           0 :   return GetAverage(size());
      27             : }
      28             : 
      29           0 : rtc::Optional<int> MovingAverage::GetAverage(size_t num_samples) const {
      30           0 :   if (num_samples > size() || num_samples == 0)
      31           0 :     return rtc::Optional<int>();
      32           0 :   int sum = sum_ - sum_history_[(count_ - num_samples) % sum_history_.size()];
      33           0 :   return rtc::Optional<int>(sum / static_cast<int>(num_samples));
      34             : }
      35             : 
      36           0 : void MovingAverage::Reset() {
      37           0 :   count_ = 0;
      38           0 :   sum_ = 0;
      39           0 :   std::fill(sum_history_.begin(), sum_history_.end(), 0);
      40           0 : }
      41             : 
      42           0 : size_t MovingAverage::size() const {
      43           0 :   return std::min(count_, sum_history_.size() - 1);
      44             : }
      45             : 
      46             : }  // namespace webrtc