Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

31 files changed, 2854 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/audio_processing/ns/BUILD.gn b/third_party/libwebrtc/modules/audio_processing/ns/BUILD.gn
new file mode 100644
index 0000000000..8c2e9dba84
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/BUILD.gn
@@ -0,0 +1,104 @@
+# Copyright (c) 2019 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.
+
+import("../../../webrtc.gni")
+
+rtc_static_library("ns") {
+  visibility = [ "*" ]
+  configs += [ "..:apm_debug_dump" ]
+  sources = [
+    "fast_math.cc",
+    "fast_math.h",
+    "histograms.cc",
+    "histograms.h",
+    "noise_estimator.cc",
+    "noise_estimator.h",
+    "noise_suppressor.cc",
+    "noise_suppressor.h",
+    "ns_common.h",
+    "ns_config.h",
+    "ns_fft.cc",
+    "ns_fft.h",
+    "prior_signal_model.cc",
+    "prior_signal_model.h",
+    "prior_signal_model_estimator.cc",
+    "prior_signal_model_estimator.h",
+    "quantile_noise_estimator.cc",
+    "quantile_noise_estimator.h",
+    "signal_model.cc",
+    "signal_model.h",
+    "signal_model_estimator.cc",
+    "signal_model_estimator.h",
+    "speech_probability_estimator.cc",
+    "speech_probability_estimator.h",
+    "suppression_params.cc",
+    "suppression_params.h",
+    "wiener_filter.cc",
+    "wiener_filter.h",
+  ]
+
+  defines = []
+  if (rtc_build_with_neon && target_cpu != "arm64") {
+    suppressed_configs += [ "//build/config/compiler:compiler_arm_fpu" ]
+    cflags = [ "-mfpu=neon" ]
+  }
+
+  deps = [
+    "..:apm_logging",
+    "..:audio_buffer",
+    "..:high_pass_filter",
+    "../../../api:array_view",
+    "../../../common_audio:common_audio_c",
+    "../../../common_audio/third_party/ooura:fft_size_128",
+    "../../../common_audio/third_party/ooura:fft_size_256",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:safe_minmax",
+    "../../../rtc_base/system:arch",
+    "../../../system_wrappers",
+    "../../../system_wrappers:field_trial",
+    "../../../system_wrappers:metrics",
+    "../utility:cascaded_biquad_filter",
+  ]
+  absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
+}
+
+if (rtc_include_tests) {
+  rtc_source_set("ns_unittests") {
+    testonly = true
+
+    configs += [ "..:apm_debug_dump" ]
+    sources = [ "noise_suppressor_unittest.cc" ]
+
+    deps = [
+      ":ns",
+      "..:apm_logging",
+      "..:audio_buffer",
+      "..:audio_processing",
+      "..:high_pass_filter",
+      "../../../api:array_view",
+      "../../../rtc_base:checks",
+      "../../../rtc_base:safe_minmax",
+      "../../../rtc_base:stringutils",
+      "../../../rtc_base/system:arch",
+      "../../../system_wrappers",
+      "../../../test:test_support",
+      "../utility:cascaded_biquad_filter",
+    ]
+    absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
+
+    defines = []
+
+    if (rtc_enable_protobuf) {
+      sources += []
+    }
+
+    if (!build_with_chromium) {
+      deps += [ "..:audio_processing_unittests" ]
+    }
+  }
+}
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/fast_math.cc b/third_party/libwebrtc/modules/audio_processing/ns/fast_math.cc
new file mode 100644
index 0000000000..d13110c43f
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/fast_math.cc
@@ -0,0 +1,84 @@
+/*
+ *  Copyright (c) 2019 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/ns/fast_math.h"
+
+#include <math.h>
+#include <stdint.h>
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+namespace {
+
+float FastLog2f(float in) {
+  RTC_DCHECK_GT(in, .0f);
+  // Read and interpret float as uint32_t and then cast to float.
+  // This is done to extract the exponent (bits 30 - 23).
+  // "Right shift" of the exponent is then performed by multiplying
+  // with the constant (1/2^23). Finally, we subtract a constant to
+  // remove the bias (https://en.wikipedia.org/wiki/Exponent_bias).
+  union {
+    float dummy;
+    uint32_t a;
+  } x = {in};
+  float out = x.a;
+  out *= 1.1920929e-7f;  // 1/2^23
+  out -= 126.942695f;    // Remove bias.
+  return out;
+}
+
+}  // namespace
+
+float SqrtFastApproximation(float f) {
+  // TODO(peah): Add fast approximate implementation.
+  return sqrtf(f);
+}
+
+float Pow2Approximation(float p) {
+  // TODO(peah): Add fast approximate implementation.
+  return powf(2.f, p);
+}
+
+float PowApproximation(float x, float p) {
+  return Pow2Approximation(p * FastLog2f(x));
+}
+
+float LogApproximation(float x) {
+  constexpr float kLogOf2 = 0.69314718056f;
+  return FastLog2f(x) * kLogOf2;
+}
+
+void LogApproximation(rtc::ArrayView<const float> x, rtc::ArrayView<float> y) {
+  for (size_t k = 0; k < x.size(); ++k) {
+    y[k] = LogApproximation(x[k]);
+  }
+}
+
+float ExpApproximation(float x) {
+  constexpr float kLog10Ofe = 0.4342944819f;
+  return PowApproximation(10.f, x * kLog10Ofe);
+}
+
+void ExpApproximation(rtc::ArrayView<const float> x, rtc::ArrayView<float> y) {
+  for (size_t k = 0; k < x.size(); ++k) {
+    y[k] = ExpApproximation(x[k]);
+  }
+}
+
+void ExpApproximationSignFlip(rtc::ArrayView<const float> x,
+                              rtc::ArrayView<float> y) {
+  for (size_t k = 0; k < x.size(); ++k) {
+    y[k] = ExpApproximation(-x[k]);
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/fast_math.h b/third_party/libwebrtc/modules/audio_processing/ns/fast_math.h
new file mode 100644
index 0000000000..0aefee940b
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/fast_math.h
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_FAST_MATH_H_
+#define MODULES_AUDIO_PROCESSING_NS_FAST_MATH_H_
+
+#include "api/array_view.h"
+
+namespace webrtc {
+
+// Sqrt approximation.
+float SqrtFastApproximation(float f);
+
+// Log base conversion log(x) = log2(x)/log2(e).
+float LogApproximation(float x);
+void LogApproximation(rtc::ArrayView<const float> x, rtc::ArrayView<float> y);
+
+// 2^x approximation.
+float Pow2Approximation(float p);
+
+// x^p approximation.
+float PowApproximation(float x, float p);
+
+// e^x approximation.
+float ExpApproximation(float x);
+void ExpApproximation(rtc::ArrayView<const float> x, rtc::ArrayView<float> y);
+void ExpApproximationSignFlip(rtc::ArrayView<const float> x,
+                              rtc::ArrayView<float> y);
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_FAST_MATH_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/histograms.cc b/third_party/libwebrtc/modules/audio_processing/ns/histograms.cc
new file mode 100644
index 0000000000..1d4f4590d2
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/histograms.cc
@@ -0,0 +1,47 @@
+/*
+ *  Copyright (c) 2019 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/ns/histograms.h"
+
+namespace webrtc {
+
+Histograms::Histograms() {
+  Clear();
+}
+
+void Histograms::Clear() {
+  lrt_.fill(0);
+  spectral_flatness_.fill(0);
+  spectral_diff_.fill(0);
+}
+
+void Histograms::Update(const SignalModel& features_) {
+  // Update the histogram for the LRT.
+  constexpr float kOneByBinSizeLrt = 1.f / kBinSizeLrt;
+  if (features_.lrt < kHistogramSize * kBinSizeLrt && features_.lrt >= 0.f) {
+    ++lrt_[kOneByBinSizeLrt * features_.lrt];
+  }
+
+  // Update histogram for the spectral flatness.
+  constexpr float kOneByBinSizeSpecFlat = 1.f / kBinSizeSpecFlat;
+  if (features_.spectral_flatness < kHistogramSize * kBinSizeSpecFlat &&
+      features_.spectral_flatness >= 0.f) {
+    ++spectral_flatness_[features_.spectral_flatness * kOneByBinSizeSpecFlat];
+  }
+
+  // Update histogram for the spectral difference.
+  constexpr float kOneByBinSizeSpecDiff = 1.f / kBinSizeSpecDiff;
+  if (features_.spectral_diff < kHistogramSize * kBinSizeSpecDiff &&
+      features_.spectral_diff >= 0.f) {
+    ++spectral_diff_[features_.spectral_diff * kOneByBinSizeSpecDiff];
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/histograms.h b/third_party/libwebrtc/modules/audio_processing/ns/histograms.h
new file mode 100644
index 0000000000..9640e743cf
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/histograms.h
@@ -0,0 +1,55 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_HISTOGRAMS_H_
+#define MODULES_AUDIO_PROCESSING_NS_HISTOGRAMS_H_
+
+#include <array>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/ns_common.h"
+#include "modules/audio_processing/ns/signal_model.h"
+
+namespace webrtc {
+
+constexpr int kHistogramSize = 1000;
+
+// Class for handling the updating of histograms.
+class Histograms {
+ public:
+  Histograms();
+  Histograms(const Histograms&) = delete;
+  Histograms& operator=(const Histograms&) = delete;
+
+  // Clears the histograms.
+  void Clear();
+
+  // Extracts thresholds for feature parameters and updates the corresponding
+  // histogram.
+  void Update(const SignalModel& features_);
+
+  // Methods for accessing the histograms.
+  rtc::ArrayView<const int, kHistogramSize> get_lrt() const { return lrt_; }
+  rtc::ArrayView<const int, kHistogramSize> get_spectral_flatness() const {
+    return spectral_flatness_;
+  }
+  rtc::ArrayView<const int, kHistogramSize> get_spectral_diff() const {
+    return spectral_diff_;
+  }
+
+ private:
+  std::array<int, kHistogramSize> lrt_;
+  std::array<int, kHistogramSize> spectral_flatness_;
+  std::array<int, kHistogramSize> spectral_diff_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_HISTOGRAMS_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/noise_estimator.cc b/third_party/libwebrtc/modules/audio_processing/ns/noise_estimator.cc
new file mode 100644
index 0000000000..5367545f25
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/noise_estimator.cc
@@ -0,0 +1,195 @@
+/*
+ *  Copyright (c) 2019 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/ns/noise_estimator.h"
+
+#include <algorithm>
+
+#include "modules/audio_processing/ns/fast_math.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+namespace {
+
+// Log(i).
+constexpr std::array<float, 129> log_table = {
+    0.f,       0.f,       0.f,       0.f,       0.f,       1.609438f, 1.791759f,
+    1.945910f, 2.079442f, 2.197225f, 2.302585f, 2.397895f, 2.484907f, 2.564949f,
+    2.639057f, 2.708050f, 2.772589f, 2.833213f, 2.890372f, 2.944439f, 2.995732f,
+    3.044522f, 3.091043f, 3.135494f, 3.178054f, 3.218876f, 3.258097f, 3.295837f,
+    3.332205f, 3.367296f, 3.401197f, 3.433987f, 3.465736f, 3.496507f, 3.526361f,
+    3.555348f, 3.583519f, 3.610918f, 3.637586f, 3.663562f, 3.688879f, 3.713572f,
+    3.737669f, 3.761200f, 3.784190f, 3.806663f, 3.828641f, 3.850147f, 3.871201f,
+    3.891820f, 3.912023f, 3.931826f, 3.951244f, 3.970292f, 3.988984f, 4.007333f,
+    4.025352f, 4.043051f, 4.060443f, 4.077538f, 4.094345f, 4.110874f, 4.127134f,
+    4.143135f, 4.158883f, 4.174387f, 4.189655f, 4.204693f, 4.219508f, 4.234107f,
+    4.248495f, 4.262680f, 4.276666f, 4.290460f, 4.304065f, 4.317488f, 4.330733f,
+    4.343805f, 4.356709f, 4.369448f, 4.382027f, 4.394449f, 4.406719f, 4.418841f,
+    4.430817f, 4.442651f, 4.454347f, 4.465908f, 4.477337f, 4.488636f, 4.499810f,
+    4.510859f, 4.521789f, 4.532599f, 4.543295f, 4.553877f, 4.564348f, 4.574711f,
+    4.584968f, 4.595119f, 4.605170f, 4.615121f, 4.624973f, 4.634729f, 4.644391f,
+    4.653960f, 4.663439f, 4.672829f, 4.682131f, 4.691348f, 4.700480f, 4.709530f,
+    4.718499f, 4.727388f, 4.736198f, 4.744932f, 4.753591f, 4.762174f, 4.770685f,
+    4.779124f, 4.787492f, 4.795791f, 4.804021f, 4.812184f, 4.820282f, 4.828314f,
+    4.836282f, 4.844187f, 4.852030f};
+
+}  // namespace
+
+NoiseEstimator::NoiseEstimator(const SuppressionParams& suppression_params)
+    : suppression_params_(suppression_params) {
+  noise_spectrum_.fill(0.f);
+  prev_noise_spectrum_.fill(0.f);
+  conservative_noise_spectrum_.fill(0.f);
+  parametric_noise_spectrum_.fill(0.f);
+}
+
+void NoiseEstimator::PrepareAnalysis() {
+  std::copy(noise_spectrum_.begin(), noise_spectrum_.end(),
+            prev_noise_spectrum_.begin());
+}
+
+void NoiseEstimator::PreUpdate(
+    int32_t num_analyzed_frames,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+    float signal_spectral_sum) {
+  quantile_noise_estimator_.Estimate(signal_spectrum, noise_spectrum_);
+
+  if (num_analyzed_frames < kShortStartupPhaseBlocks) {
+    // Compute simplified noise model during startup.
