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libtgvoip/webrtc_dsp/modules/audio_processing/aec/echo_cancellation.cc
Grishka 5caaaafa42 Updated WebRTC APM
I'm now using the entire audio processing module from WebRTC as opposed to individual DSP algorithms pulled from there before. Seems to work better this way.
2018-11-23 04:02:53 +03:00

865 lines
28 KiB
C++

/*
* 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.
*/
/*
* Contains the API functions for the AEC.
*/
#include "modules/audio_processing/aec/echo_cancellation.h"
#include <math.h>
#include <stdlib.h>
#include <string.h>
extern "C" {
#include "common_audio/ring_buffer.h"
#include "common_audio/signal_processing/include/signal_processing_library.h"
}
#include "modules/audio_processing/aec/aec_core.h"
#include "modules/audio_processing/aec/aec_resampler.h"
#include "modules/audio_processing/logging/apm_data_dumper.h"
namespace webrtc {
Aec::Aec() = default;
Aec::~Aec() = default;
// Measured delays [ms]
// Device Chrome GTP
// MacBook Air 10
// MacBook Retina 10 100
// MacPro 30?
//
// Win7 Desktop 70 80?
// Win7 T430s 110
// Win8 T420s 70
//
// Daisy 50
// Pixel (w/ preproc?) 240
// Pixel (w/o preproc?) 110 110
// The extended filter mode gives us the flexibility to ignore the system's
// reported delays. We do this for platforms which we believe provide results
// which are incompatible with the AEC's expectations. Based on measurements
// (some provided above) we set a conservative (i.e. lower than measured)
// fixed delay.
//
// WEBRTC_UNTRUSTED_DELAY will only have an impact when |extended_filter_mode|
// is enabled. See the note along with |DelayCorrection| in
// echo_cancellation_impl.h for more details on the mode.
//
// Justification:
// Chromium/Mac: Here, the true latency is so low (~10-20 ms), that it plays
// havoc with the AEC's buffering. To avoid this, we set a fixed delay of 20 ms
// and then compensate by rewinding by 10 ms (in wideband) through
// kDelayDiffOffsetSamples. This trick does not seem to work for larger rewind
// values, but fortunately this is sufficient.
//
// Chromium/Linux(ChromeOS): The values we get on this platform don't correspond
// well to reality. The variance doesn't match the AEC's buffer changes, and the
// bulk values tend to be too low. However, the range across different hardware
// appears to be too large to choose a single value.
//
// GTP/Linux(ChromeOS): TBD, but for the moment we will trust the values.
#if defined(WEBRTC_CHROMIUM_BUILD) && defined(WEBRTC_MAC)
#define WEBRTC_UNTRUSTED_DELAY
#endif
#if defined(WEBRTC_UNTRUSTED_DELAY) && defined(WEBRTC_MAC)
static const int kDelayDiffOffsetSamples = -160;
#else
// Not enabled for now.
