modules/audio_processing/aec3/comfort_noise_generator.h

/*
 *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_
#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_

#include <array>
#include <memory>

#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
#include "webrtc/modules/audio_processing/aec3/aec_state.h"
#include "webrtc/modules/audio_processing/aec3/fft_data.h"
#include "webrtc/rtc_base/constructormagic.h"

namespace webrtc {
namespace aec3 {
#if defined(WEBRTC_ARCH_X86_FAMILY)

void EstimateComfortNoise_SSE2(const std::array<float, kFftLengthBy2Plus1>& N2,
                               uint32_t* seed,
                               FftData* lower_band_noise,
                               FftData* upper_band_noise);
#endif
void EstimateComfortNoise(const std::array<float, kFftLengthBy2Plus1>& N2,
                          uint32_t* seed,
                          FftData* lower_band_noise,
                          FftData* upper_band_noise);

}  // namespace aec3

// Generates the comfort noise.
class ComfortNoiseGenerator {
 public:
  explicit ComfortNoiseGenerator(Aec3Optimization optimization);
  ~ComfortNoiseGenerator();

  // Computes the comfort noise.
  void Compute(const AecState& aec_state,
               const std::array<float, kFftLengthBy2Plus1>& capture_spectrum,
               FftData* lower_band_noise,
               FftData* upper_band_noise);

  // Returns the estimate of the background noise spectrum.
  const std::array<float, kFftLengthBy2Plus1>& NoiseSpectrum() const {
    return N2_;
  }

 private:
  const Aec3Optimization optimization_;
  uint32_t seed_;
  std::unique_ptr<std::array<float, kFftLengthBy2Plus1>> N2_initial_;
  std::array<float, kFftLengthBy2Plus1> Y2_smoothed_;
  std::array<float, kFftLengthBy2Plus1> N2_;
  int N2_counter_ = 0;

  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(ComfortNoiseGenerator);
};

}  // namespace webrtc

#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_