tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

underrun_optimizer.cc (2352B)

      1 /*
      2 *  Copyright (c) 2021 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 "modules/audio_coding/neteq/underrun_optimizer.h"
     12 
     13 #include <algorithm>
     14 #include <optional>
     15 
     16 #include "api/neteq/tick_timer.h"
     17 
     18 namespace webrtc {
     19 
     20 namespace {
     21 
     22 constexpr int kDelayBuckets = 100;
     23 constexpr int kBucketSizeMs = 20;
     24 
     25 }  // namespace
     26 
     27 UnderrunOptimizer::UnderrunOptimizer(const TickTimer* tick_timer,
     28                                     int histogram_quantile,
     29                                     int forget_factor,
     30                                     std::optional<int> start_forget_weight,
     31                                     std::optional<int> resample_interval_ms)
     32    : tick_timer_(tick_timer),
     33      histogram_(kDelayBuckets, forget_factor, start_forget_weight),
     34      histogram_quantile_(histogram_quantile),
     35      resample_interval_ms_(resample_interval_ms) {}
     36 
     37 void UnderrunOptimizer::Update(int relative_delay_ms) {
     38  std::optional<int> histogram_update;
     39  if (resample_interval_ms_) {
     40    if (!resample_stopwatch_) {
     41      resample_stopwatch_ = tick_timer_->GetNewStopwatch();
     42    }
     43    if (static_cast<int>(resample_stopwatch_->ElapsedMs()) >
     44        *resample_interval_ms_) {
     45      histogram_update = max_delay_in_interval_ms_;
     46      resample_stopwatch_ = tick_timer_->GetNewStopwatch();
     47      max_delay_in_interval_ms_ = 0;
     48    }
     49    max_delay_in_interval_ms_ =
     50        std::max(max_delay_in_interval_ms_, relative_delay_ms);
     51  } else {
     52    histogram_update = relative_delay_ms;
     53  }
     54  if (!histogram_update) {
     55    return;
     56  }
     57 
     58  const int index = *histogram_update / kBucketSizeMs;
     59  if (index < histogram_.NumBuckets()) {
     60    // Maximum delay to register is 2000 ms.
     61    histogram_.Add(index);
     62  }
     63  int bucket_index = histogram_.Quantile(histogram_quantile_);
     64  optimal_delay_ms_ = (1 + bucket_index) * kBucketSizeMs;
     65 }
     66 
     67 void UnderrunOptimizer::Reset() {
     68  histogram_.Reset();
     69  resample_stopwatch_.reset();
     70  max_delay_in_interval_ms_ = 0;
     71  optimal_delay_ms_.reset();
     72 }
     73 
     74 }  // namespace webrtc