static const int kDelayDiffOffsetSamples = 0;
#endif
#if defined(WEBRTC_MAC)
static const int kFixedDelayMs = 20;
#else
static const int kFixedDelayMs = 50;
#endif
#if !defined(WEBRTC_UNTRUSTED_DELAY)
static const int kMinTrustedDelayMs = 20;
#endif
static const int kMaxTrustedDelayMs = 500;
// Maximum length of resampled signal. Must be an integer multiple of frames
// (ceil(1/(1 + MIN_SKEW)*2) + 1)*FRAME_LEN
// The factor of 2 handles wb, and the + 1 is as a safety margin
// TODO(bjornv): Replace with kResamplerBufferSize
#define MAX_RESAMP_LEN (5 * FRAME_LEN)
static const int kMaxBufSizeStart = 62; // In partitions
static const int sampMsNb = 8; // samples per ms in nb
static const int initCheck = 42;
int Aec::instance_count = 0;
// Estimates delay to set the position of the far-end buffer read pointer
// (controlled by knownDelay)
static void EstBufDelayNormal(Aec* aecInst);
static void EstBufDelayExtended(Aec* aecInst);
static int ProcessNormal(Aec* aecInst,
const float* const* nearend,
size_t num_bands,
float* const* out,
size_t num_samples,
int16_t reported_delay_ms,
int32_t skew);
static void ProcessExtended(Aec* aecInst,
const float* const* nearend,
size_t num_bands,
float* const* out,
size_t num_samples,
int16_t reported_delay_ms,
int32_t skew);
void* WebRtcAec_Create() {
Aec* aecpc = new Aec();
if (!aecpc) {
return NULL;
}
aecpc->data_dumper.reset(new ApmDataDumper(aecpc->instance_count));
aecpc->aec = WebRtcAec_CreateAec(aecpc->instance_count);
if (!aecpc->aec) {
WebRtcAec_Free(aecpc);
return NULL;
}
aecpc->resampler = WebRtcAec_CreateResampler();
if (!aecpc->resampler) {
WebRtcAec_Free(aecpc);
return NULL;
}
// Create far-end pre-buffer. The buffer size has to be large enough for
// largest possible drift compensation (kResamplerBufferSize) + "almost" an
// FFT buffer (PART_LEN2 - 1).
aecpc->far_pre_buf =
WebRtc_CreateBuffer(PART_LEN2 + kResamplerBufferSize, sizeof(float));
if (!aecpc->far_pre_buf) {
WebRtcAec_Free(aecpc);
return NULL;
}
aecpc->initFlag = 0;
aecpc->instance_count++;
return aecpc;
}
void WebRtcAec_Free(void* aecInst) {
Aec* aecpc = reinterpret_cast<Aec*>(aecInst);
if (aecpc == NULL) {
return;
}
WebRtc_FreeBuffer(aecpc->far_pre_buf);
WebRtcAec_FreeAec(aecpc->aec);
WebRtcAec_FreeResampler(aecpc->resampler);
delete aecpc;
}
int32_t WebRtcAec_Init(void* aecInst, int32_t sampFreq, int32_t scSampFreq) {
Aec* aecpc = reinterpret_cast<Aec*>(aecInst);
aecpc->data_dumper->InitiateNewSetOfRecordings();
AecConfig aecConfig;
if (sampFreq != 8000 && sampFreq != 16000 && sampFreq != 32000 &&
sampFreq != 48000) {
return AEC_BAD_PARAMETER_ERROR;
}
aecpc->sampFreq = sampFreq;
if (scSampFreq < 1 || scSampFreq > 96000) {
return AEC_BAD_PARAMETER_ERROR;
}
aecpc->scSampFreq = scSampFreq;
// Initialize echo canceller core
if (WebRtcAec_InitAec(aecpc->aec, aecpc->sampFreq) == -1) {
return AEC_UNSPECIFIED_ERROR;
}
if (WebRtcAec_InitResampler(aecpc->resampler, aecpc->scSampFreq) == -1) {
return AEC_UNSPECIFIED_ERROR;
}
WebRtc_InitBuffer(aecpc->far_pre_buf);
WebRtc_MoveReadPtr(aecpc->far_pre_buf, -PART_LEN); // Start overlap.
aecpc->initFlag = initCheck; // indicates that initialization has been done
if (aecpc->sampFreq == 32000 || aecpc->sampFreq == 48000) {
aecpc->splitSampFreq = 16000;
} else {
aecpc->splitSampFreq = sampFreq;
}
aecpc->delayCtr = 0;
aecpc->sampFactor = (aecpc->scSampFreq * 1.0f) / aecpc->splitSampFreq;
// Sampling frequency multiplier (SWB is processed as 160 frame size).
aecpc->rate_factor = aecpc->splitSampFreq / 8000;
aecpc->sum = 0;
aecpc->counter = 0;
aecpc->checkBuffSize = 1;
aecpc->firstVal = 0;
// We skip the startup_phase completely (setting to 0) if DA-AEC is enabled,
// but not extended_filter mode.