+    const size_t kStartBand = 5;
+    float sum_log_i_log_magn = 0.f;
+    float sum_log_i = 0.f;
+    float sum_log_i_square = 0.f;
+    float sum_log_magn = 0.f;
+    for (size_t i = kStartBand; i < kFftSizeBy2Plus1; ++i) {
+      float log_i = log_table[i];
+      sum_log_i += log_i;
+      sum_log_i_square += log_i * log_i;
+      float log_signal = LogApproximation(signal_spectrum[i]);
+      sum_log_magn += log_signal;
+      sum_log_i_log_magn += log_i * log_signal;
+    }
+
+    // Estimate the parameter for the level of the white noise.
+    constexpr float kOneByFftSizeBy2Plus1 = 1.f / kFftSizeBy2Plus1;
+    white_noise_level_ += signal_spectral_sum * kOneByFftSizeBy2Plus1 *
+                          suppression_params_.over_subtraction_factor;
+
+    // Estimate pink noise parameters.
+    float denom = sum_log_i_square * (kFftSizeBy2Plus1 - kStartBand) -
+                  sum_log_i * sum_log_i;
+    float num =
+        sum_log_i_square * sum_log_magn - sum_log_i * sum_log_i_log_magn;
+    RTC_DCHECK_NE(denom, 0.f);
+    float pink_noise_adjustment = num / denom;
+
+    // Constrain the estimated spectrum to be positive.
+    pink_noise_adjustment = std::max(pink_noise_adjustment, 0.f);
+    pink_noise_numerator_ += pink_noise_adjustment;
+    num = sum_log_i * sum_log_magn -
+          (kFftSizeBy2Plus1 - kStartBand) * sum_log_i_log_magn;
+    RTC_DCHECK_NE(denom, 0.f);
+    pink_noise_adjustment = num / denom;
+
+    // Constrain the pink noise power to be in the interval [0, 1].
+    pink_noise_adjustment = std::max(std::min(pink_noise_adjustment, 1.f), 0.f);
+
+    pink_noise_exp_ += pink_noise_adjustment;
+
+    const float one_by_num_analyzed_frames_plus_1 =
+        1.f / (num_analyzed_frames + 1.f);
+
+    // Calculate the frequency-independent parts of parametric noise estimate.
+    float parametric_exp = 0.f;
+    float parametric_num = 0.f;
+    if (pink_noise_exp_ > 0.f) {
+      // Use pink noise estimate.
+      parametric_num = ExpApproximation(pink_noise_numerator_ *
+                                        one_by_num_analyzed_frames_plus_1);
+      parametric_num *= num_analyzed_frames + 1.f;
+      parametric_exp = pink_noise_exp_ * one_by_num_analyzed_frames_plus_1;
+    }
+
+    constexpr float kOneByShortStartupPhaseBlocks =
+        1.f / kShortStartupPhaseBlocks;
+    for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+      // Estimate the background noise using the white and pink noise
+      // parameters.
+      if (pink_noise_exp_ == 0.f) {
+        // Use white noise estimate.
+        parametric_noise_spectrum_[i] = white_noise_level_;
+      } else {
+        // Use pink noise estimate.
+        float use_band = i < kStartBand ? kStartBand : i;
+        float denom = PowApproximation(use_band, parametric_exp);
+        RTC_DCHECK_NE(denom, 0.f);
+        parametric_noise_spectrum_[i] = parametric_num / denom;
+      }
+    }
+
+    // Weight quantile noise with modeled noise.
+    for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+      noise_spectrum_[i] *= num_analyzed_frames;
+      float tmp = parametric_noise_spectrum_[i] *
+                  (kShortStartupPhaseBlocks - num_analyzed_frames);
+      noise_spectrum_[i] += tmp * one_by_num_analyzed_frames_plus_1;
+      noise_spectrum_[i] *= kOneByShortStartupPhaseBlocks;
+    }
+  }
+}
+
+void NoiseEstimator::PostUpdate(
+    rtc::ArrayView<const float> speech_probability,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum) {
+  // Time-avg parameter for noise_spectrum update.
+  constexpr float kNoiseUpdate = 0.9f;
+
+  float gamma = kNoiseUpdate;
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    const float prob_speech = speech_probability[i];
+    const float prob_non_speech = 1.f - prob_speech;
+
+    // Temporary noise update used for speech frames if update value is less
+    // than previous.
+    float noise_update_tmp =
+        gamma * prev_noise_spectrum_[i] +
+        (1.f - gamma) * (prob_non_speech * signal_spectrum[i] +
+                         prob_speech * prev_noise_spectrum_[i]);
+
+    // Time-constant based on speech/noise_spectrum state.
+    float gamma_old = gamma;
+
+    // Increase gamma for frame likely to be seech.
+    constexpr float kProbRange = .2f;
+    gamma = prob_speech > kProbRange ? .99f : kNoiseUpdate;
+
+    // Conservative noise_spectrum update.
+    if (prob_speech < kProbRange) {
+      conservative_noise_spectrum_[i] +=
+          0.05f * (signal_spectrum[i] - conservative_noise_spectrum_[i]);
+    }
+
+    // Noise_spectrum update.
+    if (gamma == gamma_old) {
+      noise_spectrum_[i] = noise_update_tmp;
+    } else {
+      noise_spectrum_[i] =
+          gamma * prev_noise_spectrum_[i] +
+          (1.f - gamma) * (prob_non_speech * signal_spectrum[i] +
+                           prob_speech * prev_noise_spectrum_[i]);
+      // Allow for noise_spectrum update downwards: If noise_spectrum update
+      // decreases the noise_spectrum, it is safe, so allow it to happen.
+      noise_spectrum_[i] = std::min(noise_spectrum_[i], noise_update_tmp);
+    }
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/noise_estimator.h b/third_party/libwebrtc/modules/audio_processing/ns/noise_estimator.h
new file mode 100644
index 0000000000..0c0466a679
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/noise_estimator.h
@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_NOISE_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_NS_NOISE_ESTIMATOR_H_
+
+#include <array>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/ns_common.h"
+#include "modules/audio_processing/ns/quantile_noise_estimator.h"
+#include "modules/audio_processing/ns/suppression_params.h"
+
+namespace webrtc {
+
+// Class for estimating the spectral characteristics of the noise in an incoming
+// signal.
+class NoiseEstimator {
+ public:
+  explicit NoiseEstimator(const SuppressionParams& suppression_params);
+
+  // Prepare the estimator for analysis of a new frame.
+  void PrepareAnalysis();
+
+  // Performs the first step of the estimator update.
+  void PreUpdate(int32_t num_analyzed_frames,
+                 rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+                 float signal_spectral_sum);
+
+  // Performs the second step of the estimator update.
+  void PostUpdate(
+      rtc::ArrayView<const float> speech_probability,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum);
+
+  // Returns the noise spectral estimate.
+  rtc::ArrayView<const float, kFftSizeBy2Plus1> get_noise_spectrum() const {
+    return noise_spectrum_;
+  }
+
+  // Returns the noise from the previous frame.
+  rtc::ArrayView<const float, kFftSizeBy2Plus1> get_prev_noise_spectrum()
+      const {
+    return prev_noise_spectrum_;
+  }
+
+  // Returns a noise spectral estimate based on white and pink noise parameters.
+  rtc::ArrayView<const float, kFftSizeBy2Plus1> get_parametric_noise_spectrum()
+      const {
+    return parametric_noise_spectrum_;
+  }
+  rtc::ArrayView<const float, kFftSizeBy2Plus1>
+  get_conservative_noise_spectrum() const {
+    return conservative_noise_spectrum_;
+  }
+
+ private:
+  const SuppressionParams& suppression_params_;
+  float white_noise_level_ = 0.f;
+  float pink_noise_numerator_ = 0.f;
+  float pink_noise_exp_ = 0.f;
+  std::array<float, kFftSizeBy2Plus1> prev_noise_spectrum_;
+  std::array<float, kFftSizeBy2Plus1> conservative_noise_spectrum_;
+  std::array<float, kFftSizeBy2Plus1> parametric_noise_spectrum_;
+  std::array<float, kFftSizeBy2Plus1> noise_spectrum_;
+  QuantileNoiseEstimator quantile_noise_estimator_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_NOISE_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor.cc b/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor.cc
new file mode 100644
index 0000000000..d66faa6ed4
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor.cc
@@ -0,0 +1,555 @@
+/*
+ *  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/ns/noise_suppressor.h"
+
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+#include <algorithm>
+
+#include "modules/audio_processing/ns/fast_math.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+namespace {
+
+// Maps sample rate to number of bands.
+size_t NumBandsForRate(size_t sample_rate_hz) {
+  RTC_DCHECK(sample_rate_hz == 16000 || sample_rate_hz == 32000 ||
+             sample_rate_hz == 48000);
+  return sample_rate_hz / 16000;
+}
+
+// Maximum number of channels for which the channel data is stored on
+// the stack. If the number of channels are larger than this, they are stored
+// using scratch memory that is pre-allocated on the heap. The reason for this
+// partitioning is not to waste heap space for handling the more common numbers
+// of channels, while at the same time not limiting the support for higher
+// numbers of channels by enforcing the channel data to be stored on the
+// stack using a fixed maximum value.
+constexpr size_t kMaxNumChannelsOnStack = 2;
+
+// Chooses the number of channels to store on the heap when that is required due
+// to the number of channels being larger than the pre-defined number
+// of channels to store on the stack.
+size_t NumChannelsOnHeap(size_t num_channels) {
+  return num_channels > kMaxNumChannelsOnStack ? num_channels : 0;
+}
+
+// Hybrib Hanning and flat window for the filterbank.
+constexpr std::array<float, 96> kBlocks160w256FirstHalf = {
+    0.00000000f, 0.01636173f, 0.03271908f, 0.04906767f, 0.06540313f,
+    0.08172107f, 0.09801714f, 0.11428696f, 0.13052619f, 0.14673047f,
+    0.16289547f, 0.17901686f, 0.19509032f, 0.21111155f, 0.22707626f,
+    0.24298018f, 0.25881905f, 0.27458862f, 0.29028468f, 0.30590302f,
+    0.32143947f, 0.33688985f, 0.35225005f, 0.36751594f, 0.38268343f,
+    0.39774847f, 0.41270703f, 0.42755509f, 0.44228869f, 0.45690388f,
+    0.47139674f, 0.48576339f, 0.50000000f, 0.51410274f, 0.52806785f,
+    0.54189158f, 0.55557023f, 0.56910015f, 0.58247770f, 0.59569930f,
+    0.60876143f, 0.62166057f, 0.63439328f, 0.64695615f, 0.65934582f,
+    0.67155895f, 0.68359230f, 0.69544264f, 0.70710678f, 0.71858162f,
+    0.72986407f, 0.74095113f, 0.75183981f, 0.76252720f, 0.77301045f,
+    0.78328675f, 0.79335334f, 0.80320753f, 0.81284668f, 0.82226822f,
+    0.83146961f, 0.84044840f, 0.84920218f, 0.85772861f, 0.86602540f,
+    0.87409034f, 0.88192126f, 0.88951608f, 0.89687274f, 0.90398929f,
+    0.91086382f, 0.91749450f, 0.92387953f, 0.93001722f, 0.93590593f,
+    0.94154407f, 0.94693013f, 0.95206268f, 0.95694034f, 0.96156180f,
+    0.96592583f, 0.97003125f, 0.97387698f, 0.97746197f, 0.98078528f,
+    0.98384601f, 0.98664333f, 0.98917651f, 0.99144486f, 0.99344778f,
+    0.99518473f, 0.99665524f, 0.99785892f, 0.99879546f, 0.99946459f,
+    0.99986614f};
+
+// Applies the filterbank window to a buffer.
+void ApplyFilterBankWindow(rtc::ArrayView<float, kFftSize> x) {
+  for (size_t i = 0; i < 96; ++i) {
+    x[i] = kBlocks160w256FirstHalf[i] * x[i];
+  }
+
+  for (size_t i = 161, k = 95; i < kFftSize; ++i, --k) {
+    RTC_DCHECK_NE(0, k);
+    x[i] = kBlocks160w256FirstHalf[k] * x[i];
+  }
+}
+
+// Extends a frame with previous data.
