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AEC3: Add state-specific suppressor behaviors

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This CL allows selecting an echo suppressor behavior which is specific
for whether the nearend is dominant, or the echo is dominant.

The changes in this CL are bitexact.

Bug: webrtc:9660
Change-Id: Ie32e65efe47e692de6d6a22a7ad3b469d745fd6b
Reviewed-on: https://webrtc-review.googlesource.com/95725
Commit-Queue: Per Åhgren <peah@webrtc.org>
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24434}
This commit is contained in:
Per Åhgren
2018-08-24 22:48:49 +02:00
committed by Commit Bot
parent 90ab76dd19
commit 524e878121
5 changed files with 225 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
api/audio/echo_canceller3_config.cc
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@ -25,4 +25,30 @@ EchoCanceller3Config::EchoModel::EchoModel() = default;
EchoCanceller3Config::EchoModel::EchoModel(
const EchoCanceller3Config::EchoModel& e) = default;
EchoCanceller3Config::Suppressor::Suppressor() = default;
EchoCanceller3Config::Suppressor::Suppressor(
const EchoCanceller3Config::Suppressor& e) = default;
EchoCanceller3Config::Suppressor::MaskingThresholds::MaskingThresholds(
float enr_transparent,
float enr_suppress,
float emr_transparent)
: enr_transparent(enr_transparent),
enr_suppress(enr_suppress),
emr_transparent(emr_transparent) {}
EchoCanceller3Config::Suppressor::Suppressor::MaskingThresholds::
MaskingThresholds(
const EchoCanceller3Config::Suppressor::MaskingThresholds& e) = default;
EchoCanceller3Config::Suppressor::Tuning::Tuning(MaskingThresholds mask_lf,
MaskingThresholds mask_hf,
float max_inc_factor,
float max_dec_factor_lf)
: mask_lf(mask_lf),
mask_hf(mask_hf),
max_inc_factor(max_inc_factor),
max_dec_factor_lf(max_dec_factor_lf) {}
EchoCanceller3Config::Suppressor::Tuning::Tuning(
const EchoCanceller3Config::Suppressor::Tuning& e) = default;
} // namespace webrtc

45
api/audio/echo_canceller3_config.h
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@ -112,12 +112,6 @@ struct EchoCanceller3Config {
float poor_excitation_render_limit_ds8 = 20.f;
} render_levels;
struct GainUpdates {
float max_inc_factor = 2.0f;
float max_dec_factor_lf = 0.25f;
float floor_first_increase = 0.00001f;
} gain_updates;
struct EchoRemovalControl {
struct GainRampup {
float initial_gain = 0.0f;
@ -146,15 +140,50 @@ struct EchoCanceller3Config {
} echo_model;
struct Suppressor {
Suppressor();
Suppressor(const Suppressor& e);
size_t nearend_average_blocks = 4;
struct MaskingThresholds {
MaskingThresholds(float enr_transparent,
float enr_suppress,
float emr_transparent);
MaskingThresholds(const MaskingThresholds& e);
float enr_transparent;
float enr_suppress;
float emr_transparent;
};
MaskingThresholds mask_lf = {.2f, .3f, .3f};
MaskingThresholds mask_hf = {.07f, .1f, .3f};
struct Tuning {
Tuning(MaskingThresholds mask_lf,
MaskingThresholds mask_hf,
float max_inc_factor,
float max_dec_factor_lf);
Tuning(const Tuning& e);
MaskingThresholds mask_lf;
MaskingThresholds mask_hf;
float max_inc_factor;
float max_dec_factor_lf;
};
Tuning normal_tuning = Tuning(MaskingThresholds(.2f, .3f, .3f),
MaskingThresholds(.07f, .1f, .3f),
2.0f,
0.25f);
Tuning nearend_tuning = Tuning(MaskingThresholds(.2f, .3f, .3f),
MaskingThresholds(.07f, .1f, .3f),
2.0f,
0.25f);
struct DominantNearendDetection {
float enr_threshold = 10.f;
float snr_threshold = 10.f;
int hold_duration = 25;
int trigger_threshold = 15;
} dominant_nearend_detection;
float floor_first_increase = 0.00001f;
bool enforce_transparent = false;
bool enforce_empty_higher_bands = false;
} suppressor;