aecpc->startup_phase = WebRtcAec_extended_filter_enabled(aecpc->aec) ||
!WebRtcAec_delay_agnostic_enabled(aecpc->aec);
aecpc->bufSizeStart = 0;
aecpc->checkBufSizeCtr = 0;
aecpc->msInSndCardBuf = 0;
aecpc->filtDelay = -1; // -1 indicates an initialized state.
aecpc->timeForDelayChange = 0;
aecpc->knownDelay = 0;
aecpc->lastDelayDiff = 0;
aecpc->skewFrCtr = 0;
aecpc->resample = kAecFalse;
aecpc->highSkewCtr = 0;
aecpc->skew = 0;
aecpc->farend_started = 0;
// Default settings.
aecConfig.nlpMode = kAecNlpModerate;
aecConfig.skewMode = kAecFalse;
aecConfig.metricsMode = kAecFalse;
aecConfig.delay_logging = kAecFalse;
if (WebRtcAec_set_config(aecpc, aecConfig) == -1) {
return AEC_UNSPECIFIED_ERROR;
}
return 0;
}
// Returns any error that is caused when buffering the
// far-end signal.
int32_t WebRtcAec_GetBufferFarendError(void* aecInst,
const float* farend,
size_t nrOfSamples) {
Aec* aecpc = reinterpret_cast<Aec*>(aecInst);
if (!farend)
return AEC_NULL_POINTER_ERROR;
if (aecpc->initFlag != initCheck)
return AEC_UNINITIALIZED_ERROR;
// number of samples == 160 for SWB input
if (nrOfSamples != 80 && nrOfSamples != 160)
return AEC_BAD_PARAMETER_ERROR;
return 0;
}
// only buffer L band for farend
int32_t WebRtcAec_BufferFarend(void* aecInst,
const float* farend,
size_t nrOfSamples) {
Aec* aecpc = reinterpret_cast<Aec*>(aecInst);
size_t newNrOfSamples = nrOfSamples;
float new_farend[MAX_RESAMP_LEN];
const float* farend_ptr = farend;
// Get any error caused by buffering the farend signal.
int32_t error_code =
WebRtcAec_GetBufferFarendError(aecInst, farend, nrOfSamples);
if (error_code != 0)
return error_code;
if (aecpc->skewMode == kAecTrue && aecpc->resample == kAecTrue) {
// Resample and get a new number of samples
WebRtcAec_ResampleLinear(aecpc->resampler, farend, nrOfSamples, aecpc->skew,
new_farend, &newNrOfSamples);
farend_ptr = new_farend;
}
aecpc->farend_started = 1;
WebRtcAec_SetSystemDelay(aecpc->aec, WebRtcAec_system_delay(aecpc->aec) +
static_cast<int>(newNrOfSamples));
// Write the time-domain data to |far_pre_buf|.
WebRtc_WriteBuffer(aecpc->far_pre_buf, farend_ptr, newNrOfSamples);
// TODO(minyue): reduce to |PART_LEN| samples for each buffering.
while (WebRtc_available_read(aecpc->far_pre_buf) >= PART_LEN2) {
// We have enough data to pass to the FFT, hence read PART_LEN2 samples.
{
float* ptmp = NULL;
float tmp[PART_LEN2];
WebRtc_ReadBuffer(aecpc->far_pre_buf, reinterpret_cast<void**>(&ptmp),
tmp, PART_LEN2);
WebRtcAec_BufferFarendBlock(aecpc->aec, &ptmp[PART_LEN]);
}
// Rewind |far_pre_buf| PART_LEN samples for overlap before continuing.
