Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

135 files changed, 21741 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/BUILD.gn b/third_party/libwebrtc/modules/audio_processing/agc2/BUILD.gn
new file mode 100644
index 0000000000..bd59ad3dae
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/BUILD.gn
@@ -0,0 +1,511 @@
+# Copyright (c) 2017 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_library("speech_level_estimator") {
+  sources = [
+    "speech_level_estimator.cc",
+    "speech_level_estimator.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  configs += [ "..:apm_debug_dump" ]
+
+  deps = [
+    ":common",
+    "..:api",
+    "..:apm_logging",
+    "../../../api:array_view",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:logging",
+    "../../../rtc_base:safe_minmax",
+  ]
+}
+
+rtc_library("adaptive_digital_gain_controller") {
+  sources = [
+    "adaptive_digital_gain_controller.cc",
+    "adaptive_digital_gain_controller.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  configs += [ "..:apm_debug_dump" ]
+
+  deps = [
+    ":common",
+    ":gain_applier",
+    "..:api",
+    "..:apm_logging",
+    "..:audio_frame_view",
+    "../../../common_audio",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:logging",
+    "../../../rtc_base:safe_minmax",
+    "../../../system_wrappers:metrics",
+  ]
+}
+
+rtc_library("saturation_protector") {
+  sources = [
+    "saturation_protector.cc",
+    "saturation_protector.h",
+    "saturation_protector_buffer.cc",
+    "saturation_protector_buffer.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  configs += [ "..:apm_debug_dump" ]
+
+  deps = [
+    ":common",
+    "..:apm_logging",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:safe_compare",
+    "../../../rtc_base:safe_minmax",
+  ]
+
+  absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
+}
+
+rtc_library("biquad_filter") {
+  visibility = [ "./*" ]
+  sources = [
+    "biquad_filter.cc",
+    "biquad_filter.h",
+  ]
+  deps = [
+    "../../../api:array_view",
+    "../../../rtc_base:macromagic",
+  ]
+}
+
+rtc_library("clipping_predictor") {
+  visibility = [
+    "../agc:agc",
+    "./*",
+  ]
+
+  sources = [
+    "clipping_predictor.cc",
+    "clipping_predictor.h",
+    "clipping_predictor_level_buffer.cc",
+    "clipping_predictor_level_buffer.h",
+  ]
+
+  deps = [
+    ":gain_map",
+    "..:api",
+    "..:audio_frame_view",
+    "../../../common_audio",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:logging",
+    "../../../rtc_base:safe_minmax",
+  ]
+
+  absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
+}
+
+rtc_source_set("common") {
+  sources = [ "agc2_common.h" ]
+}
+
+rtc_library("fixed_digital") {
+  sources = [
+    "fixed_digital_level_estimator.cc",
+    "fixed_digital_level_estimator.h",
+    "interpolated_gain_curve.cc",
+    "interpolated_gain_curve.h",
+    "limiter.cc",
+    "limiter.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "../../audio_mixer:audio_mixer_impl",
+    "./*",
+  ]
+
+  configs += [ "..:apm_debug_dump" ]
+
+  deps = [
+    ":common",
+    "..:apm_logging",
+    "..:audio_frame_view",
+    "../../../api:array_view",
+    "../../../common_audio",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:gtest_prod",
+    "../../../rtc_base:safe_conversions",
+    "../../../rtc_base:safe_minmax",
+    "../../../rtc_base:stringutils",
+    "../../../system_wrappers:metrics",
+  ]
+  absl_deps = [ "//third_party/abseil-cpp/absl/strings" ]
+}
+
+rtc_library("gain_applier") {
+  sources = [
+    "gain_applier.cc",
+    "gain_applier.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  deps = [
+    ":common",
+    "..:audio_frame_view",
+    "../../../api:array_view",
+    "../../../rtc_base:safe_minmax",
+  ]
+}
+
+rtc_source_set("gain_map") {
+  visibility = [
+    "..:analog_mic_simulation",
+    "../agc:agc",
+    "./*",
+  ]
+
+  sources = [ "gain_map_internal.h" ]
+}
+
+rtc_library("input_volume_controller") {
+  sources = [
+    "input_volume_controller.cc",
+    "input_volume_controller.h",
+    "speech_probability_buffer.cc",
+    "speech_probability_buffer.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  configs += [ "..:apm_debug_dump" ]
+
+  deps = [
+    ":clipping_predictor",
+    ":gain_map",
+    ":input_volume_stats_reporter",
+    "..:api",
+    "..:audio_buffer",
+    "..:audio_frame_view",
+    "../../../api:array_view",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:gtest_prod",
+    "../../../rtc_base:gtest_prod",
+    "../../../rtc_base:logging",
+    "../../../rtc_base:safe_minmax",
+    "../../../system_wrappers:field_trial",
+    "../../../system_wrappers:metrics",
+  ]
+
+  absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
+}
+
+rtc_library("noise_level_estimator") {
+  sources = [
+    "noise_level_estimator.cc",
+    "noise_level_estimator.h",
+  ]
+  deps = [
+    ":biquad_filter",
+    "..:apm_logging",
+    "..:audio_frame_view",
+    "../../../api:array_view",
+    "../../../rtc_base:checks",
+    "../../../system_wrappers",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  configs += [ "..:apm_debug_dump" ]
+}
+
+rtc_library("vad_wrapper") {
+  sources = [
+    "vad_wrapper.cc",
+    "vad_wrapper.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  defines = []
+  if (rtc_build_with_neon && current_cpu != "arm64") {
+    suppressed_configs += [ "//build/config/compiler:compiler_arm_fpu" ]
+    cflags = [ "-mfpu=neon" ]
+  }
+
+  deps = [
+    ":common",
+    ":cpu_features",
+    "..:audio_frame_view",
+    "../../../api:array_view",
+    "../../../common_audio",
+    "../../../rtc_base:checks",
+    "rnn_vad",
+    "rnn_vad:rnn_vad_common",
+  ]
+}
+
+rtc_library("cpu_features") {
+  sources = [
+    "cpu_features.cc",
+    "cpu_features.h",
+  ]
+
+  visibility = [
+    "..:gain_controller2",
+    "./*",
+  ]
+
+  deps = [
+    "../../../rtc_base:stringutils",
+    "../../../rtc_base/system:arch",
+    "../../../system_wrappers",
+  ]
+}
+
+rtc_library("speech_level_estimator_unittest") {
+  testonly = true
+  configs += [ "..:apm_debug_dump" ]
+
+  sources = [ "speech_level_estimator_unittest.cc" ]
+  deps = [
+    ":common",
+    ":speech_level_estimator",
+    "..:api",
+    "..:apm_logging",
+    "../../../rtc_base:gunit_helpers",
+    "../../../test:test_support",
+  ]
+}
+
+rtc_library("adaptive_digital_gain_controller_unittest") {
+  testonly = true
+  configs += [ "..:apm_debug_dump" ]
+
+  sources = [ "adaptive_digital_gain_controller_unittest.cc" ]
+
+  deps = [
+    ":adaptive_digital_gain_controller",
+    ":common",
+    ":test_utils",
+    "..:api",
+    "..:apm_logging",
+    "..:audio_frame_view",
+    "../../../common_audio",
+    "../../../rtc_base:gunit_helpers",
+    "../../../test:test_support",
+  ]
+}
+
+rtc_library("gain_applier_unittest") {
+  testonly = true
+  configs += [ "..:apm_debug_dump" ]
+
+  sources = [ "gain_applier_unittest.cc" ]
+  deps = [
+    ":gain_applier",
+    ":test_utils",
+    "..:audio_frame_view",
+    "../../../rtc_base:gunit_helpers",
+    "../../../test:test_support",
+  ]
+}
+
+rtc_library("saturation_protector_unittest") {
+  testonly = true
+  configs += [ "..:apm_debug_dump" ]
+
+  sources = [
+    "saturation_protector_buffer_unittest.cc",
+    "saturation_protector_unittest.cc",
+  ]
+  deps = [
+    ":common",
+    ":saturation_protector",
+    "..:apm_logging",
+    "../../../rtc_base:gunit_helpers",
+    "../../../test:test_support",
+  ]
+}
+
+rtc_library("biquad_filter_unittests") {
+  testonly = true
+  sources = [ "biquad_filter_unittest.cc" ]
+  deps = [
+    ":biquad_filter",
+    "../../../rtc_base:gunit_helpers",
+  ]
+}
+
+rtc_library("fixed_digital_unittests") {
+  testonly = true
+  configs += [ "..:apm_debug_dump" ]
+
+  sources = [
+    "agc2_testing_common_unittest.cc",
+    "compute_interpolated_gain_curve.cc",
+    "compute_interpolated_gain_curve.h",
+    "fixed_digital_level_estimator_unittest.cc",
+    "interpolated_gain_curve_unittest.cc",
+    "limiter_db_gain_curve.cc",
+    "limiter_db_gain_curve.h",
+    "limiter_db_gain_curve_unittest.cc",
+    "limiter_unittest.cc",
+  ]
+  deps = [
+    ":common",
+    ":fixed_digital",
+    ":test_utils",
+    "..:apm_logging",
+    "..:audio_frame_view",
+    "../../../api:array_view",
+    "../../../common_audio",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:gunit_helpers",
+    "../../../system_wrappers:metrics",
+  ]
+}
+
+rtc_library("input_volume_controller_unittests") {
+  testonly = true
+  sources = [
+    "clipping_predictor_level_buffer_unittest.cc",
+    "clipping_predictor_unittest.cc",
+    "input_volume_controller_unittest.cc",
+    "speech_probability_buffer_unittest.cc",
+  ]
+
+  configs += [ "..:apm_debug_dump" ]
+
+  deps = [
+    ":clipping_predictor",
+    ":gain_map",
+    ":input_volume_controller",
+    "..:api",
+    "../../../api:array_view",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:random",
+    "../../../rtc_base:safe_conversions",
+    "../../../rtc_base:safe_minmax",
+    "../../../rtc_base:stringutils",
+    "../../../system_wrappers:metrics",
+    "../../../test:field_trial",
+    "../../../test:fileutils",
+    "../../../test:test_support",
+    "//testing/gtest",
+  ]
+
+  absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
+}
+
+rtc_library("noise_estimator_unittests") {
+  testonly = true
+  configs += [ "..:apm_debug_dump" ]
+
+  sources = [ "noise_level_estimator_unittest.cc" ]
+  deps = [
+    ":noise_level_estimator",
+    ":test_utils",
+    "..:apm_logging",
+    "..:audio_frame_view",
+    "../../../api:array_view",
+    "../../../api:function_view",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:gunit_helpers",
+  ]
+}
+
+rtc_library("vad_wrapper_unittests") {
+  testonly = true
+  sources = [ "vad_wrapper_unittest.cc" ]
+  deps = [
+    ":common",
+    ":vad_wrapper",
+    "..:audio_frame_view",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:gunit_helpers",
+    "../../../rtc_base:safe_compare",
+    "../../../test:test_support",
+  ]
+}
+
+rtc_library("test_utils") {
+  testonly = true
+  visibility = [
+    ":*",
+    "..:audio_processing_unittests",
+  ]
+  sources = [
+    "agc2_testing_common.cc",
+    "agc2_testing_common.h",
+    "vector_float_frame.cc",
+    "vector_float_frame.h",
+  ]
+  deps = [
+    "..:audio_frame_view",
+    "../../../rtc_base:checks",
+    "../../../rtc_base:random",
+  ]
+}
+
+rtc_library("input_volume_stats_reporter") {
+  sources = [
+    "input_volume_stats_reporter.cc",
+    "input_volume_stats_reporter.h",
+  ]
+  deps = [
+    "../../../rtc_base:gtest_prod",
+    "../../../rtc_base:logging",
+    "../../../rtc_base:safe_minmax",
+    "../../../rtc_base:stringutils",
+    "../../../system_wrappers:metrics",
+  ]
+  absl_deps = [
+    "//third_party/abseil-cpp/absl/strings",
+    "//third_party/abseil-cpp/absl/types:optional",
+  ]
+}
+
+rtc_library("input_volume_stats_reporter_unittests") {
+  testonly = true
+  sources = [ "input_volume_stats_reporter_unittest.cc" ]
+  deps = [
+    ":input_volume_stats_reporter",
+    "../../../rtc_base:stringutils",
+    "../../../system_wrappers:metrics",
+    "../../../test:test_support",
+  ]
+  absl_deps = [ "//third_party/abseil-cpp/absl/strings" ]
+}
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller.cc b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller.cc
new file mode 100644
index 0000000000..e8edab602c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller.cc
@@ -0,0 +1,216 @@
+/*
+ *  Copyright (c) 2018 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/agc2/adaptive_digital_gain_controller.h"
+
+#include <algorithm>
+
+#include "common_audio/include/audio_util.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/safe_minmax.h"
+#include "system_wrappers/include/metrics.h"
+
+namespace webrtc {
+namespace {
+
+using AdaptiveDigitalConfig =
+    AudioProcessing::Config::GainController2::AdaptiveDigital;
+
+constexpr int kHeadroomHistogramMin = 0;
+constexpr int kHeadroomHistogramMax = 50;
+constexpr int kGainDbHistogramMax = 30;
+
+// Computes the gain for `input_level_dbfs` to reach `-config.headroom_db`.
+// Clamps the gain in [0, `config.max_gain_db`]. `config.headroom_db` is a
+// safety margin to allow transient peaks to exceed the target peak level
+// without clipping.
+float ComputeGainDb(float input_level_dbfs,
+                    const AdaptiveDigitalConfig& config) {
+  // If the level is very low, apply the maximum gain.
+  if (input_level_dbfs < -(config.headroom_db + config.max_gain_db)) {
+    return config.max_gain_db;
+  }
+  // We expect to end up here most of the time: the level is below
+  // -headroom, but we can boost it to -headroom.
+  if (input_level_dbfs < -config.headroom_db) {
+    return -config.headroom_db - input_level_dbfs;
+  }
+  // The level is too high and we can't boost.
+  RTC_DCHECK_GE(input_level_dbfs, -config.headroom_db);
+  return 0.0f;
+}
+
+// Returns `target_gain_db` if applying such a gain to `input_noise_level_dbfs`
+// does not exceed `max_output_noise_level_dbfs`. Otherwise lowers and returns
+// `target_gain_db` so that the output noise level equals
+// `max_output_noise_level_dbfs`.
+float LimitGainByNoise(float target_gain_db,
+                       float input_noise_level_dbfs,
+                       float max_output_noise_level_dbfs,
+                       ApmDataDumper& apm_data_dumper) {
+  const float max_allowed_gain_db =
+      max_output_noise_level_dbfs - input_noise_level_dbfs;
+  apm_data_dumper.DumpRaw("agc2_adaptive_gain_applier_max_allowed_gain_db",
+                          max_allowed_gain_db);
+  return std::min(target_gain_db, std::max(max_allowed_gain_db, 0.0f));
+}
+
+float LimitGainByLowConfidence(float target_gain_db,
+                               float last_gain_db,
+                               float limiter_audio_level_dbfs,
+                               bool estimate_is_confident) {
+  if (estimate_is_confident ||
+      limiter_audio_level_dbfs <= kLimiterThresholdForAgcGainDbfs) {
+    return target_gain_db;
+  }
+  const float limiter_level_dbfs_before_gain =
+      limiter_audio_level_dbfs - last_gain_db;
+
+  // Compute a new gain so that `limiter_level_dbfs_before_gain` +
+  // `new_target_gain_db` is not great than `kLimiterThresholdForAgcGainDbfs`.
+  const float new_target_gain_db = std::max(
+      kLimiterThresholdForAgcGainDbfs - limiter_level_dbfs_before_gain, 0.0f);
+  return std::min(new_target_gain_db, target_gain_db);
+}
+
+// Computes how the gain should change during this frame.
+// Return the gain difference in db to 'last_gain_db'.
+float ComputeGainChangeThisFrameDb(float target_gain_db,
+                                   float last_gain_db,
+                                   bool gain_increase_allowed,
+                                   float max_gain_decrease_db,
+                                   float max_gain_increase_db) {
+  RTC_DCHECK_GT(max_gain_decrease_db, 0);
+  RTC_DCHECK_GT(max_gain_increase_db, 0);
+  float target_gain_difference_db = target_gain_db - last_gain_db;
+  if (!gain_increase_allowed) {
+    target_gain_difference_db = std::min(target_gain_difference_db, 0.0f);
+  }
+  return rtc::SafeClamp(target_gain_difference_db, -max_gain_decrease_db,
+                        max_gain_increase_db);
+}
+
+}  // namespace
+
+AdaptiveDigitalGainController::AdaptiveDigitalGainController(
+    ApmDataDumper* apm_data_dumper,
+    const AudioProcessing::Config::GainController2::AdaptiveDigital& config,
+    int adjacent_speech_frames_threshold)
+    : apm_data_dumper_(apm_data_dumper),
+      gain_applier_(
+          /*hard_clip_samples=*/false,
+          /*initial_gain_factor=*/DbToRatio(config.initial_gain_db)),
+      config_(config),
+      adjacent_speech_frames_threshold_(adjacent_speech_frames_threshold),
+      max_gain_change_db_per_10ms_(config_.max_gain_change_db_per_second *
+                                   kFrameDurationMs / 1000.0f),
+      calls_since_last_gain_log_(0),
+      frames_to_gain_increase_allowed_(adjacent_speech_frames_threshold),
+      last_gain_db_(config_.initial_gain_db) {
+  RTC_DCHECK_GT(max_gain_change_db_per_10ms_, 0.0f);
+  RTC_DCHECK_GE(frames_to_gain_increase_allowed_, 1);
+  RTC_DCHECK_GE(config_.max_output_noise_level_dbfs, -90.0f);
+  RTC_DCHECK_LE(config_.max_output_noise_level_dbfs, 0.0f);
+}
+
+void AdaptiveDigitalGainController::Process(const FrameInfo& info,
+                                            AudioFrameView<float> frame) {
+  RTC_DCHECK_GE(info.speech_level_dbfs, -150.0f);
+  RTC_DCHECK_GE(frame.num_channels(), 1);
+  RTC_DCHECK(
+      frame.samples_per_channel() == 80 || frame.samples_per_channel() == 160 ||
+      frame.samples_per_channel() == 320 || frame.samples_per_channel() == 480)
+      << "`frame` does not look like a 10 ms frame for an APM supported sample "
+         "rate";
+
+  // Compute the input level used to select the desired gain.
+  RTC_DCHECK_GT(info.headroom_db, 0.0f);
+  const float input_level_dbfs = info.speech_level_dbfs + info.headroom_db;
+
+  const float target_gain_db = LimitGainByLowConfidence(
+      LimitGainByNoise(ComputeGainDb(input_level_dbfs, config_),
+                       info.noise_rms_dbfs, config_.max_output_noise_level_dbfs,
+                       *apm_data_dumper_),
+      last_gain_db_, info.limiter_envelope_dbfs, info.speech_level_reliable);
+
+  // Forbid increasing the gain until enough adjacent speech frames are
+  // observed.
+  bool first_confident_speech_frame = false;
+  if (info.speech_probability < kVadConfidenceThreshold) {
+    frames_to_gain_increase_allowed_ = adjacent_speech_frames_threshold_;
+  } else if (frames_to_gain_increase_allowed_ > 0) {
+    frames_to_gain_increase_allowed_--;
+    first_confident_speech_frame = frames_to_gain_increase_allowed_ == 0;
+  }
+  apm_data_dumper_->DumpRaw(
+      "agc2_adaptive_gain_applier_frames_to_gain_increase_allowed",
+      frames_to_gain_increase_allowed_);
+
+  const bool gain_increase_allowed = frames_to_gain_increase_allowed_ == 0;
+
+  float max_gain_increase_db = max_gain_change_db_per_10ms_;
+  if (first_confident_speech_frame) {
+    // No gain increase happened while waiting for a long enough speech
+    // sequence. Therefore, temporarily allow a faster gain increase.
+    RTC_DCHECK(gain_increase_allowed);
+    max_gain_increase_db *= adjacent_speech_frames_threshold_;
+  }
+
+  const float gain_change_this_frame_db = ComputeGainChangeThisFrameDb(
+      target_gain_db, last_gain_db_, gain_increase_allowed,
+      /*max_gain_decrease_db=*/max_gain_change_db_per_10ms_,
+      max_gain_increase_db);
+
+  apm_data_dumper_->DumpRaw("agc2_adaptive_gain_applier_want_to_change_by_db",
+                            target_gain_db - last_gain_db_);
+  apm_data_dumper_->DumpRaw("agc2_adaptive_gain_applier_will_change_by_db",
+                            gain_change_this_frame_db);
+
+  // Optimization: avoid calling math functions if gain does not
+  // change.
+  if (gain_change_this_frame_db != 0.f) {
+    gain_applier_.SetGainFactor(
+        DbToRatio(last_gain_db_ + gain_change_this_frame_db));
+  }
+
+  gain_applier_.ApplyGain(frame);
+
+  // Remember that the gain has changed for the next iteration.
+  last_gain_db_ = last_gain_db_ + gain_change_this_frame_db;
+  apm_data_dumper_->DumpRaw("agc2_adaptive_gain_applier_applied_gain_db",
+                            last_gain_db_);
+
+  // Log every 10 seconds.
+  calls_since_last_gain_log_++;
+  if (calls_since_last_gain_log_ == 1000) {
+    calls_since_last_gain_log_ = 0;
+    RTC_HISTOGRAM_COUNTS_LINEAR("WebRTC.Audio.Agc2.EstimatedSpeechLevel",
+                                -info.speech_level_dbfs, 0, 100, 101);
+    RTC_HISTOGRAM_COUNTS_LINEAR("WebRTC.Audio.Agc2.EstimatedNoiseLevel",
+                                -info.noise_rms_dbfs, 0, 100, 101);
+    RTC_HISTOGRAM_COUNTS_LINEAR(
+        "WebRTC.Audio.Agc2.Headroom", info.headroom_db, kHeadroomHistogramMin,
+        kHeadroomHistogramMax,
+        kHeadroomHistogramMax - kHeadroomHistogramMin + 1);
+    RTC_HISTOGRAM_COUNTS_LINEAR("WebRTC.Audio.Agc2.DigitalGainApplied",
+                                last_gain_db_, 0, kGainDbHistogramMax,
+                                kGainDbHistogramMax + 1);
+    RTC_LOG(LS_INFO) << "AGC2 adaptive digital"
+                     << " | speech_dbfs: " << info.speech_level_dbfs
+                     << " | noise_dbfs: " << info.noise_rms_dbfs
+                     << " | headroom_db: " << info.headroom_db
+                     << " | gain_db: " << last_gain_db_;
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller.h b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller.h
new file mode 100644
index 0000000000..01335e79db
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller.h
@@ -0,0 +1,66 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_ADAPTIVE_DIGITAL_GAIN_CONTROLLER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_ADAPTIVE_DIGITAL_GAIN_CONTROLLER_H_
+
+#include <vector>
+
+#include "modules/audio_processing/agc2/gain_applier.h"
+#include "modules/audio_processing/include/audio_frame_view.h"
+#include "modules/audio_processing/include/audio_processing.h"
+
+namespace webrtc {
+
+class ApmDataDumper;
+
+// Selects the target digital gain, decides when and how quickly to adapt to the
+// target and applies the current gain to 10 ms frames.
+class AdaptiveDigitalGainController {
+ public:
+  // Information about a frame to process.
+  struct FrameInfo {
+    float speech_probability;    // Probability of speech in the [0, 1] range.
+    float speech_level_dbfs;     // Estimated speech level (dBFS).
+    bool speech_level_reliable;  // True with reliable speech level estimation.
+    float noise_rms_dbfs;        // Estimated noise RMS level (dBFS).
+    float headroom_db;           // Headroom (dB).
+    // TODO(bugs.webrtc.org/7494): Remove `limiter_envelope_dbfs`.
+    float limiter_envelope_dbfs;  // Envelope level from the limiter (dBFS).
+  };
+
+  AdaptiveDigitalGainController(
+      ApmDataDumper* apm_data_dumper,
+      const AudioProcessing::Config::GainController2::AdaptiveDigital& config,
+      int adjacent_speech_frames_threshold);
+  AdaptiveDigitalGainController(const AdaptiveDigitalGainController&) = delete;
+  AdaptiveDigitalGainController& operator=(
+      const AdaptiveDigitalGainController&) = delete;
+
+  // Analyzes `info`, updates the digital gain and applies it to a 10 ms
+  // `frame`. Supports any sample rate supported by APM.
+  void Process(const FrameInfo& info, AudioFrameView<float> frame);
+
+ private:
+  ApmDataDumper* const apm_data_dumper_;
+  GainApplier gain_applier_;
+
+  const AudioProcessing::Config::GainController2::AdaptiveDigital config_;
+  const int adjacent_speech_frames_threshold_;
+  const float max_gain_change_db_per_10ms_;
+
+  int calls_since_last_gain_log_;
+  int frames_to_gain_increase_allowed_;
+  float last_gain_db_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_ADAPTIVE_DIGITAL_GAIN_CONTROLLER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller_gn/moz.build
new file mode 100644
index 0000000000..7d16c9a9f5
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller_gn/moz.build
@@ -0,0 +1,233 @@
+# 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/agc2/adaptive_digital_gain_controller.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("adaptive_digital_gain_controller_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller_unittest.cc
new file mode 100644
index 0000000000..e95cbb5067
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/adaptive_digital_gain_controller_unittest.cc
@@ -0,0 +1,312 @@
+/*
+ *  Copyright (c) 2018 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/agc2/adaptive_digital_gain_controller.h"
+
+#include <algorithm>
+#include <memory>
+
+#include "common_audio/include/audio_util.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/agc2/vector_float_frame.h"
+#include "modules/audio_processing/include/audio_processing.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kMono = 1;
+constexpr int kStereo = 2;
+constexpr int kFrameLen10ms8kHz = 80;
+constexpr int kFrameLen10ms48kHz = 480;
+
+constexpr float kMaxSpeechProbability = 1.0f;
+
+// Constants used in place of estimated noise levels.
+constexpr float kNoNoiseDbfs = kMinLevelDbfs;
+constexpr float kWithNoiseDbfs = -20.0f;
+
+// Number of additional frames to process in the tests to ensure that the tested
+// adaptation processes have converged.
+constexpr int kNumExtraFrames = 10;
+
+constexpr float GetMaxGainChangePerFrameDb(
+    float max_gain_change_db_per_second) {
+  return max_gain_change_db_per_second * kFrameDurationMs / 1000.0f;
+}
+
+using AdaptiveDigitalConfig =
+    AudioProcessing::Config::GainController2::AdaptiveDigital;
+
+constexpr AdaptiveDigitalConfig kDefaultConfig{};
+
+// Helper to create initialized `AdaptiveDigitalGainController` objects.
+struct GainApplierHelper {
+  GainApplierHelper(const AdaptiveDigitalConfig& config,
+                    int adjacent_speech_frames_threshold)
+      : apm_data_dumper(0),
+        gain_applier(std::make_unique<AdaptiveDigitalGainController>(
+            &apm_data_dumper,
+            config,
+            adjacent_speech_frames_threshold)) {}
+  ApmDataDumper apm_data_dumper;
+  std::unique_ptr<AdaptiveDigitalGainController> gain_applier;
+};
+
+// Returns a `FrameInfo` sample to simulate noiseless speech detected with
+// maximum probability and with level, headroom and limiter envelope chosen
+// so that the resulting gain equals the default initial adaptive digital gain
+// i.e., no gain adaptation is expected.
+AdaptiveDigitalGainController::FrameInfo GetFrameInfoToNotAdapt(
+    const AdaptiveDigitalConfig& config) {
+  AdaptiveDigitalGainController::FrameInfo info;
+  info.speech_probability = kMaxSpeechProbability;
+  info.speech_level_dbfs = -config.initial_gain_db - config.headroom_db;
+  info.speech_level_reliable = true;
+  info.noise_rms_dbfs = kNoNoiseDbfs;
+  info.headroom_db = config.headroom_db;
+  info.limiter_envelope_dbfs = -2.0f;
+  return info;
+}
+
+TEST(GainController2AdaptiveDigitalGainControllerTest,
+     GainApplierShouldNotCrash) {
+  GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
+  // Make one call with reasonable audio level values and settings.
+  VectorFloatFrame fake_audio(kStereo, kFrameLen10ms48kHz, 10000.0f);
+  helper.gain_applier->Process(GetFrameInfoToNotAdapt(kDefaultConfig),
+                               fake_audio.float_frame_view());
+}
+
+// Checks that the maximum allowed gain is applied.
+TEST(GainController2AdaptiveDigitalGainControllerTest, MaxGainApplied) {
+  constexpr int kNumFramesToAdapt =
+      static_cast<int>(kDefaultConfig.max_gain_db /
+                       GetMaxGainChangePerFrameDb(
+                           kDefaultConfig.max_gain_change_db_per_second)) +
+      kNumExtraFrames;
+
+  GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
+  AdaptiveDigitalGainController::FrameInfo info =
+      GetFrameInfoToNotAdapt(kDefaultConfig);
+  info.speech_level_dbfs = -60.0f;
+  float applied_gain;
+  for (int i = 0; i < kNumFramesToAdapt; ++i) {
+    VectorFloatFrame fake_audio(kMono, kFrameLen10ms8kHz, 1.0f);
+    helper.gain_applier->Process(info, fake_audio.float_frame_view());
+    applied_gain = fake_audio.float_frame_view().channel(0)[0];
+  }
+  const float applied_gain_db = 20.0f * std::log10f(applied_gain);
+  EXPECT_NEAR(applied_gain_db, kDefaultConfig.max_gain_db, 0.1f);
+}
+
+TEST(GainController2AdaptiveDigitalGainControllerTest, GainDoesNotChangeFast) {
+  GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
+
+  constexpr float initial_level_dbfs = -25.0f;
+  constexpr float kMaxGainChangeDbPerFrame =
+      GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second);
+  constexpr int kNumFramesToAdapt =
+      static_cast<int>(initial_level_dbfs / kMaxGainChangeDbPerFrame) +
+      kNumExtraFrames;
+
+  const float max_change_per_frame_linear = DbToRatio(kMaxGainChangeDbPerFrame);
+
+  float last_gain_linear = 1.f;
+  for (int i = 0; i < kNumFramesToAdapt; ++i) {
+    SCOPED_TRACE(i);
+    VectorFloatFrame fake_audio(kMono, kFrameLen10ms8kHz, 1.0f);
+    AdaptiveDigitalGainController::FrameInfo info =
+        GetFrameInfoToNotAdapt(kDefaultConfig);
+    info.speech_level_dbfs = initial_level_dbfs;
+    helper.gain_applier->Process(info, fake_audio.float_frame_view());
+    float current_gain_linear = fake_audio.float_frame_view().channel(0)[0];
+    EXPECT_LE(std::abs(current_gain_linear - last_gain_linear),
+              max_change_per_frame_linear);
+    last_gain_linear = current_gain_linear;
+  }
+
+  // Check that the same is true when gain decreases as well.
+  for (int i = 0; i < kNumFramesToAdapt; ++i) {
+    SCOPED_TRACE(i);
+    VectorFloatFrame fake_audio(kMono, kFrameLen10ms8kHz, 1.0f);
+    AdaptiveDigitalGainController::FrameInfo info =
+        GetFrameInfoToNotAdapt(kDefaultConfig);
+    info.speech_level_dbfs = 0.f;
+    helper.gain_applier->Process(info, fake_audio.float_frame_view());
+    float current_gain_linear = fake_audio.float_frame_view().channel(0)[0];
+    EXPECT_LE(std::abs(current_gain_linear - last_gain_linear),
+              max_change_per_frame_linear);
+    last_gain_linear = current_gain_linear;
+  }
+}
+
+TEST(GainController2AdaptiveDigitalGainControllerTest, GainIsRampedInAFrame) {
+  GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
+
+  constexpr float initial_level_dbfs = -25.0f;
+
+  VectorFloatFrame fake_audio(kMono, kFrameLen10ms48kHz, 1.0f);
+  AdaptiveDigitalGainController::FrameInfo info =
+      GetFrameInfoToNotAdapt(kDefaultConfig);
+  info.speech_level_dbfs = initial_level_dbfs;
+  helper.gain_applier->Process(info, fake_audio.float_frame_view());
+  float maximal_difference = 0.0f;
+  float current_value = 1.0f * DbToRatio(kDefaultConfig.initial_gain_db);
+  for (const auto& x : fake_audio.float_frame_view().channel(0)) {
+    const float difference = std::abs(x - current_value);
+    maximal_difference = std::max(maximal_difference, difference);
+    current_value = x;
+  }
+
+  const float max_change_per_frame_linear = DbToRatio(
+      GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second));
+  const float max_change_per_sample =
+      max_change_per_frame_linear / kFrameLen10ms48kHz;
+
+  EXPECT_LE(maximal_difference, max_change_per_sample);
+}
+
+TEST(GainController2AdaptiveDigitalGainControllerTest, NoiseLimitsGain) {
+  GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
+
+  constexpr float initial_level_dbfs = -25.0f;
+  constexpr int num_initial_frames =
+      kDefaultConfig.initial_gain_db /
+      GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second);
+  constexpr int num_frames = 50;
+
+  ASSERT_GT(kWithNoiseDbfs, kDefaultConfig.max_output_noise_level_dbfs)
+      << "kWithNoiseDbfs is too low";
+
+  for (int i = 0; i < num_initial_frames + num_frames; ++i) {
+    VectorFloatFrame fake_audio(kMono, kFrameLen10ms48kHz, 1.0f);
+    AdaptiveDigitalGainController::FrameInfo info =
+        GetFrameInfoToNotAdapt(kDefaultConfig);
+    info.speech_level_dbfs = initial_level_dbfs;
+    info.noise_rms_dbfs = kWithNoiseDbfs;
+    helper.gain_applier->Process(info, fake_audio.float_frame_view());
+
+    // Wait so that the adaptive gain applier has time to lower the gain.
+    if (i > num_initial_frames) {
+      const float maximal_ratio =
+          *std::max_element(fake_audio.float_frame_view().channel(0).begin(),
+                            fake_audio.float_frame_view().channel(0).end());
+
+      EXPECT_NEAR(maximal_ratio, 1.0f, 0.001f);
+    }
+  }
+}
+
+TEST(GainController2AdaptiveDigitalGainControllerTest,
+     CanHandlePositiveSpeechLevels) {
+  GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
+
+  // Make one call with positive audio level values and settings.
+  VectorFloatFrame fake_audio(kStereo, kFrameLen10ms48kHz, 10000.0f);
+  AdaptiveDigitalGainController::FrameInfo info =
+      GetFrameInfoToNotAdapt(kDefaultConfig);
+  info.speech_level_dbfs = 5.0f;
+  helper.gain_applier->Process(info, fake_audio.float_frame_view());
+}
+
+TEST(GainController2AdaptiveDigitalGainControllerTest, AudioLevelLimitsGain) {
+  GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
+
+  constexpr float initial_level_dbfs = -25.0f;
+  constexpr int num_initial_frames =
+      kDefaultConfig.initial_gain_db /
+      GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second);
+  constexpr int num_frames = 50;
+
+  ASSERT_GT(kWithNoiseDbfs, kDefaultConfig.max_output_noise_level_dbfs)
+      << "kWithNoiseDbfs is too low";
+
+  for (int i = 0; i < num_initial_frames + num_frames; ++i) {
+    VectorFloatFrame fake_audio(kMono, kFrameLen10ms48kHz, 1.0f);
+    AdaptiveDigitalGainController::FrameInfo info =
+        GetFrameInfoToNotAdapt(kDefaultConfig);
+    info.speech_level_dbfs = initial_level_dbfs;
+    info.limiter_envelope_dbfs = 1.0f;
+    info.speech_level_reliable = false;
+    helper.gain_applier->Process(info, fake_audio.float_frame_view());
+
+    // Wait so that the adaptive gain applier has time to lower the gain.
+    if (i > num_initial_frames) {
+      const float maximal_ratio =
+          *std::max_element(fake_audio.float_frame_view().channel(0).begin(),
+                            fake_audio.float_frame_view().channel(0).end());
+
+      EXPECT_NEAR(maximal_ratio, 1.0f, 0.001f);
+    }
+  }
+}
+
+class AdaptiveDigitalGainControllerParametrizedTest
+    : public ::testing::TestWithParam<int> {
+ protected:
+  int adjacent_speech_frames_threshold() const { return GetParam(); }
+};
+
+TEST_P(AdaptiveDigitalGainControllerParametrizedTest,
+       DoNotIncreaseGainWithTooFewSpeechFrames) {
+  GainApplierHelper helper(kDefaultConfig, adjacent_speech_frames_threshold());
+
+  // Lower the speech level so that the target gain will be increased.
+  AdaptiveDigitalGainController::FrameInfo info =
+      GetFrameInfoToNotAdapt(kDefaultConfig);
+  info.speech_level_dbfs -= 12.0f;
+
+  float prev_gain = 0.0f;
+  for (int i = 0; i < adjacent_speech_frames_threshold(); ++i) {
+    SCOPED_TRACE(i);
+    VectorFloatFrame audio(kMono, kFrameLen10ms48kHz, 1.0f);
+    helper.gain_applier->Process(info, audio.float_frame_view());
+    const float gain = audio.float_frame_view().channel(0)[0];
+    if (i > 0) {
+      EXPECT_EQ(prev_gain, gain);  // No gain increase applied.
+    }
+    prev_gain = gain;
+  }
+}
+
+TEST_P(AdaptiveDigitalGainControllerParametrizedTest,
+       IncreaseGainWithEnoughSpeechFrames) {
+  GainApplierHelper helper(kDefaultConfig, adjacent_speech_frames_threshold());
+
+  // Lower the speech level so that the target gain will be increased.
+  AdaptiveDigitalGainController::FrameInfo info =
+      GetFrameInfoToNotAdapt(kDefaultConfig);
+  info.speech_level_dbfs -= 12.0f;
+
+  float prev_gain = 0.0f;
+  for (int i = 0; i < adjacent_speech_frames_threshold(); ++i) {
+    SCOPED_TRACE(i);
+    VectorFloatFrame audio(kMono, kFrameLen10ms48kHz, 1.0f);
+    helper.gain_applier->Process(info, audio.float_frame_view());
+    prev_gain = audio.float_frame_view().channel(0)[0];
+  }
+
+  // Process one more speech frame.
+  VectorFloatFrame audio(kMono, kFrameLen10ms48kHz, 1.0f);
+  helper.gain_applier->Process(info, audio.float_frame_view());
+
+  // An increased gain has been applied.
+  EXPECT_GT(audio.float_frame_view().channel(0)[0], prev_gain);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    GainController2,
+    AdaptiveDigitalGainControllerParametrizedTest,
+    ::testing::Values(1, 7, 31, kAdjacentSpeechFramesThreshold));
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/agc2_common.h b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_common.h
new file mode 100644
index 0000000000..4597bcd015
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_common.h
@@ -0,0 +1,62 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_AGC2_COMMON_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_AGC2_COMMON_H_
+
+namespace webrtc {
+
+constexpr float kMinFloatS16Value = -32768.0f;
+constexpr float kMaxFloatS16Value = 32767.0f;
+constexpr float kMaxAbsFloatS16Value = 32768.0f;
+
+// Minimum audio level in dBFS scale for S16 samples.
+constexpr float kMinLevelDbfs = -90.31f;
+
+constexpr int kFrameDurationMs = 10;
+constexpr int kSubFramesInFrame = 20;
+constexpr int kMaximalNumberOfSamplesPerChannel = 480;
+
+// Adaptive digital gain applier settings.
+
+// At what limiter levels should we start decreasing the adaptive digital gain.
+constexpr float kLimiterThresholdForAgcGainDbfs = -1.0f;
+
+// Number of milliseconds to wait to periodically reset the VAD.
+constexpr int kVadResetPeriodMs = 1500;
+
+// Speech probability threshold to detect speech activity.
+constexpr float kVadConfidenceThreshold = 0.95f;
+
+// Minimum number of adjacent speech frames having a sufficiently high speech
+// probability to reliably detect speech activity.
+constexpr int kAdjacentSpeechFramesThreshold = 12;
+
+// Number of milliseconds of speech frames to observe to make the estimator
+// confident.
+constexpr float kLevelEstimatorTimeToConfidenceMs = 400;
+constexpr float kLevelEstimatorLeakFactor =
+    1.0f - 1.0f / kLevelEstimatorTimeToConfidenceMs;
+
+// Saturation Protector settings.
+constexpr float kSaturationProtectorInitialHeadroomDb = 20.0f;
+constexpr int kSaturationProtectorBufferSize = 4;
+
+// Number of interpolation points for each region of the limiter.
+// These values have been tuned to limit the interpolated gain curve error given
+// the limiter parameters and allowing a maximum error of +/- 32768^-1.
+constexpr int kInterpolatedGainCurveKneePoints = 22;
+constexpr int kInterpolatedGainCurveBeyondKneePoints = 10;
+constexpr int kInterpolatedGainCurveTotalPoints =
+    kInterpolatedGainCurveKneePoints + kInterpolatedGainCurveBeyondKneePoints;
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_AGC2_COMMON_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common.cc b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common.cc
new file mode 100644
index 0000000000..125e551b72
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common.cc
@@ -0,0 +1,93 @@
+/*
+ *  Copyright (c) 2018 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/agc2/agc2_testing_common.h"
+
+#include <cmath>
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace test {
+
+std::vector<double> LinSpace(double l, double r, int num_points) {
+  RTC_CHECK_GE(num_points, 2);
+  std::vector<double> points(num_points);
+  const double step = (r - l) / (num_points - 1.0);
+  points[0] = l;
+  for (int i = 1; i < num_points - 1; i++) {
+    points[i] = static_cast<double>(l) + i * step;
+  }
+  points[num_points - 1] = r;
+  return points;
+}
+
+WhiteNoiseGenerator::WhiteNoiseGenerator(int min_amplitude, int max_amplitude)
+    : rand_gen_(42),
+      min_amplitude_(min_amplitude),
+      max_amplitude_(max_amplitude) {
+  RTC_DCHECK_LT(min_amplitude_, max_amplitude_);
+  RTC_DCHECK_LE(kMinS16, min_amplitude_);
+  RTC_DCHECK_LE(min_amplitude_, kMaxS16);
+  RTC_DCHECK_LE(kMinS16, max_amplitude_);
+  RTC_DCHECK_LE(max_amplitude_, kMaxS16);
+}
+
+float WhiteNoiseGenerator::operator()() {
+  return static_cast<float>(rand_gen_.Rand(min_amplitude_, max_amplitude_));
+}
+
+SineGenerator::SineGenerator(float amplitude,
+                             float frequency_hz,
+                             int sample_rate_hz)
+    : amplitude_(amplitude),
+      frequency_hz_(frequency_hz),
+      sample_rate_hz_(sample_rate_hz),
+      x_radians_(0.0f) {
+  RTC_DCHECK_GT(amplitude_, 0);
+  RTC_DCHECK_LE(amplitude_, kMaxS16);
+}
+
+float SineGenerator::operator()() {
+  constexpr float kPi = 3.1415926536f;
+  x_radians_ += frequency_hz_ / sample_rate_hz_ * 2 * kPi;
+  if (x_radians_ >= 2 * kPi) {
+    x_radians_ -= 2 * kPi;
+  }
+  return amplitude_ * std::sinf(x_radians_);
+}
+
+PulseGenerator::PulseGenerator(float pulse_amplitude,
+                               float no_pulse_amplitude,
+                               float frequency_hz,
+                               int sample_rate_hz)
+    : pulse_amplitude_(pulse_amplitude),
+      no_pulse_amplitude_(no_pulse_amplitude),
+      samples_period_(
+          static_cast<int>(static_cast<float>(sample_rate_hz) / frequency_hz)),
+      sample_counter_(0) {
+  RTC_DCHECK_GE(pulse_amplitude_, kMinS16);
+  RTC_DCHECK_LE(pulse_amplitude_, kMaxS16);
+  RTC_DCHECK_GT(no_pulse_amplitude_, kMinS16);
+  RTC_DCHECK_LE(no_pulse_amplitude_, kMaxS16);
+  RTC_DCHECK_GT(sample_rate_hz, frequency_hz);
+}
+
+float PulseGenerator::operator()() {
+  sample_counter_++;
+  if (sample_counter_ >= samples_period_) {
+    sample_counter_ -= samples_period_;
+  }
+  return static_cast<float>(sample_counter_ == 0 ? pulse_amplitude_
+                                                 : no_pulse_amplitude_);
+}
+
+}  // namespace test
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common.h b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common.h
new file mode 100644
index 0000000000..afed97e83b
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common.h
@@ -0,0 +1,82 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_AGC2_TESTING_COMMON_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_AGC2_TESTING_COMMON_H_
+
+#include <limits>
+#include <vector>
+
+#include "rtc_base/random.h"
+
+namespace webrtc {
+namespace test {
+
+constexpr float kMinS16 =
+    static_cast<float>(std::numeric_limits<int16_t>::min());
+constexpr float kMaxS16 =
+    static_cast<float>(std::numeric_limits<int16_t>::max());
+
+// Level Estimator test parameters.
+constexpr float kDecayMs = 20.0f;
+
+// Limiter parameters.
+constexpr float kLimiterMaxInputLevelDbFs = 1.f;
+constexpr float kLimiterKneeSmoothnessDb = 1.f;
+constexpr float kLimiterCompressionRatio = 5.f;
+
+// Returns evenly spaced `num_points` numbers over a specified interval [l, r].
+std::vector<double> LinSpace(double l, double r, int num_points);
+
+// Generates white noise.
+class WhiteNoiseGenerator {
+ public:
+  WhiteNoiseGenerator(int min_amplitude, int max_amplitude);
+  float operator()();
+
+ private:
+  Random rand_gen_;
+  const int min_amplitude_;
+  const int max_amplitude_;
+};
+
+// Generates a sine function.
+class SineGenerator {
+ public:
+  SineGenerator(float amplitude, float frequency_hz, int sample_rate_hz);
+  float operator()();
+
+ private:
+  const float amplitude_;
+  const float frequency_hz_;
+  const int sample_rate_hz_;
+  float x_radians_;
+};
+
+// Generates periodic pulses.
+class PulseGenerator {
+ public:
+  PulseGenerator(float pulse_amplitude,
+                 float no_pulse_amplitude,
+                 float frequency_hz,
+                 int sample_rate_hz);
+  float operator()();
+
+ private:
+  const float pulse_amplitude_;
+  const float no_pulse_amplitude_;
+  const int samples_period_;
+  int sample_counter_;
+};
+
+}  // namespace test
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_AGC2_TESTING_COMMON_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common_unittest.cc
new file mode 100644
index 0000000000..79c3cc95d9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/agc2_testing_common_unittest.cc
@@ -0,0 +1,27 @@
+/*
+ *  Copyright (c) 2018 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/agc2/agc2_testing_common.h"
+
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+
+TEST(GainController2TestingCommon, LinSpace) {
+  std::vector<double> points1 = test::LinSpace(-1.0, 2.0, 4);
+  const std::vector<double> expected_points1{{-1.0, 0.0, 1.0, 2.0}};
+  EXPECT_EQ(expected_points1, points1);
+
+  std::vector<double> points2 = test::LinSpace(0.0, 1.0, 4);
+  const std::vector<double> expected_points2{{0.0, 1.0 / 3.0, 2.0 / 3.0, 1.0}};
+  EXPECT_EQ(points2, expected_points2);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter.cc b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter.cc
new file mode 100644
index 0000000000..c1b80d7320
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter.cc
@@ -0,0 +1,60 @@
+/*
+ *  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/agc2/biquad_filter.h"
+
+#include "rtc_base/arraysize.h"
+
+namespace webrtc {
+
+BiQuadFilter::BiQuadFilter(const Config& config)
+    : config_(config), state_({}) {}
+
+BiQuadFilter::~BiQuadFilter() = default;
+
+void BiQuadFilter::SetConfig(const Config& config) {
+  config_ = config;
+  state_ = {};
+}
+
+void BiQuadFilter::Reset() {
+  state_ = {};
+}
+
+void BiQuadFilter::Process(rtc::ArrayView<const float> x,
+                           rtc::ArrayView<float> y) {
+  RTC_DCHECK_EQ(x.size(), y.size());
+  const float config_a0 = config_.a[0];
+  const float config_a1 = config_.a[1];
+  const float config_b0 = config_.b[0];
+  const float config_b1 = config_.b[1];
+  const float config_b2 = config_.b[2];
+  float state_a0 = state_.a[0];
+  float state_a1 = state_.a[1];
+  float state_b0 = state_.b[0];
+  float state_b1 = state_.b[1];
+  for (size_t k = 0, x_size = x.size(); k < x_size; ++k) {
+    // Use a temporary variable for `x[k]` to allow in-place processing.