120
modules/audio_processing/aec3/suppression_gain.cc
View File

@ -1,4 +1,3 @@
/*
* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
*
@ -227,13 +226,16 @@ void SuppressionGain::GainToNoAudibleEcho(
const std::array<float, kFftLengthBy2Plus1>& min_gain,
const std::array<float, kFftLengthBy2Plus1>& max_gain,
std::array<float, kFftLengthBy2Plus1>* gain) const {
const auto& p = dominant_nearend_detector_.IsNearendState() ? nearend_params_
: normal_params_;
for (size_t k = 0; k < gain->size(); ++k) {
float enr = echo[k] / (nearend[k] + 1.f); // Echo-to-nearend ratio.
float emr = echo[k] / (masker[k] + 1.f); // Echo-to-masker (noise) ratio.
float g = 1.0f;
if (enr > enr_transparent_[k] && emr > emr_transparent_[k]) {
g = (enr_suppress_[k] - enr) / (enr_suppress_[k] - enr_transparent_[k]);
g = std::max(g, emr_transparent_[k] / emr);
if (enr > p.enr_transparent_[k] && emr > p.emr_transparent_[k]) {
g = (p.enr_suppress_[k] - enr) /
(p.enr_suppress_[k] - p.enr_transparent_[k]);
g = std::max(g, p.emr_transparent_[k] / emr);
}
(*gain)[k] = std::max(std::min(g, max_gain[k]), min_gain[k]);
}
@ -249,6 +251,9 @@ void SuppressionGain::LowerBandGain(
std::array<float, kFftLengthBy2Plus1>* gain) {
const bool saturated_echo = aec_state.SaturatedEcho();
const bool linear_echo_estimate = aec_state.UsableLinearEstimate();
const auto& params = dominant_nearend_detector_.IsNearendState()
? nearend_params_
: normal_params_;
// Weight echo power in terms of audibility. // Precompute 1/weighted echo
// (note that when the echo is zero, the precomputed value is never used).
@ -273,8 +278,7 @@ void SuppressionGain::LowerBandGain(
// quickly after strong nearend.
if (last_nearend_[k] > last_echo_[k]) {
min_gain[k] =
std::max(min_gain[k],
last_gain_[k] * config_.gain_updates.max_dec_factor_lf);
std::max(min_gain[k], last_gain_[k] * params.max_dec_factor_lf);
min_gain[k] = std::min(min_gain[k], 1.f);
}
}
@ -286,10 +290,9 @@ void SuppressionGain::LowerBandGain(
// gain.
std::array<float, kFftLengthBy2Plus1> max_gain;
for (size_t k = 0; k < gain->size(); ++k) {
max_gain[k] =
std::min(std::max(last_gain_[k] * config_.gain_updates.max_inc_factor,
config_.gain_updates.floor_first_increase),
1.f);
max_gain[k] = std::min(std::max(last_gain_[k] * params.max_inc_factor,
config_.suppressor.floor_first_increase),
1.f);
}
// Iteratively compute the gain required to attenuate the echo to a non
@ -337,34 +340,16 @@ SuppressionGain::SuppressionGain(const EchoCanceller3Config& config,
static_cast<int>(config_.filter.config_change_duration_blocks)),
enable_new_suppression_(EnableNewSuppression()),
moving_average_(kFftLengthBy2Plus1,
config.suppressor.nearend_average_blocks) {
config.suppressor.nearend_average_blocks),
nearend_params_(config_.suppressor.nearend_tuning),
normal_params_(config_.suppressor.normal_tuning),
dominant_nearend_detector_(
config_.suppressor.dominant_nearend_detection) {
RTC_DCHECK_LT(0, state_change_duration_blocks_);
one_by_state_change_duration_blocks_ = 1.f / state_change_duration_blocks_;
last_gain_.fill(1.f);
last_nearend_.fill(0.f);
last_echo_.fill(0.f);
// Compute per-band masking thresholds.
constexpr size_t kLastLfBand = 5;
constexpr size_t kFirstHfBand = 8;
RTC_DCHECK_LT(kLastLfBand, kFirstHfBand);
auto& lf = config.suppressor.mask_lf;
auto& hf = config.suppressor.mask_hf;
RTC_DCHECK_LT(lf.enr_transparent, lf.enr_suppress);
RTC_DCHECK_LT(hf.enr_transparent, hf.enr_suppress);
for (size_t k = 0; k < kFftLengthBy2Plus1; k++) {