WebRtc_MoveReadPtr(aecpc->far_pre_buf, -PART_LEN);
}
return 0;
}
int32_t WebRtcAec_Process(void* aecInst,
const float* const* nearend,
size_t num_bands,
float* const* out,
size_t nrOfSamples,
int16_t msInSndCardBuf,
int32_t skew) {
Aec* aecpc = reinterpret_cast<Aec*>(aecInst);
int32_t retVal = 0;
if (out == NULL) {
return AEC_NULL_POINTER_ERROR;
}
if (aecpc->initFlag != initCheck) {
return AEC_UNINITIALIZED_ERROR;
}
// number of samples == 160 for SWB input
if (nrOfSamples != 80 && nrOfSamples != 160) {
return AEC_BAD_PARAMETER_ERROR;
}
if (msInSndCardBuf < 0) {
msInSndCardBuf = 0;
retVal = AEC_BAD_PARAMETER_WARNING;
} else if (msInSndCardBuf > kMaxTrustedDelayMs) {
// The clamping is now done in ProcessExtended/Normal().
retVal = AEC_BAD_PARAMETER_WARNING;
}
// This returns the value of aec->extended_filter_enabled.
if (WebRtcAec_extended_filter_enabled(aecpc->aec)) {
ProcessExtended(aecpc, nearend, num_bands, out, nrOfSamples, msInSndCardBuf,
skew);
} else {
retVal = ProcessNormal(aecpc, nearend, num_bands, out, nrOfSamples,
msInSndCardBuf, skew);
}
int far_buf_size_samples = WebRtcAec_system_delay(aecpc->aec);
aecpc->data_dumper->DumpRaw("aec_system_delay", 1, &far_buf_size_samples);
aecpc->data_dumper->DumpRaw("aec_known_delay", 1, &aecpc->knownDelay);
return retVal;
}
int WebRtcAec_set_config(void* handle, AecConfig config) {
Aec* self = reinterpret_cast<Aec*>(handle);
if (self->initFlag != initCheck) {
return AEC_UNINITIALIZED_ERROR;
}
if (config.skewMode != kAecFalse && config.skewMode != kAecTrue) {
return AEC_BAD_PARAMETER_ERROR;
}
self->skewMode = config.skewMode;
if (config.nlpMode != kAecNlpConservative &&
config.nlpMode != kAecNlpModerate &&
config.nlpMode != kAecNlpAggressive) {
return AEC_BAD_PARAMETER_ERROR;
}
if (config.metricsMode != kAecFalse && config.metricsMode != kAecTrue) {
return AEC_BAD_PARAMETER_ERROR;
}
if (config.delay_logging != kAecFalse && config.delay_logging != kAecTrue) {
return AEC_BAD_PARAMETER_ERROR;
}
WebRtcAec_SetConfigCore(self->aec, config.nlpMode, config.metricsMode,
config.delay_logging);
return 0;
}
int WebRtcAec_get_echo_status(void* handle, int* status) {
Aec* self = reinterpret_cast<Aec*>(handle);
if (status == NULL) {
return AEC_NULL_POINTER_ERROR;
}
if (self->initFlag != initCheck) {
return AEC_UNINITIALIZED_ERROR;
}
*status = WebRtcAec_echo_state(self->aec);
return 0;
}
int WebRtcAec_GetMetrics(void* handle, AecMetrics* metrics) {
const float kUpWeight = 0.7f;
float dtmp;
int stmp;
Aec* self = reinterpret_cast<Aec*>(handle);
Stats erl;
Stats erle;
Stats a_nlp;
if (handle == NULL) {
return -1;
}
if (metrics == NULL) {
return AEC_NULL_POINTER_ERROR;
}
if (self->initFlag != initCheck) {
return AEC_UNINITIALIZED_ERROR;
}
WebRtcAec_GetEchoStats(self->aec, &erl, &erle, &a_nlp,
&metrics->divergent_filter_fraction);
// ERL
metrics->erl.instant = static_cast<int>(erl.instant);
if ((erl.himean > kOffsetLevel) && (erl.average > kOffsetLevel)) {
// Use a mix between regular average and upper part average.