+    const float tmp = x[k];
+    float y_k = config_b0 * tmp + config_b1 * state_b0 + config_b2 * state_b1 -
+                config_a0 * state_a0 - config_a1 * state_a1;
+    state_b1 = state_b0;
+    state_b0 = tmp;
+    state_a1 = state_a0;
+    state_a0 = y_k;
+    y[k] = y_k;
+  }
+  state_.a[0] = state_a0;
+  state_.a[1] = state_a1;
+  state_.b[0] = state_b0;
+  state_.b[1] = state_b1;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter.h b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter.h
new file mode 100644
index 0000000000..5273ff9386
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter.h
@@ -0,0 +1,56 @@
+/*
+ *  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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_AGC2_BIQUAD_FILTER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_BIQUAD_FILTER_H_
+
+#include "api/array_view.h"
+
+namespace webrtc {
+
+// Transposed direct form I implementation of a bi-quad filter.
+//        b[0] + b[1] • z^(-1) + b[2] • z^(-2)
+// H(z) = ------------------------------------
+//          1 + a[1] • z^(-1) + a[2] • z^(-2)
+class BiQuadFilter {
+ public:
+  // Normalized filter coefficients.
+  // Computed as `[b, a] = scipy.signal.butter(N=2, Wn, btype)`.
+  struct Config {
+    float b[3];  // b[0], b[1], b[2].
+    float a[2];  // a[1], a[2].
+  };
+
+  explicit BiQuadFilter(const Config& config);
+  BiQuadFilter(const BiQuadFilter&) = delete;
+  BiQuadFilter& operator=(const BiQuadFilter&) = delete;
+  ~BiQuadFilter();
+
+  // Sets the filter configuration and resets the internal state.
+  void SetConfig(const Config& config);
+
+  // Zeroes the filter state.
+  void Reset();
+
+  // Filters `x` and writes the output in `y`, which must have the same length
+  // of `x`. In-place processing is supported.
+  void Process(rtc::ArrayView<const float> x, rtc::ArrayView<float> y);
+
+ private:
+  Config config_;
+  struct State {
+    float b[2];
+    float a[2];
+  } state_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_BIQUAD_FILTER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter_gn/moz.build
new file mode 100644
index 0000000000..f396f42e57
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter_gn/moz.build
@@ -0,0 +1,221 @@
+# 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_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/agc2/biquad_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
+
+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
+
+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("biquad_filter_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter_unittest.cc
new file mode 100644
index 0000000000..a53036b08e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/biquad_filter_unittest.cc
@@ -0,0 +1,175 @@
+/*
+ *  Copyright (c) 2018 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/agc2/biquad_filter.h"
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+
+// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+// #include "test/fpe_observer.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kFrameSize = 8;
+constexpr int kNumFrames = 4;
+using FloatArraySequence =
+    std::array<std::array<float, kFrameSize>, kNumFrames>;
+
+constexpr FloatArraySequence kBiQuadInputSeq = {
+    {{{-87.166290f, -8.029022f, 101.619583f, -0.294296f, -5.825764f, -8.890625f,
+       10.310432f, 54.845333f}},
+     {{-64.647644f, -6.883945f, 11.059189f, -95.242538f, -108.870834f,
+       11.024944f, 63.044102f, -52.709583f}},
+     {{-32.350529f, -18.108028f, -74.022339f, -8.986874f, -1.525581f,
+       103.705513f, 6.346226f, -14.319557f}},
+     {{22.645832f, -64.597153f, 55.462521f, -109.393188f, 10.117825f,
+       -40.019642f, -98.612228f, -8.330326f}}}};
+
+// Computed as `scipy.signal.butter(N=2, Wn=60/24000, btype='highpass')`.
+constexpr BiQuadFilter::Config kBiQuadConfig{
+    {0.99446179f, -1.98892358f, 0.99446179f},
+    {-1.98889291f, 0.98895425f}};
+
+// Comparing to scipy. The expected output is generated as follows:
+// zi = np.float32([0, 0])
+// for i in range(4):
+//   yn, zi = scipy.signal.lfilter(B, A, x[i], zi=zi)
+//   print(yn)
+constexpr FloatArraySequence kBiQuadOutputSeq = {
+    {{{-86.68354497f, -7.02175351f, 102.10290352f, -0.37487333f, -5.87205847f,
+       -8.85521608f, 10.33772563f, 54.51157181f}},
+     {{-64.92531604f, -6.76395978f, 11.15534507f, -94.68073341f, -107.18177856f,
+       13.24642474f, 64.84288941f, -50.97822629f}},
+     {{-30.1579652f, -15.64850899f, -71.06662821f, -5.5883229f, 1.91175353f,
+       106.5572003f, 8.57183046f, -12.06298473f}},
+     {{24.84286614f, -62.18094158f, 57.91488056f, -106.65685933f, 13.38760103f,
+       -36.60367134f, -94.44880104f, -3.59920354f}}}};
+
+// Fails for every pair from two equally sized rtc::ArrayView<float> views such
+// that their relative error is above a given threshold. If the expected value
+// of a pair is 0, `tolerance` is used to check the absolute error.
+void ExpectNearRelative(rtc::ArrayView<const float> expected,
+                        rtc::ArrayView<const float> computed,
+                        const float tolerance) {
+  // The relative error is undefined when the expected value is 0.
+  // When that happens, check the absolute error instead. `safe_den` is used
+  // below to implement such logic.
+  auto safe_den = [](float x) { return (x == 0.0f) ? 1.0f : std::fabs(x); };
+  ASSERT_EQ(expected.size(), computed.size());
+  for (size_t i = 0; i < expected.size(); ++i) {
+    const float abs_diff = std::fabs(expected[i] - computed[i]);
+    // No failure when the values are equal.
+    if (abs_diff == 0.0f) {
+      continue;
+    }
+    SCOPED_TRACE(i);
+    SCOPED_TRACE(expected[i]);
+    SCOPED_TRACE(computed[i]);
+    EXPECT_LE(abs_diff / safe_den(expected[i]), tolerance);
+  }
+}
+
+// Checks that filtering works when different containers are used both as input
+// and as output.
+TEST(BiQuadFilterTest, FilterNotInPlace) {
+  BiQuadFilter filter(kBiQuadConfig);
+  std::array<float, kFrameSize> samples;
+
+  // TODO(https://bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+
+  for (int i = 0; i < kNumFrames; ++i) {
+    SCOPED_TRACE(i);
+    filter.Process(kBiQuadInputSeq[i], samples);
+    ExpectNearRelative(kBiQuadOutputSeq[i], samples, 2e-4f);
+  }
+}
+
+// Checks that filtering works when the same container is used both as input and
+// as output.
+TEST(BiQuadFilterTest, FilterInPlace) {
+  BiQuadFilter filter(kBiQuadConfig);
+  std::array<float, kFrameSize> samples;
+
+  // TODO(https://bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+
+  for (int i = 0; i < kNumFrames; ++i) {
+    SCOPED_TRACE(i);
+    std::copy(kBiQuadInputSeq[i].begin(), kBiQuadInputSeq[i].end(),
+              samples.begin());
+    filter.Process({samples}, {samples});
+    ExpectNearRelative(kBiQuadOutputSeq[i], samples, 2e-4f);
+  }
+}
+
+// Checks that different configurations produce different outputs.
+TEST(BiQuadFilterTest, SetConfigDifferentOutput) {
+  BiQuadFilter filter(/*config=*/{{0.97803048f, -1.95606096f, 0.97803048f},
+                                  {-1.95557824f, 0.95654368f}});
+
+  std::array<float, kFrameSize> samples1;
+  for (int i = 0; i < kNumFrames; ++i) {
+    filter.Process(kBiQuadInputSeq[i], samples1);
+  }
+
+  filter.SetConfig(
+      {{0.09763107f, 0.19526215f, 0.09763107f}, {-0.94280904f, 0.33333333f}});
+  std::array<float, kFrameSize> samples2;
+  for (int i = 0; i < kNumFrames; ++i) {
+    filter.Process(kBiQuadInputSeq[i], samples2);
+  }
+
+  EXPECT_NE(samples1, samples2);
+}
+
+// Checks that when `SetConfig()` is called but the filter coefficients are the
+// same the filter state is reset.
+TEST(BiQuadFilterTest, SetConfigResetsState) {
+  BiQuadFilter filter(kBiQuadConfig);
+
+  std::array<float, kFrameSize> samples1;
+  for (int i = 0; i < kNumFrames; ++i) {
+    filter.Process(kBiQuadInputSeq[i], samples1);
+  }
+
+  filter.SetConfig(kBiQuadConfig);
+  std::array<float, kFrameSize> samples2;
+  for (int i = 0; i < kNumFrames; ++i) {
+    filter.Process(kBiQuadInputSeq[i], samples2);
+  }
+
+  EXPECT_EQ(samples1, samples2);
+}
+
+// Checks that when `Reset()` is called the filter state is reset.
+TEST(BiQuadFilterTest, Reset) {
+  BiQuadFilter filter(kBiQuadConfig);
+
+  std::array<float, kFrameSize> samples1;
+  for (int i = 0; i < kNumFrames; ++i) {
+    filter.Process(kBiQuadInputSeq[i], samples1);
+  }
+
+  filter.Reset();
+  std::array<float, kFrameSize> samples2;
+  for (int i = 0; i < kNumFrames; ++i) {
+    filter.Process(kBiQuadInputSeq[i], samples2);
+  }
+
+  EXPECT_EQ(samples1, samples2);
+}
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor.cc b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor.cc
new file mode 100644
index 0000000000..fd759c63e8
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor.cc
@@ -0,0 +1,384 @@
+/*
+ *  Copyright (c) 2021 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/agc2/clipping_predictor.h"
+
+#include <algorithm>
+#include <memory>
+
+#include "common_audio/include/audio_util.h"
+#include "modules/audio_processing/agc2/clipping_predictor_level_buffer.h"
+#include "modules/audio_processing/agc2/gain_map_internal.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/safe_minmax.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kClippingPredictorMaxGainChange = 15;
+
+// Returns an input volume in the [`min_input_volume`, `max_input_volume`] range
+// that reduces `gain_error_db`, which is a gain error estimated when
+// `input_volume` was applied, according to a fixed gain map.
+int ComputeVolumeUpdate(int gain_error_db,
+                        int input_volume,
+                        int min_input_volume,
+                        int max_input_volume) {
+  RTC_DCHECK_GE(input_volume, 0);
+  RTC_DCHECK_LE(input_volume, max_input_volume);
+  if (gain_error_db == 0) {
+    return input_volume;
+  }
+  int new_volume = input_volume;
+  if (gain_error_db > 0) {
+    while (kGainMap[new_volume] - kGainMap[input_volume] < gain_error_db &&
+           new_volume < max_input_volume) {
+      ++new_volume;
+    }
+  } else {
+    while (kGainMap[new_volume] - kGainMap[input_volume] > gain_error_db &&
+           new_volume > min_input_volume) {
+      --new_volume;
+    }
+  }
+  return new_volume;
+}
+
+float ComputeCrestFactor(const ClippingPredictorLevelBuffer::Level& level) {
+  const float crest_factor =
+      FloatS16ToDbfs(level.max) - FloatS16ToDbfs(std::sqrt(level.average));
+  return crest_factor;
+}
+
+// Crest factor-based clipping prediction and clipped level step estimation.
+class ClippingEventPredictor : public ClippingPredictor {
+ public:
+  // ClippingEventPredictor with `num_channels` channels (limited to values
+  // higher than zero); window size `window_length` and reference window size
+  // `reference_window_length` (both referring to the number of frames in the
+  // respective sliding windows and limited to values higher than zero);
+  // reference window delay `reference_window_delay` (delay in frames, limited
+  // to values zero and higher with an additional requirement of
+  // `window_length` < `reference_window_length` + reference_window_delay`);
+  // and an estimation peak threshold `clipping_threshold` and a crest factor
+  // drop threshold `crest_factor_margin` (both in dB).
+  ClippingEventPredictor(int num_channels,
+                         int window_length,
+                         int reference_window_length,
+                         int reference_window_delay,
+                         float clipping_threshold,
+                         float crest_factor_margin)
+      : window_length_(window_length),
+        reference_window_length_(reference_window_length),
+        reference_window_delay_(reference_window_delay),
+        clipping_threshold_(clipping_threshold),
+        crest_factor_margin_(crest_factor_margin) {
+    RTC_DCHECK_GT(num_channels, 0);
+    RTC_DCHECK_GT(window_length, 0);
+    RTC_DCHECK_GT(reference_window_length, 0);
+    RTC_DCHECK_GE(reference_window_delay, 0);
+    RTC_DCHECK_GT(reference_window_length + reference_window_delay,
+                  window_length);
+    const int buffer_length = GetMinFramesProcessed();
+    RTC_DCHECK_GT(buffer_length, 0);
+    for (int i = 0; i < num_channels; ++i) {
+      ch_buffers_.push_back(
+          std::make_unique<ClippingPredictorLevelBuffer>(buffer_length));
+    }
+  }
+
+  ClippingEventPredictor(const ClippingEventPredictor&) = delete;
+  ClippingEventPredictor& operator=(const ClippingEventPredictor&) = delete;
+  ~ClippingEventPredictor() {}
+
+  void Reset() {
+    const int num_channels = ch_buffers_.size();
+    for (int i = 0; i < num_channels; ++i) {
+      ch_buffers_[i]->Reset();
+    }
+  }
+
+  // Analyzes a frame of audio and stores the framewise metrics in
+  // `ch_buffers_`.
+  void Analyze(const AudioFrameView<const float>& frame) {
+    const int num_channels = frame.num_channels();
+    RTC_DCHECK_EQ(num_channels, ch_buffers_.size());
+    const int samples_per_channel = frame.samples_per_channel();
+    RTC_DCHECK_GT(samples_per_channel, 0);
+    for (int channel = 0; channel < num_channels; ++channel) {
+      float sum_squares = 0.0f;
+      float peak = 0.0f;
+      for (const auto& sample : frame.channel(channel)) {
+        sum_squares += sample * sample;
+        peak = std::max(std::fabs(sample), peak);
+      }
+      ch_buffers_[channel]->Push(
+          {sum_squares / static_cast<float>(samples_per_channel), peak});
+    }
+  }
+
+  // Estimates the analog gain adjustment for channel `channel` using a
+  // sliding window over the frame-wise metrics in `ch_buffers_`. Returns an
+  // estimate for the clipped level step equal to `default_clipped_level_step_`
+  // if at least `GetMinFramesProcessed()` frames have been processed since the
+  // last reset and a clipping event is predicted. `level`, `min_mic_level`, and
+  // `max_mic_level` are limited to [0, 255] and `default_step` to [1, 255].
+  absl::optional<int> EstimateClippedLevelStep(int channel,
+                                               int level,
+                                               int default_step,
+                                               int min_mic_level,
+                                               int max_mic_level) const {
+    RTC_CHECK_GE(channel, 0);
+    RTC_CHECK_LT(channel, ch_buffers_.size());
+    RTC_DCHECK_GE(level, 0);
+    RTC_DCHECK_LE(level, 255);
+    RTC_DCHECK_GT(default_step, 0);
+    RTC_DCHECK_LE(default_step, 255);
+    RTC_DCHECK_GE(min_mic_level, 0);
+    RTC_DCHECK_LE(min_mic_level, 255);
+    RTC_DCHECK_GE(max_mic_level, 0);
+    RTC_DCHECK_LE(max_mic_level, 255);
+    if (level <= min_mic_level) {
+      return absl::nullopt;
+    }
+    if (PredictClippingEvent(channel)) {
+      const int new_level =
+          rtc::SafeClamp(level - default_step, min_mic_level, max_mic_level);
+      const int step = level - new_level;
+      if (step > 0) {
+        return step;
+      }
+    }
+    return absl::nullopt;
+  }
+
+ private:
+  int GetMinFramesProcessed() const {
+    return reference_window_delay_ + reference_window_length_;
+  }
+
+  // Predicts clipping events based on the processed audio frames. Returns
+  // true if a clipping event is likely.
+  bool PredictClippingEvent(int channel) const {
+    const auto metrics =
+        ch_buffers_[channel]->ComputePartialMetrics(0, window_length_);
+    if (!metrics.has_value() ||
+        !(FloatS16ToDbfs(metrics.value().max) > clipping_threshold_)) {
+      return false;
+    }
+    const auto reference_metrics = ch_buffers_[channel]->ComputePartialMetrics(
+        reference_window_delay_, reference_window_length_);
+    if (!reference_metrics.has_value()) {
+      return false;
+    }
+    const float crest_factor = ComputeCrestFactor(metrics.value());
+    const float reference_crest_factor =
+        ComputeCrestFactor(reference_metrics.value());
+    if (crest_factor < reference_crest_factor - crest_factor_margin_) {
+      return true;
+    }
+    return false;
+  }
+
+  std::vector<std::unique_ptr<ClippingPredictorLevelBuffer>> ch_buffers_;
+  const int window_length_;
+  const int reference_window_length_;
+  const int reference_window_delay_;
+  const float clipping_threshold_;
+  const float crest_factor_margin_;
+};
+
+// Performs crest factor-based clipping peak prediction.
+class ClippingPeakPredictor : public ClippingPredictor {
+ public:
+  // Ctor. ClippingPeakPredictor with `num_channels` channels (limited to values
+  // higher than zero); window size `window_length` and reference window size
+  // `reference_window_length` (both referring to the number of frames in the
+  // respective sliding windows and limited to values higher than zero);
+  // reference window delay `reference_window_delay` (delay in frames, limited
+  // to values zero and higher with an additional requirement of
+  // `window_length` < `reference_window_length` + reference_window_delay`);
+  // and a clipping prediction threshold `clipping_threshold` (in dB). Adaptive
+  // clipped level step estimation is used if `adaptive_step_estimation` is
+  // true.
+  explicit ClippingPeakPredictor(int num_channels,
+                                 int window_length,
+                                 int reference_window_length,
+                                 int reference_window_delay,
+                                 int clipping_threshold,
+                                 bool adaptive_step_estimation)
+      : window_length_(window_length),
+        reference_window_length_(reference_window_length),
+        reference_window_delay_(reference_window_delay),
+        clipping_threshold_(clipping_threshold),
+        adaptive_step_estimation_(adaptive_step_estimation) {
+    RTC_DCHECK_GT(num_channels, 0);
+    RTC_DCHECK_GT(window_length, 0);
+    RTC_DCHECK_GT(reference_window_length, 0);
+    RTC_DCHECK_GE(reference_window_delay, 0);
+    RTC_DCHECK_GT(reference_window_length + reference_window_delay,
+                  window_length);
+    const int buffer_length = GetMinFramesProcessed();
+    RTC_DCHECK_GT(buffer_length, 0);
+    for (int i = 0; i < num_channels; ++i) {
+      ch_buffers_.push_back(
+          std::make_unique<ClippingPredictorLevelBuffer>(buffer_length));
+    }
+  }
+
+  ClippingPeakPredictor(const ClippingPeakPredictor&) = delete;
+  ClippingPeakPredictor& operator=(const ClippingPeakPredictor&) = delete;
+  ~ClippingPeakPredictor() {}
+
+  void Reset() {
+    const int num_channels = ch_buffers_.size();
+    for (int i = 0; i < num_channels; ++i) {
+      ch_buffers_[i]->Reset();
+    }
+  }
+
+  // Analyzes a frame of audio and stores the framewise metrics in
+  // `ch_buffers_`.
+  void Analyze(const AudioFrameView<const float>& frame) {
+    const int num_channels = frame.num_channels();
+    RTC_DCHECK_EQ(num_channels, ch_buffers_.size());
+    const int samples_per_channel = frame.samples_per_channel();
+    RTC_DCHECK_GT(samples_per_channel, 0);
+    for (int channel = 0; channel < num_channels; ++channel) {
+      float sum_squares = 0.0f;
+      float peak = 0.0f;
+      for (const auto& sample : frame.channel(channel)) {
+        sum_squares += sample * sample;
+        peak = std::max(std::fabs(sample), peak);
+      }
+      ch_buffers_[channel]->Push(
+          {sum_squares / static_cast<float>(samples_per_channel), peak});
+    }
+  }
+
+  // Estimates the analog gain adjustment for channel `channel` using a
+  // sliding window over the frame-wise metrics in `ch_buffers_`. Returns an
+  // estimate for the clipped level step (equal to
+  // `default_clipped_level_step_` if `adaptive_estimation_` is false) if at
+  // least `GetMinFramesProcessed()` frames have been processed since the last
+  // reset and a clipping event is predicted. `level`, `min_mic_level`, and
+  // `max_mic_level` are limited to [0, 255] and `default_step` to [1, 255].
+  absl::optional<int> EstimateClippedLevelStep(int channel,
+                                               int level,
+                                               int default_step,
+                                               int min_mic_level,
+                                               int max_mic_level) const {
+    RTC_DCHECK_GE(channel, 0);
+    RTC_DCHECK_LT(channel, ch_buffers_.size());
+    RTC_DCHECK_GE(level, 0);
+    RTC_DCHECK_LE(level, 255);
+    RTC_DCHECK_GT(default_step, 0);
+    RTC_DCHECK_LE(default_step, 255);
+    RTC_DCHECK_GE(min_mic_level, 0);
+    RTC_DCHECK_LE(min_mic_level, 255);
+    RTC_DCHECK_GE(max_mic_level, 0);
+    RTC_DCHECK_LE(max_mic_level, 255);
+    if (level <= min_mic_level) {
+      return absl::nullopt;
+    }
+    absl::optional<float> estimate_db = EstimatePeakValue(channel);
+    if (estimate_db.has_value() && estimate_db.value() > clipping_threshold_) {
+      int step = 0;
+      if (!adaptive_step_estimation_) {
+        step = default_step;
+      } else {
+        const int estimated_gain_change =
+            rtc::SafeClamp(-static_cast<int>(std::ceil(estimate_db.value())),
+                           -kClippingPredictorMaxGainChange, 0);
+        step =
+            std::max(level - ComputeVolumeUpdate(estimated_gain_change, level,
+                                                 min_mic_level, max_mic_level),
+                     default_step);
+      }
+      const int new_level =
+          rtc::SafeClamp(level - step, min_mic_level, max_mic_level);
+      if (level > new_level) {
+        return level - new_level;
+      }
+    }
+    return absl::nullopt;
+  }
+
+ private:
+  int GetMinFramesProcessed() {
+    return reference_window_delay_ + reference_window_length_;
+  }
+
+  // Predicts clipping sample peaks based on the processed audio frames.
+  // Returns the estimated peak value if clipping is predicted. Otherwise
+  // returns absl::nullopt.
+  absl::optional<float> EstimatePeakValue(int channel) const {
+    const auto reference_metrics = ch_buffers_[channel]->ComputePartialMetrics(
+        reference_window_delay_, reference_window_length_);
+    if (!reference_metrics.has_value()) {
+      return absl::nullopt;
+    }
+    const auto metrics =
+        ch_buffers_[channel]->ComputePartialMetrics(0, window_length_);
+    if (!metrics.has_value() ||
+        !(FloatS16ToDbfs(metrics.value().max) > clipping_threshold_)) {
+      return absl::nullopt;
+    }
+    const float reference_crest_factor =
+        ComputeCrestFactor(reference_metrics.value());
+    const float& mean_squares = metrics.value().average;
+    const float projected_peak =
+        reference_crest_factor + FloatS16ToDbfs(std::sqrt(mean_squares));
+    return projected_peak;
+  }
+
+  std::vector<std::unique_ptr<ClippingPredictorLevelBuffer>> ch_buffers_;
+  const int window_length_;
+  const int reference_window_length_;
+  const int reference_window_delay_;
+  const int clipping_threshold_;
+  const bool adaptive_step_estimation_;
+};
+
+}  // namespace
+
+std::unique_ptr<ClippingPredictor> CreateClippingPredictor(
+    int num_channels,
+    const AudioProcessing::Config::GainController1::AnalogGainController::
+        ClippingPredictor& config) {
+  if (!config.enabled) {
+    RTC_LOG(LS_INFO) << "[AGC2] Clipping prediction disabled.";
+    return nullptr;
+  }
+  RTC_LOG(LS_INFO) << "[AGC2] Clipping prediction enabled.";
+  using ClippingPredictorMode = AudioProcessing::Config::GainController1::
+      AnalogGainController::ClippingPredictor::Mode;
+  switch (config.mode) {
+    case ClippingPredictorMode::kClippingEventPrediction:
+      return std::make_unique<ClippingEventPredictor>(
+          num_channels, config.window_length, config.reference_window_length,
+          config.reference_window_delay, config.clipping_threshold,
+          config.crest_factor_margin);
+    case ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction:
+      return std::make_unique<ClippingPeakPredictor>(
+          num_channels, config.window_length, config.reference_window_length,
+          config.reference_window_delay, config.clipping_threshold,
+          /*adaptive_step_estimation=*/true);
+    case ClippingPredictorMode::kFixedStepClippingPeakPrediction:
+      return std::make_unique<ClippingPeakPredictor>(
+          num_channels, config.window_length, config.reference_window_length,
+          config.reference_window_delay, config.clipping_threshold,
+          /*adaptive_step_estimation=*/false);
+  }
+  RTC_DCHECK_NOTREACHED();
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor.h b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor.h
new file mode 100644
index 0000000000..14612508c0
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor.h
@@ -0,0 +1,62 @@
+/*
+ *  Copyright (c) 2021 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_AGC2_CLIPPING_PREDICTOR_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_CLIPPING_PREDICTOR_H_
+
+#include <memory>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "modules/audio_processing/include/audio_frame_view.h"
+#include "modules/audio_processing/include/audio_processing.h"
+
+namespace webrtc {
+
+// Frame-wise clipping prediction and clipped level step estimation. Analyzes
+// 10 ms multi-channel frames and estimates an analog mic level decrease step
+// to possibly avoid clipping when predicted. `Analyze()` and
+// `EstimateClippedLevelStep()` can be called in any order.
+class ClippingPredictor {
+ public:
+  virtual ~ClippingPredictor() = default;
+
+  virtual void Reset() = 0;
+
+  // Analyzes a 10 ms multi-channel audio frame.
+  virtual void Analyze(const AudioFrameView<const float>& frame) = 0;
+
+  // Predicts if clipping is going to occur for the specified `channel` in the
+  // near-future and, if so, it returns a recommended analog mic level decrease
+  // step. Returns absl::nullopt if clipping is not predicted.
+  // `level` is the current analog mic level, `default_step` is the amount the
+  // mic level is lowered by the analog controller with every clipping event and
+  // `min_mic_level` and `max_mic_level` is the range of allowed analog mic
+  // levels.
+  virtual absl::optional<int> EstimateClippedLevelStep(
+      int channel,
+      int level,
+      int default_step,
+      int min_mic_level,
+      int max_mic_level) const = 0;
+};
+
+// Creates a ClippingPredictor based on the provided `config`. When enabled,
+// the following must hold for `config`:
+// `window_length < reference_window_length + reference_window_delay`.
+// Returns `nullptr` if `config.enabled` is false.
+std::unique_ptr<ClippingPredictor> CreateClippingPredictor(
+    int num_channels,
+    const AudioProcessing::Config::GainController1::AnalogGainController::
+        ClippingPredictor& config);
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_CLIPPING_PREDICTOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_gn/moz.build
new file mode 100644
index 0000000000..9cddd69abe
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_gn/moz.build
@@ -0,0 +1,233 @@
+# 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_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/agc2/clipping_predictor.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer.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("clipping_predictor_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer.cc b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer.cc
new file mode 100644
index 0000000000..fe4cf2a154
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer.cc
@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2021 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/agc2/clipping_predictor_level_buffer.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+
+bool ClippingPredictorLevelBuffer::Level::operator==(const Level& level) const {
+  constexpr float kEpsilon = 1e-6f;
+  return std::fabs(average - level.average) < kEpsilon &&
+         std::fabs(max - level.max) < kEpsilon;
+}
+
+ClippingPredictorLevelBuffer::ClippingPredictorLevelBuffer(int capacity)
+    : tail_(-1), size_(0), data_(std::max(1, capacity)) {
+  if (capacity > kMaxCapacity) {
+    RTC_LOG(LS_WARNING) << "[agc]: ClippingPredictorLevelBuffer exceeds the "
+                        << "maximum allowed capacity. Capacity: " << capacity;
+  }
+  RTC_DCHECK(!data_.empty());
+}
+
+void ClippingPredictorLevelBuffer::Reset() {
+  tail_ = -1;
+  size_ = 0;
+}
+
+void ClippingPredictorLevelBuffer::Push(Level level) {
+  ++tail_;
+  if (tail_ == Capacity()) {
+    tail_ = 0;
+  }
+  if (size_ < Capacity()) {
+    size_++;
+  }
+  data_[tail_] = level;
+}
+
+// TODO(bugs.webrtc.org/12774): Optimize partial computation for long buffers.
+absl::optional<ClippingPredictorLevelBuffer::Level>
+ClippingPredictorLevelBuffer::ComputePartialMetrics(int delay,
+                                                    int num_items) const {
+  RTC_DCHECK_GE(delay, 0);
+  RTC_DCHECK_LT(delay, Capacity());
+  RTC_DCHECK_GT(num_items, 0);
+  RTC_DCHECK_LE(num_items, Capacity());
+  RTC_DCHECK_LE(delay + num_items, Capacity());
+  if (delay + num_items > Size()) {
+    return absl::nullopt;
+  }
+  float sum = 0.0f;
+  float max = 0.0f;
+  for (int i = 0; i < num_items && i < Size(); ++i) {
+    int idx = tail_ - delay - i;
+    if (idx < 0) {
+      idx += Capacity();
+    }
+    sum += data_[idx].average;
+    max = std::fmax(data_[idx].max, max);
+  }
+  return absl::optional<Level>({sum / static_cast<float>(num_items), max});
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer.h b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer.h
new file mode 100644
index 0000000000..c9032773a6
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer.h
@@ -0,0 +1,71 @@
+/*
+ *  Copyright (c) 2021 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_AGC2_CLIPPING_PREDICTOR_LEVEL_BUFFER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_CLIPPING_PREDICTOR_LEVEL_BUFFER_H_
+
+#include <memory>
+#include <vector>
+
+#include "absl/types/optional.h"
+
+namespace webrtc {
+
+// A circular buffer to store frame-wise `Level` items for clipping prediction.
+// The current implementation is not optimized for large buffer lengths.
+class ClippingPredictorLevelBuffer {
+ public:
+  struct Level {
+    float average;
+    float max;
+    bool operator==(const Level& level) const;
+  };
+
+  // Recommended maximum capacity. It is possible to create a buffer with a
+  // larger capacity, but the implementation is not optimized for large values.
+  static constexpr int kMaxCapacity = 100;
+
+  // Ctor. Sets the buffer capacity to max(1, `capacity`) and logs a warning
+  // message if the capacity is greater than `kMaxCapacity`.
+  explicit ClippingPredictorLevelBuffer(int capacity);
+  ~ClippingPredictorLevelBuffer() {}
+  ClippingPredictorLevelBuffer(const ClippingPredictorLevelBuffer&) = delete;
+  ClippingPredictorLevelBuffer& operator=(const ClippingPredictorLevelBuffer&) =
+      delete;
+
+  void Reset();
+
+  // Returns the current number of items stored in the buffer.
+  int Size() const { return size_; }
+
+  // Returns the capacity of the buffer.
+  int Capacity() const { return data_.size(); }
+
+  // Adds a `level` item into the circular buffer `data_`. Stores at most
+  // `Capacity()` items. If more items are pushed, the new item replaces the
+  // least recently pushed item.
+  void Push(Level level);
+
+  // If at least `num_items` + `delay` items have been pushed, returns the
+  // average and maximum value for the `num_items` most recently pushed items
+  // from `delay` to `delay` - `num_items` (a delay equal to zero corresponds
+  // to the most recently pushed item). The value of `delay` is limited to
+  // [0, N] and `num_items` to [1, M] where N + M is the capacity of the buffer.
+  absl::optional<Level> ComputePartialMetrics(int delay, int num_items) const;
+
+ private:
+  int tail_;
+  int size_;
+  std::vector<Level> data_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_CLIPPING_PREDICTOR_LEVEL_BUFFER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer_unittest.cc
new file mode 100644
index 0000000000..7af9a436c9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_level_buffer_unittest.cc
@@ -0,0 +1,131 @@
+/*
+ *  Copyright (c) 2021 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/agc2/clipping_predictor_level_buffer.h"
+
+#include <algorithm>
+
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+using ::testing::Eq;
+using ::testing::Optional;
+
+class ClippingPredictorLevelBufferParametrization
+    : public ::testing::TestWithParam<int> {
+ protected:
+  int capacity() const { return GetParam(); }
+};
+
+TEST_P(ClippingPredictorLevelBufferParametrization, CheckEmptyBufferSize) {
+  ClippingPredictorLevelBuffer buffer(capacity());
+  EXPECT_EQ(buffer.Capacity(), std::max(capacity(), 1));
+  EXPECT_EQ(buffer.Size(), 0);
+}
+
+TEST_P(ClippingPredictorLevelBufferParametrization, CheckHalfEmptyBufferSize) {
+  ClippingPredictorLevelBuffer buffer(capacity());
+  for (int i = 0; i < buffer.Capacity() / 2; ++i) {
+    buffer.Push({2, 4});
+  }
+  EXPECT_EQ(buffer.Capacity(), std::max(capacity(), 1));
+  EXPECT_EQ(buffer.Size(), std::max(capacity(), 1) / 2);
+}
+
+TEST_P(ClippingPredictorLevelBufferParametrization, CheckFullBufferSize) {
+  ClippingPredictorLevelBuffer buffer(capacity());
+  for (int i = 0; i < buffer.Capacity(); ++i) {
+    buffer.Push({2, 4});
+  }
+  EXPECT_EQ(buffer.Capacity(), std::max(capacity(), 1));
+  EXPECT_EQ(buffer.Size(), std::max(capacity(), 1));
+}
+
+TEST_P(ClippingPredictorLevelBufferParametrization, CheckLargeBufferSize) {
+  ClippingPredictorLevelBuffer buffer(capacity());
+  for (int i = 0; i < 2 * buffer.Capacity(); ++i) {
+    buffer.Push({2, 4});
+  }
+  EXPECT_EQ(buffer.Capacity(), std::max(capacity(), 1));
+  EXPECT_EQ(buffer.Size(), std::max(capacity(), 1));
+}
+
+TEST_P(ClippingPredictorLevelBufferParametrization, CheckSizeAfterReset) {
+  ClippingPredictorLevelBuffer buffer(capacity());
+  buffer.Push({1, 1});
+  buffer.Push({1, 1});
+  buffer.Reset();
+  EXPECT_EQ(buffer.Capacity(), std::max(capacity(), 1));
+  EXPECT_EQ(buffer.Size(), 0);
+  buffer.Push({1, 1});
+  EXPECT_EQ(buffer.Capacity(), std::max(capacity(), 1));
+  EXPECT_EQ(buffer.Size(), 1);
+}
+
+INSTANTIATE_TEST_SUITE_P(ClippingPredictorLevelBufferTest,
+                         ClippingPredictorLevelBufferParametrization,
+                         ::testing::Values(-1, 0, 1, 123));
+
+TEST(ClippingPredictorLevelBufferTest, CheckMetricsAfterFullBuffer) {
+  ClippingPredictorLevelBuffer buffer(/*capacity=*/2);
+  buffer.Push({1, 2});
+  buffer.Push({3, 6});
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/0, /*num_items=*/1),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{3, 6})));
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/1, /*num_items=*/1),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{1, 2})));
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/0, /*num_items=*/2),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{2, 6})));
+}
+
+TEST(ClippingPredictorLevelBufferTest, CheckMetricsAfterPushBeyondCapacity) {
+  ClippingPredictorLevelBuffer buffer(/*capacity=*/2);
+  buffer.Push({1, 1});
+  buffer.Push({3, 6});
+  buffer.Push({5, 10});
+  buffer.Push({7, 14});
+  buffer.Push({6, 12});
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/0, /*num_items=*/1),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{6, 12})));
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/1, /*num_items=*/1),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{7, 14})));
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/0, /*num_items=*/2),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{6.5f, 14})));
+}
+
+TEST(ClippingPredictorLevelBufferTest, CheckMetricsAfterTooFewItems) {
+  ClippingPredictorLevelBuffer buffer(/*capacity=*/4);
+  buffer.Push({1, 2});
+  buffer.Push({3, 6});
+  EXPECT_EQ(buffer.ComputePartialMetrics(/*delay=*/0, /*num_items=*/3),
+            absl::nullopt);
+  EXPECT_EQ(buffer.ComputePartialMetrics(/*delay=*/2, /*num_items=*/1),
+            absl::nullopt);
+}
+
+TEST(ClippingPredictorLevelBufferTest, CheckMetricsAfterReset) {
+  ClippingPredictorLevelBuffer buffer(/*capacity=*/2);
+  buffer.Push({1, 2});
+  buffer.Reset();
+  buffer.Push({5, 10});
+  buffer.Push({7, 14});
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/0, /*num_items=*/1),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{7, 14})));
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/0, /*num_items=*/2),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{6, 14})));
+  EXPECT_THAT(buffer.ComputePartialMetrics(/*delay=*/1, /*num_items=*/1),
+              Optional(Eq(ClippingPredictorLevelBuffer::Level{5, 10})));
+}
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_unittest.cc
new file mode 100644
index 0000000000..af73107749
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/clipping_predictor_unittest.cc
@@ -0,0 +1,491 @@
+/*
+ *  Copyright (c) 2021 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/agc2/clipping_predictor.h"
+
+#include <cstdint>
+#include <limits>
+#include <tuple>
+
+#include "rtc_base/checks.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+using ::testing::Eq;
+using ::testing::Optional;
+using ClippingPredictorConfig = AudioProcessing::Config::GainController1::
+    AnalogGainController::ClippingPredictor;
+using ClippingPredictorMode = AudioProcessing::Config::GainController1::
+    AnalogGainController::ClippingPredictor::Mode;
+
+constexpr int kSampleRateHz = 32000;
+constexpr int kNumChannels = 1;
+constexpr int kSamplesPerChannel = kSampleRateHz / 100;
+constexpr int kMaxMicLevel = 255;
+constexpr int kMinMicLevel = 12;
+constexpr int kDefaultClippedLevelStep = 15;
+constexpr float kMaxSampleS16 =
+    static_cast<float>(std::numeric_limits<int16_t>::max());
+
+// Threshold in dB corresponding to a signal with an amplitude equal to 99% of
+// the dynamic range - i.e., computed as `20*log10(0.99)`.
+constexpr float kClippingThresholdDb = -0.08729610804900176f;
+
+void CallAnalyze(int num_calls,
+                 const AudioFrameView<const float>& frame,
+                 ClippingPredictor& predictor) {
+  for (int i = 0; i < num_calls; ++i) {
+    predictor.Analyze(frame);
+  }
+}
+
+// Creates and analyzes an audio frame with a non-zero (approx. 4.15dB) crest
+// factor.
+void AnalyzeNonZeroCrestFactorAudio(int num_calls,
+                                    int num_channels,
+                                    float peak_ratio,
+                                    ClippingPredictor& predictor) {
+  RTC_DCHECK_GT(num_calls, 0);
+  RTC_DCHECK_GT(num_channels, 0);
+  RTC_DCHECK_LE(peak_ratio, 1.0f);
+  std::vector<float*> audio(num_channels);
+  std::vector<float> audio_data(num_channels * kSamplesPerChannel, 0.0f);
+  for (int channel = 0; channel < num_channels; ++channel) {
+    audio[channel] = &audio_data[channel * kSamplesPerChannel];
+    for (int sample = 0; sample < kSamplesPerChannel; sample += 10) {
+      audio[channel][sample] = 0.1f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 1] = 0.2f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 2] = 0.3f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 3] = 0.4f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 4] = 0.5f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 5] = 0.6f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 6] = 0.7f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 7] = 0.8f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 8] = 0.9f * peak_ratio * kMaxSampleS16;
+      audio[channel][sample + 9] = 1.0f * peak_ratio * kMaxSampleS16;
+    }
+  }
+  AudioFrameView<const float> frame(audio.data(), num_channels,
+                                    kSamplesPerChannel);
+  CallAnalyze(num_calls, frame, predictor);
+}
+
+void CheckChannelEstimatesWithValue(int num_channels,
+                                    int level,
+                                    int default_step,
+                                    int min_mic_level,
+                                    int max_mic_level,
+                                    const ClippingPredictor& predictor,
+                                    int expected) {
+  for (int i = 0; i < num_channels; ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_THAT(predictor.EstimateClippedLevelStep(
+                    i, level, default_step, min_mic_level, max_mic_level),
+                Optional(Eq(expected)));
+  }
+}
+
+void CheckChannelEstimatesWithoutValue(int num_channels,
+                                       int level,
+                                       int default_step,
+                                       int min_mic_level,
+                                       int max_mic_level,
+                                       const ClippingPredictor& predictor) {
+  for (int i = 0; i < num_channels; ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_EQ(predictor.EstimateClippedLevelStep(i, level, default_step,
+                                                 min_mic_level, max_mic_level),
+              absl::nullopt);
+  }
+}
+
+// Creates and analyzes an audio frame with a zero crest factor.
+void AnalyzeZeroCrestFactorAudio(int num_calls,
+                                 int num_channels,
+                                 float peak_ratio,
+                                 ClippingPredictor& predictor) {
+  RTC_DCHECK_GT(num_calls, 0);
+  RTC_DCHECK_GT(num_channels, 0);
+  RTC_DCHECK_LE(peak_ratio, 1.f);
+  std::vector<float*> audio(num_channels);
+  std::vector<float> audio_data(num_channels * kSamplesPerChannel, 0.f);
+  for (int channel = 0; channel < num_channels; ++channel) {
+    audio[channel] = &audio_data[channel * kSamplesPerChannel];
+    for (int sample = 0; sample < kSamplesPerChannel; ++sample) {
+      audio[channel][sample] = peak_ratio * kMaxSampleS16;
+    }
+  }
+  auto frame = AudioFrameView<const float>(audio.data(), num_channels,
+                                           kSamplesPerChannel);
+  CallAnalyze(num_calls, frame, predictor);
+}
+
+TEST(ClippingPeakPredictorTest, NoPredictorCreated) {
+  auto predictor =
+      CreateClippingPredictor(kNumChannels, /*config=*/{/*enabled=*/false});
+  EXPECT_FALSE(predictor);
+}
+
+TEST(ClippingPeakPredictorTest, ClippingEventPredictionCreated) {
+  // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+  auto predictor = CreateClippingPredictor(
+      kNumChannels,
+      /*config=*/{/*enabled=*/true,
+                  /*mode=*/ClippingPredictorMode::kClippingEventPrediction});
+  EXPECT_TRUE(predictor);
+}
+
+TEST(ClippingPeakPredictorTest, AdaptiveStepClippingPeakPredictionCreated) {
+  // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+  auto predictor = CreateClippingPredictor(
+      kNumChannels, /*config=*/{
+          /*enabled=*/true,
+          /*mode=*/ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction});
+  EXPECT_TRUE(predictor);
+}
+
+TEST(ClippingPeakPredictorTest, FixedStepClippingPeakPredictionCreated) {
+  // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+  auto predictor = CreateClippingPredictor(
+      kNumChannels, /*config=*/{
+          /*enabled=*/true,
+          /*mode=*/ClippingPredictorMode::kFixedStepClippingPeakPrediction});
+  EXPECT_TRUE(predictor);
+}
+
+class ClippingPredictorParameterization
+    : public ::testing::TestWithParam<std::tuple<int, int, int, int>> {
+ protected:
+  int num_channels() const { return std::get<0>(GetParam()); }
+  ClippingPredictorConfig GetConfig(ClippingPredictorMode mode) const {
+    // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+    return {/*enabled=*/true,
+            /*mode=*/mode,
+            /*window_length=*/std::get<1>(GetParam()),
+            /*reference_window_length=*/std::get<2>(GetParam()),
+            /*reference_window_delay=*/std::get<3>(GetParam()),
+            /*clipping_threshold=*/-1.0f,
+            /*crest_factor_margin=*/0.5f};
+  }
+};
+
+TEST_P(ClippingPredictorParameterization,
+       CheckClippingEventPredictorEstimateAfterCrestFactorDrop) {
+  const ClippingPredictorConfig config =
+      GetConfig(ClippingPredictorMode::kClippingEventPrediction);
+  if (config.reference_window_length + config.reference_window_delay <=
+      config.window_length) {
+    return;
+  }
+  auto predictor = CreateClippingPredictor(num_channels(), config);
+  AnalyzeNonZeroCrestFactorAudio(
+      /*num_calls=*/config.reference_window_length +
+          config.reference_window_delay - config.window_length,
+      num_channels(), /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(num_channels(), /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeZeroCrestFactorAudio(config.window_length, num_channels(),
+                              /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithValue(
+      num_channels(), /*level=*/255, kDefaultClippedLevelStep, kMinMicLevel,
+      kMaxMicLevel, *predictor, kDefaultClippedLevelStep);
+}
+
+TEST_P(ClippingPredictorParameterization,
+       CheckClippingEventPredictorNoEstimateAfterConstantCrestFactor) {
+  const ClippingPredictorConfig config =
+      GetConfig(ClippingPredictorMode::kClippingEventPrediction);
+  if (config.reference_window_length + config.reference_window_delay <=
+      config.window_length) {
+    return;
+  }
+  auto predictor = CreateClippingPredictor(num_channels(), config);
+  AnalyzeNonZeroCrestFactorAudio(
+      /*num_calls=*/config.reference_window_length +
+          config.reference_window_delay - config.window_length,
+      num_channels(), /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(num_channels(), /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/config.window_length,
+                                 num_channels(),
+                                 /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(num_channels(), /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+}
+
+TEST_P(ClippingPredictorParameterization,
+       CheckClippingPeakPredictorEstimateAfterHighCrestFactor) {
+  const ClippingPredictorConfig config =
+      GetConfig(ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction);
+  if (config.reference_window_length + config.reference_window_delay <=
+      config.window_length) {
+    return;
+  }
+  auto predictor = CreateClippingPredictor(num_channels(), config);
+  AnalyzeNonZeroCrestFactorAudio(
+      /*num_calls=*/config.reference_window_length +
+          config.reference_window_delay - config.window_length,
+      num_channels(), /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(num_channels(), /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/config.window_length,
+                                 num_channels(),
+                                 /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithValue(
+      num_channels(), /*level=*/255, kDefaultClippedLevelStep, kMinMicLevel,
+      kMaxMicLevel, *predictor, kDefaultClippedLevelStep);
+}
+
+TEST_P(ClippingPredictorParameterization,
+       CheckClippingPeakPredictorNoEstimateAfterLowCrestFactor) {
+  const ClippingPredictorConfig config =
+      GetConfig(ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction);
+  if (config.reference_window_length + config.reference_window_delay <=
+      config.window_length) {
+    return;
+  }
+  auto predictor = CreateClippingPredictor(num_channels(), config);
+  AnalyzeZeroCrestFactorAudio(
+      /*num_calls=*/config.reference_window_length +
+          config.reference_window_delay - config.window_length,
+      num_channels(), /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(num_channels(), /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/config.window_length,
+                                 num_channels(),
+                                 /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(num_channels(), /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+}
+
+INSTANTIATE_TEST_SUITE_P(GainController1ClippingPredictor,
+                         ClippingPredictorParameterization,
+                         ::testing::Combine(::testing::Values(1, 5),
+                                            ::testing::Values(1, 5, 10),
+                                            ::testing::Values(1, 5),
+                                            ::testing::Values(0, 1, 5)));
+
+class ClippingEventPredictorParameterization
+    : public ::testing::TestWithParam<std::tuple<float, float>> {
+ protected:
+  ClippingPredictorConfig GetConfig() const {
+    // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+    return {/*enabled=*/true,
+            /*mode=*/ClippingPredictorMode::kClippingEventPrediction,
+            /*window_length=*/5,
+            /*reference_window_length=*/5,
+            /*reference_window_delay=*/5,
+            /*clipping_threshold=*/std::get<0>(GetParam()),
+            /*crest_factor_margin=*/std::get<1>(GetParam())};
+  }
+};
+
+TEST_P(ClippingEventPredictorParameterization,
+       CheckEstimateAfterCrestFactorDrop) {
+  const ClippingPredictorConfig config = GetConfig();
+  auto predictor = CreateClippingPredictor(kNumChannels, config);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/config.reference_window_length,
+                                 kNumChannels, /*peak_ratio=*/0.99f,
+                                 *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeZeroCrestFactorAudio(config.window_length, kNumChannels,
+                              /*peak_ratio=*/0.99f, *predictor);
+  // TODO(bugs.webrtc.org/12774): Add clarifying comment.