+void FormExtendedFrame(rtc::ArrayView<const float, kNsFrameSize> frame,
+                       rtc::ArrayView<float, kFftSize - kNsFrameSize> old_data,
+                       rtc::ArrayView<float, kFftSize> extended_frame) {
+  std::copy(old_data.begin(), old_data.end(), extended_frame.begin());
+  std::copy(frame.begin(), frame.end(),
+            extended_frame.begin() + old_data.size());
+  std::copy(extended_frame.end() - old_data.size(), extended_frame.end(),
+            old_data.begin());
+}
+
+// Uses overlap-and-add to produce an output frame.
+void OverlapAndAdd(rtc::ArrayView<const float, kFftSize> extended_frame,
+                   rtc::ArrayView<float, kOverlapSize> overlap_memory,
+                   rtc::ArrayView<float, kNsFrameSize> output_frame) {
+  for (size_t i = 0; i < kOverlapSize; ++i) {
+    output_frame[i] = overlap_memory[i] + extended_frame[i];
+  }
+  std::copy(extended_frame.begin() + kOverlapSize,
+            extended_frame.begin() + kNsFrameSize,
+            output_frame.begin() + kOverlapSize);
+  std::copy(extended_frame.begin() + kNsFrameSize, extended_frame.end(),
+            overlap_memory.begin());
+}
+
+// Produces a delayed frame.
+void DelaySignal(rtc::ArrayView<const float, kNsFrameSize> frame,
+                 rtc::ArrayView<float, kFftSize - kNsFrameSize> delay_buffer,
+                 rtc::ArrayView<float, kNsFrameSize> delayed_frame) {
+  constexpr size_t kSamplesFromFrame = kNsFrameSize - (kFftSize - kNsFrameSize);
+  std::copy(delay_buffer.begin(), delay_buffer.end(), delayed_frame.begin());
+  std::copy(frame.begin(), frame.begin() + kSamplesFromFrame,
+            delayed_frame.begin() + delay_buffer.size());
+
+  std::copy(frame.begin() + kSamplesFromFrame, frame.end(),
+            delay_buffer.begin());
+}
+
+// Computes the energy of an extended frame.
+float ComputeEnergyOfExtendedFrame(rtc::ArrayView<const float, kFftSize> x) {
+  float energy = 0.f;
+  for (float x_k : x) {
+    energy += x_k * x_k;
+  }
+
+  return energy;
+}
+
+// Computes the energy of an extended frame based on its subcomponents.
+float ComputeEnergyOfExtendedFrame(
+    rtc::ArrayView<const float, kNsFrameSize> frame,
+    rtc::ArrayView<float, kFftSize - kNsFrameSize> old_data) {
+  float energy = 0.f;
+  for (float v : old_data) {
+    energy += v * v;
+  }
+  for (float v : frame) {
+    energy += v * v;
+  }
+
+  return energy;
+}
+
+// Computes the magnitude spectrum based on an FFT output.
+void ComputeMagnitudeSpectrum(
+    rtc::ArrayView<const float, kFftSize> real,
+    rtc::ArrayView<const float, kFftSize> imag,
+    rtc::ArrayView<float, kFftSizeBy2Plus1> signal_spectrum) {
+  signal_spectrum[0] = fabsf(real[0]) + 1.f;
+  signal_spectrum[kFftSizeBy2Plus1 - 1] =
+      fabsf(real[kFftSizeBy2Plus1 - 1]) + 1.f;
+
+  for (size_t i = 1; i < kFftSizeBy2Plus1 - 1; ++i) {
+    signal_spectrum[i] =
+        SqrtFastApproximation(real[i] * real[i] + imag[i] * imag[i]) + 1.f;
+  }
+}
+
+// Compute prior and post SNR.
+void ComputeSnr(rtc::ArrayView<const float, kFftSizeBy2Plus1> filter,
+                rtc::ArrayView<const float> prev_signal_spectrum,
+                rtc::ArrayView<const float> signal_spectrum,
+                rtc::ArrayView<const float> prev_noise_spectrum,
+                rtc::ArrayView<const float> noise_spectrum,
+                rtc::ArrayView<float> prior_snr,
+                rtc::ArrayView<float> post_snr) {
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    // Previous post SNR.
+    // Previous estimate: based on previous frame with gain filter.
+    float prev_estimate = prev_signal_spectrum[i] /
+                          (prev_noise_spectrum[i] + 0.0001f) * filter[i];
+    // Post SNR.
+    if (signal_spectrum[i] > noise_spectrum[i]) {
+      post_snr[i] = signal_spectrum[i] / (noise_spectrum[i] + 0.0001f) - 1.f;
+    } else {
+      post_snr[i] = 0.f;
+    }
+    // The directed decision estimate of the prior SNR is a sum the current and
+    // previous estimates.
+    prior_snr[i] = 0.98f * prev_estimate + (1.f - 0.98f) * post_snr[i];
+  }
+}
+
+// Computes the attenuating gain for the noise suppression of the upper bands.
+float ComputeUpperBandsGain(
+    float minimum_attenuating_gain,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> filter,
+    rtc::ArrayView<const float> speech_probability,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> prev_analysis_signal_spectrum,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum) {
+  // Average speech prob and filter gain for the end of the lowest band.
+  constexpr int kNumAvgBins = 32;
+  constexpr float kOneByNumAvgBins = 1.f / kNumAvgBins;
+
+  float avg_prob_speech = 0.f;
+  float avg_filter_gain = 0.f;
+  for (size_t i = kFftSizeBy2Plus1 - kNumAvgBins - 1; i < kFftSizeBy2Plus1 - 1;
+       i++) {
+    avg_prob_speech += speech_probability[i];
+    avg_filter_gain += filter[i];
+  }
+  avg_prob_speech = avg_prob_speech * kOneByNumAvgBins;
+  avg_filter_gain = avg_filter_gain * kOneByNumAvgBins;
+
+  // If the speech was suppressed by a component between Analyze and Process, an
+  // example being by an AEC, it should not be considered speech for the purpose
+  // of high band suppression. To that end, the speech probability is scaled
+  // accordingly.
+  float sum_analysis_spectrum = 0.f;
+  float sum_processing_spectrum = 0.f;
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    sum_analysis_spectrum += prev_analysis_signal_spectrum[i];
+    sum_processing_spectrum += signal_spectrum[i];
+  }
+
+  // The magnitude spectrum computation enforces the spectrum to be strictly
+  // positive.
+  RTC_DCHECK_GT(sum_analysis_spectrum, 0.f);
+  avg_prob_speech *= sum_processing_spectrum / sum_analysis_spectrum;
+
+  // Compute gain based on speech probability.
+  float gain =
+      0.5f * (1.f + static_cast<float>(tanh(2.f * avg_prob_speech - 1.f)));
+
+  // Combine gain with low band gain.
+  if (avg_prob_speech >= 0.5f) {
+    gain = 0.25f * gain + 0.75f * avg_filter_gain;
+  } else {
+    gain = 0.5f * gain + 0.5f * avg_filter_gain;
+  }
+
+  // Make sure gain is within flooring range.
+  return std::min(std::max(gain, minimum_attenuating_gain), 1.f);
+}
+
+}  // namespace
+
+NoiseSuppressor::ChannelState::ChannelState(
+    const SuppressionParams& suppression_params,
+    size_t num_bands)
+    : wiener_filter(suppression_params),
+      noise_estimator(suppression_params),
+      process_delay_memory(num_bands > 1 ? num_bands - 1 : 0) {
+  analyze_analysis_memory.fill(0.f);
+  prev_analysis_signal_spectrum.fill(1.f);
+  process_analysis_memory.fill(0.f);
+  process_synthesis_memory.fill(0.f);
+  for (auto& d : process_delay_memory) {
+    d.fill(0.f);
+  }
+}
+
+NoiseSuppressor::NoiseSuppressor(const NsConfig& config,
+                                 size_t sample_rate_hz,
+                                 size_t num_channels)
+    : num_bands_(NumBandsForRate(sample_rate_hz)),
+      num_channels_(num_channels),
+      suppression_params_(config.target_level),
+      filter_bank_states_heap_(NumChannelsOnHeap(num_channels_)),
+      upper_band_gains_heap_(NumChannelsOnHeap(num_channels_)),
+      energies_before_filtering_heap_(NumChannelsOnHeap(num_channels_)),
+      gain_adjustments_heap_(NumChannelsOnHeap(num_channels_)),
+      channels_(num_channels_) {
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    channels_[ch] =
+        std::make_unique<ChannelState>(suppression_params_, num_bands_);
+  }
+}
+
+void NoiseSuppressor::AggregateWienerFilters(
+    rtc::ArrayView<float, kFftSizeBy2Plus1> filter) const {
+  rtc::ArrayView<const float, kFftSizeBy2Plus1> filter0 =
+      channels_[0]->wiener_filter.get_filter();
+  std::copy(filter0.begin(), filter0.end(), filter.begin());
+
+  for (size_t ch = 1; ch < num_channels_; ++ch) {
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> filter_ch =
+        channels_[ch]->wiener_filter.get_filter();
+
+    for (size_t k = 0; k < kFftSizeBy2Plus1; ++k) {
+      filter[k] = std::min(filter[k], filter_ch[k]);
+    }
+  }
+}
+
+void NoiseSuppressor::Analyze(const AudioBuffer& audio) {
+  // Prepare the noise estimator for the analysis stage.
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    channels_[ch]->noise_estimator.PrepareAnalysis();
+  }
+
+  // Check for zero frames.
+  bool zero_frame = true;
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    rtc::ArrayView<const float, kNsFrameSize> y_band0(
+        &audio.split_bands_const(ch)[0][0], kNsFrameSize);
+    float energy = ComputeEnergyOfExtendedFrame(
+        y_band0, channels_[ch]->analyze_analysis_memory);
+    if (energy > 0.f) {
+      zero_frame = false;
+      break;
+    }
+  }
+
+  if (zero_frame) {
+    // We want to avoid updating statistics in this case:
+    // Updating feature statistics when we have zeros only will cause
+    // thresholds to move towards zero signal situations. This in turn has the
+    // effect that once the signal is "turned on" (non-zero values) everything
+    // will be treated as speech and there is no noise suppression effect.
+    // Depending on the duration of the inactive signal it takes a
+    // considerable amount of time for the system to learn what is noise and
+    // what is speech.
+    return;
+  }
+
+  // Only update analysis counter for frames that are properly analyzed.
+  if (++num_analyzed_frames_ < 0) {
+    num_analyzed_frames_ = 0;
+  }
+
+  // Analyze all channels.
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    std::unique_ptr<ChannelState>& ch_p = channels_[ch];
+    rtc::ArrayView<const float, kNsFrameSize> y_band0(
+        &audio.split_bands_const(ch)[0][0], kNsFrameSize);
+
+    // Form an extended frame and apply analysis filter bank windowing.
+    std::array<float, kFftSize> extended_frame;
+    FormExtendedFrame(y_band0, ch_p->analyze_analysis_memory, extended_frame);
+    ApplyFilterBankWindow(extended_frame);
+
+    // Compute the magnitude spectrum.
+    std::array<float, kFftSize> real;
+    std::array<float, kFftSize> imag;
+    fft_.Fft(extended_frame, real, imag);
+
+    std::array<float, kFftSizeBy2Plus1> signal_spectrum;
+    ComputeMagnitudeSpectrum(real, imag, signal_spectrum);
+
+    // Compute energies.
+    float signal_energy = 0.f;
+    for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+      signal_energy += real[i] * real[i] + imag[i] * imag[i];
+    }
+    signal_energy /= kFftSizeBy2Plus1;
+
+    float signal_spectral_sum = 0.f;
+    for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+      signal_spectral_sum += signal_spectrum[i];
+    }
+
+    // Estimate the noise spectra and the probability estimates of speech
+    // presence.
+    ch_p->noise_estimator.PreUpdate(num_analyzed_frames_, signal_spectrum,
+                                    signal_spectral_sum);
+
+    std::array<float, kFftSizeBy2Plus1> post_snr;
+    std::array<float, kFftSizeBy2Plus1> prior_snr;
+    ComputeSnr(ch_p->wiener_filter.get_filter(),
+               ch_p->prev_analysis_signal_spectrum, signal_spectrum,
+               ch_p->noise_estimator.get_prev_noise_spectrum(),
+               ch_p->noise_estimator.get_noise_spectrum(), prior_snr, post_snr);
+
+    ch_p->speech_probability_estimator.Update(
+        num_analyzed_frames_, prior_snr, post_snr,
+        ch_p->noise_estimator.get_conservative_noise_spectrum(),
+        signal_spectrum, signal_spectral_sum, signal_energy);
+
+    ch_p->noise_estimator.PostUpdate(
+        ch_p->speech_probability_estimator.get_probability(), signal_spectrum);
+
+    // Store the magnitude spectrum to make it avalilable for the process
+    // method.
+    std::copy(signal_spectrum.begin(), signal_spectrum.end(),
+              ch_p->prev_analysis_signal_spectrum.begin());
+  }
+}
+
+void NoiseSuppressor::Process(AudioBuffer* audio) {
+  // Select the space for storing data during the processing.
