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 #include "rtc_base/constructor_magic.h" 22 23 namespace webrtc { 24 25 // Estimates the echo return loss based on the signal spectra. 26 class ErlEstimator { 27 public: 28 explicit ErlEstimator(size_t startup_phase_length_blocks_); 29 ~ErlEstimator(); 30 31 // Resets the ERL estimation. 32 void Reset(); 33 34 // Updates the ERL estimate. 35 void Update(const std::vector<bool>& converged_filters, 36 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> 37 render_spectra, 38 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> 39 capture_spectra); 40 41 // Returns the most recent ERL estimate. Erl()42 const std::array<float, kFftLengthBy2Plus1>& Erl() const { return erl_; } ErlTimeDomain()43 float ErlTimeDomain() const { return erl_time_domain_; } 44 45 private: 46 const size_t startup_phase_length_blocks__; 47 std::array<float, kFftLengthBy2Plus1> erl_; 48 std::array<int, kFftLengthBy2Minus1> hold_counters_; 49 float erl_time_domain_; 50 int hold_counter_time_domain_; 51 size_t blocks_since_reset_ = 0; 52 RTC_DISALLOW_COPY_AND_ASSIGN(ErlEstimator); 53 }; 54 55 } // namespace webrtc 56 57 #endif // MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_ 58