+  // TODO(bugs.webrtc.org/12774): Remove 4.15f threshold and split tests.
+  if (config.clipping_threshold < kClippingThresholdDb &&
+      config.crest_factor_margin < 4.15f) {
+    CheckChannelEstimatesWithValue(
+        kNumChannels, /*level=*/255, kDefaultClippedLevelStep, kMinMicLevel,
+        kMaxMicLevel, *predictor, kDefaultClippedLevelStep);
+  } else {
+    CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                      kDefaultClippedLevelStep, kMinMicLevel,
+                                      kMaxMicLevel, *predictor);
+  }
+}
+
+INSTANTIATE_TEST_SUITE_P(GainController1ClippingPredictor,
+                         ClippingEventPredictorParameterization,
+                         ::testing::Combine(::testing::Values(-1.0f, 0.0f),
+                                            ::testing::Values(3.0f, 4.16f)));
+
+class ClippingPredictorModeParameterization
+    : public ::testing::TestWithParam<ClippingPredictorMode> {
+ protected:
+  ClippingPredictorConfig GetConfig(float clipping_threshold_dbfs) const {
+    // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+    return {/*enabled=*/true,
+            /*mode=*/GetParam(),
+            /*window_length=*/5,
+            /*reference_window_length=*/5,
+            /*reference_window_delay=*/5,
+            /*clipping_threshold=*/clipping_threshold_dbfs,
+            /*crest_factor_margin=*/3.0f};
+  }
+};
+
+TEST_P(ClippingPredictorModeParameterization,
+       CheckEstimateAfterHighCrestFactorWithNoClippingMargin) {
+  const ClippingPredictorConfig config = GetConfig(
+      /*clipping_threshold_dbfs=*/0.0f);
+  auto predictor = CreateClippingPredictor(kNumChannels, config);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/config.reference_window_length,
+                                 kNumChannels, /*peak_ratio=*/0.99f,
+                                 *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeZeroCrestFactorAudio(config.window_length, kNumChannels,
+                              /*peak_ratio=*/0.99f, *predictor);
+  // Since the clipping threshold is set to 0 dBFS, `EstimateClippedLevelStep()`
+  // is expected to return an unavailable value.
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+}
+
+TEST_P(ClippingPredictorModeParameterization,
+       CheckEstimateAfterHighCrestFactorWithClippingMargin) {
+  const ClippingPredictorConfig config =
+      GetConfig(/*clipping_threshold_dbfs=*/-1.0f);
+  auto predictor = CreateClippingPredictor(kNumChannels, config);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/config.reference_window_length,
+                                 kNumChannels,
+                                 /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeZeroCrestFactorAudio(config.window_length, kNumChannels,
+                              /*peak_ratio=*/0.99f, *predictor);
+  // TODO(bugs.webrtc.org/12774): Add clarifying comment.
+  const float expected_step =
+      config.mode == ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction
+          ? 17
+          : kDefaultClippedLevelStep;
+  CheckChannelEstimatesWithValue(kNumChannels, /*level=*/255,
+                                 kDefaultClippedLevelStep, kMinMicLevel,
+                                 kMaxMicLevel, *predictor, expected_step);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    GainController1ClippingPredictor,
+    ClippingPredictorModeParameterization,
+    ::testing::Values(
+        ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction,
+        ClippingPredictorMode::kFixedStepClippingPeakPrediction));
+
+TEST(ClippingEventPredictorTest, CheckEstimateAfterReset) {
+  // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+  constexpr ClippingPredictorConfig kConfig{
+      /*enabled=*/true,
+      /*mode=*/ClippingPredictorMode::kClippingEventPrediction,
+      /*window_length=*/5,
+      /*reference_window_length=*/5,
+      /*reference_window_delay=*/5,
+      /*clipping_threshold=*/-1.0f,
+      /*crest_factor_margin=*/3.0f};
+  auto predictor = CreateClippingPredictor(kNumChannels, kConfig);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/kConfig.reference_window_length,
+                                 kNumChannels,
+                                 /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  predictor->Reset();
+  AnalyzeZeroCrestFactorAudio(kConfig.window_length, kNumChannels,
+                              /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+}
+
+TEST(ClippingPeakPredictorTest, CheckNoEstimateAfterReset) {
+  // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+  constexpr ClippingPredictorConfig kConfig{
+      /*enabled=*/true,
+      /*mode=*/ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction,
+      /*window_length=*/5,
+      /*reference_window_length=*/5,
+      /*reference_window_delay=*/5,
+      /*clipping_threshold=*/-1.0f};
+  auto predictor = CreateClippingPredictor(kNumChannels, kConfig);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/kConfig.reference_window_length,
+                                 kNumChannels,
+                                 /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  predictor->Reset();
+  AnalyzeZeroCrestFactorAudio(kConfig.window_length, kNumChannels,
+                              /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+}
+
+TEST(ClippingPeakPredictorTest, CheckAdaptiveStepEstimate) {
+  // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+  constexpr ClippingPredictorConfig kConfig{
+      /*enabled=*/true,
+      /*mode=*/ClippingPredictorMode::kAdaptiveStepClippingPeakPrediction,
+      /*window_length=*/5,
+      /*reference_window_length=*/5,
+      /*reference_window_delay=*/5,
+      /*clipping_threshold=*/-1.0f};
+  auto predictor = CreateClippingPredictor(kNumChannels, kConfig);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/kConfig.reference_window_length,
+                                 kNumChannels, /*peak_ratio=*/0.99f,
+                                 *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeZeroCrestFactorAudio(kConfig.window_length, kNumChannels,
+                              /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithValue(kNumChannels, /*level=*/255,
+                                 kDefaultClippedLevelStep, kMinMicLevel,
+                                 kMaxMicLevel, *predictor, /*expected=*/17);
+}
+
+TEST(ClippingPeakPredictorTest, CheckFixedStepEstimate) {
+  // TODO(bugs.webrtc.org/12874): Use designated initializers one fixed.
+  constexpr ClippingPredictorConfig kConfig{
+      /*enabled=*/true,
+      /*mode=*/ClippingPredictorMode::kFixedStepClippingPeakPrediction,
+      /*window_length=*/5,
+      /*reference_window_length=*/5,
+      /*reference_window_delay=*/5,
+      /*clipping_threshold=*/-1.0f};
+  auto predictor = CreateClippingPredictor(kNumChannels, kConfig);
+  AnalyzeNonZeroCrestFactorAudio(/*num_calls=*/kConfig.reference_window_length,
+                                 kNumChannels, /*peak_ratio=*/0.99f,
+                                 *predictor);
+  CheckChannelEstimatesWithoutValue(kNumChannels, /*level=*/255,
+                                    kDefaultClippedLevelStep, kMinMicLevel,
+                                    kMaxMicLevel, *predictor);
+  AnalyzeZeroCrestFactorAudio(kConfig.window_length, kNumChannels,
+                              /*peak_ratio=*/0.99f, *predictor);
+  CheckChannelEstimatesWithValue(
+      kNumChannels, /*level=*/255, kDefaultClippedLevelStep, kMinMicLevel,
+      kMaxMicLevel, *predictor, kDefaultClippedLevelStep);
+}
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/common_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/common_gn/moz.build
new file mode 100644
index 0000000000..274cae23a3
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/common_gn/moz.build
@@ -0,0 +1,201 @@
+# 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_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"
+]
+
+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
+
+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
+
+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
+
+if CONFIG["CPU_ARCH"] == "aarch64":
+
+    DEFINES["WEBRTC_ARCH_ARM64"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["CPU_ARCH"] == "arm":
+
+    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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("common_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.cc b/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.cc
new file mode 100644
index 0000000000..221b499e32
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.cc
@@ -0,0 +1,229 @@
+/*
+ *  Copyright (c) 2018 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/agc2/compute_interpolated_gain_curve.h"
+
+#include <algorithm>
+#include <cmath>
+#include <queue>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/agc2/agc2_testing_common.h"
+#include "modules/audio_processing/agc2/limiter_db_gain_curve.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace {
+
+std::pair<double, double> ComputeLinearApproximationParams(
+    const LimiterDbGainCurve* limiter,
+    const double x) {
+  const double m = limiter->GetGainFirstDerivativeLinear(x);
+  const double q = limiter->GetGainLinear(x) - m * x;
+  return {m, q};
+}
+
+double ComputeAreaUnderPiecewiseLinearApproximation(
+    const LimiterDbGainCurve* limiter,
+    const double x0,
+    const double x1) {
+  RTC_CHECK_LT(x0, x1);
+
+  // Linear approximation in x0 and x1.
+  double m0, q0, m1, q1;
+  std::tie(m0, q0) = ComputeLinearApproximationParams(limiter, x0);
+  std::tie(m1, q1) = ComputeLinearApproximationParams(limiter, x1);
+
+  // Intersection point between two adjacent linear pieces.
+  RTC_CHECK_NE(m1, m0);
+  const double x_split = (q0 - q1) / (m1 - m0);
+  RTC_CHECK_LT(x0, x_split);
+  RTC_CHECK_LT(x_split, x1);
+
+  auto area_under_linear_piece = [](double x_l, double x_r, double m,
+                                    double q) {
+    return x_r * (m * x_r / 2.0 + q) - x_l * (m * x_l / 2.0 + q);
+  };
+  return area_under_linear_piece(x0, x_split, m0, q0) +
+         area_under_linear_piece(x_split, x1, m1, q1);
+}
+
+// Computes the approximation error in the limiter region for a given interval.
+// The error is computed as the difference between the areas beneath the limiter
+// curve to approximate and its linear under-approximation.
+double LimiterUnderApproximationNegativeError(const LimiterDbGainCurve* limiter,
+                                              const double x0,
+                                              const double x1) {
+  const double area_limiter = limiter->GetGainIntegralLinear(x0, x1);
+  const double area_interpolated_curve =
+      ComputeAreaUnderPiecewiseLinearApproximation(limiter, x0, x1);
+  RTC_CHECK_GE(area_limiter, area_interpolated_curve);
+  return area_limiter - area_interpolated_curve;
+}
+
+// Automatically finds where to sample the beyond-knee region of a limiter using
+// a greedy optimization algorithm that iteratively decreases the approximation
+// error.
+// The solution is sub-optimal because the algorithm is greedy and the points
+// are assigned by halving intervals (starting with the whole beyond-knee region
+// as a single interval). However, even if sub-optimal, this algorithm works
+// well in practice and it is efficiently implemented using priority queues.
+std::vector<double> SampleLimiterRegion(const LimiterDbGainCurve* limiter) {
+  static_assert(kInterpolatedGainCurveBeyondKneePoints > 2, "");
+
+  struct Interval {
+    Interval() = default;  // Ctor required by std::priority_queue.
+    Interval(double l, double r, double e) : x0(l), x1(r), error(e) {
+      RTC_CHECK(x0 < x1);
+    }
+    bool operator<(const Interval& other) const { return error < other.error; }
+
+    double x0;
+    double x1;
+    double error;
+  };
+
+  std::priority_queue<Interval, std::vector<Interval>> q;
+  q.emplace(limiter->limiter_start_linear(), limiter->max_input_level_linear(),
+            LimiterUnderApproximationNegativeError(
+                limiter, limiter->limiter_start_linear(),
+                limiter->max_input_level_linear()));
+
+  // Iteratively find points by halving the interval with greatest error.
+  while (q.size() < kInterpolatedGainCurveBeyondKneePoints) {
+    // Get the interval with highest error.
+    const auto interval = q.top();
+    q.pop();
+
+    // Split `interval` and enqueue.
+    double x_split = (interval.x0 + interval.x1) / 2.0;
+    q.emplace(interval.x0, x_split,
+              LimiterUnderApproximationNegativeError(limiter, interval.x0,
+                                                     x_split));  // Left.
+    q.emplace(x_split, interval.x1,
+              LimiterUnderApproximationNegativeError(limiter, x_split,
+                                                     interval.x1));  // Right.
+  }
+
+  // Copy x1 values and sort them.
+  RTC_CHECK_EQ(q.size(), kInterpolatedGainCurveBeyondKneePoints);
+  std::vector<double> samples(kInterpolatedGainCurveBeyondKneePoints);
+  for (size_t i = 0; i < kInterpolatedGainCurveBeyondKneePoints; ++i) {
+    const auto interval = q.top();
+    q.pop();
+    samples[i] = interval.x1;
+  }
+  RTC_CHECK(q.empty());
+  std::sort(samples.begin(), samples.end());
+
+  return samples;
+}
+
+// Compute the parameters to over-approximate the knee region via linear
+// interpolation. Over-approximating is saturation-safe since the knee region is
+// convex.
+void PrecomputeKneeApproxParams(const LimiterDbGainCurve* limiter,
+                                test::InterpolatedParameters* parameters) {
+  static_assert(kInterpolatedGainCurveKneePoints > 2, "");
+  // Get `kInterpolatedGainCurveKneePoints` - 1 equally spaced points.
+  const std::vector<double> points = test::LinSpace(
+      limiter->knee_start_linear(), limiter->limiter_start_linear(),
+      kInterpolatedGainCurveKneePoints - 1);
+
+  // Set the first two points. The second is computed to help with the beginning
+  // of the knee region, which has high curvature.
+  parameters->computed_approximation_params_x[0] = points[0];
+  parameters->computed_approximation_params_x[1] =
+      (points[0] + points[1]) / 2.0;
+  // Copy the remaining points.
+  std::copy(std::begin(points) + 1, std::end(points),
+            std::begin(parameters->computed_approximation_params_x) + 2);
+
+  // Compute (m, q) pairs for each linear piece y = mx + q.
+  for (size_t i = 0; i < kInterpolatedGainCurveKneePoints - 1; ++i) {
+    const double x0 = parameters->computed_approximation_params_x[i];
+    const double x1 = parameters->computed_approximation_params_x[i + 1];
+    const double y0 = limiter->GetGainLinear(x0);
+    const double y1 = limiter->GetGainLinear(x1);
+    RTC_CHECK_NE(x1, x0);
+    parameters->computed_approximation_params_m[i] = (y1 - y0) / (x1 - x0);
+    parameters->computed_approximation_params_q[i] =
+        y0 - parameters->computed_approximation_params_m[i] * x0;
+  }
+}
+
+// Compute the parameters to under-approximate the beyond-knee region via linear
+// interpolation and greedy sampling. Under-approximating is saturation-safe
+// since the beyond-knee region is concave.
+void PrecomputeBeyondKneeApproxParams(
+    const LimiterDbGainCurve* limiter,
+    test::InterpolatedParameters* parameters) {
+  // Find points on which the linear pieces are tangent to the gain curve.
+  const auto samples = SampleLimiterRegion(limiter);
+
+  // Parametrize each linear piece.
+  double m, q;
+  std::tie(m, q) = ComputeLinearApproximationParams(
+      limiter,
+      parameters
+          ->computed_approximation_params_x[kInterpolatedGainCurveKneePoints -
+                                            1]);
+  parameters
+      ->computed_approximation_params_m[kInterpolatedGainCurveKneePoints - 1] =
+      m;
+  parameters
+      ->computed_approximation_params_q[kInterpolatedGainCurveKneePoints - 1] =
+      q;
+  for (size_t i = 0; i < samples.size(); ++i) {
+    std::tie(m, q) = ComputeLinearApproximationParams(limiter, samples[i]);
+    parameters
+        ->computed_approximation_params_m[i +
+                                          kInterpolatedGainCurveKneePoints] = m;
+    parameters
+        ->computed_approximation_params_q[i +
+                                          kInterpolatedGainCurveKneePoints] = q;
+  }
+
+  // Find the point of intersection between adjacent linear pieces. They will be
+  // used as boundaries between adjacent linear pieces.
+  for (size_t i = kInterpolatedGainCurveKneePoints;
+       i < kInterpolatedGainCurveKneePoints +
+               kInterpolatedGainCurveBeyondKneePoints;
+       ++i) {
+    RTC_CHECK_NE(parameters->computed_approximation_params_m[i],
+                 parameters->computed_approximation_params_m[i - 1]);
+    parameters->computed_approximation_params_x[i] =
+        (  // Formula: (q0 - q1) / (m1 - m0).
+            parameters->computed_approximation_params_q[i - 1] -
+            parameters->computed_approximation_params_q[i]) /
+        (parameters->computed_approximation_params_m[i] -
+         parameters->computed_approximation_params_m[i - 1]);
+  }
+}
+
+}  // namespace
+
+namespace test {
+
+InterpolatedParameters ComputeInterpolatedGainCurveApproximationParams() {
+  InterpolatedParameters parameters;
+  LimiterDbGainCurve limiter;
+  parameters.computed_approximation_params_x.fill(0.0f);
+  parameters.computed_approximation_params_m.fill(0.0f);
+  parameters.computed_approximation_params_q.fill(0.0f);
+  PrecomputeKneeApproxParams(&limiter, &parameters);
+  PrecomputeBeyondKneeApproxParams(&limiter, &parameters);
+  return parameters;
+}
+}  // namespace test
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h b/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h
new file mode 100644
index 0000000000..08b676f5fd
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/compute_interpolated_gain_curve.h
@@ -0,0 +1,48 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_COMPUTE_INTERPOLATED_GAIN_CURVE_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_COMPUTE_INTERPOLATED_GAIN_CURVE_H_
+
+#include <array>
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+
+namespace webrtc {
+
+namespace test {
+
+// Parameters for interpolated gain curve using under-approximation to
+// avoid saturation.
+//
+// The saturation gain is defined in order to let hard-clipping occur for
+// those samples having a level that falls in the saturation region. It is an
+// upper bound of the actual gain to apply - i.e., that returned by the
+// limiter.
+
+// Knee and beyond-knee regions approximation parameters.
+// The gain curve is approximated as a piece-wise linear function.
+// `approx_params_x_` are the boundaries between adjacent linear pieces,
+// `approx_params_m_` and `approx_params_q_` are the slope and the y-intercept
+// values of each piece.
+struct InterpolatedParameters {
+  std::array<float, kInterpolatedGainCurveTotalPoints>
+      computed_approximation_params_x;
+  std::array<float, kInterpolatedGainCurveTotalPoints>
+      computed_approximation_params_m;
+  std::array<float, kInterpolatedGainCurveTotalPoints>
+      computed_approximation_params_q;
+};
+
+InterpolatedParameters ComputeInterpolatedGainCurveApproximationParams();
+}  // namespace test
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_COMPUTE_INTERPOLATED_GAIN_CURVE_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features.cc b/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features.cc
new file mode 100644
index 0000000000..cced7614bc
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features.cc
@@ -0,0 +1,62 @@
+/*
+ *  Copyright (c) 2020 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/agc2/cpu_features.h"
+
+#include "rtc_base/strings/string_builder.h"
+#include "rtc_base/system/arch.h"
+#include "system_wrappers/include/cpu_features_wrapper.h"
+
+namespace webrtc {
+
+std::string AvailableCpuFeatures::ToString() const {
+  char buf[64];
+  rtc::SimpleStringBuilder builder(buf);
+  bool first = true;
+  if (sse2) {
+    builder << (first ? "SSE2" : "_SSE2");
+    first = false;
+  }
+  if (avx2) {
+    builder << (first ? "AVX2" : "_AVX2");
+    first = false;
+  }
+  if (neon) {
+    builder << (first ? "NEON" : "_NEON");
+    first = false;
+  }
+  if (first) {
+    return "none";
+  }
+  return builder.str();
+}
+
+// Detects available CPU features.
+AvailableCpuFeatures GetAvailableCpuFeatures() {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+  return {/*sse2=*/GetCPUInfo(kSSE2) != 0,
+          /*avx2=*/GetCPUInfo(kAVX2) != 0,
+          /*neon=*/false};
+#elif defined(WEBRTC_HAS_NEON)
+  return {/*sse2=*/false,
+          /*avx2=*/false,
+          /*neon=*/true};
+#else
+  return {/*sse2=*/false,
+          /*avx2=*/false,
+          /*neon=*/false};
+#endif
+}
+
+AvailableCpuFeatures NoAvailableCpuFeatures() {
+  return {/*sse2=*/false, /*avx2=*/false, /*neon=*/false};
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features.h b/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features.h
new file mode 100644
index 0000000000..54ddfb3055
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features.h
@@ -0,0 +1,39 @@
+/*
+ *  Copyright (c) 2020 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_AGC2_CPU_FEATURES_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_CPU_FEATURES_H_
+
+#include <string>
+
+namespace webrtc {
+
+// Collection of flags indicating which CPU features are available on the
+// current platform. True means available.
+struct AvailableCpuFeatures {
+  AvailableCpuFeatures(bool sse2, bool avx2, bool neon)
+      : sse2(sse2), avx2(avx2), neon(neon) {}
+  // Intel.
+  bool sse2;
+  bool avx2;
+  // ARM.
+  bool neon;
+  std::string ToString() const;
+};
+
+// Detects what CPU features are available.
+AvailableCpuFeatures GetAvailableCpuFeatures();
+
+// Returns the CPU feature flags all set to false.
+AvailableCpuFeatures NoAvailableCpuFeatures();
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_CPU_FEATURES_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features_gn/moz.build
new file mode 100644
index 0000000000..a4572251ad
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/cpu_features_gn/moz.build
@@ -0,0 +1,232 @@
+# 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_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/agc2/cpu_features.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("cpu_features_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_gn/moz.build
new file mode 100644
index 0000000000..3a54fc3171
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_gn/moz.build
@@ -0,0 +1,235 @@
+# 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/agc2/fixed_digital_level_estimator.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/limiter.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("fixed_digital_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator.cc b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator.cc
new file mode 100644
index 0000000000..1995b24913
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator.cc
@@ -0,0 +1,121 @@
+/*
+ *  Copyright (c) 2018 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/agc2/fixed_digital_level_estimator.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace {
+
+constexpr float kInitialFilterStateLevel = 0.0f;
+
+// Instant attack.
+constexpr float kAttackFilterConstant = 0.0f;
+
+// Limiter decay constant.
+// Computed as `10 ** (-1/20 * subframe_duration / kDecayMs)` where:
+// - `subframe_duration` is `kFrameDurationMs / kSubFramesInFrame`;
+// - `kDecayMs` is defined in agc2_testing_common.h.
+constexpr float kDecayFilterConstant = 0.9971259f;
+
+}  // namespace
+
+FixedDigitalLevelEstimator::FixedDigitalLevelEstimator(
+    int sample_rate_hz,
+    ApmDataDumper* apm_data_dumper)
+    : apm_data_dumper_(apm_data_dumper),
+      filter_state_level_(kInitialFilterStateLevel) {
+  SetSampleRate(sample_rate_hz);
+  CheckParameterCombination();
+  RTC_DCHECK(apm_data_dumper_);
+  apm_data_dumper_->DumpRaw("agc2_level_estimator_samplerate", sample_rate_hz);
+}
+
+void FixedDigitalLevelEstimator::CheckParameterCombination() {
+  RTC_DCHECK_GT(samples_in_frame_, 0);
+  RTC_DCHECK_LE(kSubFramesInFrame, samples_in_frame_);
+  RTC_DCHECK_EQ(samples_in_frame_ % kSubFramesInFrame, 0);
+  RTC_DCHECK_GT(samples_in_sub_frame_, 1);
+}
+
+std::array<float, kSubFramesInFrame> FixedDigitalLevelEstimator::ComputeLevel(
+    const AudioFrameView<const float>& float_frame) {
+  RTC_DCHECK_GT(float_frame.num_channels(), 0);
+  RTC_DCHECK_EQ(float_frame.samples_per_channel(), samples_in_frame_);
+
+  // Compute max envelope without smoothing.
+  std::array<float, kSubFramesInFrame> envelope{};
+  for (int channel_idx = 0; channel_idx < float_frame.num_channels();
+       ++channel_idx) {
+    const auto channel = float_frame.channel(channel_idx);
+    for (int sub_frame = 0; sub_frame < kSubFramesInFrame; ++sub_frame) {
+      for (int sample_in_sub_frame = 0;
+           sample_in_sub_frame < samples_in_sub_frame_; ++sample_in_sub_frame) {
+        envelope[sub_frame] =
+            std::max(envelope[sub_frame],
+                     std::abs(channel[sub_frame * samples_in_sub_frame_ +
+                                      sample_in_sub_frame]));
+      }
+    }
+  }
+
+  // Make sure envelope increases happen one step earlier so that the
+  // corresponding *gain decrease* doesn't miss a sudden signal
+  // increase due to interpolation.
+  for (int sub_frame = 0; sub_frame < kSubFramesInFrame - 1; ++sub_frame) {
+    if (envelope[sub_frame] < envelope[sub_frame + 1]) {
+      envelope[sub_frame] = envelope[sub_frame + 1];
+    }
+  }
+
+  // Add attack / decay smoothing.
+  for (int sub_frame = 0; sub_frame < kSubFramesInFrame; ++sub_frame) {
+    const float envelope_value = envelope[sub_frame];
+    if (envelope_value > filter_state_level_) {
+      envelope[sub_frame] = envelope_value * (1 - kAttackFilterConstant) +
+                            filter_state_level_ * kAttackFilterConstant;
+    } else {
+      envelope[sub_frame] = envelope_value * (1 - kDecayFilterConstant) +
+                            filter_state_level_ * kDecayFilterConstant;
+    }
+    filter_state_level_ = envelope[sub_frame];
+
+    // Dump data for debug.
+    RTC_DCHECK(apm_data_dumper_);
+    const auto channel = float_frame.channel(0);
+    apm_data_dumper_->DumpRaw("agc2_level_estimator_samples",
+                              samples_in_sub_frame_,
+                              &channel[sub_frame * samples_in_sub_frame_]);
+    apm_data_dumper_->DumpRaw("agc2_level_estimator_level",
+                              envelope[sub_frame]);
+  }
+
+  return envelope;
+}
+
+void FixedDigitalLevelEstimator::SetSampleRate(int sample_rate_hz) {
+  samples_in_frame_ =
+      rtc::CheckedDivExact(sample_rate_hz * kFrameDurationMs, 1000);
+  samples_in_sub_frame_ =
+      rtc::CheckedDivExact(samples_in_frame_, kSubFramesInFrame);
+  CheckParameterCombination();
+}
+
+void FixedDigitalLevelEstimator::Reset() {
+  filter_state_level_ = kInitialFilterStateLevel;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator.h b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator.h
new file mode 100644
index 0000000000..d26b55950c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator.h
@@ -0,0 +1,66 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_FIXED_DIGITAL_LEVEL_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_FIXED_DIGITAL_LEVEL_ESTIMATOR_H_
+
+#include <array>
+#include <vector>
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/include/audio_frame_view.h"
+
+namespace webrtc {
+
+class ApmDataDumper;
+// Produces a smooth signal level estimate from an input audio
+// stream. The estimate smoothing is done through exponential
+// filtering.
+class FixedDigitalLevelEstimator {
+ public:
+  // Sample rates are allowed if the number of samples in a frame
+  // (sample_rate_hz * kFrameDurationMs / 1000) is divisible by
+  // kSubFramesInSample. For kFrameDurationMs=10 and
+  // kSubFramesInSample=20, this means that sample_rate_hz has to be
+  // divisible by 2000.
+  FixedDigitalLevelEstimator(int sample_rate_hz,
+                             ApmDataDumper* apm_data_dumper);
+
+  FixedDigitalLevelEstimator(const FixedDigitalLevelEstimator&) = delete;
+  FixedDigitalLevelEstimator& operator=(const FixedDigitalLevelEstimator&) =
+      delete;
+
+  // The input is assumed to be in FloatS16 format. Scaled input will
+  // produce similarly scaled output. A frame of with kFrameDurationMs
+  // ms of audio produces a level estimates in the same scale. The
+  // level estimate contains kSubFramesInFrame values.
+  std::array<float, kSubFramesInFrame> ComputeLevel(
+      const AudioFrameView<const float>& float_frame);
+
+  // Rate may be changed at any time (but not concurrently) from the
+  // value passed to the constructor. The class is not thread safe.
+  void SetSampleRate(int sample_rate_hz);
+
+  // Resets the level estimator internal state.
+  void Reset();
+
+  float LastAudioLevel() const { return filter_state_level_; }
+
+ private:
+  void CheckParameterCombination();
+
+  ApmDataDumper* const apm_data_dumper_ = nullptr;
+  float filter_state_level_;
+  int samples_in_frame_;
+  int samples_in_sub_frame_;
+};
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_FIXED_DIGITAL_LEVEL_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator_unittest.cc
new file mode 100644
index 0000000000..97b421d04c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/fixed_digital_level_estimator_unittest.cc
@@ -0,0 +1,159 @@
+/*
+ *  Copyright (c) 2018 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/agc2/fixed_digital_level_estimator.h"
+
+#include <limits>
+
+#include "common_audio/include/audio_util.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/agc2/agc2_testing_common.h"
+#include "modules/audio_processing/agc2/vector_float_frame.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+
+constexpr float kInputLevel = 10000.f;
+
+// Run audio at specified settings through the level estimator, and
+// verify that the output level falls within the bounds.
+void TestLevelEstimator(int sample_rate_hz,
+                        int num_channels,
+                        float input_level_linear_scale,
+                        float expected_min,
+                        float expected_max) {
+  ApmDataDumper apm_data_dumper(0);
+  FixedDigitalLevelEstimator level_estimator(sample_rate_hz, &apm_data_dumper);
+
+  const VectorFloatFrame vectors_with_float_frame(
+      num_channels, rtc::CheckedDivExact(sample_rate_hz, 100),
+      input_level_linear_scale);
+
+  for (int i = 0; i < 500; ++i) {
+    const auto level = level_estimator.ComputeLevel(
+        vectors_with_float_frame.float_frame_view());
+
+    // Give the estimator some time to ramp up.
+    if (i < 50) {
+      continue;
+    }
+
+    for (const auto& x : level) {
+      EXPECT_LE(expected_min, x);
+      EXPECT_LE(x, expected_max);
+    }
+  }
+}
+
+// Returns time it takes for the level estimator to decrease its level
+// estimate by 'level_reduction_db'.
+float TimeMsToDecreaseLevel(int sample_rate_hz,
+                            int num_channels,
+                            float input_level_db,
+                            float level_reduction_db) {
+  const float input_level = DbfsToFloatS16(input_level_db);
+  RTC_DCHECK_GT(level_reduction_db, 0);
+
+  const VectorFloatFrame vectors_with_float_frame(
+      num_channels, rtc::CheckedDivExact(sample_rate_hz, 100), input_level);
+
+  ApmDataDumper apm_data_dumper(0);
+  FixedDigitalLevelEstimator level_estimator(sample_rate_hz, &apm_data_dumper);
+
+  // Give the LevelEstimator plenty of time to ramp up and stabilize
+  float last_level = 0.f;
+  for (int i = 0; i < 500; ++i) {
+    const auto level_envelope = level_estimator.ComputeLevel(
+        vectors_with_float_frame.float_frame_view());
+    last_level = *level_envelope.rbegin();
+  }
+
+  // Set input to 0.
+  VectorFloatFrame vectors_with_zero_float_frame(
+      num_channels, rtc::CheckedDivExact(sample_rate_hz, 100), 0);
+
+  const float reduced_level_linear =
+      DbfsToFloatS16(input_level_db - level_reduction_db);
+  int sub_frames_until_level_reduction = 0;
+  while (last_level > reduced_level_linear) {
+    const auto level_envelope = level_estimator.ComputeLevel(
+        vectors_with_zero_float_frame.float_frame_view());
+    for (const auto& v : level_envelope) {
+      EXPECT_LT(v, last_level);
+      sub_frames_until_level_reduction++;
+      last_level = v;
+      if (last_level <= reduced_level_linear) {
+        break;
+      }
+    }
+  }
+  return static_cast<float>(sub_frames_until_level_reduction) *
+         kFrameDurationMs / kSubFramesInFrame;
+}
+}  // namespace
+
+TEST(GainController2FixedDigitalLevelEstimator, EstimatorShouldNotCrash) {
+  TestLevelEstimator(8000, 1, 0, std::numeric_limits<float>::lowest(),
+                     std::numeric_limits<float>::max());
+}
+
+TEST(GainController2FixedDigitalLevelEstimator,
+     EstimatorShouldEstimateConstantLevel) {
+  TestLevelEstimator(10000, 1, kInputLevel, kInputLevel * 0.99,
+                     kInputLevel * 1.01);
+}
+
+TEST(GainController2FixedDigitalLevelEstimator,
+     EstimatorShouldEstimateConstantLevelForManyChannels) {
+  constexpr size_t num_channels = 10;
+  TestLevelEstimator(20000, num_channels, kInputLevel, kInputLevel * 0.99,
+                     kInputLevel * 1.01);
+}
+
+TEST(GainController2FixedDigitalLevelEstimator, TimeToDecreaseForLowLevel) {
+  constexpr float kLevelReductionDb = 25;
+  constexpr float kInitialLowLevel = -40;
+  constexpr float kExpectedTime = kLevelReductionDb * test::kDecayMs;
+
+  const float time_to_decrease =
+      TimeMsToDecreaseLevel(22000, 1, kInitialLowLevel, kLevelReductionDb);
+
+  EXPECT_LE(kExpectedTime * 0.9, time_to_decrease);
+  EXPECT_LE(time_to_decrease, kExpectedTime * 1.1);
+}
+
+TEST(GainController2FixedDigitalLevelEstimator,
+     TimeToDecreaseForFullScaleLevel) {
+  constexpr float kLevelReductionDb = 25;
+  constexpr float kExpectedTime = kLevelReductionDb * test::kDecayMs;
+
+  const float time_to_decrease =
+      TimeMsToDecreaseLevel(26000, 1, 0, kLevelReductionDb);
+
+  EXPECT_LE(kExpectedTime * 0.9, time_to_decrease);
+  EXPECT_LE(time_to_decrease, kExpectedTime * 1.1);
+}
+
+TEST(GainController2FixedDigitalLevelEstimator,
+     TimeToDecreaseForMultipleChannels) {
+  constexpr float kLevelReductionDb = 25;
+  constexpr float kExpectedTime = kLevelReductionDb * test::kDecayMs;
+  constexpr size_t kNumChannels = 10;
+
+  const float time_to_decrease =
+      TimeMsToDecreaseLevel(28000, kNumChannels, 0, kLevelReductionDb);
+
+  EXPECT_LE(kExpectedTime * 0.9, time_to_decrease);
+  EXPECT_LE(time_to_decrease, kExpectedTime * 1.1);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier.cc b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier.cc
new file mode 100644
index 0000000000..f9e276d3a8
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier.cc
@@ -0,0 +1,103 @@
+/*
+ *  Copyright (c) 2018 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/agc2/gain_applier.h"
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "rtc_base/numerics/safe_minmax.h"
+
+namespace webrtc {
+namespace {
+
+// Returns true when the gain factor is so close to 1 that it would
+// not affect int16 samples.
+bool GainCloseToOne(float gain_factor) {
+  return 1.f - 1.f / kMaxFloatS16Value <= gain_factor &&
+         gain_factor <= 1.f + 1.f / kMaxFloatS16Value;
+}
+
+void ClipSignal(AudioFrameView<float> signal) {
+  for (int k = 0; k < signal.num_channels(); ++k) {
+    rtc::ArrayView<float> channel_view = signal.channel(k);
+    for (auto& sample : channel_view) {
+      sample = rtc::SafeClamp(sample, kMinFloatS16Value, kMaxFloatS16Value);
+    }
+  }
+}
+
+void ApplyGainWithRamping(float last_gain_linear,
+                          float gain_at_end_of_frame_linear,
+                          float inverse_samples_per_channel,
+                          AudioFrameView<float> float_frame) {
+  // Do not modify the signal.
+  if (last_gain_linear == gain_at_end_of_frame_linear &&
+      GainCloseToOne(gain_at_end_of_frame_linear)) {
+    return;
+  }
+
+  // Gain is constant and different from 1.
+  if (last_gain_linear == gain_at_end_of_frame_linear) {
+    for (int k = 0; k < float_frame.num_channels(); ++k) {
+      rtc::ArrayView<float> channel_view = float_frame.channel(k);
+      for (auto& sample : channel_view) {
+        sample *= gain_at_end_of_frame_linear;
+      }
+    }
+    return;
+  }
+
+  // The gain changes. We have to change slowly to avoid discontinuities.
+  const float increment = (gain_at_end_of_frame_linear - last_gain_linear) *
+                          inverse_samples_per_channel;
+  float gain = last_gain_linear;
+  for (int i = 0; i < float_frame.samples_per_channel(); ++i) {
+    for (int ch = 0; ch < float_frame.num_channels(); ++ch) {
+      float_frame.channel(ch)[i] *= gain;
+    }
+    gain += increment;
+  }
+}
+
+}  // namespace
+
+GainApplier::GainApplier(bool hard_clip_samples, float initial_gain_factor)
+    : hard_clip_samples_(hard_clip_samples),
+      last_gain_factor_(initial_gain_factor),
+      current_gain_factor_(initial_gain_factor) {}
+
+void GainApplier::ApplyGain(AudioFrameView<float> signal) {
+  if (static_cast<int>(signal.samples_per_channel()) != samples_per_channel_) {
+    Initialize(signal.samples_per_channel());
+  }
+
+  ApplyGainWithRamping(last_gain_factor_, current_gain_factor_,
+                       inverse_samples_per_channel_, signal);
+
+  last_gain_factor_ = current_gain_factor_;
+
+  if (hard_clip_samples_) {
+    ClipSignal(signal);
+  }
+}
+
+// TODO(bugs.webrtc.org/7494): Remove once switched to gains in dB.
+void GainApplier::SetGainFactor(float gain_factor) {
+  RTC_DCHECK_GT(gain_factor, 0.f);
+  current_gain_factor_ = gain_factor;
+}
+
+void GainApplier::Initialize(int samples_per_channel) {
+  RTC_DCHECK_GT(samples_per_channel, 0);
+  samples_per_channel_ = static_cast<int>(samples_per_channel);
+  inverse_samples_per_channel_ = 1.f / samples_per_channel_;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier.h b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier.h
new file mode 100644
index 0000000000..ba8a4a4cd2
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier.h
@@ -0,0 +1,44 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_GAIN_APPLIER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_GAIN_APPLIER_H_
+
+#include <stddef.h>
+
+#include "modules/audio_processing/include/audio_frame_view.h"
+
+namespace webrtc {
+class GainApplier {
+ public:
+  GainApplier(bool hard_clip_samples, float initial_gain_factor);
+
+  void ApplyGain(AudioFrameView<float> signal);
+  void SetGainFactor(float gain_factor);
+  float GetGainFactor() const { return current_gain_factor_; }
+
+ private:
+  void Initialize(int samples_per_channel);
+
+  // Whether to clip samples after gain is applied. If 'true', result
+  // will fit in FloatS16 range.
+  const bool hard_clip_samples_;
+  float last_gain_factor_;
+
+  // If this value is not equal to 'last_gain_factor', gain will be
+  // ramped from 'last_gain_factor_' to this value during the next
+  // 'ApplyGain'.
+  float current_gain_factor_;
+  int samples_per_channel_ = -1;
+  float inverse_samples_per_channel_ = -1.f;
+};
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_GAIN_APPLIER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier_gn/moz.build
new file mode 100644
index 0000000000..394aa109fa
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier_gn/moz.build
@@ -0,0 +1,221 @@
+# 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_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/agc2/gain_applier.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
+
+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
+
+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("gain_applier_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier_unittest.cc
new file mode 100644
index 0000000000..3296345e62
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/gain_applier_unittest.cc
@@ -0,0 +1,93 @@
+/*
+ *  Copyright (c) 2018 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/agc2/gain_applier.h"
+
+#include <math.h>
+
+#include <algorithm>
+#include <limits>
+
+#include "modules/audio_processing/agc2/vector_float_frame.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+TEST(AutomaticGainController2GainApplier, InitialGainIsRespected) {
+  constexpr float initial_signal_level = 123.f;
+  constexpr float gain_factor = 10.f;
+  VectorFloatFrame fake_audio(1, 1, initial_signal_level);
+  GainApplier gain_applier(true, gain_factor);
+
+  gain_applier.ApplyGain(fake_audio.float_frame_view());
+  EXPECT_NEAR(fake_audio.float_frame_view().channel(0)[0],
+              initial_signal_level * gain_factor, 0.1f);
+}
+
+TEST(AutomaticGainController2GainApplier, ClippingIsDone) {
+  constexpr float initial_signal_level = 30000.f;
+  constexpr float gain_factor = 10.f;
+  VectorFloatFrame fake_audio(1, 1, initial_signal_level);
+  GainApplier gain_applier(true, gain_factor);
+
+  gain_applier.ApplyGain(fake_audio.float_frame_view());
+  EXPECT_NEAR(fake_audio.float_frame_view().channel(0)[0],
+              std::numeric_limits<int16_t>::max(), 0.1f);
+}
+
+TEST(AutomaticGainController2GainApplier, ClippingIsNotDone) {
+  constexpr float initial_signal_level = 30000.f;
+  constexpr float gain_factor = 10.f;
+  VectorFloatFrame fake_audio(1, 1, initial_signal_level);
+  GainApplier gain_applier(false, gain_factor);
+
+  gain_applier.ApplyGain(fake_audio.float_frame_view());
+
+  EXPECT_NEAR(fake_audio.float_frame_view().channel(0)[0],
+              initial_signal_level * gain_factor, 0.1f);
+}
+
+TEST(AutomaticGainController2GainApplier, RampingIsDone) {
+  constexpr float initial_signal_level = 30000.f;
+  constexpr float initial_gain_factor = 1.f;
+  constexpr float target_gain_factor = 0.5f;
+  constexpr int num_channels = 3;
+  constexpr int samples_per_channel = 4;
+  VectorFloatFrame fake_audio(num_channels, samples_per_channel,
+                              initial_signal_level);
+  GainApplier gain_applier(false, initial_gain_factor);
+
+  gain_applier.SetGainFactor(target_gain_factor);
+  gain_applier.ApplyGain(fake_audio.float_frame_view());
+
+  // The maximal gain change should be close to that in linear interpolation.
+  for (size_t channel = 0; channel < num_channels; ++channel) {
+    float max_signal_change = 0.f;
+    float last_signal_level = initial_signal_level;
+    for (const auto sample : fake_audio.float_frame_view().channel(channel)) {
+      const float current_change = fabs(last_signal_level - sample);
+      max_signal_change = std::max(max_signal_change, current_change);
+      last_signal_level = sample;
+    }
+    const float total_gain_change =
+        fabs((initial_gain_factor - target_gain_factor) * initial_signal_level);
+    EXPECT_NEAR(max_signal_change, total_gain_change / samples_per_channel,
+                0.1f);
+  }
+
+  // Next frame should have the desired level.
+  VectorFloatFrame next_fake_audio_frame(num_channels, samples_per_channel,
+                                         initial_signal_level);
+  gain_applier.ApplyGain(next_fake_audio_frame.float_frame_view());
+
+  // The last sample should have the new gain.
+  EXPECT_NEAR(next_fake_audio_frame.float_frame_view().channel(0)[0],
+              initial_signal_level * target_gain_factor, 0.1f);
+}
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/gain_map_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/gain_map_gn/moz.build
new file mode 100644
index 0000000000..5b1d68415a
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/gain_map_gn/moz.build
@@ -0,0 +1,201 @@
+# 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_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"
+]
+
+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
+
+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
+
+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
+
+if CONFIG["CPU_ARCH"] == "aarch64":
+
+    DEFINES["WEBRTC_ARCH_ARM64"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["CPU_ARCH"] == "arm":
+
+    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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("gain_map_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/gain_map_internal.h b/third_party/libwebrtc/modules/audio_processing/agc2/gain_map_internal.h
new file mode 100644
index 0000000000..7c669fc9dd
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/gain_map_internal.h
@@ -0,0 +1,46 @@
+/*
+ *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_AGC2_GAIN_MAP_INTERNAL_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_GAIN_MAP_INTERNAL_H_
+
+namespace webrtc {
+
+static constexpr int kGainMapSize = 256;
+// Maps input volumes, which are values in the [0, 255] range, to gains in dB.
+// The values below are generated with numpy as follows:
+// SI = 2                        # Initial slope.
+// SF = 0.25                     # Final slope.
+// D = 8/256                     # Quantization factor.
+// x = np.linspace(0, 255, 256)  # Input volumes.
+// y = (SF * x + (SI - SF) * (1 - np.exp(-D*x)) / D - 56).round()
+static const int kGainMap[kGainMapSize] = {
+    -56, -54, -52, -50, -48, -47, -45, -43, -42, -40, -38, -37, -35, -34, -33,
+    -31, -30, -29, -27, -26, -25, -24, -23, -22, -20, -19, -18, -17, -16, -15,
+    -14, -14, -13, -12, -11, -10, -9,  -8,  -8,  -7,  -6,  -5,  -5,  -4,  -3,
+    -2,  -2,  -1,  0,   0,   1,   1,   2,   3,   3,   4,   4,   5,   5,   6,
+    6,   7,   7,   8,   8,   9,   9,   10,  10,  11,  11,  12,  12,  13,  13,
+    13,  14,  14,  15,  15,  15,  16,  16,  17,  17,  17,  18,  18,  18,  19,
+    19,  19,  20,  20,  21,  21,  21,  22,  22,  22,  23,  23,  23,  24,  24,
+    24,  24,  25,  25,  25,  26,  26,  26,  27,  27,  27,  28,  28,  28,  28,
+    29,  29,  29,  30,  30,  30,  30,  31,  31,  31,  32,  32,  32,  32,  33,
+    33,  33,  33,  34,  34,  34,  35,  35,  35,  35,  36,  36,  36,  36,  37,
+    37,  37,  38,  38,  38,  38,  39,  39,  39,  39,  40,  40,  40,  40,  41,
+    41,  41,  41,  42,  42,  42,  42,  43,  43,  43,  44,  44,  44,  44,  45,
+    45,  45,  45,  46,  46,  46,  46,  47,  47,  47,  47,  48,  48,  48,  48,
+    49,  49,  49,  49,  50,  50,  50,  50,  51,  51,  51,  51,  52,  52,  52,
+    52,  53,  53,  53,  53,  54,  54,  54,  54,  55,  55,  55,  55,  56,  56,
+    56,  56,  57,  57,  57,  57,  58,  58,  58,  58,  59,  59,  59,  59,  60,
+    60,  60,  60,  61,  61,  61,  61,  62,  62,  62,  62,  63,  63,  63,  63,
+    64};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_GAIN_MAP_INTERNAL_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller.cc b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller.cc
new file mode 100644
index 0000000000..bcc650fb3e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller.cc
@@ -0,0 +1,580 @@
+/*
+ *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "modules/audio_processing/agc2/input_volume_controller.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/gain_map_internal.h"
+#include "modules/audio_processing/agc2/input_volume_stats_reporter.h"
+#include "modules/audio_processing/include/audio_frame_view.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/safe_minmax.h"
+#include "system_wrappers/include/field_trial.h"
+#include "system_wrappers/include/metrics.h"
+
+namespace webrtc {
+
+namespace {
+
+// Amount of error we tolerate in the microphone input volume (presumably due to
+// OS quantization) before we assume the user has manually adjusted the volume.