+  std::array<FilterBankState, kMaxNumChannelsOnStack> filter_bank_states_stack;
+  rtc::ArrayView<FilterBankState> filter_bank_states(
+      filter_bank_states_stack.data(), num_channels_);
+  std::array<float, kMaxNumChannelsOnStack> upper_band_gains_stack;
+  rtc::ArrayView<float> upper_band_gains(upper_band_gains_stack.data(),
+                                         num_channels_);
+  std::array<float, kMaxNumChannelsOnStack> energies_before_filtering_stack;
+  rtc::ArrayView<float> energies_before_filtering(
+      energies_before_filtering_stack.data(), num_channels_);
+  std::array<float, kMaxNumChannelsOnStack> gain_adjustments_stack;
+  rtc::ArrayView<float> gain_adjustments(gain_adjustments_stack.data(),
+                                         num_channels_);
+  if (NumChannelsOnHeap(num_channels_) > 0) {
+    // If the stack-allocated space is too small, use the heap for storing the
+    // data.
+    filter_bank_states = rtc::ArrayView<FilterBankState>(
+        filter_bank_states_heap_.data(), num_channels_);
+    upper_band_gains =
+        rtc::ArrayView<float>(upper_band_gains_heap_.data(), num_channels_);
+    energies_before_filtering = rtc::ArrayView<float>(
+        energies_before_filtering_heap_.data(), num_channels_);
+    gain_adjustments =
+        rtc::ArrayView<float>(gain_adjustments_heap_.data(), num_channels_);
+  }
+
+  // Compute the suppression filters for all channels.
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    // Form an extended frame and apply analysis filter bank windowing.
+    rtc::ArrayView<float, kNsFrameSize> y_band0(&audio->split_bands(ch)[0][0],
+                                                kNsFrameSize);
+
+    FormExtendedFrame(y_band0, channels_[ch]->process_analysis_memory,
+                      filter_bank_states[ch].extended_frame);
+
+    ApplyFilterBankWindow(filter_bank_states[ch].extended_frame);
+
+    energies_before_filtering[ch] =
+        ComputeEnergyOfExtendedFrame(filter_bank_states[ch].extended_frame);
+
+    // Perform filter bank analysis and compute the magnitude spectrum.
+    fft_.Fft(filter_bank_states[ch].extended_frame, filter_bank_states[ch].real,
+             filter_bank_states[ch].imag);
+
+    std::array<float, kFftSizeBy2Plus1> signal_spectrum;
+    ComputeMagnitudeSpectrum(filter_bank_states[ch].real,
+                             filter_bank_states[ch].imag, signal_spectrum);
+
+    // Compute the frequency domain gain filter for noise attenuation.
+    channels_[ch]->wiener_filter.Update(
+        num_analyzed_frames_,
+        channels_[ch]->noise_estimator.get_noise_spectrum(),
+        channels_[ch]->noise_estimator.get_prev_noise_spectrum(),
+        channels_[ch]->noise_estimator.get_parametric_noise_spectrum(),
+        signal_spectrum);
+
+    if (num_bands_ > 1) {
+      // Compute the time-domain gain for attenuating the noise in the upper
+      // bands.
+
+      upper_band_gains[ch] = ComputeUpperBandsGain(
+          suppression_params_.minimum_attenuating_gain,
+          channels_[ch]->wiener_filter.get_filter(),
+          channels_[ch]->speech_probability_estimator.get_probability(),
+          channels_[ch]->prev_analysis_signal_spectrum, signal_spectrum);
+    }
+  }
+
+  // Only do the below processing if the output of the audio processing module
+  // is used.
+  if (!capture_output_used_) {
+    return;
+  }
+
+  // Aggregate the Wiener filters for all channels.
+  std::array<float, kFftSizeBy2Plus1> filter_data;
+  rtc::ArrayView<const float, kFftSizeBy2Plus1> filter = filter_data;
+  if (num_channels_ == 1) {
+    filter = channels_[0]->wiener_filter.get_filter();
+  } else {
+    AggregateWienerFilters(filter_data);
+  }
+
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    // Apply the filter to the lower band.
+    for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+      filter_bank_states[ch].real[i] *= filter[i];
+      filter_bank_states[ch].imag[i] *= filter[i];
+    }
+  }
+
+  // Perform filter bank synthesis
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    fft_.Ifft(filter_bank_states[ch].real, filter_bank_states[ch].imag,
+              filter_bank_states[ch].extended_frame);
+  }
+
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    const float energy_after_filtering =
+        ComputeEnergyOfExtendedFrame(filter_bank_states[ch].extended_frame);
+
+    // Apply synthesis window.
+    ApplyFilterBankWindow(filter_bank_states[ch].extended_frame);
+
+    // Compute the adjustment of the noise attenuation filter based on the
+    // effect of the attenuation.
+    gain_adjustments[ch] =
+        channels_[ch]->wiener_filter.ComputeOverallScalingFactor(
+            num_analyzed_frames_,
+            channels_[ch]->speech_probability_estimator.get_prior_probability(),
+            energies_before_filtering[ch], energy_after_filtering);
+  }
+
+  // Select and apply adjustment of the noise attenuation filter based on the
+  // effect of the attenuation.
+  float gain_adjustment = gain_adjustments[0];
+  for (size_t ch = 1; ch < num_channels_; ++ch) {
+    gain_adjustment = std::min(gain_adjustment, gain_adjustments[ch]);
+  }
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    for (size_t i = 0; i < kFftSize; ++i) {
+      filter_bank_states[ch].extended_frame[i] =
+          gain_adjustment * filter_bank_states[ch].extended_frame[i];
+    }
+  }
+
+  // Use overlap-and-add to form the output frame of the lowest band.
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    rtc::ArrayView<float, kNsFrameSize> y_band0(&audio->split_bands(ch)[0][0],
+                                                kNsFrameSize);
+    OverlapAndAdd(filter_bank_states[ch].extended_frame,
+                  channels_[ch]->process_synthesis_memory, y_band0);
+  }
+
+  if (num_bands_ > 1) {
+    // Select the noise attenuating gain to apply to the upper band.
+    float upper_band_gain = upper_band_gains[0];
+    for (size_t ch = 1; ch < num_channels_; ++ch) {
+      upper_band_gain = std::min(upper_band_gain, upper_band_gains[ch]);
+    }
+
+    // Process the upper bands.
+    for (size_t ch = 0; ch < num_channels_; ++ch) {
+      for (size_t b = 1; b < num_bands_; ++b) {
+        // Delay the upper bands to match the delay of the filterbank applied to
+        // the lowest band.
+        rtc::ArrayView<float, kNsFrameSize> y_band(
+            &audio->split_bands(ch)[b][0], kNsFrameSize);
+        std::array<float, kNsFrameSize> delayed_frame;
+        DelaySignal(y_band, channels_[ch]->process_delay_memory[b - 1],
+                    delayed_frame);
+
+        // Apply the time-domain noise-attenuating gain.
+        for (size_t j = 0; j < kNsFrameSize; j++) {
+          y_band[j] = upper_band_gain * delayed_frame[j];
+        }
+      }
+    }
+  }
+
+  // Limit the output the allowed range.
+  for (size_t ch = 0; ch < num_channels_; ++ch) {
+    for (size_t b = 0; b < num_bands_; ++b) {
+      rtc::ArrayView<float, kNsFrameSize> y_band(&audio->split_bands(ch)[b][0],
+                                                 kNsFrameSize);
+      for (size_t j = 0; j < kNsFrameSize; j++) {
+        y_band[j] = std::min(std::max(y_band[j], -32768.f), 32767.f);
+      }
+    }
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor.h b/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor.h
new file mode 100644
index 0000000000..1e321cf4a2
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor.h
@@ -0,0 +1,92 @@
+/*
+ *  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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_
+#define MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_
+
+#include <memory>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/audio_buffer.h"
+#include "modules/audio_processing/ns/noise_estimator.h"
+#include "modules/audio_processing/ns/ns_common.h"
+#include "modules/audio_processing/ns/ns_config.h"
+#include "modules/audio_processing/ns/ns_fft.h"
+#include "modules/audio_processing/ns/speech_probability_estimator.h"
+#include "modules/audio_processing/ns/wiener_filter.h"
+
+namespace webrtc {
+
+// Class for suppressing noise in a signal.
+class NoiseSuppressor {
+ public:
+  NoiseSuppressor(const NsConfig& config,
+                  size_t sample_rate_hz,
+                  size_t num_channels);
+  NoiseSuppressor(const NoiseSuppressor&) = delete;
+  NoiseSuppressor& operator=(const NoiseSuppressor&) = delete;
+
+  // Analyses the signal (typically applied before the AEC to avoid analyzing
+  // any comfort noise signal).
+  void Analyze(const AudioBuffer& audio);
+
+  // Applies noise suppression.
+  void Process(AudioBuffer* audio);
+
+  // Specifies whether the capture output will be used. The purpose of this is
+  // to allow the noise suppressor to deactivate some of the processing when the
+  // resulting output is anyway not used, for instance when the endpoint is
+  // muted.
+  void SetCaptureOutputUsage(bool capture_output_used) {
+    capture_output_used_ = capture_output_used;
+  }
+
+ private:
+  const size_t num_bands_;
+  const size_t num_channels_;
+  const SuppressionParams suppression_params_;
+  int32_t num_analyzed_frames_ = -1;
+  NrFft fft_;
+  bool capture_output_used_ = true;
+
+  struct ChannelState {
+    ChannelState(const SuppressionParams& suppression_params, size_t num_bands);
+
+    SpeechProbabilityEstimator speech_probability_estimator;
+    WienerFilter wiener_filter;
+    NoiseEstimator noise_estimator;
+    std::array<float, kFftSizeBy2Plus1> prev_analysis_signal_spectrum;
+    std::array<float, kFftSize - kNsFrameSize> analyze_analysis_memory;
+    std::array<float, kOverlapSize> process_analysis_memory;
+    std::array<float, kOverlapSize> process_synthesis_memory;
+    std::vector<std::array<float, kOverlapSize>> process_delay_memory;
+  };
+
+  struct FilterBankState {
+    std::array<float, kFftSize> real;
+    std::array<float, kFftSize> imag;
+    std::array<float, kFftSize> extended_frame;
+  };
+
+  std::vector<FilterBankState> filter_bank_states_heap_;
+  std::vector<float> upper_band_gains_heap_;
+  std::vector<float> energies_before_filtering_heap_;
+  std::vector<float> gain_adjustments_heap_;
+  std::vector<std::unique_ptr<ChannelState>> channels_;
+
+  // Aggregates the Wiener filters into a single filter to use.
+  void AggregateWienerFilters(
+      rtc::ArrayView<float, kFftSizeBy2Plus1> filter) const;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor_unittest.cc b/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor_unittest.cc
new file mode 100644
index 0000000000..28ea63ae40
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor_unittest.cc
@@ -0,0 +1,102 @@
+/*
+ *  Copyright (c) 2016 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/ns/noise_suppressor.h"
+
+#include <deque>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "rtc_base/strings/string_builder.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+std::string ProduceDebugText(int sample_rate_hz,
+                             size_t num_channels,
+                             NsConfig::SuppressionLevel level) {
+  rtc::StringBuilder ss;
+  ss << "Sample rate: " << sample_rate_hz << ", num_channels: " << num_channels
+     << ", level: " << static_cast<int>(level);
+  return ss.Release();
+}
+
+void PopulateInputFrameWithIdenticalChannels(size_t num_channels,
+                                             size_t num_bands,
+                                             size_t frame_index,
+                                             AudioBuffer* audio) {
+  for (size_t ch = 0; ch < num_channels; ++ch) {
+    for (size_t b = 0; b < num_bands; ++b) {
+      for (size_t i = 0; i < 160; ++i) {
+        float value = static_cast<int>(frame_index * 160 + i);
+        audio->split_bands(ch)[b][i] = (value > 0 ? 5000 * b + value : 0);
+      }
+    }
+  }
+}
+
+void VerifyIdenticalChannels(size_t num_channels,
+                             size_t num_bands,
+                             size_t frame_index,
+                             const AudioBuffer& audio) {
+  EXPECT_GT(num_channels, 1u);
+  for (size_t ch = 1; ch < num_channels; ++ch) {
+    for (size_t b = 0; b < num_bands; ++b) {
+      for (size_t i = 0; i < 160; ++i) {
+        EXPECT_EQ(audio.split_bands_const(ch)[b][i],
+                  audio.split_bands_const(0)[b][i]);
+      }
+    }
+  }
+}
+
+}  // namespace
+
+// Verifies that the same noise reduction effect is applied to all channels.
