84 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			84 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C++
		
	
	
	
/*
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 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
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 *
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 *  Use of this source code is governed by a BSD-style license
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 *  that can be found in the LICENSE file in the root of the source
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 *  tree. An additional intellectual property rights grant can be found
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 *  in the file PATENTS.  All contributing project authors may
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 *  be found in the AUTHORS file in the root of the source tree.
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 */
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#ifndef MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_
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#define MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_
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#include <memory>
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#include <vector>
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#include "api/array_view.h"
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#include "modules/audio_processing/audio_buffer.h"
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#include "modules/audio_processing/ns/noise_estimator.h"
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#include "modules/audio_processing/ns/ns_common.h"
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#include "modules/audio_processing/ns/ns_config.h"
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#include "modules/audio_processing/ns/ns_fft.h"
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#include "modules/audio_processing/ns/speech_probability_estimator.h"
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#include "modules/audio_processing/ns/wiener_filter.h"
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namespace webrtc {
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// Class for suppressing noise in a signal.
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class NoiseSuppressor {
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 public:
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  NoiseSuppressor(const NsConfig& config,
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                  size_t sample_rate_hz,
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                  size_t num_channels);
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  NoiseSuppressor(const NoiseSuppressor&) = delete;
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  NoiseSuppressor& operator=(const NoiseSuppressor&) = delete;
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  // Analyses the signal (typically applied before the AEC to avoid analyzing
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  // any comfort noise signal).
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  void Analyze(const AudioBuffer& audio);
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  // Applies noise suppression.
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  void Process(AudioBuffer* audio);
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 private:
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  const size_t num_bands_;
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  const size_t num_channels_;
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  const SuppressionParams suppression_params_;
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  int32_t num_analyzed_frames_ = -1;
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  NrFft fft_;
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  struct ChannelState {
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    ChannelState(const SuppressionParams& suppression_params, size_t num_bands);
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    SpeechProbabilityEstimator speech_probability_estimator;
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    WienerFilter wiener_filter;
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    NoiseEstimator noise_estimator;
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    std::array<float, kFftSizeBy2Plus1> prev_analysis_signal_spectrum;
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    std::array<float, kFftSize - kNsFrameSize> analyze_analysis_memory;
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    std::array<float, kOverlapSize> process_analysis_memory;
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    std::array<float, kOverlapSize> process_synthesis_memory;
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    std::vector<std::array<float, kOverlapSize>> process_delay_memory;
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  };
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  struct FilterBankState {
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    std::array<float, kFftSize> real;
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    std::array<float, kFftSize> imag;
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    std::array<float, kFftSize> extended_frame;
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  };
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  std::vector<FilterBankState> filter_bank_states_heap_;
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  std::vector<float> upper_band_gains_heap_;
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  std::vector<float> energies_before_filtering_heap_;
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  std::vector<float> gain_adjustments_heap_;
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  std::vector<std::unique_ptr<ChannelState>> channels_;
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  // Aggregates the Wiener filters into a single filter to use.
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  void AggregateWienerFilters(
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      rtc::ArrayView<float, kFftSizeBy2Plus1> filter) const;
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};
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}  // namespace webrtc
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#endif  // MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_
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