+constexpr int kVolumeQuantizationSlack = 25;
+
+constexpr int kMaxInputVolume = 255;
+static_assert(kGainMapSize > kMaxInputVolume, "gain map too small");
+
+// Maximum absolute RMS error.
+constexpr int KMaxAbsRmsErrorDbfs = 15;
+static_assert(KMaxAbsRmsErrorDbfs > 0, "");
+
+using Agc1ClippingPredictorConfig = AudioProcessing::Config::GainController1::
+    AnalogGainController::ClippingPredictor;
+
+// TODO(webrtc:7494): Hardcode clipping predictor parameters and remove this
+// function after no longer needed in the ctor.
+Agc1ClippingPredictorConfig CreateClippingPredictorConfig(bool enabled) {
+  Agc1ClippingPredictorConfig config;
+  config.enabled = enabled;
+
+  return config;
+}
+
+// Returns an input volume in the [`min_input_volume`, `kMaxInputVolume`] range
+// that reduces `gain_error_db`, which is a gain error estimated when
+// `input_volume` was applied, according to a fixed gain map.
+int ComputeVolumeUpdate(int gain_error_db,
+                        int input_volume,
+                        int min_input_volume) {
+  RTC_DCHECK_GE(input_volume, 0);
+  RTC_DCHECK_LE(input_volume, kMaxInputVolume);
+  if (gain_error_db == 0) {
+    return input_volume;
+  }
+
+  int new_volume = input_volume;
+  if (gain_error_db > 0) {
+    while (kGainMap[new_volume] - kGainMap[input_volume] < gain_error_db &&
+           new_volume < kMaxInputVolume) {
+      ++new_volume;
+    }
+  } else {
+    while (kGainMap[new_volume] - kGainMap[input_volume] > gain_error_db &&
+           new_volume > min_input_volume) {
+      --new_volume;
+    }
+  }
+  return new_volume;
+}
+
+// Returns the proportion of samples in the buffer which are at full-scale
+// (and presumably clipped).
+float ComputeClippedRatio(const float* const* audio,
+                          size_t num_channels,
+                          size_t samples_per_channel) {
+  RTC_DCHECK_GT(samples_per_channel, 0);
+  int num_clipped = 0;
+  for (size_t ch = 0; ch < num_channels; ++ch) {
+    int num_clipped_in_ch = 0;
+    for (size_t i = 0; i < samples_per_channel; ++i) {
+      RTC_DCHECK(audio[ch]);
+      if (audio[ch][i] >= 32767.0f || audio[ch][i] <= -32768.0f) {
+        ++num_clipped_in_ch;
+      }
+    }
+    num_clipped = std::max(num_clipped, num_clipped_in_ch);
+  }
+  return static_cast<float>(num_clipped) / (samples_per_channel);
+}
+
+void LogClippingMetrics(int clipping_rate) {
+  RTC_LOG(LS_INFO) << "[AGC2] Input clipping rate: " << clipping_rate << "%";
+  RTC_HISTOGRAM_COUNTS_LINEAR(/*name=*/"WebRTC.Audio.Agc.InputClippingRate",
+                              /*sample=*/clipping_rate, /*min=*/0, /*max=*/100,
+                              /*bucket_count=*/50);
+}
+
+// Compares `speech_level_dbfs` to the [`target_range_min_dbfs`,
+// `target_range_max_dbfs`] range and returns the error to be compensated via
+// input volume adjustment. Returns a positive value when the level is below
+// the range, a negative value when the level is above the range, zero
+// otherwise.
+int GetSpeechLevelRmsErrorDb(float speech_level_dbfs,
+                             int target_range_min_dbfs,
+                             int target_range_max_dbfs) {
+  constexpr float kMinSpeechLevelDbfs = -90.0f;
+  constexpr float kMaxSpeechLevelDbfs = 30.0f;
+  RTC_DCHECK_GE(speech_level_dbfs, kMinSpeechLevelDbfs);
+  RTC_DCHECK_LE(speech_level_dbfs, kMaxSpeechLevelDbfs);
+  speech_level_dbfs = rtc::SafeClamp<float>(
+      speech_level_dbfs, kMinSpeechLevelDbfs, kMaxSpeechLevelDbfs);
+
+  int rms_error_db = 0;
+  if (speech_level_dbfs > target_range_max_dbfs) {
+    rms_error_db = std::round(target_range_max_dbfs - speech_level_dbfs);
+  } else if (speech_level_dbfs < target_range_min_dbfs) {
+    rms_error_db = std::round(target_range_min_dbfs - speech_level_dbfs);
+  }
+
+  return rms_error_db;
+}
+
+}  // namespace
+
+MonoInputVolumeController::MonoInputVolumeController(
+    int min_input_volume_after_clipping,
+    int min_input_volume,
+    int update_input_volume_wait_frames,
+    float speech_probability_threshold,
+    float speech_ratio_threshold)
+    : min_input_volume_(min_input_volume),
+      min_input_volume_after_clipping_(min_input_volume_after_clipping),
+      max_input_volume_(kMaxInputVolume),
+      update_input_volume_wait_frames_(
+          std::max(update_input_volume_wait_frames, 1)),
+      speech_probability_threshold_(speech_probability_threshold),
+      speech_ratio_threshold_(speech_ratio_threshold) {
+  RTC_DCHECK_GE(min_input_volume_, 0);
+  RTC_DCHECK_LE(min_input_volume_, 255);
+  RTC_DCHECK_GE(min_input_volume_after_clipping_, 0);
+  RTC_DCHECK_LE(min_input_volume_after_clipping_, 255);
+  RTC_DCHECK_GE(max_input_volume_, 0);
+  RTC_DCHECK_LE(max_input_volume_, 255);
+  RTC_DCHECK_GE(update_input_volume_wait_frames_, 0);
+  RTC_DCHECK_GE(speech_probability_threshold_, 0.0f);
+  RTC_DCHECK_LE(speech_probability_threshold_, 1.0f);
+  RTC_DCHECK_GE(speech_ratio_threshold_, 0.0f);
+  RTC_DCHECK_LE(speech_ratio_threshold_, 1.0f);
+}
+
+MonoInputVolumeController::~MonoInputVolumeController() = default;
+
+void MonoInputVolumeController::Initialize() {
+  max_input_volume_ = kMaxInputVolume;
+  capture_output_used_ = true;
+  check_volume_on_next_process_ = true;
+  frames_since_update_input_volume_ = 0;
+  speech_frames_since_update_input_volume_ = 0;
+  is_first_frame_ = true;
+}
+
+// A speeh segment is considered active if at least
+// `update_input_volume_wait_frames_` new frames have been processed since the
+// previous update and the ratio of non-silence frames (i.e., frames with a
+// `speech_probability` higher than `speech_probability_threshold_`) is at least
+// `speech_ratio_threshold_`.
+void MonoInputVolumeController::Process(absl::optional<int> rms_error_db,
+                                        float speech_probability) {
+  if (check_volume_on_next_process_) {
+    check_volume_on_next_process_ = false;
+    // We have to wait until the first process call to check the volume,
+    // because Chromium doesn't guarantee it to be valid any earlier.
+    CheckVolumeAndReset();
+  }
+
+  // Count frames with a high speech probability as speech.
+  if (speech_probability >= speech_probability_threshold_) {
+    ++speech_frames_since_update_input_volume_;
+  }
+
+  // Reset the counters and maybe update the input volume.
+  if (++frames_since_update_input_volume_ >= update_input_volume_wait_frames_) {
+    const float speech_ratio =
+        static_cast<float>(speech_frames_since_update_input_volume_) /
+        static_cast<float>(update_input_volume_wait_frames_);
+
+    // Always reset the counters regardless of whether the volume changes or
+    // not.
+    frames_since_update_input_volume_ = 0;
+    speech_frames_since_update_input_volume_ = 0;
+
+    // Update the input volume if allowed.
+    if (!is_first_frame_ && speech_ratio >= speech_ratio_threshold_ &&
+        rms_error_db.has_value()) {
+      UpdateInputVolume(*rms_error_db);
+    }
+  }
+
+  is_first_frame_ = false;
+}
+
+void MonoInputVolumeController::HandleClipping(int clipped_level_step) {
+  RTC_DCHECK_GT(clipped_level_step, 0);
+  // Always decrease the maximum input volume, even if the current input volume
+  // is below threshold.
+  SetMaxLevel(std::max(min_input_volume_after_clipping_,
+                       max_input_volume_ - clipped_level_step));
+  if (log_to_histograms_) {
+    RTC_HISTOGRAM_BOOLEAN("WebRTC.Audio.AgcClippingAdjustmentAllowed",
+                          last_recommended_input_volume_ - clipped_level_step >=
+                              min_input_volume_after_clipping_);
+  }
+  if (last_recommended_input_volume_ > min_input_volume_after_clipping_) {
+    // Don't try to adjust the input volume if we're already below the limit. As
+    // a consequence, if the user has brought the input volume above the limit,
+    // we will still not react until the postproc updates the input volume.
+    SetInputVolume(
+        std::max(min_input_volume_after_clipping_,
+                 last_recommended_input_volume_ - clipped_level_step));
+    frames_since_update_input_volume_ = 0;
+    speech_frames_since_update_input_volume_ = 0;
+    is_first_frame_ = false;
+  }
+}
+
+void MonoInputVolumeController::SetInputVolume(int new_volume) {
+  int applied_input_volume = recommended_input_volume_;
+  if (applied_input_volume == 0) {
+    RTC_DLOG(LS_INFO)
+        << "[AGC2] The applied input volume is zero, taking no action.";
+    return;
+  }
+  if (applied_input_volume < 0 || applied_input_volume > kMaxInputVolume) {
+    RTC_LOG(LS_ERROR) << "[AGC2] Invalid value for the applied input volume: "
+                      << applied_input_volume;
+    return;
+  }
+
+  // Detect manual input volume adjustments by checking if the
+  // `applied_input_volume` is outside of the `[last_recommended_input_volume_ -
+  // kVolumeQuantizationSlack, last_recommended_input_volume_ +
+  // kVolumeQuantizationSlack]` range.
+  if (applied_input_volume >
+          last_recommended_input_volume_ + kVolumeQuantizationSlack ||
+      applied_input_volume <
+          last_recommended_input_volume_ - kVolumeQuantizationSlack) {
+    RTC_DLOG(LS_INFO)
+        << "[AGC2] The input volume was manually adjusted. Updating "
+           "stored input volume from "
+        << last_recommended_input_volume_ << " to " << applied_input_volume;
+    last_recommended_input_volume_ = applied_input_volume;
+    // Always allow the user to increase the volume.
+    if (last_recommended_input_volume_ > max_input_volume_) {
+      SetMaxLevel(last_recommended_input_volume_);
+    }
+    // Take no action in this case, since we can't be sure when the volume
+    // was manually adjusted.
+    frames_since_update_input_volume_ = 0;
+    speech_frames_since_update_input_volume_ = 0;
+    is_first_frame_ = false;
+    return;
+  }
+
+  new_volume = std::min(new_volume, max_input_volume_);
+  if (new_volume == last_recommended_input_volume_) {
+    return;
+  }
+
+  recommended_input_volume_ = new_volume;
+  RTC_DLOG(LS_INFO) << "[AGC2] Applied input volume: " << applied_input_volume
+                    << " | last recommended input volume: "
+                    << last_recommended_input_volume_
+                    << " | newly recommended input volume: " << new_volume;
+  last_recommended_input_volume_ = new_volume;
+}
+
+void MonoInputVolumeController::SetMaxLevel(int input_volume) {
+  RTC_DCHECK_GE(input_volume, min_input_volume_after_clipping_);
+  max_input_volume_ = input_volume;
+  RTC_DLOG(LS_INFO) << "[AGC2] Maximum input volume updated: "
+                    << max_input_volume_;
+}
+
+void MonoInputVolumeController::HandleCaptureOutputUsedChange(
+    bool capture_output_used) {
+  if (capture_output_used_ == capture_output_used) {
+    return;
+  }
+  capture_output_used_ = capture_output_used;
+
+  if (capture_output_used) {
+    // When we start using the output, we should reset things to be safe.
+    check_volume_on_next_process_ = true;
+  }
+}
+
+int MonoInputVolumeController::CheckVolumeAndReset() {
+  int input_volume = recommended_input_volume_;
+  // Reasons for taking action at startup:
+  // 1) A person starting a call is expected to be heard.
+  // 2) Independent of interpretation of `input_volume` == 0 we should raise it
+  // so the AGC can do its job properly.
+  if (input_volume == 0 && !startup_) {
+    RTC_DLOG(LS_INFO)
+        << "[AGC2] The applied input volume is zero, taking no action.";
+    return 0;
+  }
+  if (input_volume < 0 || input_volume > kMaxInputVolume) {
+    RTC_LOG(LS_ERROR) << "[AGC2] Invalid value for the applied input volume: "
+                      << input_volume;
+    return -1;
+  }
+  RTC_DLOG(LS_INFO) << "[AGC2] Initial input volume: " << input_volume;
+
+  if (input_volume < min_input_volume_) {
+    input_volume = min_input_volume_;
+    RTC_DLOG(LS_INFO)
+        << "[AGC2] The initial input volume is too low, raising to "
+        << input_volume;
+    recommended_input_volume_ = input_volume;
+  }
+
+  last_recommended_input_volume_ = input_volume;
+  startup_ = false;
+  frames_since_update_input_volume_ = 0;
+  speech_frames_since_update_input_volume_ = 0;
+  is_first_frame_ = true;
+
+  return 0;
+}
+
+void MonoInputVolumeController::UpdateInputVolume(int rms_error_db) {
+  RTC_DLOG(LS_INFO) << "[AGC2] RMS error: " << rms_error_db << " dB";
+  // Prevent too large microphone input volume changes by clamping the RMS
+  // error.
+  rms_error_db =
+      rtc::SafeClamp(rms_error_db, -KMaxAbsRmsErrorDbfs, KMaxAbsRmsErrorDbfs);
+  if (rms_error_db == 0) {
+    return;
+  }
+  SetInputVolume(ComputeVolumeUpdate(
+      rms_error_db, last_recommended_input_volume_, min_input_volume_));
+}
+
+InputVolumeController::InputVolumeController(int num_capture_channels,
+                                             const Config& config)
+    : num_capture_channels_(num_capture_channels),
+      min_input_volume_(config.min_input_volume),
+      capture_output_used_(true),
+      clipped_level_step_(config.clipped_level_step),
+      clipped_ratio_threshold_(config.clipped_ratio_threshold),
+      clipped_wait_frames_(config.clipped_wait_frames),
+      clipping_predictor_(CreateClippingPredictor(
+          num_capture_channels,
+          CreateClippingPredictorConfig(config.enable_clipping_predictor))),
+      use_clipping_predictor_step_(
+          !!clipping_predictor_ &&
+          CreateClippingPredictorConfig(config.enable_clipping_predictor)
+              .use_predicted_step),
+      frames_since_clipped_(config.clipped_wait_frames),
+      clipping_rate_log_counter_(0),
+      clipping_rate_log_(0.0f),
+      target_range_max_dbfs_(config.target_range_max_dbfs),
+      target_range_min_dbfs_(config.target_range_min_dbfs),
+      channel_controllers_(num_capture_channels) {
+  RTC_LOG(LS_INFO)
+      << "[AGC2] Input volume controller enabled. Minimum input volume: "
+      << min_input_volume_;
+
+  for (auto& controller : channel_controllers_) {
+    controller = std::make_unique<MonoInputVolumeController>(
+        config.clipped_level_min, min_input_volume_,
+        config.update_input_volume_wait_frames,
+        config.speech_probability_threshold, config.speech_ratio_threshold);
+  }
+
+  RTC_DCHECK(!channel_controllers_.empty());
+  RTC_DCHECK_GT(clipped_level_step_, 0);
+  RTC_DCHECK_LE(clipped_level_step_, 255);
+  RTC_DCHECK_GT(clipped_ratio_threshold_, 0.0f);
+  RTC_DCHECK_LT(clipped_ratio_threshold_, 1.0f);
+  RTC_DCHECK_GT(clipped_wait_frames_, 0);
+  channel_controllers_[0]->ActivateLogging();
+}
+
+InputVolumeController::~InputVolumeController() {}
+
+void InputVolumeController::Initialize() {
+  for (auto& controller : channel_controllers_) {
+    controller->Initialize();
+  }
+  capture_output_used_ = true;
+
+  AggregateChannelLevels();
+  clipping_rate_log_ = 0.0f;
+  clipping_rate_log_counter_ = 0;
+
+  applied_input_volume_ = absl::nullopt;
+}
+
+void InputVolumeController::AnalyzeInputAudio(int applied_input_volume,
+                                              const AudioBuffer& audio_buffer) {
+  RTC_DCHECK_GE(applied_input_volume, 0);
+  RTC_DCHECK_LE(applied_input_volume, 255);
+
+  SetAppliedInputVolume(applied_input_volume);
+
+  RTC_DCHECK_EQ(audio_buffer.num_channels(), channel_controllers_.size());
+  const float* const* audio = audio_buffer.channels_const();
+  size_t samples_per_channel = audio_buffer.num_frames();
+  RTC_DCHECK(audio);
+
+  AggregateChannelLevels();
+  if (!capture_output_used_) {
+    return;
+  }
+
+  if (!!clipping_predictor_) {
+    AudioFrameView<const float> frame = AudioFrameView<const float>(
+        audio, num_capture_channels_, static_cast<int>(samples_per_channel));
+    clipping_predictor_->Analyze(frame);
+  }
+
+  // Check for clipped samples. We do this in the preprocessing phase in order
+  // to catch clipped echo as well.
+  //
+  // If we find a sufficiently clipped frame, drop the current microphone
+  // input volume and enforce a new maximum input volume, dropped the same
+  // amount from the current maximum. This harsh treatment is an effort to avoid
+  // repeated clipped echo events.
+  float clipped_ratio =
+      ComputeClippedRatio(audio, num_capture_channels_, samples_per_channel);
+  clipping_rate_log_ = std::max(clipped_ratio, clipping_rate_log_);
+  clipping_rate_log_counter_++;
+  constexpr int kNumFramesIn30Seconds = 3000;
+  if (clipping_rate_log_counter_ == kNumFramesIn30Seconds) {
+    LogClippingMetrics(std::round(100.0f * clipping_rate_log_));
+    clipping_rate_log_ = 0.0f;
+    clipping_rate_log_counter_ = 0;
+  }
+
+  if (frames_since_clipped_ < clipped_wait_frames_) {
+    ++frames_since_clipped_;
+    return;
+  }
+
+  const bool clipping_detected = clipped_ratio > clipped_ratio_threshold_;
+  bool clipping_predicted = false;
+  int predicted_step = 0;
+  if (!!clipping_predictor_) {
+    for (int channel = 0; channel < num_capture_channels_; ++channel) {
+      const auto step = clipping_predictor_->EstimateClippedLevelStep(
+          channel, recommended_input_volume_, clipped_level_step_,
+          channel_controllers_[channel]->min_input_volume_after_clipping(),
+          kMaxInputVolume);
+      if (step.has_value()) {
+        predicted_step = std::max(predicted_step, step.value());
+        clipping_predicted = true;
+      }
+    }
+  }
+
+  if (clipping_detected) {
+    RTC_DLOG(LS_INFO) << "[AGC2] Clipping detected (ratio: " << clipped_ratio
+                      << ")";
+  }
+
+  int step = clipped_level_step_;
+  if (clipping_predicted) {
+    predicted_step = std::max(predicted_step, clipped_level_step_);
+    RTC_DLOG(LS_INFO) << "[AGC2] Clipping predicted (volume down step: "
+                      << predicted_step << ")";
+    if (use_clipping_predictor_step_) {
+      step = predicted_step;
+    }
+  }
+
+  if (clipping_detected ||
+      (clipping_predicted && use_clipping_predictor_step_)) {
+    for (auto& state_ch : channel_controllers_) {
+      state_ch->HandleClipping(step);
+    }
+    frames_since_clipped_ = 0;
+    if (!!clipping_predictor_) {
+      clipping_predictor_->Reset();
+    }
+  }
+
+  AggregateChannelLevels();
+}
+
+absl::optional<int> InputVolumeController::RecommendInputVolume(
+    float speech_probability,
+    absl::optional<float> speech_level_dbfs) {
+  // Only process if applied input volume is set.
+  if (!applied_input_volume_.has_value()) {
+    RTC_LOG(LS_ERROR) << "[AGC2] Applied input volume not set.";
+    return absl::nullopt;
+  }
+
+  AggregateChannelLevels();
+  const int volume_after_clipping_handling = recommended_input_volume_;
+
+  if (!capture_output_used_) {
+    return applied_input_volume_;
+  }
+
+  absl::optional<int> rms_error_db;
+  if (speech_level_dbfs.has_value()) {
+    // Compute the error for all frames (both speech and non-speech frames).
+    rms_error_db = GetSpeechLevelRmsErrorDb(
+        *speech_level_dbfs, target_range_min_dbfs_, target_range_max_dbfs_);
+  }
+
+  for (auto& controller : channel_controllers_) {
+    controller->Process(rms_error_db, speech_probability);
+  }
+
+  AggregateChannelLevels();
+  if (volume_after_clipping_handling != recommended_input_volume_) {
+    // The recommended input volume was adjusted in order to match the target
+    // level.
+    UpdateHistogramOnRecommendedInputVolumeChangeToMatchTarget(
+        recommended_input_volume_);
+  }
+
+  applied_input_volume_ = absl::nullopt;
+  return recommended_input_volume();
+}
+
+void InputVolumeController::HandleCaptureOutputUsedChange(
+    bool capture_output_used) {
+  for (auto& controller : channel_controllers_) {
+    controller->HandleCaptureOutputUsedChange(capture_output_used);
+  }
+
+  capture_output_used_ = capture_output_used;
+}
+
+void InputVolumeController::SetAppliedInputVolume(int input_volume) {
+  applied_input_volume_ = input_volume;
+
+  for (auto& controller : channel_controllers_) {
+    controller->set_stream_analog_level(input_volume);
+  }
+
+  AggregateChannelLevels();
+}
+
+void InputVolumeController::AggregateChannelLevels() {
+  int new_recommended_input_volume =
+      channel_controllers_[0]->recommended_analog_level();
+  channel_controlling_gain_ = 0;
+  for (size_t ch = 1; ch < channel_controllers_.size(); ++ch) {
+    int input_volume = channel_controllers_[ch]->recommended_analog_level();
+    if (input_volume < new_recommended_input_volume) {
+      new_recommended_input_volume = input_volume;
+      channel_controlling_gain_ = static_cast<int>(ch);
+    }
+  }
+
+  // Enforce the minimum input volume when a recommendation is made.
+  if (applied_input_volume_.has_value() && *applied_input_volume_ > 0) {
+    new_recommended_input_volume =
+        std::max(new_recommended_input_volume, min_input_volume_);
+  }
+
+  recommended_input_volume_ = new_recommended_input_volume;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller.h b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller.h
new file mode 100644
index 0000000000..21405542dc
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller.h
@@ -0,0 +1,282 @@
+/*
+ *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_AGC2_INPUT_VOLUME_CONTROLLER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_INPUT_VOLUME_CONTROLLER_H_
+
+#include <memory>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/clipping_predictor.h"
+#include "modules/audio_processing/audio_buffer.h"
+#include "modules/audio_processing/include/audio_processing.h"
+#include "rtc_base/gtest_prod_util.h"
+
+namespace webrtc {
+
+class MonoInputVolumeController;
+
+// The input volume controller recommends what volume to use, handles volume
+// changes and clipping detection and prediction. In particular, it handles
+// changes triggered by the user (e.g., volume set to zero by a HW mute button).
+// This class is not thread-safe.
+// TODO(bugs.webrtc.org/7494): Use applied/recommended input volume naming
+// convention.
+class InputVolumeController final {
+ public:
+  // Config for the constructor.
+  struct Config {
+    // Minimum input volume that can be recommended. Not enforced when the
+    // applied input volume is zero outside startup.
+    int min_input_volume = 20;
+    // Lowest input volume level that will be applied in response to clipping.
+    int clipped_level_min = 70;
+    // Amount input volume level is lowered with every clipping event. Limited
+    // to (0, 255].
+    int clipped_level_step = 15;
+    // Proportion of clipped samples required to declare a clipping event.
+    // Limited to (0.0f, 1.0f).
+    float clipped_ratio_threshold = 0.1f;
+    // Time in frames to wait after a clipping event before checking again.
+    // Limited to values higher than 0.
+    int clipped_wait_frames = 300;
+    // Enables clipping prediction functionality.
+    bool enable_clipping_predictor = false;
+    // Speech level target range (dBFS). If the speech level is in the range
+    // [`target_range_min_dbfs`, `target_range_max_dbfs`], no input volume
+    // adjustments are done based on the speech level. For speech levels below
+    // and above the range, the targets `target_range_min_dbfs` and
+    // `target_range_max_dbfs` are used, respectively.
+    int target_range_max_dbfs = -30;
+    int target_range_min_dbfs = -50;
+    // Number of wait frames between the recommended input volume updates.
+    int update_input_volume_wait_frames = 100;
+    // Speech probability threshold: speech probabilities below the threshold
+    // are considered silence. Limited to [0.0f, 1.0f].
+    float speech_probability_threshold = 0.7f;
+    // Minimum speech frame ratio for volume updates to be allowed. Limited to
+    // [0.0f, 1.0f].
+    float speech_ratio_threshold = 0.6f;
+  };
+
+  // Ctor. `num_capture_channels` specifies the number of channels for the audio
+  // passed to `AnalyzePreProcess()` and `Process()`. Clamps
+  // `config.startup_min_level` in the [12, 255] range.
+  InputVolumeController(int num_capture_channels, const Config& config);
+
+  ~InputVolumeController();
+  InputVolumeController(const InputVolumeController&) = delete;
+  InputVolumeController& operator=(const InputVolumeController&) = delete;
+
+  // TODO(webrtc:7494): Integrate initialization into ctor and remove.
+  void Initialize();
+
+  // Analyzes `audio_buffer` before `RecommendInputVolume()` is called so tha
+  // the analysis can be performed before digital processing operations take
+  // place (e.g., echo cancellation). The analysis consists of input clipping
+  // detection and prediction (if enabled).
+  void AnalyzeInputAudio(int applied_input_volume,
+                         const AudioBuffer& audio_buffer);
+
+  // Adjusts the recommended input volume upwards/downwards based on the result
+  // of `AnalyzeInputAudio()` and on `speech_level_dbfs` (if specified). Must
+  // be called after `AnalyzeInputAudio()`.  The value of `speech_probability`
+  // is expected to be in the range [0, 1] and `speech_level_dbfs` in the range
+  // [-90, 30] and both should be estimated after echo cancellation and noise
+  // suppression are applied. Returns a non-empty input volume recommendation if
+  // available. If `capture_output_used_` is true, returns the applied input
+  // volume.
+  absl::optional<int> RecommendInputVolume(
+      float speech_probability,
+      absl::optional<float> speech_level_dbfs);
+
+  // Stores whether the capture output will be used or not. Call when the
+  // capture stream output has been flagged to be used/not-used. If unused, the
+  // controller disregards all incoming audio.
+  void HandleCaptureOutputUsedChange(bool capture_output_used);
+
+  // Returns true if clipping prediction is enabled.
+  // TODO(bugs.webrtc.org/7494): Deprecate this method.
+  bool clipping_predictor_enabled() const { return !!clipping_predictor_; }
+
+  // Returns true if clipping prediction is used to adjust the input volume.
+  // TODO(bugs.webrtc.org/7494): Deprecate this method.
+  bool use_clipping_predictor_step() const {
+    return use_clipping_predictor_step_;
+  }
+
+  // Only use for testing: Use `RecommendInputVolume()` elsewhere.
+  // Returns the value of a member variable, needed for testing
+  // `AnalyzeInputAudio()`.
+  int recommended_input_volume() const { return recommended_input_volume_; }
+
+  // Only use for testing.
+  bool capture_output_used() const { return capture_output_used_; }
+
+ private:
+  friend class InputVolumeControllerTestHelper;
+
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeControllerTest, MinInputVolumeDefault);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeControllerTest, MinInputVolumeDisabled);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeControllerTest,
+                           MinInputVolumeOutOfRangeAbove);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeControllerTest,
+                           MinInputVolumeOutOfRangeBelow);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeControllerTest, MinInputVolumeEnabled50);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeControllerParametrizedTest,
+                           ClippingParametersVerified);
+
+  // Sets the applied input volume and resets the recommended input volume.
+  void SetAppliedInputVolume(int level);
+
+  void AggregateChannelLevels();
+
+  const int num_capture_channels_;
+
+  // Minimum input volume that can be recommended.
+  const int min_input_volume_;
+
+  // TODO(bugs.webrtc.org/7494): Once
+  // `AudioProcessingImpl::recommended_stream_analog_level()` becomes a trivial
+  // getter, leave uninitialized.
+  // Recommended input volume. After `SetAppliedInputVolume()` is called it
+  // holds holds the observed input volume. Possibly updated by
+  // `AnalyzePreProcess()` and `Process()`; after these calls, holds the
+  // recommended input volume.
+  int recommended_input_volume_ = 0;
+  // Applied input volume. After `SetAppliedInputVolume()` is called it holds
+  // the current applied volume.
+  absl::optional<int> applied_input_volume_;
+
+  bool capture_output_used_;
+
+  // Clipping detection and prediction.
+  const int clipped_level_step_;
+  const float clipped_ratio_threshold_;
+  const int clipped_wait_frames_;
+  const std::unique_ptr<ClippingPredictor> clipping_predictor_;
+  const bool use_clipping_predictor_step_;
+  int frames_since_clipped_;
+  int clipping_rate_log_counter_;
+  float clipping_rate_log_;
+
+  // Target range minimum and maximum. If the seech level is in the range
+  // [`target_range_min_dbfs`, `target_range_max_dbfs`], no volume adjustments
+  // take place. Instead, the digital gain controller is assumed to adapt to
+  // compensate for the speech level RMS error.
+  const int target_range_max_dbfs_;
+  const int target_range_min_dbfs_;
+
+  // Channel controllers updating the gain upwards/downwards.
+  std::vector<std::unique_ptr<MonoInputVolumeController>> channel_controllers_;
+  int channel_controlling_gain_ = 0;
+};
+
+// TODO(bugs.webrtc.org/7494): Use applied/recommended input volume naming
+// convention.
+class MonoInputVolumeController {
+ public:
+  MonoInputVolumeController(int min_input_volume_after_clipping,
+                            int min_input_volume,
+                            int update_input_volume_wait_frames,
+                            float speech_probability_threshold,
+                            float speech_ratio_threshold);
+  ~MonoInputVolumeController();
+  MonoInputVolumeController(const MonoInputVolumeController&) = delete;
+  MonoInputVolumeController& operator=(const MonoInputVolumeController&) =
+      delete;
+
+  void Initialize();
+  void HandleCaptureOutputUsedChange(bool capture_output_used);
+
+  // Sets the current input volume.
+  void set_stream_analog_level(int input_volume) {
+    recommended_input_volume_ = input_volume;
+  }
+
+  // Lowers the recommended input volume in response to clipping based on the
+  // suggested reduction `clipped_level_step`. Must be called after
+  // `set_stream_analog_level()`.
+  void HandleClipping(int clipped_level_step);
+
+  // TODO(bugs.webrtc.org/7494): Rename, audio not passed to the method anymore.
+  // Adjusts the recommended input volume upwards/downwards depending on the
+  // result of `HandleClipping()` and on `rms_error_dbfs`. Updates are only
+  // allowed for active speech segments and when `rms_error_dbfs` is not empty.
+  // Must be called after `HandleClipping()`.
+  void Process(absl::optional<int> rms_error_dbfs, float speech_probability);
+
+  // Returns the recommended input volume. Must be called after `Process()`.
+  int recommended_analog_level() const { return recommended_input_volume_; }
+
+  void ActivateLogging() { log_to_histograms_ = true; }
+
+  int min_input_volume_after_clipping() const {
+    return min_input_volume_after_clipping_;
+  }
+
+  // Only used for testing.
+  int min_input_volume() const { return min_input_volume_; }
+
+ private:
+  // Sets a new input volume, after first checking that it hasn't been updated
+  // by the user, in which case no action is taken.
+  void SetInputVolume(int new_volume);
+
+  // Sets the maximum input volume that the input volume controller is allowed
+  // to apply. The volume must be at least `kClippedLevelMin`.
+  void SetMaxLevel(int level);
+
+  int CheckVolumeAndReset();
+
+  // Updates the recommended input volume. If the volume slider needs to be
+  // moved, we check first if the user has adjusted it, in which case we take no
+  // action and cache the updated level.
+  void UpdateInputVolume(int rms_error_dbfs);
+
+  const int min_input_volume_;
+  const int min_input_volume_after_clipping_;
+  int max_input_volume_;
+
+  int last_recommended_input_volume_ = 0;
+
+  bool capture_output_used_ = true;
+  bool check_volume_on_next_process_ = true;
+  bool startup_ = true;
+
+  // TODO(bugs.webrtc.org/7494): Create a separate member for the applied
+  // input volume.
+  // Recommended input volume. After `set_stream_analog_level()` is
+  // called, it holds the observed applied input volume. Possibly updated by
+  // `HandleClipping()` and `Process()`; after these calls, holds the
+  // recommended input volume.
+  int recommended_input_volume_ = 0;
+
+  bool log_to_histograms_ = false;
+
+  // Counters for frames and speech frames since the last update in the
+  // recommended input volume.
+  const int update_input_volume_wait_frames_;
+  int frames_since_update_input_volume_ = 0;
+  int speech_frames_since_update_input_volume_ = 0;
+  bool is_first_frame_ = true;
+
+  // Speech probability threshold for a frame to be considered speech (instead
+  // of silence). Limited to [0.0f, 1.0f].
+  const float speech_probability_threshold_;
+  // Minimum ratio of speech frames. Limited to [0.0f, 1.0f].
+  const float speech_ratio_threshold_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_INPUT_VOLUME_CONTROLLER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller_gn/moz.build
new file mode 100644
index 0000000000..582eb326f3
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller_gn/moz.build
@@ -0,0 +1,234 @@
+# 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/agc2/input_volume_controller.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer.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("input_volume_controller_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller_unittest.cc
new file mode 100644
index 0000000000..d1bdcf25a5
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_controller_unittest.cc
@@ -0,0 +1,1857 @@
+/*
+ *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "modules/audio_processing/agc2/input_volume_controller.h"
+
+#include <algorithm>
+#include <fstream>
+#include <limits>
+#include <string>
+#include <vector>
+
+#include "rtc_base/numerics/safe_minmax.h"
+#include "rtc_base/strings/string_builder.h"
+#include "system_wrappers/include/metrics.h"
+#include "test/field_trial.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+using ::testing::_;
+using ::testing::AtLeast;
+using ::testing::DoAll;
+using ::testing::Return;
+using ::testing::SetArgPointee;
+
+namespace webrtc {
+namespace {
+
+constexpr int kSampleRateHz = 32000;
+constexpr int kNumChannels = 1;
+constexpr int kInitialInputVolume = 128;
+constexpr int kClippedMin = 165;  // Arbitrary, but different from the default.
+constexpr float kAboveClippedThreshold = 0.2f;
+constexpr int kMinMicLevel = 20;
+constexpr int kClippedLevelStep = 15;
+constexpr float kClippedRatioThreshold = 0.1f;
+constexpr int kClippedWaitFrames = 300;
+constexpr float kHighSpeechProbability = 0.7f;
+constexpr float kLowSpeechProbability = 0.1f;
+constexpr float kSpeechLevel = -25.0f;
+constexpr float kSpeechProbabilityThreshold = 0.5f;
+constexpr float kSpeechRatioThreshold = 0.8f;
+
+constexpr float kMinSample = std::numeric_limits<int16_t>::min();
+constexpr float kMaxSample = std::numeric_limits<int16_t>::max();
+
+using ClippingPredictorConfig = AudioProcessing::Config::GainController1::
+    AnalogGainController::ClippingPredictor;
+
+using InputVolumeControllerConfig = InputVolumeController::Config;
+
+constexpr ClippingPredictorConfig kDefaultClippingPredictorConfig{};
+
+std::unique_ptr<InputVolumeController> CreateInputVolumeController(
+    int clipped_level_step = kClippedLevelStep,
+    float clipped_ratio_threshold = kClippedRatioThreshold,
+    int clipped_wait_frames = kClippedWaitFrames,
+    bool enable_clipping_predictor = false,
+    int update_input_volume_wait_frames = 0) {
+  InputVolumeControllerConfig config{
+      .min_input_volume = kMinMicLevel,
+      .clipped_level_min = kClippedMin,
+      .clipped_level_step = clipped_level_step,
+      .clipped_ratio_threshold = clipped_ratio_threshold,
+      .clipped_wait_frames = clipped_wait_frames,
+      .enable_clipping_predictor = enable_clipping_predictor,
+      .target_range_max_dbfs = -18,
+      .target_range_min_dbfs = -30,
+      .update_input_volume_wait_frames = update_input_volume_wait_frames,
+      .speech_probability_threshold = kSpeechProbabilityThreshold,
+      .speech_ratio_threshold = kSpeechRatioThreshold,
+  };
+
+  return std::make_unique<InputVolumeController>(/*num_capture_channels=*/1,
+                                                 config);
+}
+
+// (Over)writes `samples_value` for the samples in `audio_buffer`.
+// When `clipped_ratio`, a value in [0, 1], is greater than 0, the corresponding
+// fraction of the frame is set to a full scale value to simulate clipping.
+void WriteAudioBufferSamples(float samples_value,
+                             float clipped_ratio,
+                             AudioBuffer& audio_buffer) {
+  RTC_DCHECK_GE(samples_value, kMinSample);
+  RTC_DCHECK_LE(samples_value, kMaxSample);
+  RTC_DCHECK_GE(clipped_ratio, 0.0f);
+  RTC_DCHECK_LE(clipped_ratio, 1.0f);
+  int num_channels = audio_buffer.num_channels();
+  int num_samples = audio_buffer.num_frames();
+  int num_clipping_samples = clipped_ratio * num_samples;
+  for (int ch = 0; ch < num_channels; ++ch) {
+    int i = 0;
+    for (; i < num_clipping_samples; ++i) {
+      audio_buffer.channels()[ch][i] = 32767.0f;
+    }
+    for (; i < num_samples; ++i) {
+      audio_buffer.channels()[ch][i] = samples_value;
+    }
+  }
+}
+
+// (Over)writes samples in `audio_buffer`. Alternates samples `samples_value`
+// and zero.
+void WriteAlternatingAudioBufferSamples(float samples_value,
+                                        AudioBuffer& audio_buffer) {
+  RTC_DCHECK_GE(samples_value, kMinSample);
+  RTC_DCHECK_LE(samples_value, kMaxSample);
+  const int num_channels = audio_buffer.num_channels();
+  const int num_frames = audio_buffer.num_frames();
+  for (int ch = 0; ch < num_channels; ++ch) {
+    for (int i = 0; i < num_frames; i += 2) {
+      audio_buffer.channels()[ch][i] = samples_value;
+      audio_buffer.channels()[ch][i + 1] = 0.0f;
+    }
+  }
+}
+
+// Reads a given number of 10 ms chunks from a PCM file and feeds them to
+// `InputVolumeController`.
+class SpeechSamplesReader {
+ private:
+  // Recording properties.
+  static constexpr int kPcmSampleRateHz = 16000;
+  static constexpr int kPcmNumChannels = 1;
+  static constexpr int kPcmBytesPerSamples = sizeof(int16_t);
+
+ public:
+  SpeechSamplesReader()
+      : is_(test::ResourcePath("audio_processing/agc/agc_audio", "pcm"),
+            std::ios::binary | std::ios::ate),
+        audio_buffer_(kPcmSampleRateHz,
+                      kPcmNumChannels,
+                      kPcmSampleRateHz,
+                      kPcmNumChannels,
+                      kPcmSampleRateHz,
+                      kPcmNumChannels),
+        buffer_(audio_buffer_.num_frames()),
+        buffer_num_bytes_(buffer_.size() * kPcmBytesPerSamples) {
+    RTC_CHECK(is_);
+  }
+
+  // Reads `num_frames` 10 ms frames from the beginning of the PCM file, applies
+  // `gain_db` and feeds the frames into `controller` by calling
+  // `AnalyzeInputAudio()` and `RecommendInputVolume()` for each frame. Reads
+  // the number of 10 ms frames available in the PCM file if `num_frames` is too
+  // large - i.e., does not loop. `speech_probability` and `speech_level_dbfs`
+  // are passed to `RecommendInputVolume()`.
+  int Feed(int num_frames,
+           int applied_input_volume,
+           int gain_db,
+           float speech_probability,
+           absl::optional<float> speech_level_dbfs,
+           InputVolumeController& controller) {
+    RTC_DCHECK(controller.capture_output_used());
+
+    float gain = std::pow(10.0f, gain_db / 20.0f);  // From dB to linear gain.
+    is_.seekg(0, is_.beg);  // Start from the beginning of the PCM file.
+
+    // Read and feed frames.
+    for (int i = 0; i < num_frames; ++i) {
+      is_.read(reinterpret_cast<char*>(buffer_.data()), buffer_num_bytes_);
+      if (is_.gcount() < buffer_num_bytes_) {
+        // EOF reached. Stop.
+        break;
+      }
+      // Apply gain and copy samples into `audio_buffer_`.
+      std::transform(buffer_.begin(), buffer_.end(),
+                     audio_buffer_.channels()[0], [gain](int16_t v) -> float {
+                       return rtc::SafeClamp(static_cast<float>(v) * gain,
+                                             kMinSample, kMaxSample);
+                     });
+      controller.AnalyzeInputAudio(applied_input_volume, audio_buffer_);
+      const auto recommended_input_volume = controller.RecommendInputVolume(
+          speech_probability, speech_level_dbfs);
+
+      // Expect no errors: Applied volume set for every frame;
+      // `RecommendInputVolume()` returns a non-empty value.
+      EXPECT_TRUE(recommended_input_volume.has_value());
+
+      applied_input_volume = *recommended_input_volume;
+    }
+    return applied_input_volume;
+  }
+
+ private:
+  std::ifstream is_;
+  AudioBuffer audio_buffer_;
+  std::vector<int16_t> buffer_;
+  const std::streamsize buffer_num_bytes_;
+};
+
+// Runs the MonoInputVolumeControl processing sequence following the API
+// contract. Returns the updated recommended input volume.
+float UpdateRecommendedInputVolume(MonoInputVolumeController& mono_controller,
+                                   int applied_input_volume,
+                                   float speech_probability,
+                                   absl::optional<float> rms_error_dbfs) {
+  mono_controller.set_stream_analog_level(applied_input_volume);
+  EXPECT_EQ(mono_controller.recommended_analog_level(), applied_input_volume);
+  mono_controller.Process(rms_error_dbfs, speech_probability);
+  return mono_controller.recommended_analog_level();
+}
+
+}  // namespace
+
+// TODO(bugs.webrtc.org/12874): Use constexpr struct with designated
+// initializers once fixed.
+constexpr InputVolumeControllerConfig GetInputVolumeControllerTestConfig() {
+  InputVolumeControllerConfig config{
+      .clipped_level_min = kClippedMin,
+      .clipped_level_step = kClippedLevelStep,
+      .clipped_ratio_threshold = kClippedRatioThreshold,
+      .clipped_wait_frames = kClippedWaitFrames,
+      .enable_clipping_predictor = kDefaultClippingPredictorConfig.enabled,
+      .target_range_max_dbfs = -18,
+      .target_range_min_dbfs = -30,
+      .update_input_volume_wait_frames = 0,
+      .speech_probability_threshold = 0.5f,
+      .speech_ratio_threshold = 1.0f,
+  };
+  return config;
+}
+
+// Helper class that provides an `InputVolumeController` instance with an
+// `AudioBuffer` instance and `CallAgcSequence()`, a helper method that runs the
+// `InputVolumeController` instance on the `AudioBuffer` one by sticking to the
+// API contract.
+class InputVolumeControllerTestHelper {
+ public:
+  // Ctor. Initializes `audio_buffer` with zeros.
+  // TODO(bugs.webrtc.org/7494): Remove the default argument.
+  InputVolumeControllerTestHelper(const InputVolumeController::Config& config =
+                                      GetInputVolumeControllerTestConfig())
+      : audio_buffer(kSampleRateHz,
+                     kNumChannels,
+                     kSampleRateHz,
+                     kNumChannels,
+                     kSampleRateHz,
+                     kNumChannels),
+        controller(/*num_capture_channels=*/1, config) {
+    controller.Initialize();
+    WriteAudioBufferSamples(/*samples_value=*/0.0f, /*clipped_ratio=*/0.0f,
+                            audio_buffer);
+  }
+
+  // Calls the sequence of `InputVolumeController` methods according to the API
+  // contract, namely:
+  // - Sets the applied input volume;
+  // - Uses `audio_buffer` to call `AnalyzeInputAudio()` and
+  // `RecommendInputVolume()`;
+  //  Returns the recommended input volume.
+  absl::optional<int> CallAgcSequence(int applied_input_volume,
+                                      float speech_probability,
+                                      absl::optional<float> speech_level_dbfs,
+                                      int num_calls = 1) {
+    RTC_DCHECK_GE(num_calls, 1);
+    absl::optional<int> volume = applied_input_volume;
+    for (int i = 0; i < num_calls; ++i) {
+      // Repeat the initial volume if `RecommendInputVolume()` doesn't return a
+      // value.
+      controller.AnalyzeInputAudio(volume.value_or(applied_input_volume),
+                                   audio_buffer);
+      volume = controller.RecommendInputVolume(speech_probability,
+                                               speech_level_dbfs);
+
+      // Allow deviation from the API contract: `RecommendInputVolume()` doesn't
+      // return a recommended input volume.
+      if (volume.has_value()) {
+        EXPECT_EQ(*volume, controller.recommended_input_volume());
+      }
+    }
+    return volume;
+  }
+
+  // Deprecated.
+  // TODO(bugs.webrtc.org/7494): Let the caller write `audio_buffer` and use
+  // `CallAgcSequence()`.
+  int CallRecommendInputVolume(int num_calls,
+                               int initial_volume,
+                               float speech_probability,
+                               absl::optional<float> speech_level_dbfs) {
+    RTC_DCHECK(controller.capture_output_used());
+
+    // Create non-clipping audio for `AnalyzeInputAudio()`.
+    WriteAlternatingAudioBufferSamples(0.1f * kMaxSample, audio_buffer);
+    int volume = initial_volume;
+    for (int i = 0; i < num_calls; ++i) {
+      controller.AnalyzeInputAudio(volume, audio_buffer);
+      const auto recommended_input_volume = controller.RecommendInputVolume(
+          speech_probability, speech_level_dbfs);
+
+      // Expect no errors: Applied volume set for every frame;
+      // `RecommendInputVolume()` returns a non-empty value.
