1 /* 2 * Copyright (c) 2017 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_PROCESSING_AEC3_ERL_ESTIMATOR_H_ 12 #define MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_ 13 14 #include <stddef.h> 15 16 #include <array> 17 #include <vector> 18 19 #include "api/array_view.h" 20 #include "modules/audio_processing/aec3/aec3_common.h" 21 22 namespace webrtc { 23 24 // Estimates the echo return loss based on the signal spectra. 25 class ErlEstimator { 26 public: 27 explicit ErlEstimator(size_t startup_phase_length_blocks_); 28 ~ErlEstimator(); 29 30 ErlEstimator(const ErlEstimator&) = delete; 31 ErlEstimator& operator=(const ErlEstimator&) = delete; 32 33 // Resets the ERL estimation. 34 void Reset(); 35 36 // Updates the ERL estimate. 37 void Update(const std::vector<bool>& converged_filters, 38 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> 39 render_spectra, 40 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> 41 capture_spectra); 42 43 // Returns the most recent ERL estimate. Erl()44 const std::array<float, kFftLengthBy2Plus1>& Erl() const { return erl_; } ErlTimeDomain()45 float ErlTimeDomain() const { return erl_time_domain_; } 46 47 private: 48 const size_t startup_phase_length_blocks__; 49 std::array<float, kFftLengthBy2Plus1> erl_; 50 std::array<int, kFftLengthBy2Minus1> hold_counters_; 51 float erl_time_domain_; 52 int hold_counter_time_domain_; 53 size_t blocks_since_reset_ = 0; 54 }; 55 56 } // namespace webrtc 57 58 #endif // MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_ 59