chromium/third_party/webrtc/modules/audio_processing/aecm/aecm_core_c.cc

/*
 *  Copyright (c) 2013 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 <stddef.h>
#include <stdlib.h>

#include "modules/audio_processing/aecm/aecm_core.h"

extern "C" {
#include "common_audio/ring_buffer.h"
#include "common_audio/signal_processing/include/real_fft.h"
}
#include "modules/audio_processing/aecm/echo_control_mobile.h"
#include "modules/audio_processing/utility/delay_estimator_wrapper.h"
extern "C" {
#include "system_wrappers/include/cpu_features_wrapper.h"
}

#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "rtc_base/sanitizer.h"

namespace webrtc {

namespace {

// Square root of Hanning window in Q14.
static const ALIGN8_BEG int16_t WebRtcAecm_kSqrtHanning[] ALIGN8_END = …;

#ifdef AECM_WITH_ABS_APPROX
// Q15 alpha = 0.99439986968132  const Factor for magnitude approximation
static const uint16_t kAlpha1 = 32584;
// Q15 beta = 0.12967166976970   const Factor for magnitude approximation
static const uint16_t kBeta1 = 4249;
// Q15 alpha = 0.94234827210087  const Factor for magnitude approximation
static const uint16_t kAlpha2 = 30879;
// Q15 beta = 0.33787806009150   const Factor for magnitude approximation
static const uint16_t kBeta2 = 11072;
// Q15 alpha = 0.82247698684306  const Factor for magnitude approximation
static const uint16_t kAlpha3 = 26951;
// Q15 beta = 0.57762063060713   const Factor for magnitude approximation
static const uint16_t kBeta3 = 18927;
#endif

static const int16_t kNoiseEstQDomain = …;
static const int16_t kNoiseEstIncCount = …;

static void ComfortNoise(AecmCore* aecm,
                         const uint16_t* dfa,
                         ComplexInt16* out,
                         const int16_t* lambda) { … }

static void WindowAndFFT(AecmCore* aecm,
                         int16_t* fft,
                         const int16_t* time_signal,
                         ComplexInt16* freq_signal,
                         int time_signal_scaling) { … }

static void InverseFFTAndWindow(AecmCore* aecm,
                                int16_t* fft,
                                ComplexInt16* efw,
                                int16_t* output,
                                const int16_t* nearendClean) { … }

// Transforms a time domain signal into the frequency domain, outputting the
// complex valued signal, absolute value and sum of absolute values.
//
// time_signal          [in]    Pointer to time domain signal
// freq_signal_real     [out]   Pointer to real part of frequency domain array
// freq_signal_imag     [out]   Pointer to imaginary part of frequency domain
//                              array
// freq_signal_abs      [out]   Pointer to absolute value of frequency domain
//                              array
// freq_signal_sum_abs  [out]   Pointer to the sum of all absolute values in
//                              the frequency domain array
// return value                 The Q-domain of current frequency values
//
static int TimeToFrequencyDomain(AecmCore* aecm,
                                 const int16_t* time_signal,
                                 ComplexInt16* freq_signal,
                                 uint16_t* freq_signal_abs,
                                 uint32_t* freq_signal_sum_abs) { … }

}  // namespace

int RTC_NO_SANITIZE("signed-integer-overflow")  // bugs.webrtc.org/8200
    WebRtcAecm_ProcessBlock(AecmCore* aecm,
                            const int16_t* farend,
                            const int16_t* nearendNoisy,
                            const int16_t* nearendClean,
                            int16_t* output) { … }

}  // namespace webrtc