+      EXPECT_TRUE(recommended_input_volume.has_value());
+
+      volume = *recommended_input_volume;
+    }
+    return volume;
+  }
+
+  // Deprecated.
+  // TODO(bugs.webrtc.org/7494): Let the caller write `audio_buffer` and use
+  // `CallAgcSequence()`.
+  void CallAnalyzeInputAudio(int num_calls, float clipped_ratio) {
+    RTC_DCHECK(controller.capture_output_used());
+
+    RTC_DCHECK_GE(clipped_ratio, 0.0f);
+    RTC_DCHECK_LE(clipped_ratio, 1.0f);
+    WriteAudioBufferSamples(/*samples_value=*/0.0f, clipped_ratio,
+                            audio_buffer);
+    for (int i = 0; i < num_calls; ++i) {
+      controller.AnalyzeInputAudio(controller.recommended_input_volume(),
+                                   audio_buffer);
+    }
+  }
+
+  AudioBuffer audio_buffer;
+  InputVolumeController controller;
+};
+
+class InputVolumeControllerChannelSampleRateTest
+    : public ::testing::TestWithParam<std::tuple<int, int>> {
+ protected:
+  int GetNumChannels() const { return std::get<0>(GetParam()); }
+  int GetSampleRateHz() const { return std::get<1>(GetParam()); }
+};
+
+TEST_P(InputVolumeControllerChannelSampleRateTest, CheckIsAlive) {
+  const int num_channels = GetNumChannels();
+  const int sample_rate_hz = GetSampleRateHz();
+
+  constexpr InputVolumeController::Config kConfig{.enable_clipping_predictor =
+                                                      true};
+  InputVolumeController controller(num_channels, kConfig);
+  controller.Initialize();
+  AudioBuffer buffer(sample_rate_hz, num_channels, sample_rate_hz, num_channels,
+                     sample_rate_hz, num_channels);
+
+  constexpr int kStartupVolume = 100;
+  int applied_initial_volume = kStartupVolume;
+
+  // Trigger a downward adaptation with clipping.
+  constexpr int kLevelWithinTargetDbfs =
+      (kConfig.target_range_min_dbfs + kConfig.target_range_max_dbfs) / 2;
+  WriteAlternatingAudioBufferSamples(/*samples_value=*/kMaxSample, buffer);
+  const int initial_volume1 = applied_initial_volume;
+  for (int i = 0; i < 400; ++i) {
+    controller.AnalyzeInputAudio(applied_initial_volume, buffer);
+    auto recommended_input_volume = controller.RecommendInputVolume(
+        kLowSpeechProbability,
+        /*speech_level_dbfs=*/kLevelWithinTargetDbfs);
+    ASSERT_TRUE(recommended_input_volume.has_value());
+    applied_initial_volume = *recommended_input_volume;
+  }
+  ASSERT_LT(controller.recommended_input_volume(), initial_volume1);
+
+  // Fill in audio that does not clip.
+  WriteAlternatingAudioBufferSamples(/*samples_value=*/1234.5f, buffer);
+
+  // Trigger an upward adaptation.
+  const int initial_volume2 = controller.recommended_input_volume();
+  for (int i = 0; i < kConfig.clipped_wait_frames; ++i) {
+    controller.AnalyzeInputAudio(applied_initial_volume, buffer);
+    auto recommended_input_volume = controller.RecommendInputVolume(
+        kHighSpeechProbability,
+        /*speech_level_dbfs=*/kConfig.target_range_min_dbfs - 5);
+    ASSERT_TRUE(recommended_input_volume.has_value());
+    applied_initial_volume = *recommended_input_volume;
+  }
+  EXPECT_GT(controller.recommended_input_volume(), initial_volume2);
+
+  // Trigger a downward adaptation.
+  const int initial_volume = controller.recommended_input_volume();
+  for (int i = 0; i < kConfig.update_input_volume_wait_frames; ++i) {
+    controller.AnalyzeInputAudio(applied_initial_volume, buffer);
+    auto recommended_input_volume = controller.RecommendInputVolume(
+        kHighSpeechProbability,
+        /*speech_level_dbfs=*/kConfig.target_range_max_dbfs + 5);
+    ASSERT_TRUE(recommended_input_volume.has_value());
+    applied_initial_volume = *recommended_input_volume;
+  }
+  EXPECT_LT(controller.recommended_input_volume(), initial_volume);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    ,
+    InputVolumeControllerChannelSampleRateTest,
+    ::testing::Combine(::testing::Values(1, 2, 3, 6),
+                       ::testing::Values(8000, 16000, 32000, 48000)));
+
+class InputVolumeControllerParametrizedTest
+    : public ::testing::TestWithParam<int> {};
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       StartupMinVolumeConfigurationRespectedWhenAppliedInputVolumeAboveMin) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+
+  EXPECT_EQ(*helper.CallAgcSequence(/*applied_input_volume=*/128,
+                                    /*speech_probability=*/0.9f,
+                                    /*speech_level_dbfs=*/-80),
+            128);
+}
+
+TEST_P(
+    InputVolumeControllerParametrizedTest,
+    StartupMinVolumeConfigurationRespectedWhenAppliedInputVolumeMaybeBelowMin) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+
+  EXPECT_GE(*helper.CallAgcSequence(/*applied_input_volume=*/10,
+                                    /*speech_probability=*/0.9f,
+                                    /*speech_level_dbfs=*/-80),
+            10);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       StartupMinVolumeRespectedWhenAppliedVolumeNonZero) {
+  const int kMinInputVolume = GetParam();
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = kMinInputVolume,
+                  .target_range_min_dbfs = -30,
+                  .update_input_volume_wait_frames = 1,
+                  .speech_probability_threshold = 0.5f,
+                  .speech_ratio_threshold = 0.5f});
+
+  // Volume change possible; speech level below the digital gain window.
+  int volume = *helper.CallAgcSequence(/*applied_input_volume=*/1,
+                                       /*speech_probability=*/0.9f,
+                                       /*speech_level_dbfs=*/-80);
+
+  EXPECT_EQ(volume, kMinInputVolume);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       MinVolumeRepeatedlyRespectedWhenAppliedVolumeNonZero) {
+  const int kMinInputVolume = GetParam();
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = kMinInputVolume,
+                  .target_range_min_dbfs = -30,
+                  .update_input_volume_wait_frames = 1,
+                  .speech_probability_threshold = 0.5f,
+                  .speech_ratio_threshold = 0.5f});
+
+  // Volume change possible; speech level below the digital gain window.
+  for (int i = 0; i < 100; ++i) {
+    const int volume = *helper.CallAgcSequence(/*applied_input_volume=*/1,
+                                               /*speech_probability=*/0.9f,
+                                               /*speech_level_dbfs=*/-80);
+    EXPECT_GE(volume, kMinInputVolume);
+  }
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       StartupMinVolumeRespectedOnceWhenAppliedVolumeZero) {
+  const int kMinInputVolume = GetParam();
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = kMinInputVolume,
+                  .target_range_min_dbfs = -30,
+                  .update_input_volume_wait_frames = 1,
+                  .speech_probability_threshold = 0.5f,
+                  .speech_ratio_threshold = 0.5f});
+
+  int volume = *helper.CallAgcSequence(/*applied_input_volume=*/0,
+                                       /*speech_probability=*/0.9f,
+                                       /*speech_level_dbfs=*/-80);
+
+  EXPECT_EQ(volume, kMinInputVolume);
+
+  // No change of volume regardless of a speech level below the digital gain
+  // window; applied volume is zero.
+  volume = *helper.CallAgcSequence(/*applied_input_volume=*/0,
+                                   /*speech_probability=*/0.9f,
+                                   /*speech_level_dbfs=*/-80);
+
+  EXPECT_EQ(volume, 0);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, MicVolumeResponseToRmsError) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  int volume = *helper.CallAgcSequence(kInitialInputVolume,
+                                       kHighSpeechProbability, kSpeechLevel);
+
+  // Inside the digital gain's window; no change of volume.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -23.0f);
+
+  // Inside the digital gain's window; no change of volume.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -28.0f);
+
+  // Above the digital gain's  window; volume should be increased.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -29.0f);
+  EXPECT_EQ(volume, 128);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -38.0f);
+  EXPECT_EQ(volume, 156);
+
+  // Inside the digital gain's window; no change of volume.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -23.0f);
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -18.0f);
+
+  // Below the digial gain's window; volume should be decreased.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -17.0f);
+  EXPECT_EQ(volume, 155);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -17.0f);
+  EXPECT_EQ(volume, 151);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -9.0f);
+  EXPECT_EQ(volume, 119);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, MicVolumeIsLimited) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  const int min_input_volume = GetParam();
+  config.min_input_volume = min_input_volume;
+  InputVolumeControllerTestHelper helper(config);
+  int volume = *helper.CallAgcSequence(kInitialInputVolume,
+                                       kHighSpeechProbability, kSpeechLevel);
+
+  // Maximum upwards change is limited.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(volume, 183);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(volume, 243);
+
+  // Won't go higher than the maximum.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(volume, 255);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -17.0f);
+  EXPECT_EQ(volume, 254);
+
+  // Maximum downwards change is limited.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, 22.0f);
+  EXPECT_EQ(volume, 194);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, 22.0f);
+  EXPECT_EQ(volume, 137);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, 22.0f);
+  EXPECT_EQ(volume, 88);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, 22.0f);
+  EXPECT_EQ(volume, 54);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, 22.0f);
+  EXPECT_EQ(volume, 33);
+
+  // Won't go lower than the minimum.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, 22.0f);
+  EXPECT_EQ(volume, std::max(18, min_input_volume));
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, 22.0f);
+  EXPECT_EQ(volume, std::max(12, min_input_volume));
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, NoActionWhileMuted) {
+  InputVolumeControllerTestHelper helper_1(
+      /*config=*/{.min_input_volume = GetParam()});
+  InputVolumeControllerTestHelper helper_2(
+      /*config=*/{.min_input_volume = GetParam()});
+
+  int volume_1 = *helper_1.CallAgcSequence(/*applied_input_volume=*/255,
+                                           kHighSpeechProbability, kSpeechLevel,
+                                           /*num_calls=*/1);
+  int volume_2 = *helper_2.CallAgcSequence(/*applied_input_volume=*/255,
+                                           kHighSpeechProbability, kSpeechLevel,
+                                           /*num_calls=*/1);
+
+  EXPECT_EQ(volume_1, 255);
+  EXPECT_EQ(volume_2, 255);
+
+  helper_2.controller.HandleCaptureOutputUsedChange(false);
+
+  WriteAlternatingAudioBufferSamples(kMaxSample, helper_1.audio_buffer);
+  WriteAlternatingAudioBufferSamples(kMaxSample, helper_2.audio_buffer);
+
+  volume_1 =
+      *helper_1.CallAgcSequence(volume_1, kHighSpeechProbability, kSpeechLevel,
+                                /*num_calls=*/1);
+  volume_2 =
+      *helper_2.CallAgcSequence(volume_2, kHighSpeechProbability, kSpeechLevel,
+                                /*num_calls=*/1);
+
+  EXPECT_LT(volume_1, 255);
+  EXPECT_EQ(volume_2, 255);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       UnmutingChecksVolumeWithoutRaising) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+  helper.CallAgcSequence(kInitialInputVolume, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.controller.HandleCaptureOutputUsedChange(false);
+  helper.controller.HandleCaptureOutputUsedChange(true);
+
+  constexpr int kInputVolume = 127;
+
+  // SetMicVolume should not be called.
+  EXPECT_EQ(
+      helper.CallRecommendInputVolume(/*num_calls=*/1, kInputVolume,
+                                      kHighSpeechProbability, kSpeechLevel),
+      kInputVolume);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, UnmutingRaisesTooLowVolume) {
+  const int min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = min_input_volume});
+  helper.CallAgcSequence(kInitialInputVolume, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.controller.HandleCaptureOutputUsedChange(false);
+  helper.controller.HandleCaptureOutputUsedChange(true);
+
+  constexpr int kInputVolume = 11;
+
+  EXPECT_EQ(
+      helper.CallRecommendInputVolume(/*num_calls=*/1, kInputVolume,
+                                      kHighSpeechProbability, kSpeechLevel),
+      min_input_volume);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       ManualLevelChangeResultsInNoSetMicCall) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  int volume = *helper.CallAgcSequence(kInitialInputVolume,
+                                       kHighSpeechProbability, kSpeechLevel);
+
+  // GetMicVolume returns a value outside of the quantization slack, indicating
+  // a manual volume change.
+  ASSERT_NE(volume, 154);
+  volume = helper.CallRecommendInputVolume(
+      /*num_calls=*/1, /*initial_volume=*/154, kHighSpeechProbability, -29.0f);
+  EXPECT_EQ(volume, 154);
+
+  // Do the same thing, except downwards now.
+  volume = helper.CallRecommendInputVolume(
+      /*num_calls=*/1, /*initial_volume=*/100, kHighSpeechProbability, -17.0f);
+  EXPECT_EQ(volume, 100);
+
+  // And finally verify the AGC continues working without a manual change.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -17.0f);
+  EXPECT_EQ(volume, 99);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       RecoveryAfterManualLevelChangeFromMax) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  int volume = *helper.CallAgcSequence(kInitialInputVolume,
+                                       kHighSpeechProbability, kSpeechLevel);
+
+  // Force the mic up to max volume. Takes a few steps due to the residual
+  // gain limitation.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(volume, 183);
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(volume, 243);
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(volume, 255);
+
+  // Manual change does not result in SetMicVolume call.
+  volume = helper.CallRecommendInputVolume(
+      /*num_calls=*/1, /*initial_volume=*/50, kHighSpeechProbability, -17.0f);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 50);
+
+  // Continues working as usual afterwards.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -38.0f);
+
+  EXPECT_EQ(volume, 65);
+}
+
+// Checks that the minimum input volume is enforced during the upward adjustment
+// of the input volume.
+TEST_P(InputVolumeControllerParametrizedTest,
+       EnforceMinInputVolumeDuringUpwardsAdjustment) {
+  const int min_input_volume = GetParam();
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = min_input_volume;
+  InputVolumeControllerTestHelper helper(config);
+  int volume = *helper.CallAgcSequence(kInitialInputVolume,
+                                       kHighSpeechProbability, kSpeechLevel);
+
+  // Manual change below min, but strictly positive, otherwise no action will be
+  // taken.
+  volume = helper.CallRecommendInputVolume(
+      /*num_calls=*/1, /*initial_volume=*/1, kHighSpeechProbability, -17.0f);
+
+  // Trigger an upward adjustment of the input volume.
+  EXPECT_EQ(volume, min_input_volume);
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -29.0f);
+  EXPECT_EQ(volume, min_input_volume);
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -30.0f);
+  EXPECT_EQ(volume, min_input_volume);
+
+  // After a number of consistently low speech level observations, the input
+  // volume is eventually raised above the minimum.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/10, volume,
+                                           kHighSpeechProbability, -38.0f);
+  EXPECT_GT(volume, min_input_volume);
+}
+
+// Checks that, when the min mic level override is specified, AGC immediately
+// applies the minimum mic level after the mic level is manually set below the
+// minimum gain to enforce.
+TEST_P(InputVolumeControllerParametrizedTest,
+       RecoveryAfterManualLevelChangeBelowMin) {
+  const int min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = min_input_volume});
+  int volume = *helper.CallAgcSequence(kInitialInputVolume,
+                                       kHighSpeechProbability, kSpeechLevel);
+
+  // Manual change below min, but strictly positive, otherwise
+  // AGC won't take any action.
+  volume = helper.CallRecommendInputVolume(
+      /*num_calls=*/1, /*initial_volume=*/1, kHighSpeechProbability, -17.0f);
+  EXPECT_EQ(volume, min_input_volume);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, NoClippingHasNoImpact) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+  helper.CallAgcSequence(kInitialInputVolume, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/100, /*clipped_ratio=*/0);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 128);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       ClippingUnderThresholdHasNoImpact) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+  helper.CallAgcSequence(kInitialInputVolume, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1, /*clipped_ratio=*/0.099);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 128);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, ClippingLowersVolume) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+  helper.CallAgcSequence(/*applied_input_volume=*/255, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1, /*clipped_ratio=*/0.2);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 240);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       WaitingPeriodBetweenClippingChecks) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+  helper.CallAgcSequence(/*applied_input_volume=*/255, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 240);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/300,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 240);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 225);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, ClippingLoweringIsLimited) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  helper.CallAgcSequence(/*applied_input_volume=*/180, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), kClippedMin);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1000,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), kClippedMin);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       ClippingMaxIsRespectedWhenEqualToLevel) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+  helper.CallAgcSequence(/*applied_input_volume=*/255, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 240);
+
+  helper.CallRecommendInputVolume(/*num_calls=*/10, /*initial_volume=*/240,
+                                  kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 240);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       ClippingMaxIsRespectedWhenHigherThanLevel) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  helper.CallAgcSequence(/*applied_input_volume=*/200, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  int volume = helper.controller.recommended_input_volume();
+  EXPECT_EQ(volume, 185);
+
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -58.0f);
+  EXPECT_EQ(volume, 240);
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/10, volume,
+                                           kHighSpeechProbability, -58.0f);
+  EXPECT_EQ(volume, 240);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, UserCanRaiseVolumeAfterClipping) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  helper.CallAgcSequence(/*applied_input_volume=*/225, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 210);
+
+  // User changed the volume.
+  int volume = helper.CallRecommendInputVolume(
+      /*num_calls=*/1, /*initial_volume-*/ 250, kHighSpeechProbability, -32.0f);
+  EXPECT_EQ(volume, 250);
+
+  // Move down...
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -8.0f);
+  EXPECT_EQ(volume, 210);
+  // And back up to the new max established by the user.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -58.0f);
+  EXPECT_EQ(volume, 250);
+  // Will not move above new maximum.
+  volume = helper.CallRecommendInputVolume(/*num_calls=*/1, volume,
+                                           kHighSpeechProbability, -48.0f);
+  EXPECT_EQ(volume, 250);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       ClippingDoesNotPullLowVolumeBackUp) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  helper.CallAgcSequence(/*applied_input_volume=*/80, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  int initial_volume = helper.controller.recommended_input_volume();
+  helper.CallAnalyzeInputAudio(/*num_calls=*/1,
+                               /*clipped_ratio=*/kAboveClippedThreshold);
+  EXPECT_EQ(helper.controller.recommended_input_volume(), initial_volume);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, TakesNoActionOnZeroMicVolume) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = GetParam()});
+  helper.CallAgcSequence(kInitialInputVolume, kHighSpeechProbability,
+                         kSpeechLevel);
+
+  EXPECT_EQ(
+      helper.CallRecommendInputVolume(/*num_calls=*/10, /*initial_volume=*/0,
+                                      kHighSpeechProbability, -48.0f),
+      0);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest, ClippingDetectionLowersVolume) {
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.min_input_volume = GetParam();
+  InputVolumeControllerTestHelper helper(config);
+  int volume = *helper.CallAgcSequence(/*applied_input_volume=*/255,
+                                       kHighSpeechProbability, kSpeechLevel,
+                                       /*num_calls=*/1);
+
+  EXPECT_EQ(volume, 255);
+
+  WriteAlternatingAudioBufferSamples(0.99f * kMaxSample, helper.audio_buffer);
+  volume = *helper.CallAgcSequence(volume, kHighSpeechProbability, kSpeechLevel,
+                                   /*num_calls=*/100);
+
+  EXPECT_EQ(volume, 255);
+
+  WriteAlternatingAudioBufferSamples(kMaxSample, helper.audio_buffer);
+  volume = *helper.CallAgcSequence(volume, kHighSpeechProbability, kSpeechLevel,
+                                   /*num_calls=*/100);
+
+  EXPECT_EQ(volume, 240);
+}
+
+// TODO(bugs.webrtc.org/12774): Test the bahavior of `clipped_level_step`.
+// TODO(bugs.webrtc.org/12774): Test the bahavior of `clipped_ratio_threshold`.
+// TODO(bugs.webrtc.org/12774): Test the bahavior of `clipped_wait_frames`.
+// Verifies that configurable clipping parameters are initialized as intended.
+TEST_P(InputVolumeControllerParametrizedTest, ClippingParametersVerified) {
+  std::unique_ptr<InputVolumeController> controller =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames);
+  controller->Initialize();
+  EXPECT_EQ(controller->clipped_level_step_, kClippedLevelStep);
+  EXPECT_EQ(controller->clipped_ratio_threshold_, kClippedRatioThreshold);
+  EXPECT_EQ(controller->clipped_wait_frames_, kClippedWaitFrames);
+  std::unique_ptr<InputVolumeController> controller_custom =
+      CreateInputVolumeController(/*clipped_level_step=*/10,
+                                  /*clipped_ratio_threshold=*/0.2f,
+                                  /*clipped_wait_frames=*/50);
+  controller_custom->Initialize();
+  EXPECT_EQ(controller_custom->clipped_level_step_, 10);
+  EXPECT_EQ(controller_custom->clipped_ratio_threshold_, 0.2f);
+  EXPECT_EQ(controller_custom->clipped_wait_frames_, 50);
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       DisableClippingPredictorDisablesClippingPredictor) {
+  std::unique_ptr<InputVolumeController> controller =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/false);
+  controller->Initialize();
+
+  EXPECT_FALSE(controller->clipping_predictor_enabled());
+  EXPECT_FALSE(controller->use_clipping_predictor_step());
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       EnableClippingPredictorEnablesClippingPredictor) {
+  std::unique_ptr<InputVolumeController> controller =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/true);
+  controller->Initialize();
+
+  EXPECT_TRUE(controller->clipping_predictor_enabled());
+  EXPECT_TRUE(controller->use_clipping_predictor_step());
+}
+
+TEST_P(InputVolumeControllerParametrizedTest,
+       DisableClippingPredictorDoesNotLowerVolume) {
+  int volume = 255;
+  InputVolumeControllerConfig config = GetInputVolumeControllerTestConfig();
+  config.enable_clipping_predictor = false;
+  auto helper = InputVolumeControllerTestHelper(config);
+  helper.controller.Initialize();
+
+  EXPECT_FALSE(helper.controller.clipping_predictor_enabled());
+  EXPECT_FALSE(helper.controller.use_clipping_predictor_step());
+
+  // Expect no change if clipping prediction is enabled.
+  for (int j = 0; j < 31; ++j) {
+    WriteAlternatingAudioBufferSamples(0.99f * kMaxSample, helper.audio_buffer);
+    volume =
+        *helper.CallAgcSequence(volume, kLowSpeechProbability, kSpeechLevel,
+                                /*num_calls=*/5);
+
+    WriteAudioBufferSamples(0.99f * kMaxSample, /*clipped_ratio=*/0.0f,
+                            helper.audio_buffer);
+    volume =
+        *helper.CallAgcSequence(volume, kLowSpeechProbability, kSpeechLevel,
+                                /*num_calls=*/5);
+
+    EXPECT_EQ(volume, 255);
+  }
+}
+
+// TODO(bugs.webrtc.org/7494): Split into several smaller tests.
+TEST_P(InputVolumeControllerParametrizedTest,
+       UsedClippingPredictionsProduceLowerAnalogLevels) {
+  constexpr int kInitialLevel = 255;
+  constexpr float kCloseToClippingPeakRatio = 0.99f;
+  int volume_1 = kInitialLevel;
+  int volume_2 = kInitialLevel;
+
+  // Create two helpers, one with clipping prediction and one without.
+  auto config_1 = GetInputVolumeControllerTestConfig();
+  auto config_2 = GetInputVolumeControllerTestConfig();
+  config_1.enable_clipping_predictor = true;
+  config_2.enable_clipping_predictor = false;
+  auto helper_1 = InputVolumeControllerTestHelper(config_1);
+  auto helper_2 = InputVolumeControllerTestHelper(config_2);
+  helper_1.controller.Initialize();
+  helper_2.controller.Initialize();
+
+  EXPECT_TRUE(helper_1.controller.clipping_predictor_enabled());
+  EXPECT_FALSE(helper_2.controller.clipping_predictor_enabled());
+  EXPECT_TRUE(helper_1.controller.use_clipping_predictor_step());
+
+  // Expect a change if clipping prediction is enabled.
+  WriteAlternatingAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                                     helper_1.audio_buffer);
+  WriteAlternatingAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                                     helper_2.audio_buffer);
+  volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+  volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+
+  WriteAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                          /*clipped_ratio=*/0.0f, helper_1.audio_buffer);
+  WriteAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                          /*clipped_ratio=*/0.0f, helper_2.audio_buffer);
+  volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+  volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+
+  EXPECT_EQ(volume_1, kInitialLevel - kClippedLevelStep);
+  EXPECT_EQ(volume_2, kInitialLevel);
+
+  // Expect no change during waiting.
+  for (int i = 0; i < kClippedWaitFrames / 10; ++i) {
+    WriteAlternatingAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                                       helper_1.audio_buffer);
+    WriteAlternatingAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                                       helper_2.audio_buffer);
+    volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+    volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+
+    WriteAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                            /*clipped_ratio=*/0.0f, helper_1.audio_buffer);
+    WriteAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                            /*clipped_ratio=*/0.0f, helper_2.audio_buffer);
+    volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+    volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+
+    EXPECT_EQ(volume_1, kInitialLevel - kClippedLevelStep);
+    EXPECT_EQ(volume_2, kInitialLevel);
+  }
+
+  // Expect a change when the prediction step is used.
+  WriteAlternatingAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                                     helper_1.audio_buffer);
+  WriteAlternatingAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                                     helper_2.audio_buffer);
+  volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+  volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+
+  WriteAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                          /*clipped_ratio=*/0.0f, helper_1.audio_buffer);
+  WriteAudioBufferSamples(kCloseToClippingPeakRatio * kMaxSample,
+                          /*clipped_ratio=*/0.0f, helper_2.audio_buffer);
+  volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+  volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                       kSpeechLevel, 5);
+
+  EXPECT_EQ(volume_1, kInitialLevel - 2 * kClippedLevelStep);
+  EXPECT_EQ(volume_2, kInitialLevel);
+
+  // Expect no change when clipping is not detected or predicted.
+  for (int i = 0; i < 2 * kClippedWaitFrames / 10; ++i) {
+    WriteAlternatingAudioBufferSamples(/*samples_value=*/0.0f,
+                                       helper_1.audio_buffer);
+    WriteAlternatingAudioBufferSamples(/*samples_value=*/0.0f,
+                                       helper_2.audio_buffer);
+    volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+    volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+
+    WriteAudioBufferSamples(/*samples_value=*/0.0f, /*clipped_ratio=*/0.0f,
+                            helper_1.audio_buffer);
+    WriteAudioBufferSamples(/*samples_value=*/0.0f, /*clipped_ratio=*/0.0f,
+                            helper_2.audio_buffer);
+    volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+    volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+  }
+
+  EXPECT_EQ(volume_1, kInitialLevel - 2 * kClippedLevelStep);
+  EXPECT_EQ(volume_2, kInitialLevel);
+
+  // Expect a change for clipping frames.
+  WriteAlternatingAudioBufferSamples(kMaxSample, helper_1.audio_buffer);
+  WriteAlternatingAudioBufferSamples(kMaxSample, helper_2.audio_buffer);
+  volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                       kSpeechLevel, 1);
+  volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                       kSpeechLevel, 1);
+
+  EXPECT_EQ(volume_1, kInitialLevel - 3 * kClippedLevelStep);
+  EXPECT_EQ(volume_2, kInitialLevel - kClippedLevelStep);
+
+  // Expect no change during waiting.
+  for (int i = 0; i < kClippedWaitFrames / 10; ++i) {
+    WriteAlternatingAudioBufferSamples(kMaxSample, helper_1.audio_buffer);
+    WriteAlternatingAudioBufferSamples(kMaxSample, helper_2.audio_buffer);
+    volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+    volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+
+    WriteAudioBufferSamples(kMaxSample, /*clipped_ratio=*/1.0f,
+                            helper_1.audio_buffer);
+    WriteAudioBufferSamples(kMaxSample, /*clipped_ratio=*/1.0f,
+                            helper_2.audio_buffer);
+    volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+    volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                         kSpeechLevel, 5);
+  }
+
+  EXPECT_EQ(volume_1, kInitialLevel - 3 * kClippedLevelStep);
+  EXPECT_EQ(volume_2, kInitialLevel - kClippedLevelStep);
+
+  // Expect a change for clipping frames.
+  WriteAlternatingAudioBufferSamples(kMaxSample, helper_1.audio_buffer);
+  WriteAlternatingAudioBufferSamples(kMaxSample, helper_2.audio_buffer);
+  volume_1 = *helper_1.CallAgcSequence(volume_1, kLowSpeechProbability,
+                                       kSpeechLevel, 1);
+  volume_2 = *helper_2.CallAgcSequence(volume_2, kLowSpeechProbability,
+                                       kSpeechLevel, 1);
+
+  EXPECT_EQ(volume_1, kInitialLevel - 4 * kClippedLevelStep);
+  EXPECT_EQ(volume_2, kInitialLevel - 2 * kClippedLevelStep);
+}
+
+// Checks that passing an empty speech level has no effect on the input volume.
+TEST_P(InputVolumeControllerParametrizedTest, EmptyRmsErrorHasNoEffect) {
+  InputVolumeController controller(kNumChannels,
+                                   GetInputVolumeControllerTestConfig());
+  controller.Initialize();
+
+  // Feed speech with low energy that would trigger an upward adapation of
+  // the analog level if an speech level was not low and the RMS level empty.
+  constexpr int kNumFrames = 125;
+  constexpr int kGainDb = -20;
+  SpeechSamplesReader reader;
+  int volume = reader.Feed(kNumFrames, kInitialInputVolume, kGainDb,
+                           kLowSpeechProbability, absl::nullopt, controller);
+
+  // Check that no adaptation occurs.
+  ASSERT_EQ(volume, kInitialInputVolume);
+}
+
+// Checks that the recommended input volume is not updated unless enough
+// frames have been processed after the previous update.
+TEST(InputVolumeControllerTest, UpdateInputVolumeWaitFramesIsEffective) {
+  constexpr int kInputVolume = kInitialInputVolume;
+  std::unique_ptr<InputVolumeController> controller_wait_0 =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/false,
+                                  /*update_input_volume_wait_frames=*/0);
+  std::unique_ptr<InputVolumeController> controller_wait_100 =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/false,
+                                  /*update_input_volume_wait_frames=*/100);
+  controller_wait_0->Initialize();
+  controller_wait_100->Initialize();
+
+  SpeechSamplesReader reader_1;
+  SpeechSamplesReader reader_2;
+  int volume_wait_0 = reader_1.Feed(
+      /*num_frames=*/99, kInputVolume, /*gain_db=*/0, kHighSpeechProbability,
+      /*speech_level_dbfs=*/-42.0f, *controller_wait_0);
+  int volume_wait_100 = reader_2.Feed(
+      /*num_frames=*/99, kInputVolume, /*gain_db=*/0, kHighSpeechProbability,
+      /*speech_level_dbfs=*/-42.0f, *controller_wait_100);
+
+  // Check that adaptation only occurs if enough frames have been processed.
+  ASSERT_GT(volume_wait_0, kInputVolume);
+  ASSERT_EQ(volume_wait_100, kInputVolume);
+
+  volume_wait_0 =
+      reader_1.Feed(/*num_frames=*/1, volume_wait_0,
+                    /*gain_db=*/0, kHighSpeechProbability,
+                    /*speech_level_dbfs=*/-42.0f, *controller_wait_0);
+  volume_wait_100 =
+      reader_2.Feed(/*num_frames=*/1, volume_wait_100,
+                    /*gain_db=*/0, kHighSpeechProbability,
+                    /*speech_level_dbfs=*/-42.0f, *controller_wait_100);
+
+  // Check that adaptation only occurs when enough frames have been processed.
+  ASSERT_GT(volume_wait_0, kInputVolume);
+  ASSERT_GT(volume_wait_100, kInputVolume);
+}
+
+INSTANTIATE_TEST_SUITE_P(,
+                         InputVolumeControllerParametrizedTest,
+                         ::testing::Values(12, 20));
+
+TEST(InputVolumeControllerTest,
+     MinInputVolumeEnforcedWithClippingWhenAboveClippedLevelMin) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = 80, .clipped_level_min = 70});
+
+  // Trigger a downward adjustment caused by clipping input. Use a low speech
+  // probability to limit the volume changes to clipping handling.
+  WriteAudioBufferSamples(/*samples_value=*/4000.0f, /*clipped_ratio=*/0.8f,
+                          helper.audio_buffer);
+  constexpr int kNumCalls = 800;
+  helper.CallAgcSequence(/*applied_input_volume=*/100, kLowSpeechProbability,
+                         /*speech_level_dbfs=*/-18.0f, kNumCalls);
+
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 80);
+}
+
+TEST(InputVolumeControllerTest,
+     ClippedlevelMinEnforcedWithClippingWhenAboveMinInputVolume) {
+  InputVolumeControllerTestHelper helper(
+      /*config=*/{.min_input_volume = 70, .clipped_level_min = 80});
+
+  // Trigger a downward adjustment caused by clipping input. Use a low speech
+  // probability to limit the volume changes to clipping handling.
+  WriteAudioBufferSamples(/*samples_value=*/4000.0f, /*clipped_ratio=*/0.8f,
+                          helper.audio_buffer);
+  constexpr int kNumCalls = 800;
+  helper.CallAgcSequence(/*applied_input_volume=*/100, kLowSpeechProbability,
+                         /*speech_level_dbfs=*/-18.0f, kNumCalls);
+
+  EXPECT_EQ(helper.controller.recommended_input_volume(), 80);
+}
+
+TEST(InputVolumeControllerTest, SpeechRatioThresholdIsEffective) {
+  constexpr int kInputVolume = kInitialInputVolume;
+  // Create two input volume controllers with 10 frames between volume updates
+  // and the minimum speech ratio of 0.8 and speech probability threshold 0.5.
+  std::unique_ptr<InputVolumeController> controller_1 =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/false,
+                                  /*update_input_volume_wait_frames=*/10);
+  std::unique_ptr<InputVolumeController> controller_2 =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/false,
+                                  /*update_input_volume_wait_frames=*/10);
+  controller_1->Initialize();
+  controller_2->Initialize();
+
+  SpeechSamplesReader reader_1;
+  SpeechSamplesReader reader_2;
+
+  int volume_1 = reader_1.Feed(/*num_frames=*/1, kInputVolume, /*gain_db=*/0,
+                               /*speech_probability=*/0.7f,
+                               /*speech_level_dbfs=*/-42.0f, *controller_1);
+  int volume_2 = reader_2.Feed(/*num_frames=*/1, kInputVolume, /*gain_db=*/0,
+                               /*speech_probability=*/0.4f,
+                               /*speech_level_dbfs=*/-42.0f, *controller_2);
+
+  ASSERT_EQ(volume_1, kInputVolume);
+  ASSERT_EQ(volume_2, kInputVolume);
+
+  volume_1 = reader_1.Feed(/*num_frames=*/2, volume_1, /*gain_db=*/0,
+                           /*speech_probability=*/0.4f,
+                           /*speech_level_dbfs=*/-42.0f, *controller_1);
+  volume_2 = reader_2.Feed(/*num_frames=*/2, volume_2, /*gain_db=*/0,
+                           /*speech_probability=*/0.4f,
+                           /*speech_level_dbfs=*/-42.0f, *controller_2);
+
+  ASSERT_EQ(volume_1, kInputVolume);
+  ASSERT_EQ(volume_2, kInputVolume);
+
+  volume_1 = reader_1.Feed(
+      /*num_frames=*/7, volume_1, /*gain_db=*/0,
+      /*speech_probability=*/0.7f, /*speech_level_dbfs=*/-42.0f, *controller_1);
+  volume_2 = reader_2.Feed(
+      /*num_frames=*/7, volume_2, /*gain_db=*/0,
+      /*speech_probability=*/0.7f, /*speech_level_dbfs=*/-42.0f, *controller_2);
+
+  ASSERT_GT(volume_1, kInputVolume);
+  ASSERT_EQ(volume_2, kInputVolume);
+}
+
+TEST(InputVolumeControllerTest, SpeechProbabilityThresholdIsEffective) {
+  constexpr int kInputVolume = kInitialInputVolume;
+  // Create two input volume controllers with the exact same settings and
+  // 10 frames between volume updates.
+  std::unique_ptr<InputVolumeController> controller_1 =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/false,
+                                  /*update_input_volume_wait_frames=*/10);
+  std::unique_ptr<InputVolumeController> controller_2 =
+      CreateInputVolumeController(kClippedLevelStep, kClippedRatioThreshold,
+                                  kClippedWaitFrames,
+                                  /*enable_clipping_predictor=*/false,
+                                  /*update_input_volume_wait_frames=*/10);
+  controller_1->Initialize();
+  controller_2->Initialize();
+
+  SpeechSamplesReader reader_1;
+  SpeechSamplesReader reader_2;
+
+  // Process with two sets of inputs: Use `reader_1` to process inputs
+  // that make the volume to be adjusted after enough frames have been
+  // processsed and `reader_2` to process inputs that won't make the volume
+  // to be adjusted.
+  int volume_1 = reader_1.Feed(/*num_frames=*/1, kInputVolume, /*gain_db=*/0,
+                               /*speech_probability=*/0.5f,
+                               /*speech_level_dbfs=*/-42.0f, *controller_1);
+  int volume_2 = reader_2.Feed(/*num_frames=*/1, kInputVolume, /*gain_db=*/0,
+                               /*speech_probability=*/0.49f,
+                               /*speech_level_dbfs=*/-42.0f, *controller_2);
+
+  ASSERT_EQ(volume_1, kInputVolume);
+  ASSERT_EQ(volume_2, kInputVolume);
+
+  reader_1.Feed(/*num_frames=*/2, volume_1, /*gain_db=*/0,
+                /*speech_probability=*/0.49f, /*speech_level_dbfs=*/-42.0f,
+                *controller_1);
+  reader_2.Feed(/*num_frames=*/2, volume_2, /*gain_db=*/0,
+                /*speech_probability=*/0.49f, /*speech_level_dbfs=*/-42.0f,
+                *controller_2);
+
+  ASSERT_EQ(volume_1, kInputVolume);
+  ASSERT_EQ(volume_2, kInputVolume);
+
+  volume_1 = reader_1.Feed(
+      /*num_frames=*/7, volume_1, /*gain_db=*/0,
+      /*speech_probability=*/0.5f, /*speech_level_dbfs=*/-42.0f, *controller_1);
+  volume_2 = reader_2.Feed(
+      /*num_frames=*/7, volume_2, /*gain_db=*/0,
+      /*speech_probability=*/0.5f, /*speech_level_dbfs=*/-42.0f, *controller_2);
+
+  ASSERT_GT(volume_1, kInputVolume);
+  ASSERT_EQ(volume_2, kInputVolume);
+}
+
+TEST(InputVolumeControllerTest,
+     DoNotLogRecommendedInputVolumeOnChangeToMatchTarget) {
+  metrics::Reset();
+
+  SpeechSamplesReader reader;
+  auto controller = CreateInputVolumeController();
+  controller->Initialize();
+  // Trigger a downward volume change by inputting audio that clips. Pass a
+  // speech level that falls in the target range to make sure that the
+  // adaptation is not made to match the target range.
+  constexpr int kStartupVolume = 255;
+  const int volume = reader.Feed(/*num_frames=*/14, kStartupVolume,
+                                 /*gain_db=*/50, kHighSpeechProbability,
+                                 /*speech_level_dbfs=*/-20.0f, *controller);
+  ASSERT_LT(volume, kStartupVolume);
+  EXPECT_METRIC_THAT(
+      metrics::Samples(
+          "WebRTC.Audio.Apm.RecommendedInputVolume.OnChangeToMatchTarget"),
+      ::testing::IsEmpty());
+}
+
+TEST(InputVolumeControllerTest,
+     LogRecommendedInputVolumeOnUpwardChangeToMatchTarget) {
+  metrics::Reset();
+
+  SpeechSamplesReader reader;
+  auto controller = CreateInputVolumeController();
+  controller->Initialize();
+  constexpr int kStartupVolume = 100;
+  // Trigger an upward volume change by inputting audio that does not clip and
+  // by passing a speech level below the target range.
+  const int volume = reader.Feed(/*num_frames=*/14, kStartupVolume,
+                                 /*gain_db=*/-6, kHighSpeechProbability,
+                                 /*speech_level_dbfs=*/-50.0f, *controller);
+  ASSERT_GT(volume, kStartupVolume);
+  EXPECT_METRIC_THAT(
+      metrics::Samples(
+          "WebRTC.Audio.Apm.RecommendedInputVolume.OnChangeToMatchTarget"),
+      ::testing::Not(::testing::IsEmpty()));
+}
+
+TEST(InputVolumeControllerTest,
+     LogRecommendedInputVolumeOnDownwardChangeToMatchTarget) {
+  metrics::Reset();
+
+  SpeechSamplesReader reader;
+  auto controller = CreateInputVolumeController();
+  controller->Initialize();
+  constexpr int kStartupVolume = 100;
+  // Trigger a downward volume change by inputting audio that does not clip and
+  // by passing a speech level above the target range.
+  const int volume = reader.Feed(/*num_frames=*/14, kStartupVolume,
+                                 /*gain_db=*/-6, kHighSpeechProbability,
+                                 /*speech_level_dbfs=*/-5.0f, *controller);
+  ASSERT_LT(volume, kStartupVolume);
+  EXPECT_METRIC_THAT(
+      metrics::Samples(
+          "WebRTC.Audio.Apm.RecommendedInputVolume.OnChangeToMatchTarget"),
+      ::testing::Not(::testing::IsEmpty()));
+}
+
+TEST(MonoInputVolumeControllerTest, CheckHandleClippingLowersVolume) {
+  constexpr int kInitialInputVolume = 100;
+  constexpr int kInputVolumeStep = 29;
+  MonoInputVolumeController mono_controller(
+      /*clipped_level_min=*/70,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/3, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller.Initialize();
+
+  UpdateRecommendedInputVolume(mono_controller, kInitialInputVolume,
+                               kLowSpeechProbability,
+                               /*rms_error_dbfs*/ -10.0f);
+
+  mono_controller.HandleClipping(kInputVolumeStep);
+
+  EXPECT_EQ(mono_controller.recommended_analog_level(),
+            kInitialInputVolume - kInputVolumeStep);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckProcessNegativeRmsErrorDecreasesInputVolume) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/3, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller.Initialize();
+
+  int volume = UpdateRecommendedInputVolume(
+      mono_controller, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+  volume = UpdateRecommendedInputVolume(mono_controller, volume,
+                                        kHighSpeechProbability, -10.0f);
+  volume = UpdateRecommendedInputVolume(mono_controller, volume,
+                                        kHighSpeechProbability, -10.0f);
+
+  EXPECT_LT(volume, kInitialInputVolume);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckProcessPositiveRmsErrorIncreasesInputVolume) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/3, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller.Initialize();
+
+  int volume = UpdateRecommendedInputVolume(
+      mono_controller, kInitialInputVolume, kHighSpeechProbability, 10.0f);
+  volume = UpdateRecommendedInputVolume(mono_controller, volume,
+                                        kHighSpeechProbability, 10.0f);
+  volume = UpdateRecommendedInputVolume(mono_controller, volume,
+                                        kHighSpeechProbability, 10.0f);
+
+  EXPECT_GT(volume, kInitialInputVolume);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckProcessNegativeRmsErrorDecreasesInputVolumeWithLimit) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller_1(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_2(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_3(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2,
+      /*speech_probability_threshold=*/0.7,
+      /*speech_ratio_threshold=*/0.8);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+  mono_controller_3.Initialize();
+
+  // Process RMS errors in the range
+  // [`-kMaxResidualGainChange`, `kMaxResidualGainChange`].
+  int volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, kInitialInputVolume, kHighSpeechProbability, -14.0f);
+  volume_1 = UpdateRecommendedInputVolume(mono_controller_1, volume_1,
+                                          kHighSpeechProbability, -14.0f);
+  // Process RMS errors outside the range
+  // [`-kMaxResidualGainChange`, `kMaxResidualGainChange`].
+  int volume_2 = UpdateRecommendedInputVolume(
+      mono_controller_2, kInitialInputVolume, kHighSpeechProbability, -15.0f);
+  int volume_3 = UpdateRecommendedInputVolume(
+      mono_controller_3, kInitialInputVolume, kHighSpeechProbability, -30.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, -15.0f);
+  volume_3 = UpdateRecommendedInputVolume(mono_controller_3, volume_3,
+                                          kHighSpeechProbability, -30.0f);
+
+  EXPECT_LT(volume_1, kInitialInputVolume);
+  EXPECT_LT(volume_2, volume_1);
+  EXPECT_EQ(volume_2, volume_3);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckProcessPositiveRmsErrorIncreasesInputVolumeWithLimit) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller_1(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_2(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_3(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+  mono_controller_3.Initialize();
+
+  // Process RMS errors in the range
+  // [`-kMaxResidualGainChange`, `kMaxResidualGainChange`].
+  int volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, kInitialInputVolume, kHighSpeechProbability, 14.0f);
+  volume_1 = UpdateRecommendedInputVolume(mono_controller_1, volume_1,
+                                          kHighSpeechProbability, 14.0f);
+  // Process RMS errors outside the range
+  // [`-kMaxResidualGainChange`, `kMaxResidualGainChange`].
+  int volume_2 = UpdateRecommendedInputVolume(
+      mono_controller_2, kInitialInputVolume, kHighSpeechProbability, 15.0f);
+  int volume_3 = UpdateRecommendedInputVolume(
+      mono_controller_3, kInitialInputVolume, kHighSpeechProbability, 30.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, 15.0f);
+  volume_3 = UpdateRecommendedInputVolume(mono_controller_3, volume_3,
+                                          kHighSpeechProbability, 30.0f);
+
+  EXPECT_GT(volume_1, kInitialInputVolume);
+  EXPECT_GT(volume_2, volume_1);
+  EXPECT_EQ(volume_2, volume_3);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckProcessRmsErrorDecreasesInputVolumeRepeatedly) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller.Initialize();
+
+  int volume_before = UpdateRecommendedInputVolume(
+      mono_controller, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+  volume_before = UpdateRecommendedInputVolume(mono_controller, volume_before,
+                                               kHighSpeechProbability, -10.0f);
+
+  EXPECT_LT(volume_before, kInitialInputVolume);
+
+  int volume_after = UpdateRecommendedInputVolume(
+      mono_controller, volume_before, kHighSpeechProbability, -10.0f);
+  volume_after = UpdateRecommendedInputVolume(mono_controller, volume_after,
+                                              kHighSpeechProbability, -10.0f);
+
+  EXPECT_LT(volume_after, volume_before);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckProcessPositiveRmsErrorIncreasesInputVolumeRepeatedly) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/32,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller.Initialize();
+
+  int volume_before = UpdateRecommendedInputVolume(
+      mono_controller, kInitialInputVolume, kHighSpeechProbability, 10.0f);
+  volume_before = UpdateRecommendedInputVolume(mono_controller, volume_before,
+                                               kHighSpeechProbability, 10.0f);
+
+  EXPECT_GT(volume_before, kInitialInputVolume);
+
+  int volume_after = UpdateRecommendedInputVolume(
+      mono_controller, volume_before, kHighSpeechProbability, 10.0f);
+  volume_after = UpdateRecommendedInputVolume(mono_controller, volume_after,
+                                              kHighSpeechProbability, 10.0f);
+
+  EXPECT_GT(volume_after, volume_before);
+}
+
+TEST(MonoInputVolumeControllerTest, CheckClippedLevelMinIsEffective) {
+  constexpr int kInitialInputVolume = 100;
+  constexpr int kClippedLevelMin = 70;
+  MonoInputVolumeController mono_controller_1(
+      kClippedLevelMin,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_2(
+      kClippedLevelMin,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+
+  // Process one frame to reset the state for `HandleClipping()`.