float a;
if (k <= kLastLfBand) {
a = 0.f;
} else if (k < kFirstHfBand) {
a = (k - kLastLfBand) / static_cast<float>(kFirstHfBand - kLastLfBand);
} else {
a = 1.f;
}
enr_transparent_[k] = (1 - a) * lf.enr_transparent + a * hf.enr_transparent;
enr_suppress_[k] = (1 - a) * lf.enr_suppress + a * hf.enr_suppress;
emr_transparent_[k] = (1 - a) * lf.emr_transparent + a * hf.emr_transparent;
}
}
SuppressionGain::~SuppressionGain() = default;
@ -393,6 +378,10 @@ void SuppressionGain::GetGain(
std::array<float, kFftLengthBy2Plus1> nearend_average;
moving_average_.Average(nearend_spectrum, nearend_average);
// Update the state selection.
dominant_nearend_detector_.Update(nearend_spectrum, echo_spectrum,
comfort_noise_spectrum);
// Compute gain for the lower band.
bool low_noise_render = low_render_detector_.Detect(render);
const absl::optional<int> narrow_peak_band =
@ -444,4 +433,69 @@ bool SuppressionGain::LowNoiseRenderDetector::Detect(
return low_noise_render;
}
SuppressionGain::DominantNearendDetector::DominantNearendDetector(
const EchoCanceller3Config::Suppressor::DominantNearendDetection config)
: enr_threshold_(config.enr_threshold),
snr_threshold_(config.snr_threshold),
hold_duration_(config.hold_duration),
trigger_threshold_(config.trigger_threshold) {}
void SuppressionGain::DominantNearendDetector::Update(
rtc::ArrayView<const float> nearend_spectrum,
rtc::ArrayView<const float> echo_spectrum,
rtc::ArrayView<const float> comfort_noise_spectrum) {
auto low_frequency_energy = [](rtc::ArrayView<const float> spectrum) {
RTC_DCHECK_LE(16, spectrum.size());
return std::accumulate(spectrum.begin() + 1, spectrum.begin() + 16, 0.f);
};
const float ne_sum = low_frequency_energy(nearend_spectrum);
const float echo_sum = low_frequency_energy(echo_spectrum);
const float noise_sum = low_frequency_energy(comfort_noise_spectrum);
// Detect strong active nearend if the nearend is sufficiently stronger than
// the echo and the nearend noise.
if (ne_sum > enr_threshold_ * echo_sum &&
ne_sum > snr_threshold_ * noise_sum) {
if (++trigger_counter_ >= trigger_threshold_) {
// After a period of strong active nearend activity, flag nearend mode.
hold_counter_ = hold_duration_;
trigger_counter_ = trigger_threshold_;
}
} else {
// Forget previously detected strong active nearend activity.
trigger_counter_ = std::max(0, trigger_counter_ - 1);
}
// Remain in any nearend mode for a certain duration.
hold_counter_ = std::max(0, hold_counter_ - 1);
nearend_state_ = hold_counter_ > 0;
}
SuppressionGain::GainParameters::GainParameters(
const EchoCanceller3Config::Suppressor::Tuning& tuning)
: max_inc_factor(tuning.max_inc_factor),
max_dec_factor_lf(tuning.max_dec_factor_lf) {
// Compute per-band masking thresholds.
constexpr size_t kLastLfBand = 5;
constexpr size_t kFirstHfBand = 8;
RTC_DCHECK_LT(kLastLfBand, kFirstHfBand);
auto& lf = tuning.mask_lf;
auto& hf = tuning.mask_hf;
RTC_DCHECK_LT(lf.enr_transparent, lf.enr_suppress);
RTC_DCHECK_LT(hf.enr_transparent, hf.enr_suppress);
for (size_t k = 0; k < kFftLengthBy2Plus1; k++) {
float a;
if (k <= kLastLfBand) {
a = 0.f;
} else if (k < kFirstHfBand) {
a = (k - kLastLfBand) / static_cast<float>(kFirstHfBand - kLastLfBand);
} else {
a = 1.f;
}
enr_transparent_[k] = (1 - a) * lf.enr_transparent + a * hf.enr_transparent;
enr_suppress_[k] = (1 - a) * lf.enr_suppress + a * hf.enr_suppress;
emr_transparent_[k] = (1 - a) * lf.emr_transparent + a * hf.emr_transparent;
}
}
} // namespace webrtc