+TEST(NoiseSuppressor, IdenticalChannelEffects) {
+  for (auto rate : {16000, 32000, 48000}) {
+    for (auto num_channels : {1, 4, 8}) {
+      for (auto level :
+           {NsConfig::SuppressionLevel::k6dB, NsConfig::SuppressionLevel::k12dB,
+            NsConfig::SuppressionLevel::k18dB,
+            NsConfig::SuppressionLevel::k21dB}) {
+        SCOPED_TRACE(ProduceDebugText(rate, num_channels, level));
+
+        const size_t num_bands = rate / 16000;
+        // const int frame_length = rtc::CheckedDivExact(rate, 100);
+        AudioBuffer audio(rate, num_channels, rate, num_channels, rate,
+                          num_channels);
+        NsConfig cfg;
+        NoiseSuppressor ns(cfg, rate, num_channels);
+        for (size_t frame_index = 0; frame_index < 1000; ++frame_index) {
+          if (rate > 16000) {
+            audio.SplitIntoFrequencyBands();
+          }
+
+          PopulateInputFrameWithIdenticalChannels(num_channels, num_bands,
+                                                  frame_index, &audio);
+
+          ns.Analyze(audio);
+          ns.Process(&audio);
+          if (num_channels > 1) {
+            VerifyIdenticalChannels(num_channels, num_bands, frame_index,
+                                    audio);
+          }
+        }
+      }
+    }
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/ns_common.h b/third_party/libwebrtc/modules/audio_processing/ns/ns_common.h
new file mode 100644
index 0000000000..d6149f72a7
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/ns_common.h
@@ -0,0 +1,34 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_NS_COMMON_H_
+#define MODULES_AUDIO_PROCESSING_NS_NS_COMMON_H_
+
+#include <cstddef>
+
+namespace webrtc {
+
+constexpr size_t kFftSize = 256;
+constexpr size_t kFftSizeBy2Plus1 = kFftSize / 2 + 1;
+constexpr size_t kNsFrameSize = 160;
+constexpr size_t kOverlapSize = kFftSize - kNsFrameSize;
+
+constexpr int kShortStartupPhaseBlocks = 50;
+constexpr int kLongStartupPhaseBlocks = 200;
+constexpr int kFeatureUpdateWindowSize = 500;
+
+constexpr float kLtrFeatureThr = 0.5f;
+constexpr float kBinSizeLrt = 0.1f;
+constexpr float kBinSizeSpecFlat = 0.05f;
+constexpr float kBinSizeSpecDiff = 0.1f;
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_NS_COMMON_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/ns_config.h b/third_party/libwebrtc/modules/audio_processing/ns/ns_config.h
new file mode 100644
index 0000000000..0a285e9cea
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/ns_config.h
@@ -0,0 +1,24 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_NS_CONFIG_H_
+#define MODULES_AUDIO_PROCESSING_NS_NS_CONFIG_H_
+
+namespace webrtc {
+
+// Config struct for the noise suppressor
+struct NsConfig {
+  enum class SuppressionLevel { k6dB, k12dB, k18dB, k21dB };
+  SuppressionLevel target_level = SuppressionLevel::k12dB;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_NS_CONFIG_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/ns_fft.cc b/third_party/libwebrtc/modules/audio_processing/ns/ns_fft.cc
new file mode 100644
index 0000000000..264c46972c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/ns_fft.cc
@@ -0,0 +1,64 @@
+/*
+ *  Copyright (c) 2019 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/ns/ns_fft.h"
+
+#include "common_audio/third_party/ooura/fft_size_256/fft4g.h"
+
+namespace webrtc {
+
+NrFft::NrFft() : bit_reversal_state_(kFftSize / 2), tables_(kFftSize / 2) {
+  // Initialize WebRtc_rdt (setting (bit_reversal_state_[0] to 0 triggers
+  // initialization)
+  bit_reversal_state_[0] = 0.f;
+  std::array<float, kFftSize> tmp_buffer;
+  tmp_buffer.fill(0.f);
+  WebRtc_rdft(kFftSize, 1, tmp_buffer.data(), bit_reversal_state_.data(),
+              tables_.data());
+}
+
+void NrFft::Fft(rtc::ArrayView<float, kFftSize> time_data,
+                rtc::ArrayView<float, kFftSize> real,
+                rtc::ArrayView<float, kFftSize> imag) {
+  WebRtc_rdft(kFftSize, 1, time_data.data(), bit_reversal_state_.data(),
+              tables_.data());
+
+  imag[0] = 0;
+  real[0] = time_data[0];
+
+  imag[kFftSizeBy2Plus1 - 1] = 0;
+  real[kFftSizeBy2Plus1 - 1] = time_data[1];
+
+  for (size_t i = 1; i < kFftSizeBy2Plus1 - 1; ++i) {
+    real[i] = time_data[2 * i];
+    imag[i] = time_data[2 * i + 1];
+  }
+}
+
+void NrFft::Ifft(rtc::ArrayView<const float> real,
+                 rtc::ArrayView<const float> imag,
+                 rtc::ArrayView<float> time_data) {
+  time_data[0] = real[0];
+  time_data[1] = real[kFftSizeBy2Plus1 - 1];
+  for (size_t i = 1; i < kFftSizeBy2Plus1 - 1; ++i) {
+    time_data[2 * i] = real[i];
+    time_data[2 * i + 1] = imag[i];
+  }
+  WebRtc_rdft(kFftSize, -1, time_data.data(), bit_reversal_state_.data(),
+              tables_.data());
+
+  // Scale the output
+  constexpr float kScaling = 2.f / kFftSize;
+  for (float& d : time_data) {
+    d *= kScaling;
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/ns_fft.h b/third_party/libwebrtc/modules/audio_processing/ns/ns_fft.h
new file mode 100644
index 0000000000..539251eef2
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/ns_fft.h
@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_
+#define MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_
+
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/ns_common.h"
+
+namespace webrtc {
+
+// Wrapper class providing 256 point FFT functionality.
+class NrFft {
+ public:
+  NrFft();
+  NrFft(const NrFft&) = delete;
+  NrFft& operator=(const NrFft&) = delete;
+
+  // Transforms the signal from time to frequency domain.
+  void Fft(rtc::ArrayView<float, kFftSize> time_data,
+           rtc::ArrayView<float, kFftSize> real,
+           rtc::ArrayView<float, kFftSize> imag);
+
+  // Transforms the signal from frequency to time domain.
+  void Ifft(rtc::ArrayView<const float> real,
+            rtc::ArrayView<const float> imag,
+            rtc::ArrayView<float> time_data);
+
+ private:
+  std::vector<size_t> bit_reversal_state_;
+  std::vector<float> tables_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/ns_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/ns/ns_gn/moz.build
new file mode 100644
index 0000000000..12076eedcb
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/ns_gn/moz.build
@@ -0,0 +1,245 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+  ### This moz.build was AUTOMATICALLY GENERATED from a GN config,  ###
+  ### DO NOT edit it by hand.                                       ###
+
+COMPILE_FLAGS["OS_INCLUDES"] = []
+AllowCompilerWarnings()
+
+DEFINES["ABSL_ALLOCATOR_NOTHROW"] = "1"
+DEFINES["RTC_DAV1D_IN_INTERNAL_DECODER_FACTORY"] = True
+DEFINES["RTC_ENABLE_VP9"] = True
+DEFINES["WEBRTC_APM_DEBUG_DUMP"] = "0"
+DEFINES["WEBRTC_ENABLE_PROTOBUF"] = "0"
+DEFINES["WEBRTC_LIBRARY_IMPL"] = True
+DEFINES["WEBRTC_MOZILLA_BUILD"] = True
+DEFINES["WEBRTC_NON_STATIC_TRACE_EVENT_HANDLERS"] = "0"
+DEFINES["WEBRTC_STRICT_FIELD_TRIALS"] = "0"
+
+FINAL_LIBRARY = "webrtc"
+
+
+LOCAL_INCLUDES += [
+    "!/ipc/ipdl/_ipdlheaders",
+    "!/third_party/libwebrtc/gen",
+    "/ipc/chromium/src",
+    "/third_party/libwebrtc/",
+    "/third_party/libwebrtc/third_party/abseil-cpp/",
+    "/tools/profiler/public"
+]
+
+UNIFIED_SOURCES += [
+    "/third_party/libwebrtc/modules/audio_processing/ns/fast_math.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/histograms.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/noise_estimator.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/noise_suppressor.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/ns_fft.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model_estimator.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/quantile_noise_estimator.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/signal_model.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/signal_model_estimator.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/speech_probability_estimator.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/suppression_params.cc",
+    "/third_party/libwebrtc/modules/audio_processing/ns/wiener_filter.cc"
+]
+
+if not CONFIG["MOZ_DEBUG"]:
+
+    DEFINES["DYNAMIC_ANNOTATIONS_ENABLED"] = "0"
+    DEFINES["NDEBUG"] = True
+    DEFINES["NVALGRIND"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1":
+
+    DEFINES["DYNAMIC_ANNOTATIONS_ENABLED"] = "1"
+
+if CONFIG["OS_TARGET"] == "Android":
+
+    DEFINES["ANDROID"] = True
+    DEFINES["ANDROID_NDK_VERSION_ROLL"] = "r22_1"
+    DEFINES["HAVE_SYS_UIO_H"] = True
+    DEFINES["WEBRTC_ANDROID"] = True
+    DEFINES["WEBRTC_ANDROID_OPENSLES"] = True
+    DEFINES["WEBRTC_LINUX"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_GNU_SOURCE"] = True
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+    OS_LIBS += [
+        "log"
+    ]
+
+if CONFIG["OS_TARGET"] == "Darwin":
+
+    DEFINES["WEBRTC_MAC"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_LIBCPP_HAS_NO_ALIGNED_ALLOCATION"] = True
+    DEFINES["__ASSERT_MACROS_DEFINE_VERSIONS_WITHOUT_UNDERSCORES"] = "0"
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+if CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["USE_AURA"] = "1"
+    DEFINES["USE_GLIB"] = "1"
+    DEFINES["USE_NSS_CERTS"] = "1"
+    DEFINES["USE_OZONE"] = "1"
+    DEFINES["USE_UDEV"] = True
+    DEFINES["WEBRTC_LINUX"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_FILE_OFFSET_BITS"] = "64"
+    DEFINES["_LARGEFILE64_SOURCE"] = True
+    DEFINES["_LARGEFILE_SOURCE"] = True
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+    OS_LIBS += [
+        "rt"
+    ]
+
+if CONFIG["OS_TARGET"] == "OpenBSD":
+
+    DEFINES["USE_GLIB"] = "1"
+    DEFINES["USE_OZONE"] = "1"
+    DEFINES["USE_X11"] = "1"
+    DEFINES["WEBRTC_BSD"] = True
+    DEFINES["WEBRTC_POSIX"] = True
+    DEFINES["_FILE_OFFSET_BITS"] = "64"
+    DEFINES["_LARGEFILE64_SOURCE"] = True
+    DEFINES["_LARGEFILE_SOURCE"] = True
+    DEFINES["__STDC_CONSTANT_MACROS"] = True
+    DEFINES["__STDC_FORMAT_MACROS"] = True
+
+if CONFIG["OS_TARGET"] == "WINNT":
+
+    DEFINES["CERT_CHAIN_PARA_HAS_EXTRA_FIELDS"] = True
+    DEFINES["NOMINMAX"] = True
+    DEFINES["NTDDI_VERSION"] = "0x0A000000"
+    DEFINES["PSAPI_VERSION"] = "2"
+    DEFINES["UNICODE"] = True
+    DEFINES["USE_AURA"] = "1"
+    DEFINES["WEBRTC_WIN"] = True
+    DEFINES["WIN32"] = True
+    DEFINES["WIN32_LEAN_AND_MEAN"] = True
+    DEFINES["WINAPI_FAMILY"] = "WINAPI_FAMILY_DESKTOP_APP"
+    DEFINES["WINVER"] = "0x0A00"
+    DEFINES["_ATL_NO_OPENGL"] = True
+    DEFINES["_CRT_RAND_S"] = True
+    DEFINES["_CRT_SECURE_NO_DEPRECATE"] = True
+    DEFINES["_ENABLE_EXTENDED_ALIGNED_STORAGE"] = True
+    DEFINES["_HAS_EXCEPTIONS"] = "0"
+    DEFINES["_HAS_NODISCARD"] = True
+    DEFINES["_SCL_SECURE_NO_DEPRECATE"] = True
+    DEFINES["_SECURE_ATL"] = True
+    DEFINES["_UNICODE"] = True
+    DEFINES["_WIN32_WINNT"] = "0x0A00"
+    DEFINES["_WINDOWS"] = True
+    DEFINES["__STD_C"] = True
+
+    OS_LIBS += [
+        "crypt32",
+        "iphlpapi",
+        "secur32",
+        "winmm"
+    ]
+
+if CONFIG["CPU_ARCH"] == "aarch64":
+
+    DEFINES["WEBRTC_ARCH_ARM64"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["CPU_ARCH"] == "arm":
+
+    CXXFLAGS += [
+        "-mfpu=neon"
+    ]
+
+    DEFINES["WEBRTC_ARCH_ARM"] = True
+    DEFINES["WEBRTC_ARCH_ARM_V7"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["CPU_ARCH"] == "mips32":
+
+    DEFINES["MIPS32_LE"] = True
+    DEFINES["MIPS_FPU_LE"] = True
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "mips64":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86":
+
+    DEFINES["WEBRTC_ENABLE_AVX2"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64":
+
+    DEFINES["WEBRTC_ENABLE_AVX2"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "Android":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "Darwin":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "OpenBSD":
+
+    DEFINES["_DEBUG"] = True
+
+if CONFIG["MOZ_DEBUG"] == "1" and CONFIG["OS_TARGET"] == "WINNT":
+
+    DEFINES["_HAS_ITERATOR_DEBUGGING"] = "0"
+
+if CONFIG["MOZ_X11"] == "1" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["USE_X11"] = "1"
+
+if CONFIG["CPU_ARCH"] == "arm" and CONFIG["OS_TARGET"] == "Android":
+
+    OS_LIBS += [
+        "android_support",
+        "unwind"
+    ]
+
+if CONFIG["CPU_ARCH"] == "x86" and CONFIG["OS_TARGET"] == "Android":
+
+    CXXFLAGS += [
+        "-msse2"
+    ]
+
+    OS_LIBS += [
+        "android_support"
+    ]
+
+if CONFIG["CPU_ARCH"] == "aarch64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "arm" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86" and CONFIG["OS_TARGET"] == "Linux":
+
+    CXXFLAGS += [
+        "-msse2"
+    ]
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("ns_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model.cc b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model.cc
new file mode 100644
index 0000000000..f25a1e2060
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model.cc
@@ -0,0 +1,18 @@
+/*
+ *  Copyright (c) 2019 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/ns/prior_signal_model.h"
+
+namespace webrtc {
+
+PriorSignalModel::PriorSignalModel(float lrt_initial_value)
+    : lrt(lrt_initial_value) {}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model.h b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model.h
new file mode 100644
index 0000000000..dcfa7ea709
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model.h
@@ -0,0 +1,32 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_PRIOR_SIGNAL_MODEL_H_
+#define MODULES_AUDIO_PROCESSING_NS_PRIOR_SIGNAL_MODEL_H_
+
+namespace webrtc {
+
+// Struct for storing the prior signal model parameters.
