aecm_core.cc | Explore in Territory

/*
 *  Copyright (c) 2012 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/aecm/aecm_core.h"

#include <stddef.h>
#include <stdlib.h>
#include <string.h>

extern "C" {
#include "common_audio/ring_buffer.h"
#include "common_audio/signal_processing/include/real_fft.h"
}
#include "common_audio/signal_processing/include/signal_processing_library.h"
#include "modules/audio_processing/aecm/echo_control_mobile.h"
#include "modules/audio_processing/utility/delay_estimator_wrapper.h"
#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_conversions.h"

namespace webrtc {

namespace {

#ifdef AEC_DEBUG
FILE* dfile;
FILE* testfile;
#endif

// Initialization table for echo channel in 8 kHz
static const int16_t kChannelStored8kHz[PART_LEN1] = …;

// Initialization table for echo channel in 16 kHz
static const int16_t kChannelStored16kHz[PART_LEN1] = …;

}  // namespace

const int16_t WebRtcAecm_kCosTable[] = …;

const int16_t WebRtcAecm_kSinTable[] = …;

// Moves the pointer to the next entry and inserts `far_spectrum` and
// corresponding Q-domain in its buffer.
//
// Inputs:
//      - self          : Pointer to the delay estimation instance
//      - far_spectrum  : Pointer to the far end spectrum
//      - far_q         : Q-domain of far end spectrum
//
void WebRtcAecm_UpdateFarHistory(AecmCore* self,
                                 uint16_t* far_spectrum,
                                 int far_q) { … }

// Returns a pointer to the far end spectrum aligned to current near end
// spectrum. The function WebRtc_DelayEstimatorProcessFix(...) should have been
// called before AlignedFarend(...). Otherwise, you get the pointer to the
// previous frame. The memory is only valid until the next call of
// WebRtc_DelayEstimatorProcessFix(...).
//
// Inputs:
//      - self              : Pointer to the AECM instance.
//      - delay             : Current delay estimate.
//
// Output:
//      - far_q             : The Q-domain of the aligned far end spectrum
//
// Return value:
//      - far_spectrum      : Pointer to the aligned far end spectrum
//                            NULL - Error
//
const uint16_t* WebRtcAecm_AlignedFarend(AecmCore* self,
                                         int* far_q,
                                         int delay) { … }

// Declare function pointers.
CalcLinearEnergies WebRtcAecm_CalcLinearEnergies;
StoreAdaptiveChannel WebRtcAecm_StoreAdaptiveChannel;
ResetAdaptiveChannel WebRtcAecm_ResetAdaptiveChannel;

AecmCore* WebRtcAecm_CreateCore() { … }

void WebRtcAecm_InitEchoPathCore(AecmCore* aecm, const int16_t* echo_path) { … }

static void CalcLinearEnergiesC(AecmCore* aecm,
                                const uint16_t* far_spectrum,
                                int32_t* echo_est,
                                uint32_t* far_energy,
                                uint32_t* echo_energy_adapt,
                                uint32_t* echo_energy_stored) { … }

static void StoreAdaptiveChannelC(AecmCore* aecm,
                                  const uint16_t* far_spectrum,
                                  int32_t* echo_est) { … }

static void ResetAdaptiveChannelC(AecmCore* aecm) { … }

// Initialize function pointers for ARM Neon platform.
#if defined(WEBRTC_HAS_NEON)
static void WebRtcAecm_InitNeon(void) {
  WebRtcAecm_StoreAdaptiveChannel = WebRtcAecm_StoreAdaptiveChannelNeon;
  WebRtcAecm_ResetAdaptiveChannel = WebRtcAecm_ResetAdaptiveChannelNeon;
  WebRtcAecm_CalcLinearEnergies = WebRtcAecm_CalcLinearEnergiesNeon;
}
#endif

// Initialize function pointers for MIPS platform.
#if defined(MIPS32_LE)
static void WebRtcAecm_InitMips(void) {
#if defined(MIPS_DSP_R1_LE)
  WebRtcAecm_StoreAdaptiveChannel = WebRtcAecm_StoreAdaptiveChannel_mips;
  WebRtcAecm_ResetAdaptiveChannel = WebRtcAecm_ResetAdaptiveChannel_mips;
#endif
  WebRtcAecm_CalcLinearEnergies = WebRtcAecm_CalcLinearEnergies_mips;
}
#endif

// WebRtcAecm_InitCore(...)
//
// This function initializes the AECM instant created with
// WebRtcAecm_CreateCore(...) Input:
//      - aecm            : Pointer to the Echo Suppression instance
//      - samplingFreq   : Sampling Frequency
//
// Output:
//      - aecm            : Initialized instance
//
// Return value         :  0 - Ok
//                        -1 - Error
//
int WebRtcAecm_InitCore(AecmCore* const aecm, int samplingFreq) { … }

