noise_suppressor.h (3433B)
1 /* 2 * Copyright (c) 2012 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_NS_NOISE_SUPPRESSOR_H_ 12 #define MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_ 13 14 #include <array> 15 #include <cstddef> 16 #include <cstdint> 17 #include <memory> 18 #include <vector> 19 20 #include "api/array_view.h" 21 #include "modules/audio_processing/audio_buffer.h" 22 #include "modules/audio_processing/ns/noise_estimator.h" 23 #include "modules/audio_processing/ns/ns_common.h" 24 #include "modules/audio_processing/ns/ns_config.h" 25 #include "modules/audio_processing/ns/ns_fft.h" 26 #include "modules/audio_processing/ns/speech_probability_estimator.h" 27 #include "modules/audio_processing/ns/suppression_params.h" 28 #include "modules/audio_processing/ns/wiener_filter.h" 29 30 namespace webrtc { 31 32 // Class for suppressing noise in a signal. 33 class NoiseSuppressor { 34 public: 35 NoiseSuppressor(const NsConfig& config, 36 size_t sample_rate_hz, 37 size_t num_channels); 38 NoiseSuppressor(const NoiseSuppressor&) = delete; 39 NoiseSuppressor& operator=(const NoiseSuppressor&) = delete; 40 41 // Analyses the signal (typically applied before the AEC to avoid analyzing 42 // any comfort noise signal). 43 void Analyze(const AudioBuffer& audio); 44 45 // Applies noise suppression. 46 void Process(AudioBuffer* audio); 47 48 // Specifies whether the capture output will be used. The purpose of this is 49 // to allow the noise suppressor to deactivate some of the processing when the 50 // resulting output is anyway not used, for instance when the endpoint is 51 // muted. 52 void SetCaptureOutputUsage(bool capture_output_used) { 53 capture_output_used_ = capture_output_used; 54 } 55 56 private: 57 const size_t num_bands_; 58 const size_t num_channels_; 59 const SuppressionParams suppression_params_; 60 int32_t num_analyzed_frames_ = -1; 61 NrFft fft_; 62 bool capture_output_used_ = true; 63 64 struct ChannelState { 65 ChannelState(const SuppressionParams& suppression_params, size_t num_bands); 66 67 SpeechProbabilityEstimator speech_probability_estimator; 68 WienerFilter wiener_filter; 69 NoiseEstimator noise_estimator; 70 std::array<float, kFftSizeBy2Plus1> prev_analysis_signal_spectrum; 71 std::array<float, kFftSize - kNsFrameSize> analyze_analysis_memory; 72 std::array<float, kOverlapSize> process_analysis_memory; 73 std::array<float, kOverlapSize> process_synthesis_memory; 74 std::vector<std::array<float, kOverlapSize>> process_delay_memory; 75 }; 76 77 struct FilterBankState { 78 std::array<float, kFftSize> real; 79 std::array<float, kFftSize> imag; 80 std::array<float, kFftSize> extended_frame; 81 }; 82 83 std::vector<FilterBankState> filter_bank_states_heap_; 84 std::vector<float> upper_band_gains_heap_; 85 std::vector<float> energies_before_filtering_heap_; 86 std::vector<float> gain_adjustments_heap_; 87 std::vector<std::unique_ptr<ChannelState>> channels_; 88 89 // Aggregates the Wiener filters into a single filter to use. 90 void AggregateWienerFilters(ArrayView<float, kFftSizeBy2Plus1> filter) const; 91 }; 92 93 } // namespace webrtc 94 95 #endif // MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_