chromium/third_party/webrtc/modules/audio_processing/aec3/comfort_noise_generator.cc

/*
 *  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.
 */

#include "modules/audio_processing/aec3/comfort_noise_generator.h"

// Defines WEBRTC_ARCH_X86_FAMILY, used below.
#include "rtc_base/system/arch.h"

#if defined(WEBRTC_ARCH_X86_FAMILY)
#include <emmintrin.h>
#endif
#include <algorithm>
#include <array>
#include <cmath>
#include <cstdint>
#include <functional>
#include <numeric>

#include "common_audio/signal_processing/include/signal_processing_library.h"
#include "modules/audio_processing/aec3/vector_math.h"
#include "rtc_base/checks.h"

namespace webrtc {

namespace {

// Computes the noise floor value that matches a WGN input of noise_floor_dbfs.
float GetNoiseFloorFactor(float noise_floor_dbfs) { … }

// Table of sqrt(2) * sin(2*pi*i/32).
constexpr float kSqrt2Sin[32] = …;

void GenerateComfortNoise(Aec3Optimization optimization,
                          const std::array<float, kFftLengthBy2Plus1>& N2,
                          uint32_t* seed,
                          FftData* lower_band_noise,
                          FftData* upper_band_noise) { … }

}  // namespace

ComfortNoiseGenerator::ComfortNoiseGenerator(const EchoCanceller3Config& config,
                                             Aec3Optimization optimization,
                                             size_t num_capture_channels)
    : … { … }

ComfortNoiseGenerator::~ComfortNoiseGenerator() = default;

void ComfortNoiseGenerator::Compute(
    bool saturated_capture,
    rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>>
        capture_spectrum,
    rtc::ArrayView<FftData> lower_band_noise,
    rtc::ArrayView<FftData> upper_band_noise) { … }

}  // namespace webrtc