+struct PriorSignalModel {
+  explicit PriorSignalModel(float lrt_initial_value);
+  PriorSignalModel(const PriorSignalModel&) = delete;
+  PriorSignalModel& operator=(const PriorSignalModel&) = delete;
+
+  float lrt;
+  float flatness_threshold = .5f;
+  float template_diff_threshold = .5f;
+  float lrt_weighting = 1.f;
+  float flatness_weighting = 0.f;
+  float difference_weighting = 0.f;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_PRIOR_SIGNAL_MODEL_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model_estimator.cc b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model_estimator.cc
new file mode 100644
index 0000000000..c814658e57
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model_estimator.cc
@@ -0,0 +1,170 @@
+/*
+ *  Copyright (c) 2019 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/ns/prior_signal_model_estimator.h"
+
+#include <math.h>
+#include <algorithm>
+
+#include "modules/audio_processing/ns/fast_math.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+namespace {
+
+// Identifies the first of the two largest peaks in the histogram.
+void FindFirstOfTwoLargestPeaks(
+    float bin_size,
+    rtc::ArrayView<const int, kHistogramSize> spectral_flatness,
+    float* peak_position,
+    int* peak_weight) {
+  RTC_DCHECK(peak_position);
+  RTC_DCHECK(peak_weight);
+
+  int peak_value = 0;
+  int secondary_peak_value = 0;
+  *peak_position = 0.f;
+  float secondary_peak_position = 0.f;
+  *peak_weight = 0;
+  int secondary_peak_weight = 0;
+
+  // Identify the two largest peaks.
+  for (int i = 0; i < kHistogramSize; ++i) {
+    const float bin_mid = (i + 0.5f) * bin_size;
+    if (spectral_flatness[i] > peak_value) {
+      // Found new "first" peak candidate.
+      secondary_peak_value = peak_value;
+      secondary_peak_weight = *peak_weight;
+      secondary_peak_position = *peak_position;
+
+      peak_value = spectral_flatness[i];
+      *peak_weight = spectral_flatness[i];
+      *peak_position = bin_mid;
+    } else if (spectral_flatness[i] > secondary_peak_value) {
+      // Found new "second" peak candidate.
+      secondary_peak_value = spectral_flatness[i];
+      secondary_peak_weight = spectral_flatness[i];
+      secondary_peak_position = bin_mid;
+    }
+  }
+
+  // Merge the peaks if they are close.
+  if ((fabs(secondary_peak_position - *peak_position) < 2 * bin_size) &&
+      (secondary_peak_weight > 0.5f * (*peak_weight))) {
+    *peak_weight += secondary_peak_weight;
+    *peak_position = 0.5f * (*peak_position + secondary_peak_position);
+  }
+}
+
+void UpdateLrt(rtc::ArrayView<const int, kHistogramSize> lrt_histogram,
+               float* prior_model_lrt,
+               bool* low_lrt_fluctuations) {
+  RTC_DCHECK(prior_model_lrt);
+  RTC_DCHECK(low_lrt_fluctuations);
+
+  float average = 0.f;
+  float average_compl = 0.f;
+  float average_squared = 0.f;
+  int count = 0;
+
+  for (int i = 0; i < 10; ++i) {
+    float bin_mid = (i + 0.5f) * kBinSizeLrt;
+    average += lrt_histogram[i] * bin_mid;
+    count += lrt_histogram[i];
+  }
+  if (count > 0) {
+    average = average / count;
+  }
+
+  for (int i = 0; i < kHistogramSize; ++i) {
+    float bin_mid = (i + 0.5f) * kBinSizeLrt;
+    average_squared += lrt_histogram[i] * bin_mid * bin_mid;
+    average_compl += lrt_histogram[i] * bin_mid;
+  }
+  constexpr float kOneFeatureUpdateWindowSize = 1.f / kFeatureUpdateWindowSize;
+  average_squared = average_squared * kOneFeatureUpdateWindowSize;
+  average_compl = average_compl * kOneFeatureUpdateWindowSize;
+
+  // Fluctuation limit of LRT feature.
+  *low_lrt_fluctuations = average_squared - average * average_compl < 0.05f;
+
+  // Get threshold for LRT feature.
+  constexpr float kMaxLrt = 1.f;
+  constexpr float kMinLrt = .2f;
+  if (*low_lrt_fluctuations) {
+    // Very low fluctuation, so likely noise.
+    *prior_model_lrt = kMaxLrt;
+  } else {
+    *prior_model_lrt = std::min(kMaxLrt, std::max(kMinLrt, 1.2f * average));
+  }
+}
+
+}  // namespace
+
+PriorSignalModelEstimator::PriorSignalModelEstimator(float lrt_initial_value)
+    : prior_model_(lrt_initial_value) {}
+
+// Extract thresholds for feature parameters and computes the threshold/weights.
+void PriorSignalModelEstimator::Update(const Histograms& histograms) {
+  bool low_lrt_fluctuations;
+  UpdateLrt(histograms.get_lrt(), &prior_model_.lrt, &low_lrt_fluctuations);
+
+  // For spectral flatness and spectral difference: compute the main peaks of
+  // the histograms.
+  float spectral_flatness_peak_position;
+  int spectral_flatness_peak_weight;
+  FindFirstOfTwoLargestPeaks(
+      kBinSizeSpecFlat, histograms.get_spectral_flatness(),
+      &spectral_flatness_peak_position, &spectral_flatness_peak_weight);
+
+  float spectral_diff_peak_position = 0.f;
+  int spectral_diff_peak_weight = 0;
+  FindFirstOfTwoLargestPeaks(kBinSizeSpecDiff, histograms.get_spectral_diff(),
+                             &spectral_diff_peak_position,
+                             &spectral_diff_peak_weight);
+
+  // Reject if weight of peaks is not large enough, or peak value too small.
+  // Peak limit for spectral flatness (varies between 0 and 1).
+  const int use_spec_flat = spectral_flatness_peak_weight < 0.3f * 500 ||
+                                    spectral_flatness_peak_position < 0.6f
+                                ? 0
+                                : 1;
+
+  // Reject if weight of peaks is not large enough or if fluctuation of the LRT
+  // feature are very low, indicating a noise state.
+  const int use_spec_diff =
+      spectral_diff_peak_weight < 0.3f * 500 || low_lrt_fluctuations ? 0 : 1;
+
+  // Update the model.
+  prior_model_.template_diff_threshold = 1.2f * spectral_diff_peak_position;
+  prior_model_.template_diff_threshold =
+      std::min(1.f, std::max(0.16f, prior_model_.template_diff_threshold));
+
+  float one_by_feature_sum = 1.f / (1.f + use_spec_flat + use_spec_diff);
+  prior_model_.lrt_weighting = one_by_feature_sum;
+
+  if (use_spec_flat == 1) {
+    prior_model_.flatness_threshold = 0.9f * spectral_flatness_peak_position;
+    prior_model_.flatness_threshold =
+        std::min(.95f, std::max(0.1f, prior_model_.flatness_threshold));
+    prior_model_.flatness_weighting = one_by_feature_sum;
+  } else {
+    prior_model_.flatness_weighting = 0.f;
+  }
+
+  if (use_spec_diff == 1) {
+    prior_model_.difference_weighting = one_by_feature_sum;
+  } else {
+    prior_model_.difference_weighting = 0.f;
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model_estimator.h b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model_estimator.h
new file mode 100644
index 0000000000..d178323dba
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/prior_signal_model_estimator.h
@@ -0,0 +1,39 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_PRIOR_SIGNAL_MODEL_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_NS_PRIOR_SIGNAL_MODEL_ESTIMATOR_H_
+
+#include "modules/audio_processing/ns/histograms.h"
+#include "modules/audio_processing/ns/prior_signal_model.h"
+
+namespace webrtc {
+
+// Estimator of the prior signal model parameters.
+class PriorSignalModelEstimator {
+ public:
+  explicit PriorSignalModelEstimator(float lrt_initial_value);
+  PriorSignalModelEstimator(const PriorSignalModelEstimator&) = delete;
+  PriorSignalModelEstimator& operator=(const PriorSignalModelEstimator&) =
+      delete;
+
+  // Updates the model estimate.
+  void Update(const Histograms& h);
+
+  // Returns the estimated model.
+  const PriorSignalModel& get_prior_model() const { return prior_model_; }
+
+ private:
+  PriorSignalModel prior_model_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_PRIOR_SIGNAL_MODEL_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/quantile_noise_estimator.cc b/third_party/libwebrtc/modules/audio_processing/ns/quantile_noise_estimator.cc
new file mode 100644
index 0000000000..bab494ff21
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/quantile_noise_estimator.cc
@@ -0,0 +1,88 @@
+/*
+ *  Copyright (c) 2019 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/ns/quantile_noise_estimator.h"
+
+#include <algorithm>
+
+#include "modules/audio_processing/ns/fast_math.h"
+
+namespace webrtc {
+
+QuantileNoiseEstimator::QuantileNoiseEstimator() {
+  quantile_.fill(0.f);
+  density_.fill(0.3f);
+  log_quantile_.fill(8.f);
+
+  constexpr float kOneBySimult = 1.f / kSimult;
+  for (size_t i = 0; i < kSimult; ++i) {
+    counter_[i] = floor(kLongStartupPhaseBlocks * (i + 1.f) * kOneBySimult);
+  }
+}
+
+void QuantileNoiseEstimator::Estimate(
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+    rtc::ArrayView<float, kFftSizeBy2Plus1> noise_spectrum) {
+  std::array<float, kFftSizeBy2Plus1> log_spectrum;
+  LogApproximation(signal_spectrum, log_spectrum);
+
+  int quantile_index_to_return = -1;
+  // Loop over simultaneous estimates.
+  for (int s = 0, k = 0; s < kSimult;
+       ++s, k += static_cast<int>(kFftSizeBy2Plus1)) {
+    const float one_by_counter_plus_1 = 1.f / (counter_[s] + 1.f);
+    for (int i = 0, j = k; i < static_cast<int>(kFftSizeBy2Plus1); ++i, ++j) {
+      // Update log quantile estimate.
+      const float delta = density_[j] > 1.f ? 40.f / density_[j] : 40.f;
+
+      const float multiplier = delta * one_by_counter_plus_1;
+      if (log_spectrum[i] > log_quantile_[j]) {
+        log_quantile_[j] += 0.25f * multiplier;
+      } else {
+        log_quantile_[j] -= 0.75f * multiplier;
+      }
+
+      // Update density estimate.
+      constexpr float kWidth = 0.01f;
+      constexpr float kOneByWidthPlus2 = 1.f / (2.f * kWidth);
+      if (fabs(log_spectrum[i] - log_quantile_[j]) < kWidth) {
+        density_[j] = (counter_[s] * density_[j] + kOneByWidthPlus2) *
+                      one_by_counter_plus_1;
+      }
+    }
+
+    if (counter_[s] >= kLongStartupPhaseBlocks) {
+      counter_[s] = 0;
+      if (num_updates_ >= kLongStartupPhaseBlocks) {
+        quantile_index_to_return = k;
+      }
+    }
+
+    ++counter_[s];
+  }
+
+  // Sequentially update the noise during startup.