dtmp = kUpWeight * erl.himean + (1 - kUpWeight) * erl.average;
metrics->erl.average = static_cast<int>(dtmp);
} else {
metrics->erl.average = kOffsetLevel;
}
metrics->erl.max = static_cast<int>(erl.max);
if (erl.min < (kOffsetLevel * (-1))) {
metrics->erl.min = static_cast<int>(erl.min);
} else {
metrics->erl.min = kOffsetLevel;
}
// ERLE
metrics->erle.instant = static_cast<int>(erle.instant);
if ((erle.himean > kOffsetLevel) && (erle.average > kOffsetLevel)) {
// Use a mix between regular average and upper part average.
dtmp = kUpWeight * erle.himean + (1 - kUpWeight) * erle.average;
metrics->erle.average = static_cast<int>(dtmp);
} else {
metrics->erle.average = kOffsetLevel;
}
metrics->erle.max = static_cast<int>(erle.max);
if (erle.min < (kOffsetLevel * (-1))) {
metrics->erle.min = static_cast<int>(erle.min);
} else {
metrics->erle.min = kOffsetLevel;
}
// RERL
if ((metrics->erl.average > kOffsetLevel) &&
(metrics->erle.average > kOffsetLevel)) {
stmp = metrics->erl.average + metrics->erle.average;
} else {
stmp = kOffsetLevel;
}
metrics->rerl.average = stmp;
// No other statistics needed, but returned for completeness.
metrics->rerl.instant = stmp;
metrics->rerl.max = stmp;
metrics->rerl.min = stmp;
// A_NLP
metrics->aNlp.instant = static_cast<int>(a_nlp.instant);
if ((a_nlp.himean > kOffsetLevel) && (a_nlp.average > kOffsetLevel)) {
// Use a mix between regular average and upper part average.
dtmp = kUpWeight * a_nlp.himean + (1 - kUpWeight) * a_nlp.average;
metrics->aNlp.average = static_cast<int>(dtmp);
} else {
metrics->aNlp.average = kOffsetLevel;
}
metrics->aNlp.max = static_cast<int>(a_nlp.max);
if (a_nlp.min < (kOffsetLevel * (-1))) {
metrics->aNlp.min = static_cast<int>(a_nlp.min);
} else {
metrics->aNlp.min = kOffsetLevel;
}
return 0;
}
int WebRtcAec_GetDelayMetrics(void* handle,
int* median,
int* std,
float* fraction_poor_delays) {
Aec* self = reinterpret_cast<Aec*>(handle);
if (median == NULL) {
return AEC_NULL_POINTER_ERROR;
}
if (std == NULL) {
return AEC_NULL_POINTER_ERROR;
}
if (self->initFlag != initCheck) {
return AEC_UNINITIALIZED_ERROR;
}
if (WebRtcAec_GetDelayMetricsCore(self->aec, median, std,
fraction_poor_delays) == -1) {
// Logging disabled.
return AEC_UNSUPPORTED_FUNCTION_ERROR;
}
return 0;
}
AecCore* WebRtcAec_aec_core(void* handle) {
if (!handle) {
return NULL;
}
return reinterpret_cast<Aec*>(handle)->aec;
}
static int ProcessNormal(Aec* aecInst,
const float* const* nearend,
size_t num_bands,
float* const* out,
size_t num_samples,
int16_t reported_delay_ms,
int32_t skew) {
int retVal = 0;
size_t i;
size_t nBlocks10ms;
// Limit resampling to doubling/halving of signal
const float minSkewEst = -0.5f;
const float maxSkewEst = 1.0f;
reported_delay_ms = reported_delay_ms > kMaxTrustedDelayMs
? kMaxTrustedDelayMs
: reported_delay_ms;
// TODO(andrew): we need to investigate if this +10 is really wanted.
