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 #ifndef MODULES_AUDIO_CODING_NETEQ_UNDERRUN_OPTIMIZER_H_ 12 #define MODULES_AUDIO_CODING_NETEQ_UNDERRUN_OPTIMIZER_H_ 13 14 #include <memory> 15 16 #include "absl/types/optional.h" 17 #include "api/neteq/tick_timer.h" 18 #include "modules/audio_coding/neteq/histogram.h" 19 20 namespace webrtc { 21 22 // Estimates probability of buffer underrun due to late packet arrival. 23 // The optimal delay is decided such that the probability of underrun is lower 24 // than 1 - `histogram_quantile`. 25 class UnderrunOptimizer { 26 public: 27 UnderrunOptimizer(const TickTimer* tick_timer, 28 int histogram_quantile, 29 int forget_factor, 30 absl::optional<int> start_forget_weight, 31 absl::optional<int> resample_interval_ms); 32 33 void Update(int relative_delay_ms); 34 GetOptimalDelayMs()35 absl::optional<int> GetOptimalDelayMs() const { return optimal_delay_ms_; } 36 37 void Reset(); 38 39 private: 40 const TickTimer* tick_timer_; 41 Histogram histogram_; 42 const int histogram_quantile_; // In Q30. 43 const absl::optional<int> resample_interval_ms_; 44 std::unique_ptr<TickTimer::Stopwatch> resample_stopwatch_; 45 int max_delay_in_interval_ms_ = 0; 46 absl::optional<int> optimal_delay_ms_; 47 }; 48 49 } // namespace webrtc 50 #endif // MODULES_AUDIO_CODING_NETEQ_UNDERRUN_OPTIMIZER_H_ 51