+  EXPECT_EQ(UpdateRecommendedInputVolume(mono_controller_1, kInitialInputVolume,
+                                         kLowSpeechProbability, -10.0f),
+            kInitialInputVolume);
+  EXPECT_EQ(UpdateRecommendedInputVolume(mono_controller_2, kInitialInputVolume,
+                                         kLowSpeechProbability, -10.0f),
+            kInitialInputVolume);
+
+  mono_controller_1.HandleClipping(29);
+  mono_controller_2.HandleClipping(31);
+
+  EXPECT_EQ(mono_controller_2.recommended_analog_level(), kClippedLevelMin);
+  EXPECT_LT(mono_controller_2.recommended_analog_level(),
+            mono_controller_1.recommended_analog_level());
+}
+
+TEST(MonoInputVolumeControllerTest, CheckMinMicLevelIsEffective) {
+  constexpr int kInitialInputVolume = 100;
+  constexpr int kMinMicLevel = 64;
+  MonoInputVolumeController mono_controller_1(
+      /*clipped_level_min=*/64, kMinMicLevel,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_2(
+      /*clipped_level_min=*/64, kMinMicLevel,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+
+  int volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+  int volume_2 = UpdateRecommendedInputVolume(
+      mono_controller_2, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_EQ(volume_2, kInitialInputVolume);
+
+  volume_1 = UpdateRecommendedInputVolume(mono_controller_1, volume_1,
+                                          kHighSpeechProbability, -10.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, -30.0f);
+
+  EXPECT_LT(volume_1, kInitialInputVolume);
+  EXPECT_LT(volume_2, volume_1);
+  EXPECT_EQ(volume_2, kMinMicLevel);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckUpdateInputVolumeWaitFramesIsEffective) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller_1(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/1, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_2(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/3, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+
+  int volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+  int volume_2 = UpdateRecommendedInputVolume(
+      mono_controller_2, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_EQ(volume_2, kInitialInputVolume);
+
+  volume_1 = UpdateRecommendedInputVolume(mono_controller_1, volume_1,
+                                          kHighSpeechProbability, -10.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, -10.0f);
+
+  EXPECT_LT(volume_1, kInitialInputVolume);
+  EXPECT_EQ(volume_2, kInitialInputVolume);
+
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, -10.0f);
+
+  EXPECT_LT(volume_2, kInitialInputVolume);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckSpeechProbabilityThresholdIsEffective) {
+  constexpr int kInitialInputVolume = 100;
+  constexpr float kSpeechProbabilityThreshold = 0.8f;
+  MonoInputVolumeController mono_controller_1(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/2, kSpeechProbabilityThreshold,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_2(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/2, kSpeechProbabilityThreshold,
+      kSpeechRatioThreshold);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+
+  int volume_1 =
+      UpdateRecommendedInputVolume(mono_controller_1, kInitialInputVolume,
+                                   kSpeechProbabilityThreshold, -10.0f);
+  int volume_2 =
+      UpdateRecommendedInputVolume(mono_controller_2, kInitialInputVolume,
+                                   kSpeechProbabilityThreshold, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_EQ(volume_2, kInitialInputVolume);
+
+  volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, volume_1, kSpeechProbabilityThreshold - 0.1f, -10.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kSpeechProbabilityThreshold, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_LT(volume_2, volume_1);
+}
+
+TEST(MonoInputVolumeControllerTest, CheckSpeechRatioThresholdIsEffective) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller_1(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/4, kHighSpeechProbability,
+      /*speech_ratio_threshold=*/0.75f);
+  MonoInputVolumeController mono_controller_2(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/4, kHighSpeechProbability,
+      /*speech_ratio_threshold=*/0.75f);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+
+  int volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+  int volume_2 = UpdateRecommendedInputVolume(
+      mono_controller_2, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+
+  volume_1 = UpdateRecommendedInputVolume(mono_controller_1, volume_1,
+                                          kHighSpeechProbability, -10.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, -10.0f);
+
+  volume_1 = UpdateRecommendedInputVolume(mono_controller_1, volume_1,
+                                          kLowSpeechProbability, -10.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kLowSpeechProbability, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_EQ(volume_2, kInitialInputVolume);
+
+  volume_1 = UpdateRecommendedInputVolume(mono_controller_1, volume_1,
+                                          kLowSpeechProbability, -10.0f);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_LT(volume_2, volume_1);
+}
+
+TEST(MonoInputVolumeControllerTest,
+     CheckProcessEmptyRmsErrorDoesNotLowerVolume) {
+  constexpr int kInitialInputVolume = 100;
+  MonoInputVolumeController mono_controller_1(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  MonoInputVolumeController mono_controller_2(
+      /*clipped_level_min=*/64,
+      /*min_mic_level=*/84,
+      /*update_input_volume_wait_frames=*/2, kHighSpeechProbability,
+      kSpeechRatioThreshold);
+  mono_controller_1.Initialize();
+  mono_controller_2.Initialize();
+
+  int volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+  int volume_2 = UpdateRecommendedInputVolume(
+      mono_controller_2, kInitialInputVolume, kHighSpeechProbability, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_EQ(volume_2, kInitialInputVolume);
+
+  volume_1 = UpdateRecommendedInputVolume(
+      mono_controller_1, volume_1, kHighSpeechProbability, absl::nullopt);
+  volume_2 = UpdateRecommendedInputVolume(mono_controller_2, volume_2,
+                                          kHighSpeechProbability, -10.0f);
+
+  EXPECT_EQ(volume_1, kInitialInputVolume);
+  EXPECT_LT(volume_2, volume_1);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter.cc b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter.cc
new file mode 100644
index 0000000000..05624b1f92
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter.cc
@@ -0,0 +1,171 @@
+/*
+ *  Copyright (c) 2021 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/agc2/input_volume_stats_reporter.h"
+
+#include <cmath>
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/safe_minmax.h"
+#include "rtc_base/strings/string_builder.h"
+#include "system_wrappers/include/metrics.h"
+
+namespace webrtc {
+namespace {
+
+using InputVolumeType = InputVolumeStatsReporter::InputVolumeType;
+
+constexpr int kFramesIn60Seconds = 6000;
+constexpr int kMinInputVolume = 0;
+constexpr int kMaxInputVolume = 255;
+constexpr int kMaxUpdate = kMaxInputVolume - kMinInputVolume;
+
+int ComputeAverageUpdate(int sum_updates, int num_updates) {
+  RTC_DCHECK_GE(sum_updates, 0);
+  RTC_DCHECK_LE(sum_updates, kMaxUpdate * kFramesIn60Seconds);
+  RTC_DCHECK_GE(num_updates, 0);
+  RTC_DCHECK_LE(num_updates, kFramesIn60Seconds);
+  if (num_updates == 0) {
+    return 0;
+  }
+  return std::round(static_cast<float>(sum_updates) /
+                    static_cast<float>(num_updates));
+}
+
+constexpr absl::string_view MetricNamePrefix(
+    InputVolumeType input_volume_type) {
+  switch (input_volume_type) {
+    case InputVolumeType::kApplied:
+      return "WebRTC.Audio.Apm.AppliedInputVolume.";
+    case InputVolumeType::kRecommended:
+      return "WebRTC.Audio.Apm.RecommendedInputVolume.";
+  }
+}
+
+metrics::Histogram* CreateVolumeHistogram(InputVolumeType input_volume_type) {
+  char buffer[64];
+  rtc::SimpleStringBuilder builder(buffer);
+  builder << MetricNamePrefix(input_volume_type) << "OnChange";
+  return metrics::HistogramFactoryGetCountsLinear(/*name=*/builder.str(),
+                                                  /*min=*/1,
+                                                  /*max=*/kMaxInputVolume,
+                                                  /*bucket_count=*/50);
+}
+
+metrics::Histogram* CreateRateHistogram(InputVolumeType input_volume_type,
+                                        absl::string_view name) {
+  char buffer[64];
+  rtc::SimpleStringBuilder builder(buffer);
+  builder << MetricNamePrefix(input_volume_type) << name;
+  return metrics::HistogramFactoryGetCountsLinear(/*name=*/builder.str(),
+                                                  /*min=*/1,
+                                                  /*max=*/kFramesIn60Seconds,
+                                                  /*bucket_count=*/50);
+}
+
+metrics::Histogram* CreateAverageHistogram(InputVolumeType input_volume_type,
+                                           absl::string_view name) {
+  char buffer[64];
+  rtc::SimpleStringBuilder builder(buffer);
+  builder << MetricNamePrefix(input_volume_type) << name;
+  return metrics::HistogramFactoryGetCountsLinear(/*name=*/builder.str(),
+                                                  /*min=*/1,
+                                                  /*max=*/kMaxUpdate,
+                                                  /*bucket_count=*/50);
+}
+
+}  // namespace
+
+InputVolumeStatsReporter::InputVolumeStatsReporter(InputVolumeType type)
+    : histograms_(
+          {.on_volume_change = CreateVolumeHistogram(type),
+           .decrease_rate = CreateRateHistogram(type, "DecreaseRate"),
+           .decrease_average = CreateAverageHistogram(type, "DecreaseAverage"),
+           .increase_rate = CreateRateHistogram(type, "IncreaseRate"),
+           .increase_average = CreateAverageHistogram(type, "IncreaseAverage"),
+           .update_rate = CreateRateHistogram(type, "UpdateRate"),
+           .update_average = CreateAverageHistogram(type, "UpdateAverage")}),
+      cannot_log_stats_(!histograms_.AllPointersSet()) {
+  if (cannot_log_stats_) {
+    RTC_LOG(LS_WARNING) << "Will not log any `" << MetricNamePrefix(type)
+                        << "*` histogram stats.";
+  }
+}
+
+InputVolumeStatsReporter::~InputVolumeStatsReporter() = default;
+
+void InputVolumeStatsReporter::UpdateStatistics(int input_volume) {
+  if (cannot_log_stats_) {
+    // Since the stats cannot be logged, do not bother updating them.
+    return;
+  }
+
+  RTC_DCHECK_GE(input_volume, kMinInputVolume);
+  RTC_DCHECK_LE(input_volume, kMaxInputVolume);
+  if (previous_input_volume_.has_value() &&
+      input_volume != previous_input_volume_.value()) {
+    // Update stats when the input volume changes.
+    metrics::HistogramAdd(histograms_.on_volume_change, input_volume);
+    // Update stats that are periodically logged.
+    const int volume_change = input_volume - previous_input_volume_.value();
+    if (volume_change < 0) {
+      ++volume_update_stats_.num_decreases;
+      volume_update_stats_.sum_decreases -= volume_change;
+    } else {
+      ++volume_update_stats_.num_increases;
+      volume_update_stats_.sum_increases += volume_change;
+    }
+  }
+  // Periodically log input volume change metrics.
+  if (++log_volume_update_stats_counter_ >= kFramesIn60Seconds) {
+    LogVolumeUpdateStats();
+    volume_update_stats_ = {};
+    log_volume_update_stats_counter_ = 0;
+  }
+  previous_input_volume_ = input_volume;
+}
+
+void InputVolumeStatsReporter::LogVolumeUpdateStats() const {
+  // Decrease rate and average.
+  metrics::HistogramAdd(histograms_.decrease_rate,
+                        volume_update_stats_.num_decreases);
+  if (volume_update_stats_.num_decreases > 0) {
+    int average_decrease = ComputeAverageUpdate(
+        volume_update_stats_.sum_decreases, volume_update_stats_.num_decreases);
+    metrics::HistogramAdd(histograms_.decrease_average, average_decrease);
+  }
+  // Increase rate and average.
+  metrics::HistogramAdd(histograms_.increase_rate,
+                        volume_update_stats_.num_increases);
+  if (volume_update_stats_.num_increases > 0) {
+    int average_increase = ComputeAverageUpdate(
+        volume_update_stats_.sum_increases, volume_update_stats_.num_increases);
+    metrics::HistogramAdd(histograms_.increase_average, average_increase);
+  }
+  // Update rate and average.
+  int num_updates =
+      volume_update_stats_.num_decreases + volume_update_stats_.num_increases;
+  metrics::HistogramAdd(histograms_.update_rate, num_updates);
+  if (num_updates > 0) {
+    int average_update = ComputeAverageUpdate(
+        volume_update_stats_.sum_decreases + volume_update_stats_.sum_increases,
+        num_updates);
+    metrics::HistogramAdd(histograms_.update_average, average_update);
+  }
+}
+
+void UpdateHistogramOnRecommendedInputVolumeChangeToMatchTarget(int volume) {
+  RTC_HISTOGRAM_COUNTS_LINEAR(
+      "WebRTC.Audio.Apm.RecommendedInputVolume.OnChangeToMatchTarget", volume,
+      1, kMaxInputVolume, 50);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter.h b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter.h
new file mode 100644
index 0000000000..31b110031c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter.h
@@ -0,0 +1,96 @@
+/*
+ *  Copyright (c) 2021 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_AGC2_INPUT_VOLUME_STATS_REPORTER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_INPUT_VOLUME_STATS_REPORTER_H_
+
+#include "absl/types/optional.h"
+#include "rtc_base/gtest_prod_util.h"
+#include "system_wrappers/include/metrics.h"
+
+namespace webrtc {
+
+// Input volume statistics calculator. Computes aggregate stats based on the
+// framewise input volume observed by `UpdateStatistics()`. Periodically logs
+// the statistics into a histogram.
+class InputVolumeStatsReporter {
+ public:
+  enum class InputVolumeType {
+    kApplied = 0,
+    kRecommended = 1,
+  };
+
+  explicit InputVolumeStatsReporter(InputVolumeType input_volume_type);
+  InputVolumeStatsReporter(const InputVolumeStatsReporter&) = delete;
+  InputVolumeStatsReporter operator=(const InputVolumeStatsReporter&) = delete;
+  ~InputVolumeStatsReporter();
+
+  // Updates the stats based on `input_volume`. Periodically logs the stats into
+  // a histogram.
+  void UpdateStatistics(int input_volume);
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeStatsReporterTest,
+                           CheckVolumeUpdateStatsForEmptyStats);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeStatsReporterTest,
+                           CheckVolumeUpdateStatsAfterNoVolumeChange);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeStatsReporterTest,
+                           CheckVolumeUpdateStatsAfterVolumeIncrease);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeStatsReporterTest,
+                           CheckVolumeUpdateStatsAfterVolumeDecrease);
+  FRIEND_TEST_ALL_PREFIXES(InputVolumeStatsReporterTest,
+                           CheckVolumeUpdateStatsAfterReset);
+
+  // Stores input volume update stats to enable calculation of update rate and
+  // average update separately for volume increases and decreases.
+  struct VolumeUpdateStats {
+    int num_decreases = 0;
+    int num_increases = 0;
+    int sum_decreases = 0;
+    int sum_increases = 0;
+  } volume_update_stats_;
+
+  // Returns a copy of the stored statistics. Use only for testing.
+  VolumeUpdateStats volume_update_stats() const { return volume_update_stats_; }
+
+  // Computes aggregate stat and logs them into a histogram.
+  void LogVolumeUpdateStats() const;
+
+  // Histograms.
+  struct Histograms {
+    metrics::Histogram* const on_volume_change;
+    metrics::Histogram* const decrease_rate;
+    metrics::Histogram* const decrease_average;
+    metrics::Histogram* const increase_rate;
+    metrics::Histogram* const increase_average;
+    metrics::Histogram* const update_rate;
+    metrics::Histogram* const update_average;
+    bool AllPointersSet() const {
+      return !!on_volume_change && !!decrease_rate && !!decrease_average &&
+             !!increase_rate && !!increase_average && !!update_rate &&
+             !!update_average;
+    }
+  } histograms_;
+
+  // True if the stats cannot be logged.
+  const bool cannot_log_stats_;
+
+  int log_volume_update_stats_counter_ = 0;
+  absl::optional<int> previous_input_volume_ = absl::nullopt;
+};
+
+// Updates the histogram that keeps track of recommended input volume changes
+// required in order to match the target level in the input volume adaptation
+// process.
+void UpdateHistogramOnRecommendedInputVolumeChangeToMatchTarget(int volume);
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_INPUT_VOLUME_STATS_REPORTER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter_gn/moz.build
new file mode 100644
index 0000000000..5a662f4079
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter_gn/moz.build
@@ -0,0 +1,225 @@
+# 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_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/agc2/input_volume_stats_reporter.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
+
+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 += [
+        "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("input_volume_stats_reporter_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter_unittest.cc
new file mode 100644
index 0000000000..e762c1fb59
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/input_volume_stats_reporter_unittest.cc
@@ -0,0 +1,246 @@
+/*
+ *  Copyright (c) 2021 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/agc2/input_volume_stats_reporter.h"
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/strings/string_builder.h"
+#include "system_wrappers/include/metrics.h"
+#include "test/gmock.h"
+
+namespace webrtc {
+namespace {
+
+using InputVolumeType = InputVolumeStatsReporter::InputVolumeType;
+
+constexpr int kFramesIn60Seconds = 6000;
+
+constexpr absl::string_view kLabelPrefix = "WebRTC.Audio.Apm.";
+
+class InputVolumeStatsReporterTest
+    : public ::testing::TestWithParam<InputVolumeType> {
+ public:
+  InputVolumeStatsReporterTest() { metrics::Reset(); }
+
+ protected:
+  InputVolumeType InputVolumeType() const { return GetParam(); }
+  std::string VolumeLabel() const {
+    return (rtc::StringBuilder(kLabelPrefix) << VolumeTypeLabel() << "OnChange")
+        .str();
+  }
+  std::string DecreaseRateLabel() const {
+    return (rtc::StringBuilder(kLabelPrefix)
+            << VolumeTypeLabel() << "DecreaseRate")
+        .str();
+  }
+  std::string DecreaseAverageLabel() const {
+    return (rtc::StringBuilder(kLabelPrefix)
+            << VolumeTypeLabel() << "DecreaseAverage")
+        .str();
+  }
+  std::string IncreaseRateLabel() const {
+    return (rtc::StringBuilder(kLabelPrefix)
+            << VolumeTypeLabel() << "IncreaseRate")
+        .str();
+  }
+  std::string IncreaseAverageLabel() const {
+    return (rtc::StringBuilder(kLabelPrefix)
+            << VolumeTypeLabel() << "IncreaseAverage")
+        .str();
+  }
+  std::string UpdateRateLabel() const {
+    return (rtc::StringBuilder(kLabelPrefix)
+            << VolumeTypeLabel() << "UpdateRate")
+        .str();
+  }
+  std::string UpdateAverageLabel() const {
+    return (rtc::StringBuilder(kLabelPrefix)
+            << VolumeTypeLabel() << "UpdateAverage")
+        .str();
+  }
+
+ private:
+  absl::string_view VolumeTypeLabel() const {
+    switch (InputVolumeType()) {
+      case InputVolumeType::kApplied:
+        return "AppliedInputVolume.";
+      case InputVolumeType::kRecommended:
+        return "RecommendedInputVolume.";
+    }
+  }
+};
+
+TEST_P(InputVolumeStatsReporterTest, CheckVolumeOnChangeIsEmpty) {
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+  stats_reporter.UpdateStatistics(10);
+  EXPECT_METRIC_THAT(metrics::Samples(VolumeLabel()), ::testing::ElementsAre());
+}
+
+TEST_P(InputVolumeStatsReporterTest, CheckRateAverageStatsEmpty) {
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+  constexpr int kInputVolume = 10;
+  stats_reporter.UpdateStatistics(kInputVolume);
+  // Update almost until the periodic logging and reset.
+  for (int i = 0; i < kFramesIn60Seconds - 2; i += 2) {
+    stats_reporter.UpdateStatistics(kInputVolume + 2);
+    stats_reporter.UpdateStatistics(kInputVolume);
+  }
+  EXPECT_METRIC_THAT(metrics::Samples(UpdateRateLabel()),
+                     ::testing::ElementsAre());
+  EXPECT_METRIC_THAT(metrics::Samples(DecreaseRateLabel()),
+                     ::testing::ElementsAre());
+  EXPECT_METRIC_THAT(metrics::Samples(IncreaseRateLabel()),
+                     ::testing::ElementsAre());
+  EXPECT_METRIC_THAT(metrics::Samples(UpdateAverageLabel()),
+                     ::testing::ElementsAre());
+  EXPECT_METRIC_THAT(metrics::Samples(DecreaseAverageLabel()),
+                     ::testing::ElementsAre());
+  EXPECT_METRIC_THAT(metrics::Samples(IncreaseAverageLabel()),
+                     ::testing::ElementsAre());
+}
+
+TEST_P(InputVolumeStatsReporterTest, CheckSamples) {
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+
+  constexpr int kInputVolume1 = 10;
+  stats_reporter.UpdateStatistics(kInputVolume1);
+  // Update until periodic logging.
+  constexpr int kInputVolume2 = 12;
+  for (int i = 0; i < kFramesIn60Seconds; i += 2) {
+    stats_reporter.UpdateStatistics(kInputVolume2);
+    stats_reporter.UpdateStatistics(kInputVolume1);
+  }
+  // Update until periodic logging.
+  constexpr int kInputVolume3 = 13;
+  for (int i = 0; i < kFramesIn60Seconds; i += 2) {
+    stats_reporter.UpdateStatistics(kInputVolume3);
+    stats_reporter.UpdateStatistics(kInputVolume1);
+  }
+
+  // Check volume changes stats.
+  EXPECT_METRIC_THAT(
+      metrics::Samples(VolumeLabel()),
+      ::testing::ElementsAre(
+          ::testing::Pair(kInputVolume1, kFramesIn60Seconds),
+          ::testing::Pair(kInputVolume2, kFramesIn60Seconds / 2),
+          ::testing::Pair(kInputVolume3, kFramesIn60Seconds / 2)));
+
+  // Check volume change rate stats.
+  EXPECT_METRIC_THAT(
+      metrics::Samples(UpdateRateLabel()),
+      ::testing::ElementsAre(::testing::Pair(kFramesIn60Seconds - 1, 1),
+                             ::testing::Pair(kFramesIn60Seconds, 1)));
+  EXPECT_METRIC_THAT(
+      metrics::Samples(DecreaseRateLabel()),
+      ::testing::ElementsAre(::testing::Pair(kFramesIn60Seconds / 2 - 1, 1),
+                             ::testing::Pair(kFramesIn60Seconds / 2, 1)));
+  EXPECT_METRIC_THAT(
+      metrics::Samples(IncreaseRateLabel()),
+      ::testing::ElementsAre(::testing::Pair(kFramesIn60Seconds / 2, 2)));
+
+  // Check volume change average stats.
+  EXPECT_METRIC_THAT(
+      metrics::Samples(UpdateAverageLabel()),
+      ::testing::ElementsAre(::testing::Pair(2, 1), ::testing::Pair(3, 1)));
+  EXPECT_METRIC_THAT(
+      metrics::Samples(DecreaseAverageLabel()),
+      ::testing::ElementsAre(::testing::Pair(2, 1), ::testing::Pair(3, 1)));
+  EXPECT_METRIC_THAT(
+      metrics::Samples(IncreaseAverageLabel()),
+      ::testing::ElementsAre(::testing::Pair(2, 1), ::testing::Pair(3, 1)));
+}
+}  // namespace
+
+TEST_P(InputVolumeStatsReporterTest, CheckVolumeUpdateStatsForEmptyStats) {
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+  const auto& update_stats = stats_reporter.volume_update_stats();
+  EXPECT_EQ(update_stats.num_decreases, 0);
+  EXPECT_EQ(update_stats.sum_decreases, 0);
+  EXPECT_EQ(update_stats.num_increases, 0);
+  EXPECT_EQ(update_stats.sum_increases, 0);
+}
+
+TEST_P(InputVolumeStatsReporterTest,
+       CheckVolumeUpdateStatsAfterNoVolumeChange) {
+  constexpr int kInputVolume = 10;
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+  stats_reporter.UpdateStatistics(kInputVolume);
+  stats_reporter.UpdateStatistics(kInputVolume);
+  stats_reporter.UpdateStatistics(kInputVolume);
+  const auto& update_stats = stats_reporter.volume_update_stats();
+  EXPECT_EQ(update_stats.num_decreases, 0);
+  EXPECT_EQ(update_stats.sum_decreases, 0);
+  EXPECT_EQ(update_stats.num_increases, 0);
+  EXPECT_EQ(update_stats.sum_increases, 0);
+}
+
+TEST_P(InputVolumeStatsReporterTest,
+       CheckVolumeUpdateStatsAfterVolumeIncrease) {
+  constexpr int kInputVolume = 10;
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+  stats_reporter.UpdateStatistics(kInputVolume);
+  stats_reporter.UpdateStatistics(kInputVolume + 4);
+  stats_reporter.UpdateStatistics(kInputVolume + 5);
+  const auto& update_stats = stats_reporter.volume_update_stats();
+  EXPECT_EQ(update_stats.num_decreases, 0);
+  EXPECT_EQ(update_stats.sum_decreases, 0);
+  EXPECT_EQ(update_stats.num_increases, 2);
+  EXPECT_EQ(update_stats.sum_increases, 5);
+}
+
+TEST_P(InputVolumeStatsReporterTest,
+       CheckVolumeUpdateStatsAfterVolumeDecrease) {
+  constexpr int kInputVolume = 10;
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+  stats_reporter.UpdateStatistics(kInputVolume);
+  stats_reporter.UpdateStatistics(kInputVolume - 4);
+  stats_reporter.UpdateStatistics(kInputVolume - 5);
+  const auto& stats_update = stats_reporter.volume_update_stats();
+  EXPECT_EQ(stats_update.num_decreases, 2);
+  EXPECT_EQ(stats_update.sum_decreases, 5);
+  EXPECT_EQ(stats_update.num_increases, 0);
+  EXPECT_EQ(stats_update.sum_increases, 0);
+}
+
+TEST_P(InputVolumeStatsReporterTest, CheckVolumeUpdateStatsAfterReset) {
+  InputVolumeStatsReporter stats_reporter(InputVolumeType());
+  constexpr int kInputVolume = 10;
+  stats_reporter.UpdateStatistics(kInputVolume);
+  // Update until the periodic reset.
+  for (int i = 0; i < kFramesIn60Seconds - 2; i += 2) {
+    stats_reporter.UpdateStatistics(kInputVolume + 2);
+    stats_reporter.UpdateStatistics(kInputVolume);
+  }
+  const auto& stats_before_reset = stats_reporter.volume_update_stats();
+  EXPECT_EQ(stats_before_reset.num_decreases, kFramesIn60Seconds / 2 - 1);
+  EXPECT_EQ(stats_before_reset.sum_decreases, kFramesIn60Seconds - 2);
+  EXPECT_EQ(stats_before_reset.num_increases, kFramesIn60Seconds / 2 - 1);
+  EXPECT_EQ(stats_before_reset.sum_increases, kFramesIn60Seconds - 2);
+  stats_reporter.UpdateStatistics(kInputVolume + 2);
+  const auto& stats_during_reset = stats_reporter.volume_update_stats();
+  EXPECT_EQ(stats_during_reset.num_decreases, 0);
+  EXPECT_EQ(stats_during_reset.sum_decreases, 0);
+  EXPECT_EQ(stats_during_reset.num_increases, 0);
+  EXPECT_EQ(stats_during_reset.sum_increases, 0);
+  stats_reporter.UpdateStatistics(kInputVolume);
+  stats_reporter.UpdateStatistics(kInputVolume + 3);
+  const auto& stats_after_reset = stats_reporter.volume_update_stats();
+  EXPECT_EQ(stats_after_reset.num_decreases, 1);
+  EXPECT_EQ(stats_after_reset.sum_decreases, 2);
+  EXPECT_EQ(stats_after_reset.num_increases, 1);
+  EXPECT_EQ(stats_after_reset.sum_increases, 3);
+}
+
+INSTANTIATE_TEST_SUITE_P(,
+                         InputVolumeStatsReporterTest,
+                         ::testing::Values(InputVolumeType::kApplied,
+                                           InputVolumeType::kRecommended));
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve.cc b/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve.cc
new file mode 100644
index 0000000000..bb6e038514
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve.cc
@@ -0,0 +1,204 @@
+/*
+ *  Copyright (c) 2018 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/agc2/interpolated_gain_curve.h"
+
+#include <algorithm>
+#include <iterator>
+
+#include "absl/strings/string_view.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/strings/string_builder.h"
+
+namespace webrtc {
+
+constexpr std::array<float, kInterpolatedGainCurveTotalPoints>
+    InterpolatedGainCurve::approximation_params_x_;
+
+constexpr std::array<float, kInterpolatedGainCurveTotalPoints>
+    InterpolatedGainCurve::approximation_params_m_;
+
+constexpr std::array<float, kInterpolatedGainCurveTotalPoints>
+    InterpolatedGainCurve::approximation_params_q_;
+
+InterpolatedGainCurve::InterpolatedGainCurve(
+    ApmDataDumper* apm_data_dumper,
+    absl::string_view histogram_name_prefix)
+    : region_logger_(
+          (rtc::StringBuilder("WebRTC.Audio.")
+           << histogram_name_prefix << ".FixedDigitalGainCurveRegion.Identity")
+              .str(),
+          (rtc::StringBuilder("WebRTC.Audio.")
+           << histogram_name_prefix << ".FixedDigitalGainCurveRegion.Knee")
+              .str(),
+          (rtc::StringBuilder("WebRTC.Audio.")
+           << histogram_name_prefix << ".FixedDigitalGainCurveRegion.Limiter")
+              .str(),
+          (rtc::StringBuilder("WebRTC.Audio.")
+           << histogram_name_prefix
+           << ".FixedDigitalGainCurveRegion.Saturation")
+              .str()),
+      apm_data_dumper_(apm_data_dumper) {}
+
+InterpolatedGainCurve::~InterpolatedGainCurve() {
+  if (stats_.available) {
+    RTC_DCHECK(apm_data_dumper_);
+    apm_data_dumper_->DumpRaw("agc2_interp_gain_curve_lookups_identity",
+                              stats_.look_ups_identity_region);
+    apm_data_dumper_->DumpRaw("agc2_interp_gain_curve_lookups_knee",
+                              stats_.look_ups_knee_region);
+    apm_data_dumper_->DumpRaw("agc2_interp_gain_curve_lookups_limiter",
+                              stats_.look_ups_limiter_region);
+    apm_data_dumper_->DumpRaw("agc2_interp_gain_curve_lookups_saturation",
+                              stats_.look_ups_saturation_region);
+    region_logger_.LogRegionStats(stats_);
+  }
+}
+
+InterpolatedGainCurve::RegionLogger::RegionLogger(
+    absl::string_view identity_histogram_name,
+    absl::string_view knee_histogram_name,
+    absl::string_view limiter_histogram_name,
+    absl::string_view saturation_histogram_name)
+    : identity_histogram(
+          metrics::HistogramFactoryGetCounts(identity_histogram_name,
+                                             1,
+                                             10000,
+                                             50)),
+      knee_histogram(metrics::HistogramFactoryGetCounts(knee_histogram_name,
+                                                        1,
+                                                        10000,
+                                                        50)),
+      limiter_histogram(
+          metrics::HistogramFactoryGetCounts(limiter_histogram_name,
+                                             1,
+                                             10000,
+                                             50)),
+      saturation_histogram(
+          metrics::HistogramFactoryGetCounts(saturation_histogram_name,
+                                             1,
+                                             10000,
+                                             50)) {}
+
+InterpolatedGainCurve::RegionLogger::~RegionLogger() = default;
+
+void InterpolatedGainCurve::RegionLogger::LogRegionStats(
+    const InterpolatedGainCurve::Stats& stats) const {
+  using Region = InterpolatedGainCurve::GainCurveRegion;
+  const int duration_s =
+      stats.region_duration_frames / (1000 / kFrameDurationMs);
+
+  switch (stats.region) {
+    case Region::kIdentity: {
+      if (identity_histogram) {
+        metrics::HistogramAdd(identity_histogram, duration_s);
+      }
+      break;
+    }
+    case Region::kKnee: {
+      if (knee_histogram) {
+        metrics::HistogramAdd(knee_histogram, duration_s);
+      }
+      break;
+    }
+    case Region::kLimiter: {
+      if (limiter_histogram) {
+        metrics::HistogramAdd(limiter_histogram, duration_s);
+      }
+      break;
+    }
+    case Region::kSaturation: {
+      if (saturation_histogram) {
+        metrics::HistogramAdd(saturation_histogram, duration_s);
+      }
+      break;
+    }
+    default: {
+      RTC_DCHECK_NOTREACHED();
+    }
+  }
+}
+
+void InterpolatedGainCurve::UpdateStats(float input_level) const {
+  stats_.available = true;
+
+  GainCurveRegion region;
+
+  if (input_level < approximation_params_x_[0]) {
+    stats_.look_ups_identity_region++;
+    region = GainCurveRegion::kIdentity;
+  } else if (input_level <
+             approximation_params_x_[kInterpolatedGainCurveKneePoints - 1]) {
+    stats_.look_ups_knee_region++;
+    region = GainCurveRegion::kKnee;
+  } else if (input_level < kMaxInputLevelLinear) {
+    stats_.look_ups_limiter_region++;
+    region = GainCurveRegion::kLimiter;
+  } else {
+    stats_.look_ups_saturation_region++;
+    region = GainCurveRegion::kSaturation;
+  }
+
+  if (region == stats_.region) {
+    ++stats_.region_duration_frames;
+  } else {
+    region_logger_.LogRegionStats(stats_);
+
+    stats_.region_duration_frames = 0;
+    stats_.region = region;
+  }
+}
+
+// Looks up a gain to apply given a non-negative input level.
+// The cost of this operation depends on the region in which `input_level`
+// falls.
+// For the identity and the saturation regions the cost is O(1).
+// For the other regions, namely knee and limiter, the cost is
+// O(2 + log2(`LightkInterpolatedGainCurveTotalPoints`), plus O(1) for the
+// linear interpolation (one product and one sum).
+float InterpolatedGainCurve::LookUpGainToApply(float input_level) const {
+  UpdateStats(input_level);
+
+  if (input_level <= approximation_params_x_[0]) {
+    // Identity region.
+    return 1.0f;
+  }
+
+  if (input_level >= kMaxInputLevelLinear) {
+    // Saturating lower bound. The saturing samples exactly hit the clipping
+    // level. This method achieves has the lowest harmonic distorsion, but it
+    // may reduce the amplitude of the non-saturating samples too much.
+    return 32768.f / input_level;
+  }
+
+  // Knee and limiter regions; find the linear piece index. Spelling
+  // out the complete type was the only way to silence both the clang
+  // plugin and the windows compilers.
+  std::array<float, kInterpolatedGainCurveTotalPoints>::const_iterator it =
+      std::lower_bound(approximation_params_x_.begin(),
+                       approximation_params_x_.end(), input_level);
+  const size_t index = std::distance(approximation_params_x_.begin(), it) - 1;
+  RTC_DCHECK_LE(0, index);
+  RTC_DCHECK_LT(index, approximation_params_m_.size());
+  RTC_DCHECK_LE(approximation_params_x_[index], input_level);
+  if (index < approximation_params_m_.size() - 1) {
+    RTC_DCHECK_LE(input_level, approximation_params_x_[index + 1]);
+  }
+
+  // Piece-wise linear interploation.
+  const float gain = approximation_params_m_[index] * input_level +
+                     approximation_params_q_[index];
+  RTC_DCHECK_LE(0.f, gain);
+  return gain;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve.h b/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve.h
new file mode 100644
index 0000000000..8dd3e48f21
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve.h
@@ -0,0 +1,152 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_INTERPOLATED_GAIN_CURVE_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_INTERPOLATED_GAIN_CURVE_H_
+
+#include <array>
+
+#include "absl/strings/string_view.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "rtc_base/gtest_prod_util.h"
+#include "system_wrappers/include/metrics.h"
+
+namespace webrtc {
+
+class ApmDataDumper;
+
+constexpr float kInputLevelScalingFactor = 32768.0f;
+
+// Defined as DbfsToLinear(kLimiterMaxInputLevelDbFs)
+constexpr float kMaxInputLevelLinear = static_cast<float>(36766.300710566735);
+
+// Interpolated gain curve using under-approximation to avoid saturation.
+//
+// The goal of this class is allowing fast look ups to get an accurate
+// estimates of the gain to apply given an estimated input level.
+class InterpolatedGainCurve {
+ public:
+  enum class GainCurveRegion {
+    kIdentity = 0,
+    kKnee = 1,
+    kLimiter = 2,
+    kSaturation = 3
+  };
+
+  struct Stats {
+    // Region in which the output level equals the input one.
+    size_t look_ups_identity_region = 0;
+    // Smoothing between the identity and the limiter regions.
+    size_t look_ups_knee_region = 0;
+    // Limiter region in which the output and input levels are linearly related.
+    size_t look_ups_limiter_region = 0;
+    // Region in which saturation may occur since the input level is beyond the
+    // maximum expected by the limiter.
+    size_t look_ups_saturation_region = 0;
+    // True if stats have been populated.
+    bool available = false;
+
+    // The current region, and for how many frames the level has been
+    // in that region.
+    GainCurveRegion region = GainCurveRegion::kIdentity;
+    int64_t region_duration_frames = 0;
+  };
+
+  InterpolatedGainCurve(ApmDataDumper* apm_data_dumper,
+                        absl::string_view histogram_name_prefix);
+  ~InterpolatedGainCurve();
+
+  InterpolatedGainCurve(const InterpolatedGainCurve&) = delete;
+  InterpolatedGainCurve& operator=(const InterpolatedGainCurve&) = delete;
+
+  Stats get_stats() const { return stats_; }
+
+  // Given a non-negative input level (linear scale), a scalar factor to apply
+  // to a sub-frame is returned.
+  // Levels above kLimiterMaxInputLevelDbFs will be reduced to 0 dBFS
+  // after applying this gain
+  float LookUpGainToApply(float input_level) const;
+
+ private:
+  // For comparing 'approximation_params_*_' with ones computed by
+  // ComputeInterpolatedGainCurve.
+  FRIEND_TEST_ALL_PREFIXES(GainController2InterpolatedGainCurve,
+                           CheckApproximationParams);
+
+  struct RegionLogger {
+    metrics::Histogram* identity_histogram;
+    metrics::Histogram* knee_histogram;
+    metrics::Histogram* limiter_histogram;
+    metrics::Histogram* saturation_histogram;
+
+    RegionLogger(absl::string_view identity_histogram_name,
+                 absl::string_view knee_histogram_name,
+                 absl::string_view limiter_histogram_name,
+                 absl::string_view saturation_histogram_name);
+
+    ~RegionLogger();
+
+    void LogRegionStats(const InterpolatedGainCurve::Stats& stats) const;
+  } region_logger_;
+
+  void UpdateStats(float input_level) const;
+
+  ApmDataDumper* const apm_data_dumper_;
+
+  static constexpr std::array<float, kInterpolatedGainCurveTotalPoints>
+      approximation_params_x_ = {
+          {30057.296875,    30148.986328125, 30240.67578125,  30424.052734375,
+           30607.4296875,   30790.806640625, 30974.18359375,  31157.560546875,
+           31340.939453125, 31524.31640625,  31707.693359375, 31891.0703125,
+           32074.447265625, 32257.82421875,  32441.201171875, 32624.580078125,
+           32807.95703125,  32991.33203125,  33174.7109375,   33358.08984375,
+           33541.46484375,  33724.84375,     33819.53515625,  34009.5390625,
+           34200.05859375,  34389.81640625,  34674.48828125,  35054.375,
+           35434.86328125,  35814.81640625,  36195.16796875,  36575.03125}};
+  static constexpr std::array<float, kInterpolatedGainCurveTotalPoints>
+      approximation_params_m_ = {
+          {-3.515235675877192989e-07, -1.050251626111275982e-06,
+           -2.085213736791047268e-06, -3.443004743530764244e-06,
+           -4.773849468620028347e-06, -6.077375928725814447e-06,
+           -7.353257842623861507e-06, -8.601219633419532329e-06,
+           -9.821013009059242904e-06, -1.101243378798244521e-05,
+           -1.217532644659513608e-05, -1.330956911260727793e-05,
+           -1.441507538402220234e-05, -1.549179251014720649e-05,
+           -1.653970684856176376e-05, -1.755882840370759368e-05,
+           -1.854918446042574942e-05, -1.951086778717581183e-05,
+           -2.044398024736437947e-05, -2.1348627342376858e-05,
+           -2.222496914328075945e-05, -2.265374678245279938e-05,
+           -2.242570917587727308e-05, -2.220122041762806475e-05,
+           -2.19802095671184361e-05,  -2.176260204578284174e-05,
+           -2.133731686626560986e-05, -2.092481918225530535e-05,
+           -2.052459603874012828e-05, -2.013615448959171772e-05,
+           -1.975903069251216948e-05, -1.939277899509761482e-05}};
+
+  static constexpr std::array<float, kInterpolatedGainCurveTotalPoints>
+      approximation_params_q_ = {
+          {1.010565876960754395, 1.031631827354431152, 1.062929749488830566,
+           1.104239225387573242, 1.144973039627075195, 1.185109615325927734,
+           1.224629044532775879, 1.263512492179870605, 1.301741957664489746,
+           1.339300632476806641, 1.376173257827758789, 1.412345528602600098,
+           1.447803974151611328, 1.482536554336547852, 1.516532182693481445,
+           1.549780607223510742, 1.582272171974182129, 1.613999366760253906,
+           1.644955039024353027, 1.675132393836975098, 1.704526185989379883,
+           1.718986630439758301, 1.711274504661560059, 1.703639745712280273,
+           1.696081161499023438, 1.688597679138183594, 1.673851132392883301,
+           1.659391283988952637, 1.645209431648254395, 1.631297469139099121,
+           1.617647409439086914, 1.604251742362976074}};
+
+  // Stats.
+  mutable Stats stats_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_INTERPOLATED_GAIN_CURVE_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve_unittest.cc
new file mode 100644
index 0000000000..7861ae997d
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/interpolated_gain_curve_unittest.cc
@@ -0,0 +1,203 @@
+/*
+ *  Copyright (c) 2018 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/agc2/interpolated_gain_curve.h"
+
+#include <array>
+#include <type_traits>
+#include <vector>
+
+#include "api/array_view.h"
+#include "common_audio/include/audio_util.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/agc2/compute_interpolated_gain_curve.h"
+#include "modules/audio_processing/agc2/limiter_db_gain_curve.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+
+constexpr double kLevelEpsilon = 1e-2 * kMaxAbsFloatS16Value;
+constexpr float kInterpolatedGainCurveTolerance = 1.f / 32768.f;
+ApmDataDumper apm_data_dumper(0);
+static_assert(std::is_trivially_destructible<LimiterDbGainCurve>::value, "");
+const LimiterDbGainCurve limiter;
+
+}  // namespace
+
+TEST(GainController2InterpolatedGainCurve, CreateUse) {
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels = test::LinSpace(
+      kLevelEpsilon, DbfsToFloatS16(limiter.max_input_level_db() + 1), 500);
+  for (const auto level : levels) {
+    EXPECT_GE(igc.LookUpGainToApply(level), 0.0f);
+  }
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckValidOutput) {
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels = test::LinSpace(
+      kLevelEpsilon, limiter.max_input_level_linear() * 2.0, 500);
+  for (const auto level : levels) {
+    SCOPED_TRACE(std::to_string(level));
+    const float gain = igc.LookUpGainToApply(level);
+    EXPECT_LE(0.0f, gain);
+    EXPECT_LE(gain, 1.0f);
+  }
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckMonotonicity) {
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels = test::LinSpace(
+      kLevelEpsilon, limiter.max_input_level_linear() + kLevelEpsilon + 0.5,
+      500);
+  float prev_gain = igc.LookUpGainToApply(0.0f);
+  for (const auto level : levels) {
+    const float gain = igc.LookUpGainToApply(level);
+    EXPECT_GE(prev_gain, gain);
+    prev_gain = gain;
+  }
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckApproximation) {
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels = test::LinSpace(
+      kLevelEpsilon, limiter.max_input_level_linear() - kLevelEpsilon, 500);
+  for (const auto level : levels) {
+    SCOPED_TRACE(std::to_string(level));
+    EXPECT_LT(
+        std::fabs(limiter.GetGainLinear(level) - igc.LookUpGainToApply(level)),
+        kInterpolatedGainCurveTolerance);
+  }
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckRegionBoundaries) {
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const std::vector<double> levels{
+      {kLevelEpsilon, limiter.knee_start_linear() + kLevelEpsilon,
+       limiter.limiter_start_linear() + kLevelEpsilon,
+       limiter.max_input_level_linear() + kLevelEpsilon}};
+  for (const auto level : levels) {
+    igc.LookUpGainToApply(level);
+  }
+
+  const auto stats = igc.get_stats();
+  EXPECT_EQ(1ul, stats.look_ups_identity_region);
+  EXPECT_EQ(1ul, stats.look_ups_knee_region);
+  EXPECT_EQ(1ul, stats.look_ups_limiter_region);
+  EXPECT_EQ(1ul, stats.look_ups_saturation_region);
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckIdentityRegion) {
+  constexpr size_t kNumSteps = 10;
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels =
+      test::LinSpace(kLevelEpsilon, limiter.knee_start_linear(), kNumSteps);
+  for (const auto level : levels) {
+    SCOPED_TRACE(std::to_string(level));
+    EXPECT_EQ(1.0f, igc.LookUpGainToApply(level));
+  }
+
+  const auto stats = igc.get_stats();
+  EXPECT_EQ(kNumSteps - 1, stats.look_ups_identity_region);
+  EXPECT_EQ(1ul, stats.look_ups_knee_region);
+  EXPECT_EQ(0ul, stats.look_ups_limiter_region);
+  EXPECT_EQ(0ul, stats.look_ups_saturation_region);
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckNoOverApproximationKnee) {
+  constexpr size_t kNumSteps = 10;
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels =
+      test::LinSpace(limiter.knee_start_linear() + kLevelEpsilon,
+                     limiter.limiter_start_linear(), kNumSteps);
+  for (const auto level : levels) {
+    SCOPED_TRACE(std::to_string(level));
+    // Small tolerance added (needed because comparing a float with a double).
+    EXPECT_LE(igc.LookUpGainToApply(level),
+              limiter.GetGainLinear(level) + 1e-7);
+  }
+
+  const auto stats = igc.get_stats();
+  EXPECT_EQ(0ul, stats.look_ups_identity_region);
+  EXPECT_EQ(kNumSteps - 1, stats.look_ups_knee_region);
+  EXPECT_EQ(1ul, stats.look_ups_limiter_region);
+  EXPECT_EQ(0ul, stats.look_ups_saturation_region);
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckNoOverApproximationBeyondKnee) {
+  constexpr size_t kNumSteps = 10;
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels = test::LinSpace(
+      limiter.limiter_start_linear() + kLevelEpsilon,
+      limiter.max_input_level_linear() - kLevelEpsilon, kNumSteps);
+  for (const auto level : levels) {
+    SCOPED_TRACE(std::to_string(level));
+    // Small tolerance added (needed because comparing a float with a double).