42
modules/audio_processing/aec3/suppression_gain.h
View File

@ -68,6 +68,42 @@ class SuppressionGain {
float average_power_ = 32768.f * 32768.f;
};
// Class for selecting whether the suppressor is in the nearend or echo state.
class DominantNearendDetector {
public:
explicit DominantNearendDetector(
const EchoCanceller3Config::Suppressor::DominantNearendDetection
config);
// Returns whether the current state is the nearend state.
bool IsNearendState() const { return nearend_state_; }
// Updates the state selection based on latest spectral estimates.
void Update(rtc::ArrayView<const float> nearend_spectrum,
rtc::ArrayView<const float> echo_spectrum,
rtc::ArrayView<const float> comfort_noise_spectrum);
private:
const float enr_threshold_;
const float snr_threshold_;
const int hold_duration_;
const int trigger_threshold_;
bool nearend_state_ = false;
int trigger_counter_ = 0;
int hold_counter_ = 0;
};
struct GainParameters {
explicit GainParameters(
const EchoCanceller3Config::Suppressor::Tuning& tuning);
const float max_inc_factor;
const float max_dec_factor_lf;
std::array<float, kFftLengthBy2Plus1> enr_transparent_;
std::array<float, kFftLengthBy2Plus1> enr_suppress_;
std::array<float, kFftLengthBy2Plus1> emr_transparent_;
};
static int instance_count_;
std::unique_ptr<ApmDataDumper> data_dumper_;
const Aec3Optimization optimization_;
@ -77,14 +113,14 @@ class SuppressionGain {
std::array<float, kFftLengthBy2Plus1> last_gain_;
std::array<float, kFftLengthBy2Plus1> last_nearend_;
std::array<float, kFftLengthBy2Plus1> last_echo_;
std::array<float, kFftLengthBy2Plus1> enr_transparent_;
std::array<float, kFftLengthBy2Plus1> enr_suppress_;
std::array<float, kFftLengthBy2Plus1> emr_transparent_;
LowNoiseRenderDetector low_render_detector_;
bool initial_state_ = true;
int initial_state_change_counter_ = 0;
const bool enable_new_suppression_;
aec3::MovingAverage moving_average_;
const GainParameters nearend_params_;
const GainParameters normal_params_;
DominantNearendDetector dominant_nearend_detector_;
RTC_DISALLOW_COPY_AND_ASSIGN(SuppressionGain);
};

46
modules/audio_processing/test/audio_processing_simulator.cc
View File

@ -290,14 +290,6 @@ class Aec3ParametersParser {
&cfg.echo_audibility.use_stationary_properties);
}
if (rtc::GetValueFromJsonObject(root, "gain_updates", &section)) {
ReadParam(section, "max_inc_factor", &cfg.gain_updates.max_inc_factor);
ReadParam(section, "max_dec_factor_lf",
&cfg.gain_updates.max_dec_factor_lf);
ReadParam(section, "floor_first_increase",
&cfg.gain_updates.floor_first_increase);
}
if (rtc::GetValueFromJsonObject(root, "echo_removal_control", &section)) {
Json::Value subsection;
if (rtc::GetValueFromJsonObject(section, "gain_rampup", &subsection)) {
@ -338,11 +330,45 @@ class Aec3ParametersParser {
&cfg.echo_model.nonlinear_release);
}
Json::Value subsection;
if (rtc::GetValueFromJsonObject(root, "suppressor", &section)) {
ReadParam(section, "nearend_average_blocks",
&cfg.suppressor.nearend_average_blocks);
ReadParam(section, "mask_lf", &cfg.suppressor.mask_lf);
ReadParam(section, "mask_hf", &cfg.suppressor.mask_hf);
if (rtc::GetValueFromJsonObject(section, "normal_tuning", &subsection)) {
ReadParam(subsection, "mask_lf", &cfg.suppressor.normal_tuning.mask_lf);
ReadParam(subsection, "mask_hf", &cfg.suppressor.normal_tuning.mask_hf);
ReadParam(subsection, "max_inc_factor",
&cfg.suppressor.normal_tuning.max_inc_factor);
ReadParam(subsection, "max_dec_factor_lf",
&cfg.suppressor.normal_tuning.max_dec_factor_lf);
}
if (rtc::GetValueFromJsonObject(section, "nearend_tuning", &subsection)) {
ReadParam(subsection, "mask_lf",
&cfg.suppressor.nearend_tuning.mask_lf);
ReadParam(subsection, "mask_hf",
&cfg.suppressor.nearend_tuning.mask_hf);
ReadParam(subsection, "max_inc_factor",
&cfg.suppressor.nearend_tuning.max_inc_factor);
ReadParam(subsection, "max_dec_factor_lf",
&cfg.suppressor.nearend_tuning.max_dec_factor_lf);
}
if (rtc::GetValueFromJsonObject(section, "dominant_nearend_detection",
&subsection)) {
ReadParam(subsection, "enr_threshold",
&cfg.suppressor.dominant_nearend_detection.enr_threshold);
ReadParam(subsection, "snr_threshold",
&cfg.suppressor.dominant_nearend_detection.snr_threshold);
ReadParam(subsection, "hold_duration",
&cfg.suppressor.dominant_nearend_detection.hold_duration);
ReadParam(subsection, "trigger_threshold",
&cfg.suppressor.dominant_nearend_detection.trigger_threshold);
}
ReadParam(section, "floor_first_increase",
&cfg.suppressor.floor_first_increase);
ReadParam(section, "enforce_transparent",
&cfg.suppressor.enforce_transparent);
ReadParam(section, "enforce_empty_higher_bands",