reported_delay_ms += 10;
aecInst->msInSndCardBuf = reported_delay_ms;
if (aecInst->skewMode == kAecTrue) {
if (aecInst->skewFrCtr < 25) {
aecInst->skewFrCtr++;
} else {
retVal = WebRtcAec_GetSkew(aecInst->resampler, skew, &aecInst->skew);
if (retVal == -1) {
aecInst->skew = 0;
retVal = AEC_BAD_PARAMETER_WARNING;
}
aecInst->skew /= aecInst->sampFactor * num_samples;
if (aecInst->skew < 1.0e-3 && aecInst->skew > -1.0e-3) {
aecInst->resample = kAecFalse;
} else {
aecInst->resample = kAecTrue;
}
if (aecInst->skew < minSkewEst) {
aecInst->skew = minSkewEst;
} else if (aecInst->skew > maxSkewEst) {
aecInst->skew = maxSkewEst;
}
aecInst->data_dumper->DumpRaw("aec_skew", 1, &aecInst->skew);
}
}
nBlocks10ms = num_samples / (FRAME_LEN * aecInst->rate_factor);
if (aecInst->startup_phase) {
for (i = 0; i < num_bands; ++i) {
// Only needed if they don't already point to the same place.
if (nearend[i] != out[i]) {
memcpy(out[i], nearend[i], sizeof(nearend[i][0]) * num_samples);
}
}
// The AEC is in the start up mode
// AEC is disabled until the system delay is OK
// Mechanism to ensure that the system delay is reasonably stable.
if (aecInst->checkBuffSize) {
aecInst->checkBufSizeCtr++;
// Before we fill up the far-end buffer we require the system delay
// to be stable (+/-8 ms) compared to the first value. This
// comparison is made during the following 6 consecutive 10 ms
// blocks. If it seems to be stable then we start to fill up the
// far-end buffer.
if (aecInst->counter == 0) {
aecInst->firstVal = aecInst->msInSndCardBuf;
aecInst->sum = 0;
}
if (abs(aecInst->firstVal - aecInst->msInSndCardBuf) <
WEBRTC_SPL_MAX(0.2 * aecInst->msInSndCardBuf, sampMsNb)) {
aecInst->sum += aecInst->msInSndCardBuf;
aecInst->counter++;
} else {
aecInst->counter = 0;
}
if (aecInst->counter * nBlocks10ms >= 6) {
// The far-end buffer size is determined in partitions of
// PART_LEN samples. Use 75% of the average value of the system
// delay as buffer size to start with.
aecInst->bufSizeStart =
WEBRTC_SPL_MIN((3 * aecInst->sum * aecInst->rate_factor * 8) /
(4 * aecInst->counter * PART_LEN),
kMaxBufSizeStart);
// Buffer size has now been determined.
aecInst->checkBuffSize = 0;
}
if (aecInst->checkBufSizeCtr * nBlocks10ms > 50) {
// For really bad systems, don't disable the echo canceller for
// more than 0.5 sec.
aecInst->bufSizeStart = WEBRTC_SPL_MIN(
(aecInst->msInSndCardBuf * aecInst->rate_factor * 3) / 40,
kMaxBufSizeStart);
aecInst->checkBuffSize = 0;
}
}
// If |checkBuffSize| changed in the if-statement above.
if (!aecInst->checkBuffSize) {
// The system delay is now reasonably stable (or has been unstable
// for too long). When the far-end buffer is filled with
// approximately the same amount of data as reported by the system
// we end the startup phase.
int overhead_elements = WebRtcAec_system_delay(aecInst->aec) / PART_LEN -
aecInst->bufSizeStart;
if (overhead_elements == 0) {
// Enable the AEC
aecInst->startup_phase = 0;
} else if (overhead_elements > 0) {
// TODO(bjornv): Do we need a check on how much we actually
// moved the read pointer? It should always be possible to move
// the pointer |overhead_elements| since we have only added data
// to the buffer and no delay compensation nor AEC processing
// has been done.