+    EXPECT_LE(igc.LookUpGainToApply(level),
+              limiter.GetGainLinear(level) + 1e-7);
+  }
+
+  const auto stats = igc.get_stats();
+  EXPECT_EQ(0ul, stats.look_ups_identity_region);
+  EXPECT_EQ(0ul, stats.look_ups_knee_region);
+  EXPECT_EQ(kNumSteps, stats.look_ups_limiter_region);
+  EXPECT_EQ(0ul, stats.look_ups_saturation_region);
+}
+
+TEST(GainController2InterpolatedGainCurve,
+     CheckNoOverApproximationWithSaturation) {
+  constexpr size_t kNumSteps = 3;
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  const auto levels = test::LinSpace(
+      limiter.max_input_level_linear() + kLevelEpsilon,
+      limiter.max_input_level_linear() + kLevelEpsilon + 0.5, kNumSteps);
+  for (const auto level : levels) {
+    SCOPED_TRACE(std::to_string(level));
+    EXPECT_LE(igc.LookUpGainToApply(level), limiter.GetGainLinear(level));
+  }
+
+  const auto stats = igc.get_stats();
+  EXPECT_EQ(0ul, stats.look_ups_identity_region);
+  EXPECT_EQ(0ul, stats.look_ups_knee_region);
+  EXPECT_EQ(0ul, stats.look_ups_limiter_region);
+  EXPECT_EQ(kNumSteps, stats.look_ups_saturation_region);
+}
+
+TEST(GainController2InterpolatedGainCurve, CheckApproximationParams) {
+  test::InterpolatedParameters parameters =
+      test::ComputeInterpolatedGainCurveApproximationParams();
+
+  InterpolatedGainCurve igc(&apm_data_dumper, "");
+
+  for (size_t i = 0; i < kInterpolatedGainCurveTotalPoints; ++i) {
+    // The tolerance levels are chosen to account for deviations due
+    // to computing with single precision floating point numbers.
+    EXPECT_NEAR(igc.approximation_params_x_[i],
+                parameters.computed_approximation_params_x[i], 0.9f);
+    EXPECT_NEAR(igc.approximation_params_m_[i],
+                parameters.computed_approximation_params_m[i], 0.00001f);
+    EXPECT_NEAR(igc.approximation_params_q_[i],
+                parameters.computed_approximation_params_q[i], 0.001f);
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/limiter.cc b/third_party/libwebrtc/modules/audio_processing/agc2/limiter.cc
new file mode 100644
index 0000000000..7a1e2202be
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/limiter.cc
@@ -0,0 +1,155 @@
+/*
+ *  Copyright (c) 2018 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/agc2/limiter.h"
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+
+#include "absl/strings/string_view.h"
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_conversions.h"
+#include "rtc_base/numerics/safe_minmax.h"
+
+namespace webrtc {
+namespace {
+
+// This constant affects the way scaling factors are interpolated for the first
+// sub-frame of a frame. Only in the case in which the first sub-frame has an
+// estimated level which is greater than the that of the previous analyzed
+// sub-frame, linear interpolation is replaced with a power function which
+// reduces the chances of over-shooting (and hence saturation), however reducing
+// the fixed gain effectiveness.
+constexpr float kAttackFirstSubframeInterpolationPower = 8.0f;
+
+void InterpolateFirstSubframe(float last_factor,
+                              float current_factor,
+                              rtc::ArrayView<float> subframe) {
+  const int n = rtc::dchecked_cast<int>(subframe.size());
+  constexpr float p = kAttackFirstSubframeInterpolationPower;
+  for (int i = 0; i < n; ++i) {
+    subframe[i] = std::pow(1.f - i / n, p) * (last_factor - current_factor) +
+                  current_factor;
+  }
+}
+
+void ComputePerSampleSubframeFactors(
+    const std::array<float, kSubFramesInFrame + 1>& scaling_factors,
+    int samples_per_channel,
+    rtc::ArrayView<float> per_sample_scaling_factors) {
+  const int num_subframes = scaling_factors.size() - 1;
+  const int subframe_size =
+      rtc::CheckedDivExact(samples_per_channel, num_subframes);
+
+  // Handle first sub-frame differently in case of attack.
+  const bool is_attack = scaling_factors[0] > scaling_factors[1];
+  if (is_attack) {
+    InterpolateFirstSubframe(
+        scaling_factors[0], scaling_factors[1],
+        rtc::ArrayView<float>(
+            per_sample_scaling_factors.subview(0, subframe_size)));
+  }
+
+  for (int i = is_attack ? 1 : 0; i < num_subframes; ++i) {
+    const int subframe_start = i * subframe_size;
+    const float scaling_start = scaling_factors[i];
+    const float scaling_end = scaling_factors[i + 1];
+    const float scaling_diff = (scaling_end - scaling_start) / subframe_size;
+    for (int j = 0; j < subframe_size; ++j) {
+      per_sample_scaling_factors[subframe_start + j] =
+          scaling_start + scaling_diff * j;
+    }
+  }
+}
+
+void ScaleSamples(rtc::ArrayView<const float> per_sample_scaling_factors,
+                  AudioFrameView<float> signal) {
+  const int samples_per_channel = signal.samples_per_channel();
+  RTC_DCHECK_EQ(samples_per_channel, per_sample_scaling_factors.size());
+  for (int i = 0; i < signal.num_channels(); ++i) {
+    rtc::ArrayView<float> channel = signal.channel(i);
+    for (int j = 0; j < samples_per_channel; ++j) {
+      channel[j] = rtc::SafeClamp(channel[j] * per_sample_scaling_factors[j],
+                                  kMinFloatS16Value, kMaxFloatS16Value);
+    }
+  }
+}
+
+void CheckLimiterSampleRate(int sample_rate_hz) {
+  // Check that per_sample_scaling_factors_ is large enough.
+  RTC_DCHECK_LE(sample_rate_hz,
+                kMaximalNumberOfSamplesPerChannel * 1000 / kFrameDurationMs);
+}
+
+}  // namespace
+
+Limiter::Limiter(int sample_rate_hz,
+                 ApmDataDumper* apm_data_dumper,
+                 absl::string_view histogram_name)
+    : interp_gain_curve_(apm_data_dumper, histogram_name),
+      level_estimator_(sample_rate_hz, apm_data_dumper),
+      apm_data_dumper_(apm_data_dumper) {
+  CheckLimiterSampleRate(sample_rate_hz);
+}
+
+Limiter::~Limiter() = default;
+
+void Limiter::Process(AudioFrameView<float> signal) {
+  const std::array<float, kSubFramesInFrame> level_estimate =
+      level_estimator_.ComputeLevel(signal);
+
+  RTC_DCHECK_EQ(level_estimate.size() + 1, scaling_factors_.size());
+  scaling_factors_[0] = last_scaling_factor_;
+  std::transform(level_estimate.begin(), level_estimate.end(),
+                 scaling_factors_.begin() + 1, [this](float x) {
+                   return interp_gain_curve_.LookUpGainToApply(x);
+                 });
+
+  const int samples_per_channel = signal.samples_per_channel();
+  RTC_DCHECK_LE(samples_per_channel, kMaximalNumberOfSamplesPerChannel);
+
+  auto per_sample_scaling_factors = rtc::ArrayView<float>(
+      &per_sample_scaling_factors_[0], samples_per_channel);
+  ComputePerSampleSubframeFactors(scaling_factors_, samples_per_channel,
+                                  per_sample_scaling_factors);
+  ScaleSamples(per_sample_scaling_factors, signal);
+
+  last_scaling_factor_ = scaling_factors_.back();
+
+  // Dump data for debug.
+  apm_data_dumper_->DumpRaw("agc2_limiter_last_scaling_factor",
+                            last_scaling_factor_);
+  apm_data_dumper_->DumpRaw(
+      "agc2_limiter_region",
+      static_cast<int>(interp_gain_curve_.get_stats().region));
+}
+
+InterpolatedGainCurve::Stats Limiter::GetGainCurveStats() const {
+  return interp_gain_curve_.get_stats();
+}
+
+void Limiter::SetSampleRate(int sample_rate_hz) {
+  CheckLimiterSampleRate(sample_rate_hz);
+  level_estimator_.SetSampleRate(sample_rate_hz);
+}
+
+void Limiter::Reset() {
+  level_estimator_.Reset();
+}
+
+float Limiter::LastAudioLevel() const {
+  return level_estimator_.LastAudioLevel();
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/limiter.h b/third_party/libwebrtc/modules/audio_processing/agc2/limiter.h
new file mode 100644
index 0000000000..d4d556349c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/limiter.h
@@ -0,0 +1,63 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_LIMITER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_LIMITER_H_
+
+#include <vector>
+
+#include "absl/strings/string_view.h"
+#include "modules/audio_processing/agc2/fixed_digital_level_estimator.h"
+#include "modules/audio_processing/agc2/interpolated_gain_curve.h"
+#include "modules/audio_processing/include/audio_frame_view.h"
+
+namespace webrtc {
+class ApmDataDumper;
+
+class Limiter {
+ public:
+  Limiter(int sample_rate_hz,
+          ApmDataDumper* apm_data_dumper,
+          absl::string_view histogram_name_prefix);
+  Limiter(const Limiter& limiter) = delete;
+  Limiter& operator=(const Limiter& limiter) = delete;
+  ~Limiter();
+
+  // Applies limiter and hard-clipping to `signal`.
+  void Process(AudioFrameView<float> signal);
+  InterpolatedGainCurve::Stats GetGainCurveStats() const;
+
+  // Supported rates must be
+  // * supported by FixedDigitalLevelEstimator
+  // * below kMaximalNumberOfSamplesPerChannel*1000/kFrameDurationMs
+  //   so that samples_per_channel fit in the
+  //   per_sample_scaling_factors_ array.
+  void SetSampleRate(int sample_rate_hz);
+
+  // Resets the internal state.
+  void Reset();
+
+  float LastAudioLevel() const;
+
+ private:
+  const InterpolatedGainCurve interp_gain_curve_;
+  FixedDigitalLevelEstimator level_estimator_;
+  ApmDataDumper* const apm_data_dumper_ = nullptr;
+
+  // Work array containing the sub-frame scaling factors to be interpolated.
+  std::array<float, kSubFramesInFrame + 1> scaling_factors_ = {};
+  std::array<float, kMaximalNumberOfSamplesPerChannel>
+      per_sample_scaling_factors_ = {};
+  float last_scaling_factor_ = 1.f;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_LIMITER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve.cc b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve.cc
new file mode 100644
index 0000000000..d47c0b2e17
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve.cc
@@ -0,0 +1,138 @@
+/*
+ *  Copyright (c) 2018 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/agc2/limiter_db_gain_curve.h"
+
+#include <cmath>
+
+#include "common_audio/include/audio_util.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace {
+
+double ComputeKneeStart(double max_input_level_db,
+                        double knee_smoothness_db,
+                        double compression_ratio) {
+  RTC_CHECK_LT((compression_ratio - 1.0) * knee_smoothness_db /
+                   (2.0 * compression_ratio),
+               max_input_level_db);
+  return -knee_smoothness_db / 2.0 -
+         max_input_level_db / (compression_ratio - 1.0);
+}
+
+std::array<double, 3> ComputeKneeRegionPolynomial(double knee_start_dbfs,
+                                                  double knee_smoothness_db,
+                                                  double compression_ratio) {
+  const double a = (1.0 - compression_ratio) /
+                   (2.0 * knee_smoothness_db * compression_ratio);
+  const double b = 1.0 - 2.0 * a * knee_start_dbfs;
+  const double c = a * knee_start_dbfs * knee_start_dbfs;
+  return {{a, b, c}};
+}
+
+double ComputeLimiterD1(double max_input_level_db, double compression_ratio) {
+  return (std::pow(10.0, -max_input_level_db / (20.0 * compression_ratio)) *
+          (1.0 - compression_ratio) / compression_ratio) /
+         kMaxAbsFloatS16Value;
+}
+
+constexpr double ComputeLimiterD2(double compression_ratio) {
+  return (1.0 - 2.0 * compression_ratio) / compression_ratio;
+}
+
+double ComputeLimiterI2(double max_input_level_db,
+                        double compression_ratio,
+                        double gain_curve_limiter_i1) {
+  RTC_CHECK_NE(gain_curve_limiter_i1, 0.f);
+  return std::pow(10.0, -max_input_level_db / (20.0 * compression_ratio)) /
+         gain_curve_limiter_i1 /
+         std::pow(kMaxAbsFloatS16Value, gain_curve_limiter_i1 - 1);
+}
+
+}  // namespace
+
+LimiterDbGainCurve::LimiterDbGainCurve()
+    : max_input_level_linear_(DbfsToFloatS16(max_input_level_db_)),
+      knee_start_dbfs_(ComputeKneeStart(max_input_level_db_,
+                                        knee_smoothness_db_,
+                                        compression_ratio_)),
+      knee_start_linear_(DbfsToFloatS16(knee_start_dbfs_)),
+      limiter_start_dbfs_(knee_start_dbfs_ + knee_smoothness_db_),
+      limiter_start_linear_(DbfsToFloatS16(limiter_start_dbfs_)),
+      knee_region_polynomial_(ComputeKneeRegionPolynomial(knee_start_dbfs_,
+                                                          knee_smoothness_db_,
+                                                          compression_ratio_)),
+      gain_curve_limiter_d1_(
+          ComputeLimiterD1(max_input_level_db_, compression_ratio_)),
+      gain_curve_limiter_d2_(ComputeLimiterD2(compression_ratio_)),
+      gain_curve_limiter_i1_(1.0 / compression_ratio_),
+      gain_curve_limiter_i2_(ComputeLimiterI2(max_input_level_db_,
+                                              compression_ratio_,
+                                              gain_curve_limiter_i1_)) {
+  static_assert(knee_smoothness_db_ > 0.0f, "");
+  static_assert(compression_ratio_ > 1.0f, "");
+  RTC_CHECK_GE(max_input_level_db_, knee_start_dbfs_ + knee_smoothness_db_);
+}
+
+constexpr double LimiterDbGainCurve::max_input_level_db_;
+constexpr double LimiterDbGainCurve::knee_smoothness_db_;
+constexpr double LimiterDbGainCurve::compression_ratio_;
+
+double LimiterDbGainCurve::GetOutputLevelDbfs(double input_level_dbfs) const {
+  if (input_level_dbfs < knee_start_dbfs_) {
+    return input_level_dbfs;
+  } else if (input_level_dbfs < limiter_start_dbfs_) {
+    return GetKneeRegionOutputLevelDbfs(input_level_dbfs);
+  }
+  return GetCompressorRegionOutputLevelDbfs(input_level_dbfs);
+}
+
+double LimiterDbGainCurve::GetGainLinear(double input_level_linear) const {
+  if (input_level_linear < knee_start_linear_) {
+    return 1.0;
+  }
+  return DbfsToFloatS16(
+             GetOutputLevelDbfs(FloatS16ToDbfs(input_level_linear))) /
+         input_level_linear;
+}
+
+// Computes the first derivative of GetGainLinear() in `x`.
+double LimiterDbGainCurve::GetGainFirstDerivativeLinear(double x) const {
+  // Beyond-knee region only.
+  RTC_CHECK_GE(x, limiter_start_linear_ - 1e-7 * kMaxAbsFloatS16Value);
+  return gain_curve_limiter_d1_ *
+         std::pow(x / kMaxAbsFloatS16Value, gain_curve_limiter_d2_);
+}
+
+// Computes the integral of GetGainLinear() in the range [x0, x1].
+double LimiterDbGainCurve::GetGainIntegralLinear(double x0, double x1) const {
+  RTC_CHECK_LE(x0, x1);                     // Valid interval.
+  RTC_CHECK_GE(x0, limiter_start_linear_);  // Beyond-knee region only.
+  auto limiter_integral = [this](const double& x) {
+    return gain_curve_limiter_i2_ * std::pow(x, gain_curve_limiter_i1_);
+  };
+  return limiter_integral(x1) - limiter_integral(x0);
+}
+
+double LimiterDbGainCurve::GetKneeRegionOutputLevelDbfs(
+    double input_level_dbfs) const {
+  return knee_region_polynomial_[0] * input_level_dbfs * input_level_dbfs +
+         knee_region_polynomial_[1] * input_level_dbfs +
+         knee_region_polynomial_[2];
+}
+
+double LimiterDbGainCurve::GetCompressorRegionOutputLevelDbfs(
+    double input_level_dbfs) const {
+  return (input_level_dbfs - max_input_level_db_) / compression_ratio_;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve.h b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve.h
new file mode 100644
index 0000000000..9086e26739
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve.h
@@ -0,0 +1,76 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_LIMITER_DB_GAIN_CURVE_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_LIMITER_DB_GAIN_CURVE_H_
+
+#include <array>
+
+#include "modules/audio_processing/agc2/agc2_testing_common.h"
+
+namespace webrtc {
+
+// A class for computing a limiter gain curve (in dB scale) given a set of
+// hard-coded parameters (namely, kLimiterDbGainCurveMaxInputLevelDbFs,
+// kLimiterDbGainCurveKneeSmoothnessDb, and
+// kLimiterDbGainCurveCompressionRatio). The generated curve consists of four
+// regions: identity (linear), knee (quadratic polynomial), compression
+// (linear), saturation (linear). The aforementioned constants are used to shape
+// the different regions.
+class LimiterDbGainCurve {
+ public:
+  LimiterDbGainCurve();
+
+  double max_input_level_db() const { return max_input_level_db_; }
+  double max_input_level_linear() const { return max_input_level_linear_; }
+  double knee_start_linear() const { return knee_start_linear_; }
+  double limiter_start_linear() const { return limiter_start_linear_; }
+
+  // These methods can be marked 'constexpr' in C++ 14.
+  double GetOutputLevelDbfs(double input_level_dbfs) const;
+  double GetGainLinear(double input_level_linear) const;
+  double GetGainFirstDerivativeLinear(double x) const;
+  double GetGainIntegralLinear(double x0, double x1) const;
+
+ private:
+  double GetKneeRegionOutputLevelDbfs(double input_level_dbfs) const;
+  double GetCompressorRegionOutputLevelDbfs(double input_level_dbfs) const;
+
+  static constexpr double max_input_level_db_ = test::kLimiterMaxInputLevelDbFs;
+  static constexpr double knee_smoothness_db_ = test::kLimiterKneeSmoothnessDb;
+  static constexpr double compression_ratio_ = test::kLimiterCompressionRatio;
+
+  const double max_input_level_linear_;
+
+  // Do not modify signal with level <= knee_start_dbfs_.
+  const double knee_start_dbfs_;
+  const double knee_start_linear_;
+
+  // The upper end of the knee region, which is between knee_start_dbfs_ and
+  // limiter_start_dbfs_.
+  const double limiter_start_dbfs_;
+  const double limiter_start_linear_;
+
+  // Coefficients {a, b, c} of the knee region polynomial
+  // ax^2 + bx + c in the DB scale.
+  const std::array<double, 3> knee_region_polynomial_;
+
+  // Parameters for the computation of the first derivative of GetGainLinear().
+  const double gain_curve_limiter_d1_;
+  const double gain_curve_limiter_d2_;
+
+  // Parameters for the computation of the integral of GetGainLinear().
+  const double gain_curve_limiter_i1_;
+  const double gain_curve_limiter_i2_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_LIMITER_DB_GAIN_CURVE_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve_unittest.cc
new file mode 100644
index 0000000000..049c8d568e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_db_gain_curve_unittest.cc
@@ -0,0 +1,60 @@
+/*
+ *  Copyright (c) 2018 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/agc2/limiter_db_gain_curve.h"
+
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+
+TEST(FixedDigitalGainController2Limiter, ConstructDestruct) {
+  LimiterDbGainCurve l;
+}
+
+TEST(FixedDigitalGainController2Limiter, GainCurveShouldBeMonotone) {
+  LimiterDbGainCurve l;
+  float last_output_level = 0.f;
+  bool has_last_output_level = false;
+  for (float level = -90.f; level <= l.max_input_level_db(); level += 0.5f) {
+    const float current_output_level = l.GetOutputLevelDbfs(level);
+    if (!has_last_output_level) {
+      last_output_level = current_output_level;
+      has_last_output_level = true;
+    }
+    EXPECT_LE(last_output_level, current_output_level);
+    last_output_level = current_output_level;
+  }
+}
+
+TEST(FixedDigitalGainController2Limiter, GainCurveShouldBeContinuous) {
+  LimiterDbGainCurve l;
+  float last_output_level = 0.f;
+  bool has_last_output_level = false;
+  constexpr float kMaxDelta = 0.5f;
+  for (float level = -90.f; level <= l.max_input_level_db(); level += 0.5f) {
+    const float current_output_level = l.GetOutputLevelDbfs(level);
+    if (!has_last_output_level) {
+      last_output_level = current_output_level;
+      has_last_output_level = true;
+    }
+    EXPECT_LE(current_output_level, last_output_level + kMaxDelta);
+    last_output_level = current_output_level;
+  }
+}
+
+TEST(FixedDigitalGainController2Limiter, OutputGainShouldBeLessThanFullScale) {
+  LimiterDbGainCurve l;
+  for (float level = -90.f; level <= l.max_input_level_db(); level += 0.5f) {
+    const float current_output_level = l.GetOutputLevelDbfs(level);
+    EXPECT_LE(current_output_level, 0.f);
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/limiter_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_unittest.cc
new file mode 100644
index 0000000000..e662a7fc89
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/limiter_unittest.cc
@@ -0,0 +1,60 @@
+/*
+ *  Copyright (c) 2018 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/agc2/limiter.h"
+
+#include "common_audio/include/audio_util.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/agc2/agc2_testing_common.h"
+#include "modules/audio_processing/agc2/vector_float_frame.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+
+TEST(Limiter, LimiterShouldConstructAndRun) {
+  const int sample_rate_hz = 48000;
+  ApmDataDumper apm_data_dumper(0);
+
+  Limiter limiter(sample_rate_hz, &apm_data_dumper, "");
+
+  VectorFloatFrame vectors_with_float_frame(1, sample_rate_hz / 100,
+                                            kMaxAbsFloatS16Value);
+  limiter.Process(vectors_with_float_frame.float_frame_view());
+}
+
+TEST(Limiter, OutputVolumeAboveThreshold) {
+  const int sample_rate_hz = 48000;
+  const float input_level =
+      (kMaxAbsFloatS16Value + DbfsToFloatS16(test::kLimiterMaxInputLevelDbFs)) /
+      2.f;
+  ApmDataDumper apm_data_dumper(0);
+
+  Limiter limiter(sample_rate_hz, &apm_data_dumper, "");
+
+  // Give the level estimator time to adapt.
+  for (int i = 0; i < 5; ++i) {
+    VectorFloatFrame vectors_with_float_frame(1, sample_rate_hz / 100,
+                                              input_level);
+    limiter.Process(vectors_with_float_frame.float_frame_view());
+  }
+
+  VectorFloatFrame vectors_with_float_frame(1, sample_rate_hz / 100,
+                                            input_level);
+  limiter.Process(vectors_with_float_frame.float_frame_view());
+  rtc::ArrayView<const float> channel =
+      vectors_with_float_frame.float_frame_view().channel(0);
+
+  for (const auto& sample : channel) {
+    EXPECT_LT(0.9f * kMaxAbsFloatS16Value, sample);
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator.cc b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator.cc
new file mode 100644
index 0000000000..691513b509
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator.cc
@@ -0,0 +1,172 @@
+/*
+ *  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/agc2/noise_level_estimator.h"
+
+#include <stddef.h>
+
+#include <algorithm>
+#include <cmath>
+#include <numeric>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kFramesPerSecond = 100;
+
+float FrameEnergy(const AudioFrameView<const float>& audio) {
+  float energy = 0.0f;
+  for (int k = 0; k < audio.num_channels(); ++k) {
+    float channel_energy =
+        std::accumulate(audio.channel(k).begin(), audio.channel(k).end(), 0.0f,
+                        [](float a, float b) -> float { return a + b * b; });
+    energy = std::max(channel_energy, energy);
+  }
+  return energy;
+}
+
+float EnergyToDbfs(float signal_energy, int num_samples) {
+  RTC_DCHECK_GE(signal_energy, 0.0f);
+  const float rms_square = signal_energy / num_samples;
+  constexpr float kMinDbfs = -90.30899869919436f;
+  if (rms_square <= 1.0f) {
+    return kMinDbfs;
+  }
+  return 10.0f * std::log10(rms_square) + kMinDbfs;
+}
+
+// Updates the noise floor with instant decay and slow attack. This tuning is
+// specific for AGC2, so that (i) it can promptly increase the gain if the noise
+// floor drops (instant decay) and (ii) in case of music or fast speech, due to
+// which the noise floor can be overestimated, the gain reduction is slowed
+// down.
+float SmoothNoiseFloorEstimate(float current_estimate, float new_estimate) {
+  constexpr float kAttack = 0.5f;
+  if (current_estimate < new_estimate) {
+    // Attack phase.
+    return kAttack * new_estimate + (1.0f - kAttack) * current_estimate;
+  }
+  // Instant attack.
+  return new_estimate;
+}
+
+class NoiseFloorEstimator : public NoiseLevelEstimator {
+ public:
+  // Update the noise floor every 5 seconds.
+  static constexpr int kUpdatePeriodNumFrames = 500;
+  static_assert(kUpdatePeriodNumFrames >= 200,
+                "A too small value may cause noise level overestimation.");
+  static_assert(kUpdatePeriodNumFrames <= 1500,
+                "A too large value may make AGC2 slow at reacting to increased "
+                "noise levels.");
+
+  NoiseFloorEstimator(ApmDataDumper* data_dumper) : data_dumper_(data_dumper) {
+    RTC_DCHECK(data_dumper_);
+    // Initially assume that 48 kHz will be used. `Analyze()` will detect the
+    // used sample rate and call `Initialize()` again if needed.
+    Initialize(/*sample_rate_hz=*/48000);
+  }
+  NoiseFloorEstimator(const NoiseFloorEstimator&) = delete;
+  NoiseFloorEstimator& operator=(const NoiseFloorEstimator&) = delete;
+  ~NoiseFloorEstimator() = default;
+
+  float Analyze(const AudioFrameView<const float>& frame) override {
+    // Detect sample rate changes.
+    const int sample_rate_hz =
+        static_cast<int>(frame.samples_per_channel() * kFramesPerSecond);
+    if (sample_rate_hz != sample_rate_hz_) {
+      Initialize(sample_rate_hz);
+    }
+
+    const float frame_energy = FrameEnergy(frame);
+    if (frame_energy <= min_noise_energy_) {
+      // Ignore frames when muted or below the minimum measurable energy.
+      if (data_dumper_)
+        data_dumper_->DumpRaw("agc2_noise_floor_estimator_preliminary_level",
+                              noise_energy_);
+      return EnergyToDbfs(noise_energy_,
+                          static_cast<int>(frame.samples_per_channel()));
+    }
+
+    if (preliminary_noise_energy_set_) {
+      preliminary_noise_energy_ =
+          std::min(preliminary_noise_energy_, frame_energy);
+    } else {
+      preliminary_noise_energy_ = frame_energy;
+      preliminary_noise_energy_set_ = true;
+    }
+    if (data_dumper_)
+      data_dumper_->DumpRaw("agc2_noise_floor_estimator_preliminary_level",
+                            preliminary_noise_energy_);
+
+    if (counter_ == 0) {
+      // Full period observed.
+      first_period_ = false;
+      // Update the estimated noise floor energy with the preliminary
+      // estimation.
+      noise_energy_ = SmoothNoiseFloorEstimate(
+          /*current_estimate=*/noise_energy_,
+          /*new_estimate=*/preliminary_noise_energy_);
+      // Reset for a new observation period.
+      counter_ = kUpdatePeriodNumFrames;
+      preliminary_noise_energy_set_ = false;
+    } else if (first_period_) {
+      // While analyzing the signal during the initial period, continuously
+      // update the estimated noise energy, which is monotonic.
+      noise_energy_ = preliminary_noise_energy_;
+      counter_--;
+    } else {
+      // During the observation period it's only allowed to lower the energy.
+      noise_energy_ = std::min(noise_energy_, preliminary_noise_energy_);
+      counter_--;
+    }
+
+    float noise_rms_dbfs = EnergyToDbfs(
+        noise_energy_, static_cast<int>(frame.samples_per_channel()));
+    if (data_dumper_)
+      data_dumper_->DumpRaw("agc2_noise_rms_dbfs", noise_rms_dbfs);
+
+    return noise_rms_dbfs;
+  }
+
+ private:
+  void Initialize(int sample_rate_hz) {
+    sample_rate_hz_ = sample_rate_hz;
+    first_period_ = true;
+    preliminary_noise_energy_set_ = false;
+    // Initialize the minimum noise energy to -84 dBFS.
+    min_noise_energy_ = sample_rate_hz * 2.0f * 2.0f / kFramesPerSecond;
+    preliminary_noise_energy_ = min_noise_energy_;
+    noise_energy_ = min_noise_energy_;
+    counter_ = kUpdatePeriodNumFrames;
+  }
+
+  ApmDataDumper* const data_dumper_;
+  int sample_rate_hz_;
+  float min_noise_energy_;
+  bool first_period_;
+  bool preliminary_noise_energy_set_;
+  float preliminary_noise_energy_;
+  float noise_energy_;
+  int counter_;
+};
+
+}  // namespace
+
+std::unique_ptr<NoiseLevelEstimator> CreateNoiseFloorEstimator(
+    ApmDataDumper* data_dumper) {
+  return std::make_unique<NoiseFloorEstimator>(data_dumper);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator.h b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator.h
new file mode 100644
index 0000000000..9f3b957486
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator.h
@@ -0,0 +1,36 @@
+/*
+ *  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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_AGC2_NOISE_LEVEL_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_NOISE_LEVEL_ESTIMATOR_H_
+
+#include <memory>
+
+#include "modules/audio_processing/include/audio_frame_view.h"
+
+namespace webrtc {
+class ApmDataDumper;
+
+// Noise level estimator interface.
+class NoiseLevelEstimator {
+ public:
+  virtual ~NoiseLevelEstimator() = default;
+  // Analyzes a 10 ms `frame`, updates the noise level estimation and returns
+  // the value for the latter in dBFS.
+  virtual float Analyze(const AudioFrameView<const float>& frame) = 0;
+};
+
+// Creates a noise level estimator based on noise floor detection.
+std::unique_ptr<NoiseLevelEstimator> CreateNoiseFloorEstimator(
+    ApmDataDumper* data_dumper);
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_NOISE_LEVEL_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator_gn/moz.build
new file mode 100644
index 0000000000..ba000d3862
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator_gn/moz.build
@@ -0,0 +1,233 @@
+# 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/agc2/noise_level_estimator.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("noise_level_estimator_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator_unittest.cc
new file mode 100644
index 0000000000..8168c5a229
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/noise_level_estimator_unittest.cc
@@ -0,0 +1,98 @@
+/*
+ *  Copyright (c) 2018 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/agc2/noise_level_estimator.h"
+
+#include <array>
+#include <cmath>
+#include <functional>
+#include <limits>
+
+#include "api/function_view.h"
+#include "modules/audio_processing/agc2/agc2_testing_common.h"
+#include "modules/audio_processing/agc2/vector_float_frame.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kNumIterations = 200;
+constexpr int kFramesPerSecond = 100;
+
+// Runs the noise estimator on audio generated by 'sample_generator'
+// for kNumIterations. Returns the last noise level estimate.
+float RunEstimator(rtc::FunctionView<float()> sample_generator,
+                   NoiseLevelEstimator& estimator,
+                   int sample_rate_hz) {
+  const int samples_per_channel =
+      rtc::CheckedDivExact(sample_rate_hz, kFramesPerSecond);
+  VectorFloatFrame signal(1, samples_per_channel, 0.0f);
+  for (int i = 0; i < kNumIterations; ++i) {
+    AudioFrameView<float> frame_view = signal.float_frame_view();
+    for (int j = 0; j < samples_per_channel; ++j) {
+      frame_view.channel(0)[j] = sample_generator();
+    }
+    estimator.Analyze(frame_view);
+  }
+  return estimator.Analyze(signal.float_frame_view());
+}
+
+class NoiseEstimatorParametrization : public ::testing::TestWithParam<int> {
+ protected:
+  int sample_rate_hz() const { return GetParam(); }
+};
+
+// Checks that full scale white noise maps to about -5.5 dBFS.
+TEST_P(NoiseEstimatorParametrization, NoiseFloorEstimatorWithRandomNoise) {
+  ApmDataDumper data_dumper(0);
+  auto estimator = CreateNoiseFloorEstimator(&data_dumper);
+
+  test::WhiteNoiseGenerator gen(/*min_amplitude=*/test::kMinS16,
+                                /*max_amplitude=*/test::kMaxS16);
+  const float noise_level_dbfs =
+      RunEstimator(gen, *estimator, sample_rate_hz());
+  EXPECT_NEAR(noise_level_dbfs, -5.5f, 0.5f);
+}
+
+// Checks that a full scale sine wave maps to about -3 dBFS.
+TEST_P(NoiseEstimatorParametrization, NoiseFloorEstimatorWithSineTone) {
+  ApmDataDumper data_dumper(0);
+  auto estimator = CreateNoiseFloorEstimator(&data_dumper);
+
+  test::SineGenerator gen(/*amplitude=*/test::kMaxS16, /*frequency_hz=*/600.0f,
+                          sample_rate_hz());
+  const float noise_level_dbfs =
+      RunEstimator(gen, *estimator, sample_rate_hz());
+  EXPECT_NEAR(noise_level_dbfs, -3.0f, 0.1f);
+}
+
+// Check that sufficiently spaced periodic pulses do not raise the estimated
+// noise floor, which is determined by the amplitude of the non-pulse samples.
+TEST_P(NoiseEstimatorParametrization, NoiseFloorEstimatorWithPulseTone) {
+  ApmDataDumper data_dumper(0);
+  auto estimator = CreateNoiseFloorEstimator(&data_dumper);
+
+  constexpr float kNoPulseAmplitude = 10.0f;
+  test::PulseGenerator gen(/*pulse_amplitude=*/test::kMaxS16, kNoPulseAmplitude,
+                           /*frequency_hz=*/20.0f, sample_rate_hz());
+  const float noise_level_dbfs =
+      RunEstimator(gen, *estimator, sample_rate_hz());
+  const float expected_noise_floor_dbfs =
+      20.0f * std::log10f(kNoPulseAmplitude / test::kMaxS16);
+  EXPECT_NEAR(noise_level_dbfs, expected_noise_floor_dbfs, 0.5f);
+}
+
+INSTANTIATE_TEST_SUITE_P(GainController2NoiseEstimator,
+                         NoiseEstimatorParametrization,
+                         ::testing::Values(8000, 16000, 32000, 48000));
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/BUILD.gn b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/BUILD.gn
new file mode 100644
index 0000000000..d709eb3699
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/BUILD.gn
@@ -0,0 +1,334 @@
+# Copyright (c) 2018 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_library("rnn_vad") {
+  visibility = [ "../*" ]
+  sources = [
+    "features_extraction.cc",
+    "features_extraction.h",
+    "rnn.cc",
+    "rnn.h",
+  ]
+
+  defines = []
+  if (rtc_build_with_neon && target_cpu != "arm64") {
+    suppressed_configs += [ "//build/config/compiler:compiler_arm_fpu" ]
+    cflags = [ "-mfpu=neon" ]
+  }
+
+  deps = [
+    ":rnn_vad_common",
+    ":rnn_vad_layers",
+    ":rnn_vad_lp_residual",
+    ":rnn_vad_pitch",
+    ":rnn_vad_sequence_buffer",
+    ":rnn_vad_spectral_features",
+    "..:biquad_filter",
+    "..:cpu_features",
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+    "../../../../rtc_base:safe_compare",
+    "../../../../rtc_base:safe_conversions",
+    "//third_party/rnnoise:rnn_vad",
+  ]
+}
+
+rtc_library("rnn_vad_auto_correlation") {
+  sources = [
+    "auto_correlation.cc",
+    "auto_correlation.h",
+  ]
+  deps = [
+    ":rnn_vad_common",
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+    "../../utility:pffft_wrapper",
+  ]
+}
+
+rtc_source_set("rnn_vad_common") {
+  # TODO(alessiob): Make this target visibility private.
+  visibility = [
+    ":*",
+    "..:vad_wrapper",
+  ]
+  sources = [ "common.h" ]
+  deps = [
+    "../../../../rtc_base/system:arch",
+    "../../../../system_wrappers",
+  ]
+}
+
+rtc_library("rnn_vad_lp_residual") {
+  sources = [
+    "lp_residual.cc",
+    "lp_residual.h",
+  ]
+  deps = [
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+    "../../../../rtc_base:safe_compare",
+  ]
+}
+
+rtc_source_set("rnn_vad_layers") {
+  sources = [
+    "rnn_fc.cc",
+    "rnn_fc.h",
+    "rnn_gru.cc",
+    "rnn_gru.h",
+  ]
+
+  defines = []
+  if (rtc_build_with_neon && current_cpu != "arm64") {
+    suppressed_configs += [ "//build/config/compiler:compiler_arm_fpu" ]
+    cflags = [ "-mfpu=neon" ]
+  }
+
+  deps = [
+    ":rnn_vad_common",
+    ":vector_math",
+    "..:cpu_features",
+    "../../../../api:array_view",
+    "../../../../api:function_view",
+    "../../../../rtc_base:checks",
+    "../../../../rtc_base:safe_conversions",
+    "//third_party/rnnoise:rnn_vad",
+  ]
+  if (current_cpu == "x86" || current_cpu == "x64") {
+    deps += [ ":vector_math_avx2" ]
+  }
+  absl_deps = [ "//third_party/abseil-cpp/absl/strings" ]
+}
+
+rtc_source_set("vector_math") {
+  sources = [ "vector_math.h" ]
+  deps = [
+    "..:cpu_features",
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+    "../../../../rtc_base:safe_conversions",
+    "../../../../rtc_base/system:arch",
+  ]
+}
+
+if (current_cpu == "x86" || current_cpu == "x64") {
+  rtc_library("vector_math_avx2") {
+    sources = [ "vector_math_avx2.cc" ]
+    if (is_win && !build_with_mozilla) {
+      cflags = [ "/arch:AVX2" ]
+    } else {
+      cflags = [
+        "-mavx2",
+        "-mfma",
+      ]
+    }
+    deps = [
+      ":vector_math",
+      "../../../../api:array_view",
+      "../../../../rtc_base:checks",
+      "../../../../rtc_base:safe_conversions",
+    ]
+  }
+}
+
+rtc_library("rnn_vad_pitch") {
+  sources = [
+    "pitch_search.cc",
+    "pitch_search.h",
+    "pitch_search_internal.cc",
+    "pitch_search_internal.h",
+  ]
+
+  defines = []
+  if (rtc_build_with_neon && current_cpu != "arm64") {
+    suppressed_configs += [ "//build/config/compiler:compiler_arm_fpu" ]
+    cflags = [ "-mfpu=neon" ]
+  }
+
+  deps = [
+    ":rnn_vad_auto_correlation",
+    ":rnn_vad_common",
+    ":vector_math",
+    "..:cpu_features",
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+    "../../../../rtc_base:gtest_prod",
+    "../../../../rtc_base:safe_compare",
+    "../../../../rtc_base:safe_conversions",
+    "../../../../rtc_base/system:arch",
+  ]
+  if (current_cpu == "x86" || current_cpu == "x64") {
+    deps += [ ":vector_math_avx2" ]
+  }
+}
+
+rtc_source_set("rnn_vad_ring_buffer") {
+  sources = [ "ring_buffer.h" ]
+  deps = [
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+  ]
+}
+
+rtc_source_set("rnn_vad_sequence_buffer") {
+  sources = [ "sequence_buffer.h" ]
+  deps = [
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+  ]
+}
+
+rtc_library("rnn_vad_spectral_features") {
+  sources = [
+    "spectral_features.cc",
+    "spectral_features.h",
+    "spectral_features_internal.cc",
+    "spectral_features_internal.h",
+  ]
+  deps = [
+    ":rnn_vad_common",
+    ":rnn_vad_ring_buffer",
+    ":rnn_vad_symmetric_matrix_buffer",
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+    "../../../../rtc_base:safe_compare",
+    "../../utility:pffft_wrapper",
+  ]
+}
+
+rtc_source_set("rnn_vad_symmetric_matrix_buffer") {
+  sources = [ "symmetric_matrix_buffer.h" ]
+  deps = [
+    "../../../../api:array_view",
+    "../../../../rtc_base:checks",
+    "../../../../rtc_base:safe_compare",
+  ]
+}
+
+if (rtc_include_tests) {
+  rtc_library("test_utils") {
+    testonly = true
+    sources = [
+      "test_utils.cc",
+      "test_utils.h",
+    ]
+    deps = [
+      ":rnn_vad",
+      ":rnn_vad_common",
+      "../../../../api:array_view",
+      "../../../../api:scoped_refptr",
+      "../../../../rtc_base:checks",
+      "../../../../rtc_base:safe_compare",
+      "../../../../test:fileutils",
+      "../../../../test:test_support",
+    ]
+    absl_deps = [ "//third_party/abseil-cpp/absl/strings" ]
+  }
+
+  unittest_resources = [
+    "../../../../resources/audio_processing/agc2/rnn_vad/band_energies.dat",
+    "../../../../resources/audio_processing/agc2/rnn_vad/pitch_buf_24k.dat",
+    "../../../../resources/audio_processing/agc2/rnn_vad/pitch_lp_res.dat",
+    "../../../../resources/audio_processing/agc2/rnn_vad/pitch_search_int.dat",
+    "../../../../resources/audio_processing/agc2/rnn_vad/samples.pcm",
+    "../../../../resources/audio_processing/agc2/rnn_vad/vad_prob.dat",
+  ]
+
+  if (is_ios) {
+    bundle_data("unittests_bundle_data") {
+      testonly = true
+      sources = unittest_resources
+      outputs = [ "{{bundle_resources_dir}}/{{source_file_part}}" ]
+    }
+  }
+
+  rtc_library("unittests") {
+    testonly = true
+    sources = [
+      "auto_correlation_unittest.cc",
+      "features_extraction_unittest.cc",
+      "lp_residual_unittest.cc",
+      "pitch_search_internal_unittest.cc",
+      "pitch_search_unittest.cc",
+      "ring_buffer_unittest.cc",
+      "rnn_fc_unittest.cc",
+      "rnn_gru_unittest.cc",
+      "rnn_unittest.cc",
+      "rnn_vad_unittest.cc",
+      "sequence_buffer_unittest.cc",
+      "spectral_features_internal_unittest.cc",
+      "spectral_features_unittest.cc",
+      "symmetric_matrix_buffer_unittest.cc",
+      "vector_math_unittest.cc",
+    ]
+
+    defines = []
+    if (rtc_build_with_neon && current_cpu != "arm64") {
+      suppressed_configs += [ "//build/config/compiler:compiler_arm_fpu" ]
+      cflags = [ "-mfpu=neon" ]
+    }
+
+    deps = [
+      ":rnn_vad",
+      ":rnn_vad_auto_correlation",
+      ":rnn_vad_common",
+      ":rnn_vad_layers",
+      ":rnn_vad_lp_residual",
+      ":rnn_vad_pitch",
+      ":rnn_vad_ring_buffer",
+      ":rnn_vad_sequence_buffer",
+      ":rnn_vad_spectral_features",
+      ":rnn_vad_symmetric_matrix_buffer",
+      ":test_utils",
+      ":vector_math",
+      "..:cpu_features",
+      "../..:audioproc_test_utils",
+      "../../../../api:array_view",
+      "../../../../common_audio/",
+      "../../../../rtc_base:checks",
+      "../../../../rtc_base:logging",
+      "../../../../rtc_base:safe_compare",
+      "../../../../rtc_base:safe_conversions",
+      "../../../../rtc_base:stringutils",
+      "../../../../rtc_base/system:arch",
+      "../../../../test:test_support",
+      "../../utility:pffft_wrapper",
+      "//third_party/rnnoise:rnn_vad",
+    ]
+    if (current_cpu == "x86" || current_cpu == "x64") {
+      deps += [ ":vector_math_avx2" ]
+    }
+    absl_deps = [ "//third_party/abseil-cpp/absl/memory" ]
+    data = unittest_resources
+    if (is_ios) {
+      deps += [ ":unittests_bundle_data" ]
+    }
+  }
+
+  if (!build_with_chromium) {
+    rtc_executable("rnn_vad_tool") {
+      testonly = true
+      sources = [ "rnn_vad_tool.cc" ]
+      deps = [
+        ":rnn_vad",
+        ":rnn_vad_common",
+        "..:cpu_features",
+        "../../../../api:array_view",
+        "../../../../common_audio",
+        "../../../../rtc_base:logging",
+        "../../../../rtc_base:safe_compare",
+        "../../../../test:test_support",
+        "//third_party/abseil-cpp/absl/flags:flag",
+        "//third_party/abseil-cpp/absl/flags:parse",
+      ]
+    }
+  }
+}
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/DEPS b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/DEPS
new file mode 100644
index 0000000000..773c2d7edd
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/DEPS
@@ -0,0 +1,3 @@
+include_rules = [
+  "+third_party/rnnoise",
+]
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation.cc
new file mode 100644
index 0000000000..3ddeec8dba
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation.cc
@@ -0,0 +1,91 @@
+/*
+ *  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/agc2/rnn_vad/auto_correlation.h"
+
+#include <algorithm>
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr int kAutoCorrelationFftOrder = 9;  // Length-512 FFT.
+static_assert(1 << kAutoCorrelationFftOrder >
+                  kNumLags12kHz + kBufSize12kHz - kMaxPitch12kHz,
+              "");
+
+}  // namespace
+
+AutoCorrelationCalculator::AutoCorrelationCalculator()
+    : fft_(1 << kAutoCorrelationFftOrder, Pffft::FftType::kReal),
+      tmp_(fft_.CreateBuffer()),
+      X_(fft_.CreateBuffer()),
+      H_(fft_.CreateBuffer()) {}
+
+AutoCorrelationCalculator::~AutoCorrelationCalculator() = default;
+
+// The auto-correlations coefficients are computed as follows:
+// |.........|...........|  <- pitch buffer
+//           [ x (fixed) ]
+// [   y_0   ]
+//         [ y_{m-1} ]
+// x and y are sub-array of equal length; x is never moved, whereas y slides.
+// The cross-correlation between y_0 and x corresponds to the auto-correlation
+// for the maximum pitch period. Hence, the first value in `auto_corr` has an
+// inverted lag equal to 0 that corresponds to a lag equal to the maximum
+// pitch period.
+void AutoCorrelationCalculator::ComputeOnPitchBuffer(
+    rtc::ArrayView<const float, kBufSize12kHz> pitch_buf,
+    rtc::ArrayView<float, kNumLags12kHz> auto_corr) {
+  RTC_DCHECK_LT(auto_corr.size(), kMaxPitch12kHz);
+  RTC_DCHECK_GT(pitch_buf.size(), kMaxPitch12kHz);
+  constexpr int kFftFrameSize = 1 << kAutoCorrelationFftOrder;
+  constexpr int kConvolutionLength = kBufSize12kHz - kMaxPitch12kHz;
+  static_assert(kConvolutionLength == kFrameSize20ms12kHz,
+                "Mismatch between pitch buffer size, frame size and maximum "
+                "pitch period.");
+  static_assert(kFftFrameSize > kNumLags12kHz + kConvolutionLength,
+                "The FFT length is not sufficiently big to avoid cyclic "
+                "convolution errors.");
+  auto tmp = tmp_->GetView();
+
+  // Compute the FFT for the reversed reference frame - i.e.,
+  // pitch_buf[-kConvolutionLength:].
+  std::reverse_copy(pitch_buf.end() - kConvolutionLength, pitch_buf.end(),
+                    tmp.begin());
+  std::fill(tmp.begin() + kConvolutionLength, tmp.end(), 0.f);
+  fft_.ForwardTransform(*tmp_, H_.get(), /*ordered=*/false);
+
+  // Compute the FFT for the sliding frames chunk. The sliding frames are
+  // defined as pitch_buf[i:i+kConvolutionLength] where i in
+  // [0, kNumLags12kHz). The chunk includes all of them, hence it is
+  // defined as pitch_buf[:kNumLags12kHz+kConvolutionLength].
+  std::copy(pitch_buf.begin(),
+            pitch_buf.begin() + kConvolutionLength + kNumLags12kHz,
+            tmp.begin());
+  std::fill(tmp.begin() + kNumLags12kHz + kConvolutionLength, tmp.end(), 0.f);
+  fft_.ForwardTransform(*tmp_, X_.get(), /*ordered=*/false);
+
+  // Convolve in the frequency domain.