+  if (num_updates_ < kLongStartupPhaseBlocks) {
+    // Use the last "s" to get noise during startup that differ from zero.
+    quantile_index_to_return = kFftSizeBy2Plus1 * (kSimult - 1);
+    ++num_updates_;
+  }
+
+  if (quantile_index_to_return >= 0) {
+    ExpApproximation(
+        rtc::ArrayView<const float>(&log_quantile_[quantile_index_to_return],
+                                    kFftSizeBy2Plus1),
+        quantile_);
+  }
+
+  std::copy(quantile_.begin(), quantile_.end(), noise_spectrum.begin());
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/quantile_noise_estimator.h b/third_party/libwebrtc/modules/audio_processing/ns/quantile_noise_estimator.h
new file mode 100644
index 0000000000..67d1512209
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/quantile_noise_estimator.h
@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_QUANTILE_NOISE_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_NS_QUANTILE_NOISE_ESTIMATOR_H_
+
+#include <math.h>
+#include <array>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/ns_common.h"
+
+namespace webrtc {
+
+constexpr int kSimult = 3;
+
+// For quantile noise estimation.
+class QuantileNoiseEstimator {
+ public:
+  QuantileNoiseEstimator();
+  QuantileNoiseEstimator(const QuantileNoiseEstimator&) = delete;
+  QuantileNoiseEstimator& operator=(const QuantileNoiseEstimator&) = delete;
+
+  // Estimate noise.
+  void Estimate(rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+                rtc::ArrayView<float, kFftSizeBy2Plus1> noise_spectrum);
+
+ private:
+  std::array<float, kSimult * kFftSizeBy2Plus1> density_;
+  std::array<float, kSimult * kFftSizeBy2Plus1> log_quantile_;
+  std::array<float, kFftSizeBy2Plus1> quantile_;
+  std::array<int, kSimult> counter_;
+  int num_updates_ = 1;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_QUANTILE_NOISE_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/signal_model.cc b/third_party/libwebrtc/modules/audio_processing/ns/signal_model.cc
new file mode 100644
index 0000000000..364bfd00d8
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/signal_model.cc
@@ -0,0 +1,24 @@
+/*
+ *  Copyright (c) 2019 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/ns/signal_model.h"
+
+namespace webrtc {
+
+SignalModel::SignalModel() {
+  constexpr float kSfFeatureThr = 0.5f;
+
+  lrt = kLtrFeatureThr;
+  spectral_flatness = kSfFeatureThr;
+  spectral_diff = kSfFeatureThr;
+  avg_log_lrt.fill(kLtrFeatureThr);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/signal_model.h b/third_party/libwebrtc/modules/audio_processing/ns/signal_model.h
new file mode 100644
index 0000000000..6614d38a38
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/signal_model.h
@@ -0,0 +1,34 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_SIGNAL_MODEL_H_
+#define MODULES_AUDIO_PROCESSING_NS_SIGNAL_MODEL_H_
+
+#include <array>
+
+#include "modules/audio_processing/ns/ns_common.h"
+
+namespace webrtc {
+
+struct SignalModel {
+  SignalModel();
+  SignalModel(const SignalModel&) = delete;
+  SignalModel& operator=(const SignalModel&) = delete;
+
+  float lrt;
+  float spectral_diff;
+  float spectral_flatness;
+  // Log LRT factor with time-smoothing.
+  std::array<float, kFftSizeBy2Plus1> avg_log_lrt;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_SIGNAL_MODEL_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/signal_model_estimator.cc b/third_party/libwebrtc/modules/audio_processing/ns/signal_model_estimator.cc
new file mode 100644
index 0000000000..67dd3bb687
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/signal_model_estimator.cc
@@ -0,0 +1,175 @@
+/*
+ *  Copyright (c) 2019 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/ns/signal_model_estimator.h"
+
+#include "modules/audio_processing/ns/fast_math.h"
+
+namespace webrtc {
+
+namespace {
+
+constexpr float kOneByFftSizeBy2Plus1 = 1.f / kFftSizeBy2Plus1;
+
+// Computes the difference measure between input spectrum and a template/learned
+// noise spectrum.
+float ComputeSpectralDiff(
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> conservative_noise_spectrum,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+    float signal_spectral_sum,
+    float diff_normalization) {
+  // spectral_diff = var(signal_spectrum) - cov(signal_spectrum, magnAvgPause)^2
+  // / var(magnAvgPause)
+
+  // Compute average quantities.
+  float noise_average = 0.f;
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    // Conservative smooth noise spectrum from pause frames.
+    noise_average += conservative_noise_spectrum[i];
+  }
+  noise_average = noise_average * kOneByFftSizeBy2Plus1;
+  float signal_average = signal_spectral_sum * kOneByFftSizeBy2Plus1;
+
+  // Compute variance and covariance quantities.
+  float covariance = 0.f;
+  float noise_variance = 0.f;
+  float signal_variance = 0.f;
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    float signal_diff = signal_spectrum[i] - signal_average;
+    float noise_diff = conservative_noise_spectrum[i] - noise_average;
+    covariance += signal_diff * noise_diff;
+    noise_variance += noise_diff * noise_diff;
+    signal_variance += signal_diff * signal_diff;
+  }
+  covariance *= kOneByFftSizeBy2Plus1;
+  noise_variance *= kOneByFftSizeBy2Plus1;
+  signal_variance *= kOneByFftSizeBy2Plus1;
+
+  // Update of average magnitude spectrum.
+  float spectral_diff =
+      signal_variance - (covariance * covariance) / (noise_variance + 0.0001f);
+  // Normalize.
+  return spectral_diff / (diff_normalization + 0.0001f);
+}
+
+// Updates the spectral flatness based on the input spectrum.
+void UpdateSpectralFlatness(
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+    float signal_spectral_sum,
+    float* spectral_flatness) {
+  RTC_DCHECK(spectral_flatness);
+
+  // Compute log of ratio of the geometric to arithmetic mean (handle the log(0)
+  // separately).
+  constexpr float kAveraging = 0.3f;
+  float avg_spect_flatness_num = 0.f;
+  for (size_t i = 1; i < kFftSizeBy2Plus1; ++i) {
+    if (signal_spectrum[i] == 0.f) {
+      *spectral_flatness -= kAveraging * (*spectral_flatness);
+      return;
+    }
+  }
+
+  for (size_t i = 1; i < kFftSizeBy2Plus1; ++i) {
+    avg_spect_flatness_num += LogApproximation(signal_spectrum[i]);
+  }
+
+  float avg_spect_flatness_denom = signal_spectral_sum - signal_spectrum[0];
+
+  avg_spect_flatness_denom = avg_spect_flatness_denom * kOneByFftSizeBy2Plus1;
+  avg_spect_flatness_num = avg_spect_flatness_num * kOneByFftSizeBy2Plus1;
+
+  float spectral_tmp =
+      ExpApproximation(avg_spect_flatness_num) / avg_spect_flatness_denom;
+
+  // Time-avg update of spectral flatness feature.
+  *spectral_flatness += kAveraging * (spectral_tmp - *spectral_flatness);
+}
+
+// Updates the log LRT measures.
+void UpdateSpectralLrt(rtc::ArrayView<const float, kFftSizeBy2Plus1> prior_snr,
+                       rtc::ArrayView<const float, kFftSizeBy2Plus1> post_snr,
+                       rtc::ArrayView<float, kFftSizeBy2Plus1> avg_log_lrt,
+                       float* lrt) {
+  RTC_DCHECK(lrt);
+
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    float tmp1 = 1.f + 2.f * prior_snr[i];
+    float tmp2 = 2.f * prior_snr[i] / (tmp1 + 0.0001f);
+    float bessel_tmp = (post_snr[i] + 1.f) * tmp2;
+    avg_log_lrt[i] +=
+        .5f * (bessel_tmp - LogApproximation(tmp1) - avg_log_lrt[i]);
+  }
+
+  float log_lrt_time_avg_k_sum = 0.f;
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    log_lrt_time_avg_k_sum += avg_log_lrt[i];
+  }
+  *lrt = log_lrt_time_avg_k_sum * kOneByFftSizeBy2Plus1;
+}
+
+}  // namespace
+
+SignalModelEstimator::SignalModelEstimator()
+    : prior_model_estimator_(kLtrFeatureThr) {}
+
+void SignalModelEstimator::AdjustNormalization(int32_t num_analyzed_frames,
+                                               float signal_energy) {
+  diff_normalization_ *= num_analyzed_frames;
+  diff_normalization_ += signal_energy;
+  diff_normalization_ /= (num_analyzed_frames + 1);
+}
+
+// Update the noise features.
+void SignalModelEstimator::Update(
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> prior_snr,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> post_snr,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> conservative_noise_spectrum,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+    float signal_spectral_sum,
+    float signal_energy) {
+  // Compute spectral flatness on input spectrum.
+  UpdateSpectralFlatness(signal_spectrum, signal_spectral_sum,
+                         &features_.spectral_flatness);
+
+  // Compute difference of input spectrum with learned/estimated noise spectrum.
+  float spectral_diff =
+      ComputeSpectralDiff(conservative_noise_spectrum, signal_spectrum,
+                          signal_spectral_sum, diff_normalization_);
+  // Compute time-avg update of difference feature.
+  features_.spectral_diff += 0.3f * (spectral_diff - features_.spectral_diff);
+
+  signal_energy_sum_ += signal_energy;
+
+  // Compute histograms for parameter decisions (thresholds and weights for
+  // features). Parameters are extracted periodically.
+  if (--histogram_analysis_counter_ > 0) {
+    histograms_.Update(features_);
+  } else {
+    // Compute model parameters.
+    prior_model_estimator_.Update(histograms_);
+
+    // Clear histograms for next update.
+    histograms_.Clear();
+
+    histogram_analysis_counter_ = kFeatureUpdateWindowSize;
+
+    // Update every window:
+    // Compute normalization for the spectral difference for next estimation.
+    signal_energy_sum_ = signal_energy_sum_ / kFeatureUpdateWindowSize;
+    diff_normalization_ = 0.5f * (signal_energy_sum_ + diff_normalization_);
+    signal_energy_sum_ = 0.f;
+  }
+
+  // Compute the LRT.
+  UpdateSpectralLrt(prior_snr, post_snr, features_.avg_log_lrt, &features_.lrt);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/signal_model_estimator.h b/third_party/libwebrtc/modules/audio_processing/ns/signal_model_estimator.h
new file mode 100644
index 0000000000..58ce00acbf
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/signal_model_estimator.h
@@ -0,0 +1,58 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_SIGNAL_MODEL_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_NS_SIGNAL_MODEL_ESTIMATOR_H_
+
+#include <array>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/histograms.h"
+#include "modules/audio_processing/ns/ns_common.h"
+#include "modules/audio_processing/ns/prior_signal_model.h"
+#include "modules/audio_processing/ns/prior_signal_model_estimator.h"
+#include "modules/audio_processing/ns/signal_model.h"
+
+namespace webrtc {
+
+class SignalModelEstimator {
+ public:
+  SignalModelEstimator();
+  SignalModelEstimator(const SignalModelEstimator&) = delete;
+  SignalModelEstimator& operator=(const SignalModelEstimator&) = delete;
+
+  // Compute signal normalization during the initial startup phase.
+  void AdjustNormalization(int32_t num_analyzed_frames, float signal_energy);
+
+  void Update(
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> prior_snr,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> post_snr,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> conservative_noise_spectrum,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+      float signal_spectral_sum,
+      float signal_energy);
+
+  const PriorSignalModel& get_prior_model() const {
+    return prior_model_estimator_.get_prior_model();
+  }
+  const SignalModel& get_model() { return features_; }
+
+ private:
+  float diff_normalization_ = 0.f;
+  float signal_energy_sum_ = 0.f;
+  Histograms histograms_;
+  int histogram_analysis_counter_ = 500;
+  PriorSignalModelEstimator prior_model_estimator_;
+  SignalModel features_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_SIGNAL_MODEL_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/speech_probability_estimator.cc b/third_party/libwebrtc/modules/audio_processing/ns/speech_probability_estimator.cc
new file mode 100644
index 0000000000..fce9bc8e07
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/speech_probability_estimator.cc
@@ -0,0 +1,103 @@
+/*
+ *  Copyright (c) 2019 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/ns/speech_probability_estimator.h"
+
+#include <math.h>
+#include <algorithm>
+
+#include "modules/audio_processing/ns/fast_math.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+SpeechProbabilityEstimator::SpeechProbabilityEstimator() {
+  speech_probability_.fill(0.f);
+}
+
+void SpeechProbabilityEstimator::Update(
+    int32_t num_analyzed_frames,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> prior_snr,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> post_snr,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> conservative_noise_spectrum,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+    float signal_spectral_sum,
+    float signal_energy) {
+  // Update models.