WebRtcAec_AdjustFarendBufferSizeAndSystemDelay(aecInst->aec,
overhead_elements);
// Enable the AEC
aecInst->startup_phase = 0;
}
}
} else {
// AEC is enabled.
EstBufDelayNormal(aecInst);
// Call the AEC.
// TODO(bjornv): Re-structure such that we don't have to pass
// |aecInst->knownDelay| as input. Change name to something like
// |system_buffer_diff|.
WebRtcAec_ProcessFrames(aecInst->aec, nearend, num_bands, num_samples,
aecInst->knownDelay, out);
}
return retVal;
}
static void ProcessExtended(Aec* self,
const float* const* nearend,
size_t num_bands,
float* const* out,
size_t num_samples,
int16_t reported_delay_ms,
int32_t skew) {
size_t i;
const int delay_diff_offset = kDelayDiffOffsetSamples;
RTC_DCHECK(num_samples == 80 || num_samples == 160);
#if defined(WEBRTC_UNTRUSTED_DELAY)
reported_delay_ms = kFixedDelayMs;
#else
// This is the usual mode where we trust the reported system delay values.
// Due to the longer filter, we no longer add 10 ms to the reported delay
// to reduce chance of non-causality. Instead we apply a minimum here to avoid
// issues with the read pointer jumping around needlessly.
reported_delay_ms = reported_delay_ms < kMinTrustedDelayMs
? kMinTrustedDelayMs
: reported_delay_ms;
// If the reported delay appears to be bogus, we attempt to recover by using
// the measured fixed delay values. We use >= here because higher layers
// may already clamp to this maximum value, and we would otherwise not
// detect it here.
reported_delay_ms = reported_delay_ms >= kMaxTrustedDelayMs
? kFixedDelayMs
: reported_delay_ms;
#endif
self->msInSndCardBuf = reported_delay_ms;
if (!self->farend_started) {
for (i = 0; i < num_bands; ++i) {
// Only needed if they don't already point to the same place.
if (nearend[i] != out[i]) {
memcpy(out[i], nearend[i], sizeof(nearend[i][0]) * num_samples);
}
}
return;
}
if (self->startup_phase) {
// In the extended mode, there isn't a startup "phase", just a special
// action on the first frame. In the trusted delay case, we'll take the
// current reported delay, unless it's less then our conservative
// measurement.
int startup_size_ms =
reported_delay_ms < kFixedDelayMs ? kFixedDelayMs : reported_delay_ms;
#if defined(WEBRTC_ANDROID)
int target_delay = startup_size_ms * self->rate_factor * 8;
#else
// To avoid putting the AEC in a non-causal state we're being slightly
// conservative and scale by 2. On Android we use a fixed delay and
// therefore there is no need to scale the target_delay.
int target_delay = startup_size_ms * self->rate_factor * 8 / 2;
#endif
int overhead_elements =
(WebRtcAec_system_delay(self->aec) - target_delay) / PART_LEN;
WebRtcAec_AdjustFarendBufferSizeAndSystemDelay(self->aec,
overhead_elements);
self->startup_phase = 0;
}
EstBufDelayExtended(self);
{
// |delay_diff_offset| gives us the option to manually rewind the delay on
// very low delay platforms which can't be expressed purely through
// |reported_delay_ms|.
const int adjusted_known_delay =
WEBRTC_SPL_MAX(0, self->knownDelay + delay_diff_offset);
WebRtcAec_ProcessFrames(self->aec, nearend, num_bands, num_samples,
adjusted_known_delay, out);
}
}
static void EstBufDelayNormal(Aec* aecInst) {
int nSampSndCard = aecInst->msInSndCardBuf * sampMsNb * aecInst->rate_factor;
int current_delay = nSampSndCard - WebRtcAec_system_delay(aecInst->aec);
int delay_difference = 0;
// Before we proceed with the delay estimate filtering we:
// 1) Compensate for the frame that will be read.
// 2) Compensate for drift resampling.
// 3) Compensate for non-causality if needed, since the estimated delay can't
// be negative.
