1 /* 2 * Copyright (c) 2018 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_SIGNAL_DEPENDENT_ERLE_ESTIMATOR_H_ 12 #define MODULES_AUDIO_PROCESSING_AEC3_SIGNAL_DEPENDENT_ERLE_ESTIMATOR_H_ 13 14 #include <memory> 15 #include <vector> 16 17 #include "api/array_view.h" 18 #include "api/audio/echo_canceller3_config.h" 19 #include "modules/audio_processing/aec3/aec3_common.h" 20 #include "modules/audio_processing/aec3/render_buffer.h" 21 #include "modules/audio_processing/logging/apm_data_dumper.h" 22 23 namespace webrtc { 24 25 // This class estimates the dependency of the Erle to the input signal. By 26 // looking at the input signal, an estimation on whether the current echo 27 // estimate is due to the direct path or to a more reverberant one is performed. 28 // Once that estimation is done, it is possible to refine the average Erle that 29 // this class receive as an input. 30 class SignalDependentErleEstimator { 31 public: 32 SignalDependentErleEstimator(const EchoCanceller3Config& config, 33 size_t num_capture_channels); 34 35 ~SignalDependentErleEstimator(); 36 37 void Reset(); 38 39 // Returns the Erle per frequency subband. Erle()40 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Erle() const { 41 return erle_; 42 } 43 44 // Updates the Erle estimate. The Erle that is passed as an input is required 45 // to be an estimation of the average Erle achieved by the linear filter. 46 void Update( 47 const RenderBuffer& render_buffer, 48 rtc::ArrayView<const std::vector<std::array<float, kFftLengthBy2Plus1>>> 49 filter_frequency_response, 50 rtc::ArrayView<const float, kFftLengthBy2Plus1> X2, 51 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Y2, 52 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> E2, 53 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> average_erle, 54 const std::vector<bool>& converged_filters); 55 56 void Dump(const std::unique_ptr<ApmDataDumper>& data_dumper) const; 57 58 static constexpr size_t kSubbands = 6; 59 60 private: 61 void ComputeNumberOfActiveFilterSections( 62 const RenderBuffer& render_buffer, 63 rtc::ArrayView<const std::vector<std::array<float, kFftLengthBy2Plus1>>> 64 filter_frequency_responses); 65 66 void UpdateCorrectionFactors( 67 rtc::ArrayView<const float, kFftLengthBy2Plus1> X2, 68 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Y2, 69 rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> E2, 70 const std::vector<bool>& converged_filters); 71 72 void ComputeEchoEstimatePerFilterSection( 73 const RenderBuffer& render_buffer, 74 rtc::ArrayView<const std::vector<std::array<float, kFftLengthBy2Plus1>>> 75 filter_frequency_responses); 76 77 void ComputeActiveFilterSections(); 78 79 const float min_erle_; 80 const size_t num_sections_; 81 const size_t num_blocks_; 82 const size_t delay_headroom_blocks_; 83 const std::array<size_t, kFftLengthBy2Plus1> band_to_subband_; 84 const std::array<float, kSubbands> max_erle_; 85 const std::vector<size_t> section_boundaries_blocks_; 86 std::vector<std::array<float, kFftLengthBy2Plus1>> erle_; 87 std::vector<std::vector<std::array<float, kFftLengthBy2Plus1>>> 88 S2_section_accum_; 89 std::vector<std::vector<std::array<float, kSubbands>>> erle_estimators_; 90 std::vector<std::array<float, kSubbands>> erle_ref_; 91 std::vector<std::vector<std::array<float, kSubbands>>> correction_factors_; 92 std::vector<std::array<int, kSubbands>> num_updates_; 93 std::vector<std::array<size_t, kFftLengthBy2Plus1>> n_active_sections_; 94 }; 95 96 } // namespace webrtc 97 98 #endif // MODULES_AUDIO_PROCESSING_AEC3_SIGNAL_DEPENDENT_ERLE_ESTIMATOR_H_ 99