// TODO(bjornv): This function is currently not used. Add support for these
// parameters from a higher level
int WebRtcAecm_Control(AecmCore* aecm, int delay, int nlpFlag) { … }

void WebRtcAecm_FreeCore(AecmCore* aecm) { … }

int WebRtcAecm_ProcessFrame(AecmCore* aecm,
                            const int16_t* farend,
                            const int16_t* nearendNoisy,
                            const int16_t* nearendClean,
                            int16_t* out) { … }

// WebRtcAecm_AsymFilt(...)
//
// Performs asymmetric filtering.
//
// Inputs:
//      - filtOld       : Previous filtered value.
//      - inVal         : New input value.
//      - stepSizePos   : Step size when we have a positive contribution.
//      - stepSizeNeg   : Step size when we have a negative contribution.
//
// Output:
//
// Return: - Filtered value.
//
int16_t WebRtcAecm_AsymFilt(const int16_t filtOld,
                            const int16_t inVal,
                            const int16_t stepSizePos,
                            const int16_t stepSizeNeg) { … }

// ExtractFractionPart(a, zeros)
//
// returns the fraction part of `a`, with `zeros` number of leading zeros, as an
// int16_t scaled to Q8. There is no sanity check of `a` in the sense that the
// number of zeros match.
static int16_t ExtractFractionPart(uint32_t a, int zeros) { … }

// Calculates and returns the log of `energy` in Q8. The input `energy` is
// supposed to be in Q(`q_domain`).
static int16_t LogOfEnergyInQ8(uint32_t energy, int q_domain) { … }

// WebRtcAecm_CalcEnergies(...)
//
// This function calculates the log of energies for nearend, farend and
// estimated echoes. There is also an update of energy decision levels, i.e.
// internal VAD.
//
//
// @param  aecm         [i/o]   Handle of the AECM instance.
// @param  far_spectrum [in]    Pointer to farend spectrum.
// @param  far_q        [in]    Q-domain of farend spectrum.
// @param  nearEner     [in]    Near end energy for current block in
//                              Q(aecm->dfaQDomain).
// @param  echoEst      [out]   Estimated echo in Q(xfa_q+RESOLUTION_CHANNEL16).
//
void WebRtcAecm_CalcEnergies(AecmCore* aecm,
                             const uint16_t* far_spectrum,
                             const int16_t far_q,
                             const uint32_t nearEner,
                             int32_t* echoEst) { … }

// WebRtcAecm_CalcStepSize(...)
//
// This function calculates the step size used in channel estimation
//
//
// @param  aecm  [in]    Handle of the AECM instance.
// @param  mu    [out]   (Return value) Stepsize in log2(), i.e. number of
// shifts.
//
//
int16_t WebRtcAecm_CalcStepSize(AecmCore* const aecm) { … }

// WebRtcAecm_UpdateChannel(...)
//
// This function performs channel estimation. NLMS and decision on channel
// storage.
//
//
// @param  aecm         [i/o]   Handle of the AECM instance.
// @param  far_spectrum [in]    Absolute value of the farend signal in Q(far_q)
// @param  far_q        [in]    Q-domain of the farend signal
// @param  dfa          [in]    Absolute value of the nearend signal
// (Q[aecm->dfaQDomain])
// @param  mu           [in]    NLMS step size.
// @param  echoEst      [i/o]   Estimated echo in Q(far_q+RESOLUTION_CHANNEL16).
//
void WebRtcAecm_UpdateChannel(AecmCore* aecm,
                              const uint16_t* far_spectrum,
                              const int16_t far_q,
                              const uint16_t* const dfa,
                              const int16_t mu,
                              int32_t* echoEst) { … }

// CalcSuppressionGain(...)
//
// This function calculates the suppression gain that is used in the Wiener
// filter.
//
//
// @param  aecm     [i/n]   Handle of the AECM instance.
// @param  supGain  [out]   (Return value) Suppression gain with which to scale
// the noise
//                          level (Q14).
//
//
int16_t WebRtcAecm_CalcSuppressionGain(AecmCore* const aecm) { … }

void WebRtcAecm_BufferFarFrame(AecmCore* const aecm,
                               const int16_t* const farend,
                               const int farLen) { … }

void WebRtcAecm_FetchFarFrame(AecmCore* const aecm,
                              int16_t* const farend,
                              const int farLen,
                              const int knownDelay) { … }

}  // namespace webrtc
chromium/third_party/webrtc/modules/audio_processing/aecm/aecm_core.cc