+  if (num_analyzed_frames < kLongStartupPhaseBlocks) {
+    signal_model_estimator_.AdjustNormalization(num_analyzed_frames,
+                                                signal_energy);
+  }
+  signal_model_estimator_.Update(prior_snr, post_snr,
+                                 conservative_noise_spectrum, signal_spectrum,
+                                 signal_spectral_sum, signal_energy);
+
+  const SignalModel& model = signal_model_estimator_.get_model();
+  const PriorSignalModel& prior_model =
+      signal_model_estimator_.get_prior_model();
+
+  // Width parameter in sigmoid map for prior model.
+  constexpr float kWidthPrior0 = 4.f;
+  // Width for pause region: lower range, so increase width in tanh map.
+  constexpr float kWidthPrior1 = 2.f * kWidthPrior0;
+
+  // Average LRT feature: use larger width in tanh map for pause regions.
+  float width_prior = model.lrt < prior_model.lrt ? kWidthPrior1 : kWidthPrior0;
+
+  // Compute indicator function: sigmoid map.
+  float indicator0 =
+      0.5f * (tanh(width_prior * (model.lrt - prior_model.lrt)) + 1.f);
+
+  // Spectral flatness feature: use larger width in tanh map for pause regions.
+  width_prior = model.spectral_flatness > prior_model.flatness_threshold
+                    ? kWidthPrior1
+                    : kWidthPrior0;
+
+  // Compute indicator function: sigmoid map.
+  float indicator1 =
+      0.5f * (tanh(1.f * width_prior *
+                   (prior_model.flatness_threshold - model.spectral_flatness)) +
+              1.f);
+
+  // For template spectrum-difference : use larger width in tanh map for pause
+  // regions.
+  width_prior = model.spectral_diff < prior_model.template_diff_threshold
+                    ? kWidthPrior1
+                    : kWidthPrior0;
+
+  // Compute indicator function: sigmoid map.
+  float indicator2 =
+      0.5f * (tanh(width_prior * (model.spectral_diff -
+                                  prior_model.template_diff_threshold)) +
+              1.f);
+
+  // Combine the indicator function with the feature weights.
+  float ind_prior = prior_model.lrt_weighting * indicator0 +
+                    prior_model.flatness_weighting * indicator1 +
+                    prior_model.difference_weighting * indicator2;
+
+  // Compute the prior probability.
+  prior_speech_prob_ += 0.1f * (ind_prior - prior_speech_prob_);
+
+  // Make sure probabilities are within range: keep floor to 0.01.
+  prior_speech_prob_ = std::max(std::min(prior_speech_prob_, 1.f), 0.01f);
+
+  // Final speech probability: combine prior model with LR factor:.
+  float gain_prior =
+      (1.f - prior_speech_prob_) / (prior_speech_prob_ + 0.0001f);
+
+  std::array<float, kFftSizeBy2Plus1> inv_lrt;
+  ExpApproximationSignFlip(model.avg_log_lrt, inv_lrt);
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    speech_probability_[i] = 1.f / (1.f + gain_prior * inv_lrt[i]);
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/speech_probability_estimator.h b/third_party/libwebrtc/modules/audio_processing/ns/speech_probability_estimator.h
new file mode 100644
index 0000000000..259c3b6776
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/speech_probability_estimator.h
@@ -0,0 +1,51 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_SPEECH_PROBABILITY_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_NS_SPEECH_PROBABILITY_ESTIMATOR_H_
+
+#include <array>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/ns_common.h"
+#include "modules/audio_processing/ns/signal_model_estimator.h"
+
+namespace webrtc {
+
+// Class for estimating the probability of speech.
+class SpeechProbabilityEstimator {
+ public:
+  SpeechProbabilityEstimator();
+  SpeechProbabilityEstimator(const SpeechProbabilityEstimator&) = delete;
+  SpeechProbabilityEstimator& operator=(const SpeechProbabilityEstimator&) =
+      delete;
+
+  // Compute speech probability.
+  void Update(
+      int32_t num_analyzed_frames,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> prior_snr,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> post_snr,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> conservative_noise_spectrum,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
+      float signal_spectral_sum,
+      float signal_energy);
+
+  float get_prior_probability() const { return prior_speech_prob_; }
+  rtc::ArrayView<const float> get_probability() { return speech_probability_; }
+
+ private:
+  SignalModelEstimator signal_model_estimator_;
+  float prior_speech_prob_ = .5f;
+  std::array<float, kFftSizeBy2Plus1> speech_probability_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_SPEECH_PROBABILITY_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/suppression_params.cc b/third_party/libwebrtc/modules/audio_processing/ns/suppression_params.cc
new file mode 100644
index 0000000000..7bf18346f9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/suppression_params.cc
@@ -0,0 +1,49 @@
+/*
+ *  Copyright (c) 2019 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/ns/suppression_params.h"
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+SuppressionParams::SuppressionParams(
+    NsConfig::SuppressionLevel suppression_level) {
+  switch (suppression_level) {
+    case NsConfig::SuppressionLevel::k6dB:
+      over_subtraction_factor = 1.f;
+      // 6 dB attenuation.
+      minimum_attenuating_gain = 0.5f;
+      use_attenuation_adjustment = false;
+      break;
+    case NsConfig::SuppressionLevel::k12dB:
+      over_subtraction_factor = 1.f;
+      // 12 dB attenuation.
+      minimum_attenuating_gain = 0.25f;
+      use_attenuation_adjustment = true;
+      break;
+    case NsConfig::SuppressionLevel::k18dB:
+      over_subtraction_factor = 1.1f;
+      // 18 dB attenuation.
+      minimum_attenuating_gain = 0.125f;
+      use_attenuation_adjustment = true;
+      break;
+    case NsConfig::SuppressionLevel::k21dB:
+      over_subtraction_factor = 1.25f;
+      // 20.9 dB attenuation.
+      minimum_attenuating_gain = 0.09f;
+      use_attenuation_adjustment = true;
+      break;
+    default:
+      RTC_DCHECK_NOTREACHED();
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/suppression_params.h b/third_party/libwebrtc/modules/audio_processing/ns/suppression_params.h
new file mode 100644
index 0000000000..ad11977d81
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/suppression_params.h
@@ -0,0 +1,30 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_SUPPRESSION_PARAMS_H_
+#define MODULES_AUDIO_PROCESSING_NS_SUPPRESSION_PARAMS_H_
+
+#include "modules/audio_processing/ns/ns_config.h"
+
+namespace webrtc {
+
+struct SuppressionParams {
+  explicit SuppressionParams(NsConfig::SuppressionLevel suppression_level);
+  SuppressionParams(const SuppressionParams&) = delete;
+  SuppressionParams& operator=(const SuppressionParams&) = delete;
+
+  float over_subtraction_factor;
+  float minimum_attenuating_gain;
+  bool use_attenuation_adjustment;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_SUPPRESSION_PARAMS_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/wiener_filter.cc b/third_party/libwebrtc/modules/audio_processing/ns/wiener_filter.cc
new file mode 100644
index 0000000000..e14b7970d9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/wiener_filter.cc
@@ -0,0 +1,120 @@
+/*
+ *  Copyright (c) 2019 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/ns/wiener_filter.h"
+
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+#include <algorithm>
+
+#include "modules/audio_processing/ns/fast_math.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+WienerFilter::WienerFilter(const SuppressionParams& suppression_params)
+    : suppression_params_(suppression_params) {
+  filter_.fill(1.f);
+  initial_spectral_estimate_.fill(0.f);
+  spectrum_prev_process_.fill(0.f);
+}
+
+void WienerFilter::Update(
+    int32_t num_analyzed_frames,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> noise_spectrum,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> prev_noise_spectrum,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> parametric_noise_spectrum,
+    rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum) {
+  for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+    // Previous estimate based on previous frame with gain filter.
+    float prev_tsa = spectrum_prev_process_[i] /
+                     (prev_noise_spectrum[i] + 0.0001f) * filter_[i];
+
+    // Current estimate.
+    float current_tsa;
+    if (signal_spectrum[i] > noise_spectrum[i]) {
+      current_tsa = signal_spectrum[i] / (noise_spectrum[i] + 0.0001f) - 1.f;
+    } else {
+      current_tsa = 0.f;
+    }
+
+    // Directed decision estimate is sum of two terms: current estimate and
+    // previous estimate.
+    float snr_prior = 0.98f * prev_tsa + (1.f - 0.98f) * current_tsa;
+    filter_[i] =
+        snr_prior / (suppression_params_.over_subtraction_factor + snr_prior);
+    filter_[i] = std::max(std::min(filter_[i], 1.f),
+                          suppression_params_.minimum_attenuating_gain);
+  }
+
+  if (num_analyzed_frames < kShortStartupPhaseBlocks) {
+    for (size_t i = 0; i < kFftSizeBy2Plus1; ++i) {
+      initial_spectral_estimate_[i] += signal_spectrum[i];
+      float filter_initial = initial_spectral_estimate_[i] -
+                             suppression_params_.over_subtraction_factor *
+                                 parametric_noise_spectrum[i];
+      filter_initial /= initial_spectral_estimate_[i] + 0.0001f;
+
+      filter_initial = std::max(std::min(filter_initial, 1.f),
+                                suppression_params_.minimum_attenuating_gain);
+
+      // Weight the two suppression filters.
+      constexpr float kOnyByShortStartupPhaseBlocks =
+          1.f / kShortStartupPhaseBlocks;
+      filter_initial *= kShortStartupPhaseBlocks - num_analyzed_frames;
+      filter_[i] *= num_analyzed_frames;
+      filter_[i] += filter_initial;
+      filter_[i] *= kOnyByShortStartupPhaseBlocks;
+    }
+  }
+
+  std::copy(signal_spectrum.begin(), signal_spectrum.end(),
+            spectrum_prev_process_.begin());
+}
+
+float WienerFilter::ComputeOverallScalingFactor(
+    int32_t num_analyzed_frames,
+    float prior_speech_probability,
+    float energy_before_filtering,
+    float energy_after_filtering) const {
+  if (!suppression_params_.use_attenuation_adjustment ||
+      num_analyzed_frames <= kLongStartupPhaseBlocks) {
+    return 1.f;
+  }
+
+  float gain = SqrtFastApproximation(energy_after_filtering /
+                                     (energy_before_filtering + 1.f));
+
+  // Scaling for new version. Threshold in final energy gain factor calculation.
+  constexpr float kBLim = 0.5f;
+  float scale_factor1 = 1.f;
+  if (gain > kBLim) {
+    scale_factor1 = 1.f + 1.3f * (gain - kBLim);
+    if (gain * scale_factor1 > 1.f) {
+      scale_factor1 = 1.f / gain;
+    }
+  }
+
+  float scale_factor2 = 1.f;
+  if (gain < kBLim) {
+    // Do not reduce scale too much for pause regions: attenuation here should
+    // be controlled by flooring.
+    gain = std::max(gain, suppression_params_.minimum_attenuating_gain);
+    scale_factor2 = 1.f - 0.3f * (kBLim - gain);
+  }
+
+  // Combine both scales with speech/noise prob: note prior
+  // (prior_speech_probability) is not frequency dependent.
+  return prior_speech_probability * scale_factor1 +
+         (1.f - prior_speech_probability) * scale_factor2;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/ns/wiener_filter.h b/third_party/libwebrtc/modules/audio_processing/ns/wiener_filter.h
new file mode 100644
index 0000000000..b55c5dc59d
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/ns/wiener_filter.h
@@ -0,0 +1,57 @@
+/*
+ *  Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_WIENER_FILTER_H_
+#define MODULES_AUDIO_PROCESSING_NS_WIENER_FILTER_H_
+
+#include <array>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/ns_common.h"
+#include "modules/audio_processing/ns/suppression_params.h"
+
+namespace webrtc {
+
+// Estimates a Wiener-filter based frequency domain noise reduction filter.
+class WienerFilter {
+ public:
+  explicit WienerFilter(const SuppressionParams& suppression_params);
+  WienerFilter(const WienerFilter&) = delete;
+  WienerFilter& operator=(const WienerFilter&) = delete;
+
+  // Updates the filter estimate.
+  void Update(
+      int32_t num_analyzed_frames,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> noise_spectrum,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> prev_noise_spectrum,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> parametric_noise_spectrum,
+      rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum);
+
+  // Compute an overall gain scaling factor.
+  float ComputeOverallScalingFactor(int32_t num_analyzed_frames,
+                                    float prior_speech_probability,
+                                    float energy_before_filtering,
+                                    float energy_after_filtering) const;
+
+  // Returns the filter.
+  rtc::ArrayView<const float, kFftSizeBy2Plus1> get_filter() const {
+    return filter_;
+  }
+
+ private:
+  const SuppressionParams& suppression_params_;
+  std::array<float, kFftSizeBy2Plus1> spectrum_prev_process_;
+  std::array<float, kFftSizeBy2Plus1> initial_spectral_estimate_;
+  std::array<float, kFftSizeBy2Plus1> filter_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_NS_WIENER_FILTER_H_