// 1) Compensating for the frame(s) that will be read/processed.
current_delay += FRAME_LEN * aecInst->rate_factor;
// 2) Account for resampling frame delay.
if (aecInst->skewMode == kAecTrue && aecInst->resample == kAecTrue) {
current_delay -= kResamplingDelay;
}
// 3) Compensate for non-causality, if needed, by flushing one block.
if (current_delay < PART_LEN) {
current_delay +=
WebRtcAec_AdjustFarendBufferSizeAndSystemDelay(aecInst->aec, 1) *
PART_LEN;
}
// We use -1 to signal an initialized state in the "extended" implementation;
// compensate for that.
aecInst->filtDelay = aecInst->filtDelay < 0 ? 0 : aecInst->filtDelay;
aecInst->filtDelay = WEBRTC_SPL_MAX(
0, static_cast<int16_t>(0.8 * aecInst->filtDelay + 0.2 * current_delay));
delay_difference = aecInst->filtDelay - aecInst->knownDelay;
if (delay_difference > 224) {
if (aecInst->lastDelayDiff < 96) {
aecInst->timeForDelayChange = 0;
} else {
aecInst->timeForDelayChange++;
}
} else if (delay_difference < 96 && aecInst->knownDelay > 0) {
if (aecInst->lastDelayDiff > 224) {
aecInst->timeForDelayChange = 0;
} else {
aecInst->timeForDelayChange++;
}
} else {
aecInst->timeForDelayChange = 0;
}
aecInst->lastDelayDiff = delay_difference;
if (aecInst->timeForDelayChange > 25) {
aecInst->knownDelay = WEBRTC_SPL_MAX((int)aecInst->filtDelay - 160, 0);
}
}
static void EstBufDelayExtended(Aec* aecInst) {
int reported_delay =
aecInst->msInSndCardBuf * sampMsNb * aecInst->rate_factor;
int current_delay = reported_delay - WebRtcAec_system_delay(aecInst->aec);
int delay_difference = 0;
// Before we proceed with the delay estimate filtering we:
// 1) Compensate for the frame that will be read.
// 2) Compensate for drift resampling.
// 3) Compensate for non-causality if needed, since the estimated delay can't
// be negative.
// 1) Compensating for the frame(s) that will be read/processed.
current_delay += FRAME_LEN * aecInst->rate_factor;
// 2) Account for resampling frame delay.
if (aecInst->skewMode == kAecTrue && aecInst->resample == kAecTrue) {
current_delay -= kResamplingDelay;
}
// 3) Compensate for non-causality, if needed, by flushing two blocks.
if (current_delay < PART_LEN) {
current_delay +=
WebRtcAec_AdjustFarendBufferSizeAndSystemDelay(aecInst->aec, 2) *
PART_LEN;
}
if (aecInst->filtDelay == -1) {
aecInst->filtDelay = WEBRTC_SPL_MAX(0, 0.5 * current_delay);
} else {
aecInst->filtDelay = WEBRTC_SPL_MAX(
0,
static_cast<int16_t>(0.95 * aecInst->filtDelay + 0.05 * current_delay));
}
delay_difference = aecInst->filtDelay - aecInst->knownDelay;
if (delay_difference > 384) {
if (aecInst->lastDelayDiff < 128) {
aecInst->timeForDelayChange = 0;
} else {
aecInst->timeForDelayChange++;
}
} else if (delay_difference < 128 && aecInst->knownDelay > 0) {
if (aecInst->lastDelayDiff > 384) {
aecInst->timeForDelayChange = 0;
} else {
aecInst->timeForDelayChange++;
}
} else {
aecInst->timeForDelayChange = 0;
}
aecInst->lastDelayDiff = delay_difference;
if (aecInst->timeForDelayChange > 25) {
aecInst->knownDelay = WEBRTC_SPL_MAX((int)aecInst->filtDelay - 256, 0);
}
}
} // namespace webrtc