+  constexpr float kScalingFactor = 1.f / static_cast<float>(kFftFrameSize);
+  std::fill(tmp.begin(), tmp.end(), 0.f);
+  fft_.FrequencyDomainConvolve(*X_, *H_, tmp_.get(), kScalingFactor);
+  fft_.BackwardTransform(*tmp_, tmp_.get(), /*ordered=*/false);
+
+  // Extract the auto-correlation coefficients.
+  std::copy(tmp.begin() + kConvolutionLength - 1,
+            tmp.begin() + kConvolutionLength + kNumLags12kHz - 1,
+            auto_corr.begin());
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation.h
new file mode 100644
index 0000000000..1ae5054567
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation.h
@@ -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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_AUTO_CORRELATION_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_AUTO_CORRELATION_H_
+
+#include <memory>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/utility/pffft_wrapper.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Class to compute the auto correlation on the pitch buffer for a target pitch
+// interval.
+class AutoCorrelationCalculator {
+ public:
+  AutoCorrelationCalculator();
+  AutoCorrelationCalculator(const AutoCorrelationCalculator&) = delete;
+  AutoCorrelationCalculator& operator=(const AutoCorrelationCalculator&) =
+      delete;
+  ~AutoCorrelationCalculator();
+
+  // Computes the auto-correlation coefficients for a target pitch interval.
+  // `auto_corr` indexes are inverted lags.
+  void ComputeOnPitchBuffer(
+      rtc::ArrayView<const float, kBufSize12kHz> pitch_buf,
+      rtc::ArrayView<float, kNumLags12kHz> auto_corr);
+
+ private:
+  Pffft fft_;
+  std::unique_ptr<Pffft::FloatBuffer> tmp_;
+  std::unique_ptr<Pffft::FloatBuffer> X_;
+  std::unique_ptr<Pffft::FloatBuffer> H_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_AUTO_CORRELATION_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation_unittest.cc
new file mode 100644
index 0000000000..76001ed7b7
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/auto_correlation_unittest.cc
@@ -0,0 +1,66 @@
+/*
+ *  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/agc2/rnn_vad/auto_correlation.h"
+
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/pitch_search_internal.h"
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// Checks that the auto correlation function produces output within tolerance
+// given test input data.
+TEST(RnnVadTest, PitchBufferAutoCorrelationWithinTolerance) {
+  PitchTestData test_data;
+  std::array<float, kBufSize12kHz> pitch_buf_decimated;
+  Decimate2x(test_data.PitchBuffer24kHzView(), pitch_buf_decimated);
+  std::array<float, kNumLags12kHz> computed_output;
+  {
+    // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+    // FloatingPointExceptionObserver fpe_observer;
+    AutoCorrelationCalculator auto_corr_calculator;
+    auto_corr_calculator.ComputeOnPitchBuffer(pitch_buf_decimated,
+                                              computed_output);
+  }
+  auto auto_corr_view = test_data.AutoCorrelation12kHzView();
+  ExpectNearAbsolute({auto_corr_view.data(), auto_corr_view.size()},
+                     computed_output, 3e-3f);
+}
+
+// Checks that the auto correlation function computes the right thing for a
+// simple use case.
+TEST(RnnVadTest, CheckAutoCorrelationOnConstantPitchBuffer) {
+  // Create constant signal with no pitch.
+  std::array<float, kBufSize12kHz> pitch_buf_decimated;
+  std::fill(pitch_buf_decimated.begin(), pitch_buf_decimated.end(), 1.f);
+  std::array<float, kNumLags12kHz> computed_output;
+  {
+    // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+    // FloatingPointExceptionObserver fpe_observer;
+    AutoCorrelationCalculator auto_corr_calculator;
+    auto_corr_calculator.ComputeOnPitchBuffer(pitch_buf_decimated,
+                                              computed_output);
+  }
+  // The expected output is a vector filled with the same expected
+  // auto-correlation value. The latter equals the length of a 20 ms frame.
+  constexpr int kFrameSize20ms12kHz = kFrameSize20ms24kHz / 2;
+  std::array<float, kNumLags12kHz> expected_output;
+  std::fill(expected_output.begin(), expected_output.end(),
+            static_cast<float>(kFrameSize20ms12kHz));
+  ExpectNearAbsolute(expected_output, computed_output, 4e-5f);
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/common.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/common.h
new file mode 100644
index 0000000000..c099373200
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/common.h
@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_COMMON_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_COMMON_H_
+
+#include <stddef.h>
+
+namespace webrtc {
+namespace rnn_vad {
+
+constexpr double kPi = 3.14159265358979323846;
+
+constexpr int kSampleRate24kHz = 24000;
+constexpr int kFrameSize10ms24kHz = kSampleRate24kHz / 100;
+constexpr int kFrameSize20ms24kHz = kFrameSize10ms24kHz * 2;
+
+// Pitch buffer.
+constexpr int kMinPitch24kHz = kSampleRate24kHz / 800;   // 0.00125 s.
+constexpr int kMaxPitch24kHz = kSampleRate24kHz / 62.5;  // 0.016 s.
+constexpr int kBufSize24kHz = kMaxPitch24kHz + kFrameSize20ms24kHz;
+static_assert((kBufSize24kHz & 1) == 0, "The buffer size must be even.");
+
+// 24 kHz analysis.
+// Define a higher minimum pitch period for the initial search. This is used to
+// avoid searching for very short periods, for which a refinement step is
+// responsible.
+constexpr int kInitialMinPitch24kHz = 3 * kMinPitch24kHz;
+static_assert(kMinPitch24kHz < kInitialMinPitch24kHz, "");
+static_assert(kInitialMinPitch24kHz < kMaxPitch24kHz, "");
+static_assert(kMaxPitch24kHz > kInitialMinPitch24kHz, "");
+// Number of (inverted) lags during the initial pitch search phase at 24 kHz.
+constexpr int kInitialNumLags24kHz = kMaxPitch24kHz - kInitialMinPitch24kHz;
+// Number of (inverted) lags during the pitch search refinement phase at 24 kHz.
+constexpr int kRefineNumLags24kHz = kMaxPitch24kHz + 1;
+static_assert(
+    kRefineNumLags24kHz > kInitialNumLags24kHz,
+    "The refinement step must search the pitch in an extended pitch range.");
+
+// 12 kHz analysis.
+constexpr int kSampleRate12kHz = 12000;
+constexpr int kFrameSize10ms12kHz = kSampleRate12kHz / 100;
+constexpr int kFrameSize20ms12kHz = kFrameSize10ms12kHz * 2;
+constexpr int kBufSize12kHz = kBufSize24kHz / 2;
+constexpr int kInitialMinPitch12kHz = kInitialMinPitch24kHz / 2;
+constexpr int kMaxPitch12kHz = kMaxPitch24kHz / 2;
+static_assert(kMaxPitch12kHz > kInitialMinPitch12kHz, "");
+// The inverted lags for the pitch interval [`kInitialMinPitch12kHz`,
+// `kMaxPitch12kHz`] are in the range [0, `kNumLags12kHz`].
+constexpr int kNumLags12kHz = kMaxPitch12kHz - kInitialMinPitch12kHz;
+
+// 48 kHz constants.
+constexpr int kMinPitch48kHz = kMinPitch24kHz * 2;
+constexpr int kMaxPitch48kHz = kMaxPitch24kHz * 2;
+
+// Spectral features.
+constexpr int kNumBands = 22;
+constexpr int kNumLowerBands = 6;
+static_assert((0 < kNumLowerBands) && (kNumLowerBands < kNumBands), "");
+constexpr int kCepstralCoeffsHistorySize = 8;
+static_assert(kCepstralCoeffsHistorySize > 2,
+              "The history size must at least be 3 to compute first and second "
+              "derivatives.");
+
+constexpr int kFeatureVectorSize = 42;
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_COMMON_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction.cc
new file mode 100644
index 0000000000..502023428d
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction.cc
@@ -0,0 +1,90 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/features_extraction.h"
+
+#include <array>
+
+#include "modules/audio_processing/agc2/rnn_vad/lp_residual.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// Computed as `scipy.signal.butter(N=2, Wn=60/24000, btype='highpass')`.
+constexpr BiQuadFilter::Config kHpfConfig24k{
+    {0.99446179f, -1.98892358f, 0.99446179f},
+    {-1.98889291f, 0.98895425f}};
+
+}  // namespace
+
+FeaturesExtractor::FeaturesExtractor(const AvailableCpuFeatures& cpu_features)
+    : use_high_pass_filter_(false),
+      hpf_(kHpfConfig24k),
+      pitch_buf_24kHz_(),
+      pitch_buf_24kHz_view_(pitch_buf_24kHz_.GetBufferView()),
+      lp_residual_(kBufSize24kHz),
+      lp_residual_view_(lp_residual_.data(), kBufSize24kHz),
+      pitch_estimator_(cpu_features),
+      reference_frame_view_(pitch_buf_24kHz_.GetMostRecentValuesView()) {
+  RTC_DCHECK_EQ(kBufSize24kHz, lp_residual_.size());
+  Reset();
+}
+
+FeaturesExtractor::~FeaturesExtractor() = default;
+
+void FeaturesExtractor::Reset() {
+  pitch_buf_24kHz_.Reset();
+  spectral_features_extractor_.Reset();
+  if (use_high_pass_filter_) {
+    hpf_.Reset();
+  }
+}
+
+bool FeaturesExtractor::CheckSilenceComputeFeatures(
+    rtc::ArrayView<const float, kFrameSize10ms24kHz> samples,
+    rtc::ArrayView<float, kFeatureVectorSize> feature_vector) {
+  // Pre-processing.
+  if (use_high_pass_filter_) {
+    std::array<float, kFrameSize10ms24kHz> samples_filtered;
+    hpf_.Process(samples, samples_filtered);
+    // Feed buffer with the pre-processed version of `samples`.
+    pitch_buf_24kHz_.Push(samples_filtered);
+  } else {
+    // Feed buffer with `samples`.
+    pitch_buf_24kHz_.Push(samples);
+  }
+  // Extract the LP residual.
+  float lpc_coeffs[kNumLpcCoefficients];
+  ComputeAndPostProcessLpcCoefficients(pitch_buf_24kHz_view_, lpc_coeffs);
+  ComputeLpResidual(lpc_coeffs, pitch_buf_24kHz_view_, lp_residual_view_);
+  // Estimate pitch on the LP-residual and write the normalized pitch period
+  // into the output vector (normalization based on training data stats).
+  pitch_period_48kHz_ = pitch_estimator_.Estimate(lp_residual_view_);
+  feature_vector[kFeatureVectorSize - 2] = 0.01f * (pitch_period_48kHz_ - 300);
+  // Extract lagged frames (according to the estimated pitch period).
+  RTC_DCHECK_LE(pitch_period_48kHz_ / 2, kMaxPitch24kHz);
+  auto lagged_frame = pitch_buf_24kHz_view_.subview(
+      kMaxPitch24kHz - pitch_period_48kHz_ / 2, kFrameSize20ms24kHz);
+  // Analyze reference and lagged frames checking if silence has been detected
+  // and write the feature vector.
+  return spectral_features_extractor_.CheckSilenceComputeFeatures(
+      reference_frame_view_, {lagged_frame.data(), kFrameSize20ms24kHz},
+      {feature_vector.data() + kNumLowerBands, kNumBands - kNumLowerBands},
+      {feature_vector.data(), kNumLowerBands},
+      {feature_vector.data() + kNumBands, kNumLowerBands},
+      {feature_vector.data() + kNumBands + kNumLowerBands, kNumLowerBands},
+      {feature_vector.data() + kNumBands + 2 * kNumLowerBands, kNumLowerBands},
+      &feature_vector[kFeatureVectorSize - 1]);
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction.h
new file mode 100644
index 0000000000..d47a85bfb0
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction.h
@@ -0,0 +1,61 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_FEATURES_EXTRACTION_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_FEATURES_EXTRACTION_H_
+
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/biquad_filter.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/pitch_search.h"
+#include "modules/audio_processing/agc2/rnn_vad/sequence_buffer.h"
+#include "modules/audio_processing/agc2/rnn_vad/spectral_features.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Feature extractor to feed the VAD RNN.
+class FeaturesExtractor {
+ public:
+  explicit FeaturesExtractor(const AvailableCpuFeatures& cpu_features);
+  FeaturesExtractor(const FeaturesExtractor&) = delete;
+  FeaturesExtractor& operator=(const FeaturesExtractor&) = delete;
+  ~FeaturesExtractor();
+  void Reset();
+  // Analyzes the samples, computes the feature vector and returns true if
+  // silence is detected (false if not). When silence is detected,
+  // `feature_vector` is partially written and therefore must not be used to
+  // feed the VAD RNN.
+  bool CheckSilenceComputeFeatures(
+      rtc::ArrayView<const float, kFrameSize10ms24kHz> samples,
+      rtc::ArrayView<float, kFeatureVectorSize> feature_vector);
+
+ private:
+  const bool use_high_pass_filter_;
+  // TODO(bugs.webrtc.org/7494): Remove HPF depending on how AGC2 is used in APM
+  // and on whether an HPF is already used as pre-processing step in APM.
+  BiQuadFilter hpf_;
+  SequenceBuffer<float, kBufSize24kHz, kFrameSize10ms24kHz, kFrameSize20ms24kHz>
+      pitch_buf_24kHz_;
+  rtc::ArrayView<const float, kBufSize24kHz> pitch_buf_24kHz_view_;
+  std::vector<float> lp_residual_;
+  rtc::ArrayView<float, kBufSize24kHz> lp_residual_view_;
+  PitchEstimator pitch_estimator_;
+  rtc::ArrayView<const float, kFrameSize20ms24kHz> reference_frame_view_;
+  SpectralFeaturesExtractor spectral_features_extractor_;
+  int pitch_period_48kHz_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_FEATURES_EXTRACTION_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction_unittest.cc
new file mode 100644
index 0000000000..96f956adfe
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/features_extraction_unittest.cc
@@ -0,0 +1,103 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/features_extraction.h"
+
+#include <cmath>
+#include <vector>
+
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "rtc_base/numerics/safe_compare.h"
+#include "rtc_base/numerics/safe_conversions.h"
+// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+// #include "test/fpe_observer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr int ceil(int n, int m) {
+  return (n + m - 1) / m;
+}
+
+// Number of 10 ms frames required to fill a pitch buffer having size
+// `kBufSize24kHz`.
+constexpr int kNumTestDataFrames = ceil(kBufSize24kHz, kFrameSize10ms24kHz);
+// Number of samples for the test data.
+constexpr int kNumTestDataSize = kNumTestDataFrames * kFrameSize10ms24kHz;
+
+// Verifies that the pitch in Hz is in the detectable range.
+bool PitchIsValid(float pitch_hz) {
+  const int pitch_period = static_cast<float>(kSampleRate24kHz) / pitch_hz;
+  return kInitialMinPitch24kHz <= pitch_period &&
+         pitch_period <= kMaxPitch24kHz;
+}
+
+void CreatePureTone(float amplitude, float freq_hz, rtc::ArrayView<float> dst) {
+  for (int i = 0; rtc::SafeLt(i, dst.size()); ++i) {
+    dst[i] = amplitude * std::sin(2.f * kPi * freq_hz * i / kSampleRate24kHz);
+  }
+}
+
+// Feeds `features_extractor` with `samples` splitting it in 10 ms frames.
+// For every frame, the output is written into `feature_vector`. Returns true
+// if silence is detected in the last frame.
+bool FeedTestData(FeaturesExtractor& features_extractor,
+                  rtc::ArrayView<const float> samples,
+                  rtc::ArrayView<float, kFeatureVectorSize> feature_vector) {
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+  bool is_silence = true;
+  const int num_frames = samples.size() / kFrameSize10ms24kHz;
+  for (int i = 0; i < num_frames; ++i) {
+    is_silence = features_extractor.CheckSilenceComputeFeatures(
+        {samples.data() + i * kFrameSize10ms24kHz, kFrameSize10ms24kHz},
+        feature_vector);
+  }
+  return is_silence;
+}
+
+// Extracts the features for two pure tones and verifies that the pitch field
+// values reflect the known tone frequencies.
+TEST(RnnVadTest, FeatureExtractionLowHighPitch) {
+  constexpr float amplitude = 1000.f;
+  constexpr float low_pitch_hz = 150.f;
+  constexpr float high_pitch_hz = 250.f;
+  ASSERT_TRUE(PitchIsValid(low_pitch_hz));
+  ASSERT_TRUE(PitchIsValid(high_pitch_hz));
+
+  const AvailableCpuFeatures cpu_features = GetAvailableCpuFeatures();
+  FeaturesExtractor features_extractor(cpu_features);
+  std::vector<float> samples(kNumTestDataSize);
+  std::vector<float> feature_vector(kFeatureVectorSize);
+  ASSERT_EQ(kFeatureVectorSize, rtc::dchecked_cast<int>(feature_vector.size()));
+  rtc::ArrayView<float, kFeatureVectorSize> feature_vector_view(
+      feature_vector.data(), kFeatureVectorSize);
+
+  // Extract the normalized scalar feature that is proportional to the estimated
+  // pitch period.
+  constexpr int pitch_feature_index = kFeatureVectorSize - 2;
+  // Low frequency tone - i.e., high period.
+  CreatePureTone(amplitude, low_pitch_hz, samples);
+  ASSERT_FALSE(FeedTestData(features_extractor, samples, feature_vector_view));
+  float high_pitch_period = feature_vector_view[pitch_feature_index];
+  // High frequency tone - i.e., low period.
+  features_extractor.Reset();
+  CreatePureTone(amplitude, high_pitch_hz, samples);
+  ASSERT_FALSE(FeedTestData(features_extractor, samples, feature_vector_view));
+  float low_pitch_period = feature_vector_view[pitch_feature_index];
+  // Check.
+  EXPECT_LT(low_pitch_period, high_pitch_period);
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual.cc
new file mode 100644
index 0000000000..484bfba459
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual.cc
@@ -0,0 +1,141 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/lp_residual.h"
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+#include <numeric>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// Computes auto-correlation coefficients for `x` and writes them in
+// `auto_corr`. The lag values are in {0, ..., max_lag - 1}, where max_lag
+// equals the size of `auto_corr`.
+void ComputeAutoCorrelation(
+    rtc::ArrayView<const float> x,
+    rtc::ArrayView<float, kNumLpcCoefficients> auto_corr) {
+  constexpr int max_lag = auto_corr.size();
+  RTC_DCHECK_LT(max_lag, x.size());
+  for (int lag = 0; lag < max_lag; ++lag) {
+    auto_corr[lag] =
+        std::inner_product(x.begin(), x.end() - lag, x.begin() + lag, 0.f);
+  }
+}
+
+// Applies denoising to the auto-correlation coefficients.
+void DenoiseAutoCorrelation(
+    rtc::ArrayView<float, kNumLpcCoefficients> auto_corr) {
+  // Assume -40 dB white noise floor.
+  auto_corr[0] *= 1.0001f;
+  // Hard-coded values obtained as
+  // [np.float32((0.008*0.008*i*i)) for i in range(1,5)].
+  auto_corr[1] -= auto_corr[1] * 0.000064f;
+  auto_corr[2] -= auto_corr[2] * 0.000256f;
+  auto_corr[3] -= auto_corr[3] * 0.000576f;
+  auto_corr[4] -= auto_corr[4] * 0.001024f;
+  static_assert(kNumLpcCoefficients == 5, "Update `auto_corr`.");
+}
+
+// Computes the initial inverse filter coefficients given the auto-correlation
+// coefficients of an input frame.
+void ComputeInitialInverseFilterCoefficients(
+    rtc::ArrayView<const float, kNumLpcCoefficients> auto_corr,
+    rtc::ArrayView<float, kNumLpcCoefficients - 1> lpc_coeffs) {
+  float error = auto_corr[0];
+  for (int i = 0; i < kNumLpcCoefficients - 1; ++i) {
+    float reflection_coeff = 0.f;
+    for (int j = 0; j < i; ++j) {
+      reflection_coeff += lpc_coeffs[j] * auto_corr[i - j];
+    }
+    reflection_coeff += auto_corr[i + 1];
+
+    // Avoid division by numbers close to zero.
+    constexpr float kMinErrorMagnitude = 1e-6f;
+    if (std::fabs(error) < kMinErrorMagnitude) {
+      error = std::copysign(kMinErrorMagnitude, error);
+    }
+
+    reflection_coeff /= -error;
+    // Update LPC coefficients and total error.
+    lpc_coeffs[i] = reflection_coeff;
+    for (int j = 0; j < ((i + 1) >> 1); ++j) {
+      const float tmp1 = lpc_coeffs[j];
+      const float tmp2 = lpc_coeffs[i - 1 - j];
+      lpc_coeffs[j] = tmp1 + reflection_coeff * tmp2;
+      lpc_coeffs[i - 1 - j] = tmp2 + reflection_coeff * tmp1;
+    }
+    error -= reflection_coeff * reflection_coeff * error;
+    if (error < 0.001f * auto_corr[0]) {
+      break;
+    }
+  }
+}
+
+}  // namespace
+
+void ComputeAndPostProcessLpcCoefficients(
+    rtc::ArrayView<const float> x,
+    rtc::ArrayView<float, kNumLpcCoefficients> lpc_coeffs) {
+  std::array<float, kNumLpcCoefficients> auto_corr;
+  ComputeAutoCorrelation(x, auto_corr);
+  if (auto_corr[0] == 0.f) {  // Empty frame.
+    std::fill(lpc_coeffs.begin(), lpc_coeffs.end(), 0);
+    return;
+  }
+  DenoiseAutoCorrelation(auto_corr);
+  std::array<float, kNumLpcCoefficients - 1> lpc_coeffs_pre{};
+  ComputeInitialInverseFilterCoefficients(auto_corr, lpc_coeffs_pre);
+  // LPC coefficients post-processing.
+  // TODO(bugs.webrtc.org/9076): Consider removing these steps.
+  lpc_coeffs_pre[0] *= 0.9f;
+  lpc_coeffs_pre[1] *= 0.9f * 0.9f;
+  lpc_coeffs_pre[2] *= 0.9f * 0.9f * 0.9f;
+  lpc_coeffs_pre[3] *= 0.9f * 0.9f * 0.9f * 0.9f;
+  constexpr float kC = 0.8f;
+  lpc_coeffs[0] = lpc_coeffs_pre[0] + kC;
+  lpc_coeffs[1] = lpc_coeffs_pre[1] + kC * lpc_coeffs_pre[0];
+  lpc_coeffs[2] = lpc_coeffs_pre[2] + kC * lpc_coeffs_pre[1];
+  lpc_coeffs[3] = lpc_coeffs_pre[3] + kC * lpc_coeffs_pre[2];
+  lpc_coeffs[4] = kC * lpc_coeffs_pre[3];
+  static_assert(kNumLpcCoefficients == 5, "Update `lpc_coeffs(_pre)`.");
+}
+
+void ComputeLpResidual(
+    rtc::ArrayView<const float, kNumLpcCoefficients> lpc_coeffs,
+    rtc::ArrayView<const float> x,
+    rtc::ArrayView<float> y) {
+  RTC_DCHECK_GT(x.size(), kNumLpcCoefficients);
+  RTC_DCHECK_EQ(x.size(), y.size());
+  // The code below implements the following operation:
+  // y[i] = x[i] + dot_product({x[i], ..., x[i - kNumLpcCoefficients + 1]},
+  //                           lpc_coeffs)
+  // Edge case: i < kNumLpcCoefficients.
+  y[0] = x[0];
+  for (int i = 1; i < kNumLpcCoefficients; ++i) {
+    y[i] =
+        std::inner_product(x.crend() - i, x.crend(), lpc_coeffs.cbegin(), x[i]);
+  }
+  // Regular case.
+  auto last = x.crend();
+  for (int i = kNumLpcCoefficients; rtc::SafeLt(i, y.size()); ++i, --last) {
+    y[i] = std::inner_product(last - kNumLpcCoefficients, last,
+                              lpc_coeffs.cbegin(), x[i]);
+  }
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual.h
new file mode 100644
index 0000000000..d04c536ec1
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual.h
@@ -0,0 +1,41 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_LP_RESIDUAL_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_LP_RESIDUAL_H_
+
+#include <stddef.h>
+
+#include "api/array_view.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Linear predictive coding (LPC) inverse filter length.
+constexpr int kNumLpcCoefficients = 5;
+
+// Given a frame `x`, computes a post-processed version of LPC coefficients
+// tailored for pitch estimation.
+void ComputeAndPostProcessLpcCoefficients(
+    rtc::ArrayView<const float> x,
+    rtc::ArrayView<float, kNumLpcCoefficients> lpc_coeffs);
+
+// Computes the LP residual for the input frame `x` and the LPC coefficients
+// `lpc_coeffs`. `y` and `x` can point to the same array for in-place
+// computation.
+void ComputeLpResidual(
+    rtc::ArrayView<const float, kNumLpcCoefficients> lpc_coeffs,
+    rtc::ArrayView<const float> x,
+    rtc::ArrayView<float> y);
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_LP_RESIDUAL_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual_unittest.cc
new file mode 100644
index 0000000000..7b3a4a3f65
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/lp_residual_unittest.cc
@@ -0,0 +1,80 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/lp_residual.h"
+
+#include <algorithm>
+#include <array>
+#include <vector>
+
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+// #include "test/fpe_observer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// Checks that the LP residual can be computed on an empty frame.
+TEST(RnnVadTest, LpResidualOfEmptyFrame) {
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+
+  // Input frame (empty, i.e., all samples set to 0).
+  std::array<float, kFrameSize10ms24kHz> empty_frame;
+  empty_frame.fill(0.f);
+  // Compute inverse filter coefficients.
+  std::array<float, kNumLpcCoefficients> lpc;
+  ComputeAndPostProcessLpcCoefficients(empty_frame, lpc);
+  // Compute LP residual.
+  std::array<float, kFrameSize10ms24kHz> lp_residual;
+  ComputeLpResidual(lpc, empty_frame, lp_residual);
+}
+
+// Checks that the computed LP residual is bit-exact given test input data.
+TEST(RnnVadTest, LpResidualPipelineBitExactness) {
+  // Input and expected output readers.
+  ChunksFileReader pitch_buffer_reader = CreatePitchBuffer24kHzReader();
+  ChunksFileReader lp_pitch_reader = CreateLpResidualAndPitchInfoReader();
+
+  // Buffers.
+  std::vector<float> pitch_buffer_24kHz(kBufSize24kHz);
+  std::array<float, kNumLpcCoefficients> lpc;
+  std::vector<float> computed_lp_residual(kBufSize24kHz);
+  std::vector<float> expected_lp_residual(kBufSize24kHz);
+
+  // Test length.
+  const int num_frames =
+      std::min(pitch_buffer_reader.num_chunks, 300);  // Max 3 s.
+  ASSERT_GE(lp_pitch_reader.num_chunks, num_frames);
+
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+  for (int i = 0; i < num_frames; ++i) {
+    SCOPED_TRACE(i);
+    // Read input.
+    ASSERT_TRUE(pitch_buffer_reader.reader->ReadChunk(pitch_buffer_24kHz));
+    // Read expected output (ignore pitch gain and period).
+    ASSERT_TRUE(lp_pitch_reader.reader->ReadChunk(expected_lp_residual));
+    lp_pitch_reader.reader->SeekForward(2);  // Pitch period and strength.
+    // Check every 200 ms.
+    if (i % 20 == 0) {
+      ComputeAndPostProcessLpcCoefficients(pitch_buffer_24kHz, lpc);
+      ComputeLpResidual(lpc, pitch_buffer_24kHz, computed_lp_residual);
+      ExpectNearAbsolute(expected_lp_residual, computed_lp_residual, kFloatMin);
+    }
+  }
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search.cc
new file mode 100644
index 0000000000..419620fc0c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search.cc
@@ -0,0 +1,70 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/pitch_search.h"
+
+#include <array>
+#include <cstddef>
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+PitchEstimator::PitchEstimator(const AvailableCpuFeatures& cpu_features)
+    : cpu_features_(cpu_features),
+      y_energy_24kHz_(kRefineNumLags24kHz, 0.f),
+      pitch_buffer_12kHz_(kBufSize12kHz),
+      auto_correlation_12kHz_(kNumLags12kHz) {}
+
+PitchEstimator::~PitchEstimator() = default;
+
+int PitchEstimator::Estimate(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer) {
+  rtc::ArrayView<float, kBufSize12kHz> pitch_buffer_12kHz_view(
+      pitch_buffer_12kHz_.data(), kBufSize12kHz);
+  RTC_DCHECK_EQ(pitch_buffer_12kHz_.size(), pitch_buffer_12kHz_view.size());
+  rtc::ArrayView<float, kNumLags12kHz> auto_correlation_12kHz_view(
+      auto_correlation_12kHz_.data(), kNumLags12kHz);
+  RTC_DCHECK_EQ(auto_correlation_12kHz_.size(),
+                auto_correlation_12kHz_view.size());
+
+  // TODO(bugs.chromium.org/10480): Use `cpu_features_` to estimate pitch.
+  // Perform the initial pitch search at 12 kHz.
+  Decimate2x(pitch_buffer, pitch_buffer_12kHz_view);
+  auto_corr_calculator_.ComputeOnPitchBuffer(pitch_buffer_12kHz_view,
+                                             auto_correlation_12kHz_view);
+  CandidatePitchPeriods pitch_periods = ComputePitchPeriod12kHz(
+      pitch_buffer_12kHz_view, auto_correlation_12kHz_view, cpu_features_);
+  // The refinement is done using the pitch buffer that contains 24 kHz samples.
+  // Therefore, adapt the inverted lags in `pitch_candidates_inv_lags` from 12
+  // to 24 kHz.
+  pitch_periods.best *= 2;
+  pitch_periods.second_best *= 2;
+
+  // Refine the initial pitch period estimation from 12 kHz to 48 kHz.
+  // Pre-compute frame energies at 24 kHz.
+  rtc::ArrayView<float, kRefineNumLags24kHz> y_energy_24kHz_view(
+      y_energy_24kHz_.data(), kRefineNumLags24kHz);
+  RTC_DCHECK_EQ(y_energy_24kHz_.size(), y_energy_24kHz_view.size());
+  ComputeSlidingFrameSquareEnergies24kHz(pitch_buffer, y_energy_24kHz_view,
+                                         cpu_features_);
+  // Estimation at 48 kHz.
+  const int pitch_lag_48kHz = ComputePitchPeriod48kHz(
+      pitch_buffer, y_energy_24kHz_view, pitch_periods, cpu_features_);
+  last_pitch_48kHz_ = ComputeExtendedPitchPeriod48kHz(
+      pitch_buffer, y_energy_24kHz_view,
+      /*initial_pitch_period_48kHz=*/kMaxPitch48kHz - pitch_lag_48kHz,
+      last_pitch_48kHz_, cpu_features_);
+  return last_pitch_48kHz_.period;
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search.h
new file mode 100644
index 0000000000..42c448eb56
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search.h
@@ -0,0 +1,54 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_PITCH_SEARCH_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_PITCH_SEARCH_H_
+
+#include <memory>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/auto_correlation.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/pitch_search_internal.h"
+#include "rtc_base/gtest_prod_util.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Pitch estimator.
+class PitchEstimator {
+ public:
+  explicit PitchEstimator(const AvailableCpuFeatures& cpu_features);
+  PitchEstimator(const PitchEstimator&) = delete;
+  PitchEstimator& operator=(const PitchEstimator&) = delete;
+  ~PitchEstimator();
+  // Returns the estimated pitch period at 48 kHz.
+  int Estimate(rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer);
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(RnnVadTest, PitchSearchWithinTolerance);
+  float GetLastPitchStrengthForTesting() const {
+    return last_pitch_48kHz_.strength;
+  }
+
+  const AvailableCpuFeatures cpu_features_;
+  PitchInfo last_pitch_48kHz_{};
+  AutoCorrelationCalculator auto_corr_calculator_;
+  std::vector<float> y_energy_24kHz_;
+  std::vector<float> pitch_buffer_12kHz_;
+  std::vector<float> auto_correlation_12kHz_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_PITCH_SEARCH_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal.cc
new file mode 100644
index 0000000000..e8c912518d
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal.cc
@@ -0,0 +1,513 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/pitch_search_internal.h"
+
+#include <stdlib.h>
+
+#include <algorithm>
+#include <cmath>
+#include <cstddef>
+#include <numeric>
+
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/vector_math.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+#include "rtc_base/numerics/safe_conversions.h"
+#include "rtc_base/system/arch.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+float ComputeAutoCorrelation(
+    int inverted_lag,
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    const VectorMath& vector_math) {
+  RTC_DCHECK_LT(inverted_lag, kBufSize24kHz);
+  RTC_DCHECK_LT(inverted_lag, kRefineNumLags24kHz);
+  static_assert(kMaxPitch24kHz < kBufSize24kHz, "");
+  return vector_math.DotProduct(
+      pitch_buffer.subview(/*offset=*/kMaxPitch24kHz),
+      pitch_buffer.subview(inverted_lag, kFrameSize20ms24kHz));
+}
+
+// Given an auto-correlation coefficient `curr_auto_correlation` and its
+// neighboring values `prev_auto_correlation` and `next_auto_correlation`
+// computes a pseudo-interpolation offset to be applied to the pitch period
+// associated to `curr`. The output is a lag in {-1, 0, +1}.
+// TODO(bugs.webrtc.org/9076): Consider removing this method.
+// `GetPitchPseudoInterpolationOffset()` it is relevant only if the spectral
+// analysis works at a sample rate that is twice as that of the pitch buffer;
+// In particular, it is not relevant for the estimated pitch period feature fed
+// into the RNN.
+int GetPitchPseudoInterpolationOffset(float prev_auto_correlation,
+                                      float curr_auto_correlation,
+                                      float next_auto_correlation) {
+  if ((next_auto_correlation - prev_auto_correlation) >
+      0.7f * (curr_auto_correlation - prev_auto_correlation)) {
+    return 1;  // `next_auto_correlation` is the largest auto-correlation
+               // coefficient.
+  } else if ((prev_auto_correlation - next_auto_correlation) >
+             0.7f * (curr_auto_correlation - next_auto_correlation)) {
+    return -1;  // `prev_auto_correlation` is the largest auto-correlation
+                // coefficient.
+  }
+  return 0;
+}
+
+// Refines a pitch period `lag` encoded as lag with pseudo-interpolation. The
+// output sample rate is twice as that of `lag`.
+int PitchPseudoInterpolationLagPitchBuf(
+    int lag,
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    const VectorMath& vector_math) {
+  int offset = 0;
+  // Cannot apply pseudo-interpolation at the boundaries.
+  if (lag > 0 && lag < kMaxPitch24kHz) {
+    const int inverted_lag = kMaxPitch24kHz - lag;
+    offset = GetPitchPseudoInterpolationOffset(
+        ComputeAutoCorrelation(inverted_lag + 1, pitch_buffer, vector_math),
+        ComputeAutoCorrelation(inverted_lag, pitch_buffer, vector_math),
+        ComputeAutoCorrelation(inverted_lag - 1, pitch_buffer, vector_math));
+  }
+  return 2 * lag + offset;
+}
+
+// Integer multipliers used in ComputeExtendedPitchPeriod48kHz() when
+// looking for sub-harmonics.
+// The values have been chosen to serve the following algorithm. Given the
+// initial pitch period T, we examine whether one of its harmonics is the true
+// fundamental frequency. We consider T/k with k in {2, ..., 15}. For each of
+// these harmonics, in addition to the pitch strength of itself, we choose one
+// multiple of its pitch period, n*T/k, to validate it (by averaging their pitch
+// strengths). The multiplier n is chosen so that n*T/k is used only one time
+// over all k. When for example k = 4, we should also expect a peak at 3*T/4.
+// When k = 8 instead we don't want to look at 2*T/8, since we have already
+// checked T/4 before. Instead, we look at T*3/8.
+// The array can be generate in Python as follows:
+//   from fractions import Fraction
+//   # Smallest positive integer not in X.
+//   def mex(X):
+//     for i in range(1, int(max(X)+2)):
+//       if i not in X:
+//         return i
+//   # Visited multiples of the period.
+//   S = {1}
+//   for n in range(2, 16):
+//     sn = mex({n * i for i in S} | {1})
+//     S = S | {Fraction(1, n), Fraction(sn, n)}
+//     print(sn, end=', ')
+constexpr std::array<int, 14> kSubHarmonicMultipliers = {
+    {3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2}};
+
+struct Range {
+  int min;
+  int max;
+};
+
+// Number of analyzed pitches to the left(right) of a pitch candidate.
+constexpr int kPitchNeighborhoodRadius = 2;
+
+// Creates a pitch period interval centered in `inverted_lag` with hard-coded
+// radius. Clipping is applied so that the interval is always valid for a 24 kHz
+// pitch buffer.
+Range CreateInvertedLagRange(int inverted_lag) {
+  return {std::max(inverted_lag - kPitchNeighborhoodRadius, 0),
+          std::min(inverted_lag + kPitchNeighborhoodRadius,
+                   kInitialNumLags24kHz - 1)};
+}
+
+constexpr int kNumPitchCandidates = 2;  // Best and second best.
+// Maximum number of analyzed pitch periods.
+constexpr int kMaxPitchPeriods24kHz =
+    kNumPitchCandidates * (2 * kPitchNeighborhoodRadius + 1);
+
+// Collection of inverted lags.
+class InvertedLagsIndex {
+ public:
+  InvertedLagsIndex() : num_entries_(0) {}
+  // Adds an inverted lag to the index. Cannot add more than
+  // `kMaxPitchPeriods24kHz` values.
+  void Append(int inverted_lag) {
+    RTC_DCHECK_LT(num_entries_, kMaxPitchPeriods24kHz);
+    inverted_lags_[num_entries_++] = inverted_lag;
+  }
+  const int* data() const { return inverted_lags_.data(); }
+  int size() const { return num_entries_; }
+
+ private:
+  std::array<int, kMaxPitchPeriods24kHz> inverted_lags_;
+  int num_entries_;
+};
+
+// Computes the auto correlation coefficients for the inverted lags in the
+// closed interval `inverted_lags`. Updates `inverted_lags_index` by appending
+// the inverted lags for the computed auto correlation values.
+void ComputeAutoCorrelation(
+    Range inverted_lags,
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<float, kInitialNumLags24kHz> auto_correlation,
+    InvertedLagsIndex& inverted_lags_index,
+    const VectorMath& vector_math) {
+  // Check valid range.
+  RTC_DCHECK_LE(inverted_lags.min, inverted_lags.max);
+  // Trick to avoid zero initialization of `auto_correlation`.
+  // Needed by the pseudo-interpolation.
+  if (inverted_lags.min > 0) {
+    auto_correlation[inverted_lags.min - 1] = 0.f;
+  }
+  if (inverted_lags.max < kInitialNumLags24kHz - 1) {
+    auto_correlation[inverted_lags.max + 1] = 0.f;
+  }
+  // Check valid `inverted_lag` indexes.
+  RTC_DCHECK_GE(inverted_lags.min, 0);
+  RTC_DCHECK_LT(inverted_lags.max, kInitialNumLags24kHz);
+  for (int inverted_lag = inverted_lags.min; inverted_lag <= inverted_lags.max;
+       ++inverted_lag) {
+    auto_correlation[inverted_lag] =
+        ComputeAutoCorrelation(inverted_lag, pitch_buffer, vector_math);
+    inverted_lags_index.Append(inverted_lag);
+  }
+}
+
+// Searches the strongest pitch period at 24 kHz and returns its inverted lag at
+// 48 kHz.
+int ComputePitchPeriod48kHz(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<const int> inverted_lags,
+    rtc::ArrayView<const float, kInitialNumLags24kHz> auto_correlation,
+    rtc::ArrayView<const float, kRefineNumLags24kHz> y_energy,
+    const VectorMath& vector_math) {
+  static_assert(kMaxPitch24kHz > kInitialNumLags24kHz, "");
+  static_assert(kMaxPitch24kHz < kBufSize24kHz, "");
+  int best_inverted_lag = 0;     // Pitch period.
+  float best_numerator = -1.f;   // Pitch strength numerator.
+  float best_denominator = 0.f;  // Pitch strength denominator.
+  for (int inverted_lag : inverted_lags) {
+    // A pitch candidate must have positive correlation.
+    if (auto_correlation[inverted_lag] > 0.f) {
+      // Auto-correlation energy normalized by frame energy.
+      const float numerator =
+          auto_correlation[inverted_lag] * auto_correlation[inverted_lag];
+      const float denominator = y_energy[inverted_lag];
+      // Compare numerator/denominator ratios without using divisions.
+      if (numerator * best_denominator > best_numerator * denominator) {
+        best_inverted_lag = inverted_lag;
+        best_numerator = numerator;
+        best_denominator = denominator;
+      }
+    }
+  }
+  // Pseudo-interpolation to transform `best_inverted_lag` (24 kHz pitch) to a
+  // 48 kHz pitch period.
+  if (best_inverted_lag == 0 || best_inverted_lag >= kInitialNumLags24kHz - 1) {
+    // Cannot apply pseudo-interpolation at the boundaries.
+    return best_inverted_lag * 2;
+  }
+  int offset = GetPitchPseudoInterpolationOffset(
+      auto_correlation[best_inverted_lag + 1],
+      auto_correlation[best_inverted_lag],
+      auto_correlation[best_inverted_lag - 1]);
+  // TODO(bugs.webrtc.org/9076): When retraining, check if `offset` below should
+  // be subtracted since `inverted_lag` is an inverted lag but offset is a lag.
+  return 2 * best_inverted_lag + offset;
+}
+
+// Returns an alternative pitch period for `pitch_period` given a `multiplier`
+// and a `divisor` of the period.
+constexpr int GetAlternativePitchPeriod(int pitch_period,
+                                        int multiplier,
+                                        int divisor) {
+  RTC_DCHECK_GT(divisor, 0);
+  // Same as `round(multiplier * pitch_period / divisor)`.
+  return (2 * multiplier * pitch_period + divisor) / (2 * divisor);
+}
+
+// Returns true if the alternative pitch period is stronger than the initial one
+// given the last estimated pitch and the value of `period_divisor` used to
+// compute the alternative pitch period via `GetAlternativePitchPeriod()`.
+bool IsAlternativePitchStrongerThanInitial(PitchInfo last,
+                                           PitchInfo initial,
+                                           PitchInfo alternative,
+                                           int period_divisor) {
+  // Initial pitch period candidate thresholds for a sample rate of 24 kHz.
+  // Computed as [5*k*k for k in range(16)].
+  constexpr std::array<int, 14> kInitialPitchPeriodThresholds = {
+      {20, 45, 80, 125, 180, 245, 320, 405, 500, 605, 720, 845, 980, 1125}};
+  static_assert(
+      kInitialPitchPeriodThresholds.size() == kSubHarmonicMultipliers.size(),
+      "");
+  RTC_DCHECK_GE(last.period, 0);
+  RTC_DCHECK_GE(initial.period, 0);
+  RTC_DCHECK_GE(alternative.period, 0);
+  RTC_DCHECK_GE(period_divisor, 2);
+  // Compute a term that lowers the threshold when `alternative.period` is close
+  // to the last estimated period `last.period` - i.e., pitch tracking.
+  float lower_threshold_term = 0.f;
+  if (std::abs(alternative.period - last.period) <= 1) {
+    // The candidate pitch period is within 1 sample from the last one.
+    // Make the candidate at `alternative.period` very easy to be accepted.
+    lower_threshold_term = last.strength;
+  } else if (std::abs(alternative.period - last.period) == 2 &&
+             initial.period >
+                 kInitialPitchPeriodThresholds[period_divisor - 2]) {
+    // The candidate pitch period is 2 samples far from the last one and the
+    // period `initial.period` (from which `alternative.period` has been
+    // derived) is greater than a threshold. Make `alternative.period` easy to
+    // be accepted.
+    lower_threshold_term = 0.5f * last.strength;
+  }
+  // Set the threshold based on the strength of the initial estimate
+  // `initial.period`. Also reduce the chance of false positives caused by a
+  // bias towards high frequencies (originating from short-term correlations).
+  float threshold =
+      std::max(0.3f, 0.7f * initial.strength - lower_threshold_term);
+  if (alternative.period < 3 * kMinPitch24kHz) {
+    // High frequency.
+    threshold = std::max(0.4f, 0.85f * initial.strength - lower_threshold_term);
+  } else if (alternative.period < 2 * kMinPitch24kHz) {
+    // Even higher frequency.
+    threshold = std::max(0.5f, 0.9f * initial.strength - lower_threshold_term);
+  }
+  return alternative.strength > threshold;
+}
+
+}  // namespace
+
+void Decimate2x(rtc::ArrayView<const float, kBufSize24kHz> src,
+                rtc::ArrayView<float, kBufSize12kHz> dst) {
+  // TODO(bugs.webrtc.org/9076): Consider adding anti-aliasing filter.
+  static_assert(2 * kBufSize12kHz == kBufSize24kHz, "");
+  for (int i = 0; i < kBufSize12kHz; ++i) {
+    dst[i] = src[2 * i];
+  }
+}
+
+void ComputeSlidingFrameSquareEnergies24kHz(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<float, kRefineNumLags24kHz> y_energy,
+    AvailableCpuFeatures cpu_features) {
+  VectorMath vector_math(cpu_features);
+  static_assert(kFrameSize20ms24kHz < kBufSize24kHz, "");
+  const auto frame_20ms_view = pitch_buffer.subview(0, kFrameSize20ms24kHz);
+  float yy = vector_math.DotProduct(frame_20ms_view, frame_20ms_view);
+  y_energy[0] = yy;
+  static_assert(kMaxPitch24kHz - 1 + kFrameSize20ms24kHz < kBufSize24kHz, "");
+  static_assert(kMaxPitch24kHz < kRefineNumLags24kHz, "");
+  for (int inverted_lag = 0; inverted_lag < kMaxPitch24kHz; ++inverted_lag) {
+    yy -= pitch_buffer[inverted_lag] * pitch_buffer[inverted_lag];
+    yy += pitch_buffer[inverted_lag + kFrameSize20ms24kHz] *
+          pitch_buffer[inverted_lag + kFrameSize20ms24kHz];
+    yy = std::max(1.f, yy);
+    y_energy[inverted_lag + 1] = yy;
+  }
+}
+
+CandidatePitchPeriods ComputePitchPeriod12kHz(
+    rtc::ArrayView<const float, kBufSize12kHz> pitch_buffer,
+    rtc::ArrayView<const float, kNumLags12kHz> auto_correlation,
+    AvailableCpuFeatures cpu_features) {
+  static_assert(kMaxPitch12kHz > kNumLags12kHz, "");
+  static_assert(kMaxPitch12kHz < kBufSize12kHz, "");
+
+  // Stores a pitch candidate period and strength information.
+  struct PitchCandidate {
+    // Pitch period encoded as inverted lag.
+    int period_inverted_lag = 0;
+    // Pitch strength encoded as a ratio.
+    float strength_numerator = -1.f;
+    float strength_denominator = 0.f;
+    // Compare the strength of two pitch candidates.
+    bool HasStrongerPitchThan(const PitchCandidate& b) const {
+      // Comparing the numerator/denominator ratios without using divisions.
+      return strength_numerator * b.strength_denominator >
+             b.strength_numerator * strength_denominator;
+    }
+  };
+
+  VectorMath vector_math(cpu_features);
+  static_assert(kFrameSize20ms12kHz + 1 < kBufSize12kHz, "");
+  const auto frame_view = pitch_buffer.subview(0, kFrameSize20ms12kHz + 1);
+  float denominator = 1.f + vector_math.DotProduct(frame_view, frame_view);
+  // Search best and second best pitches by looking at the scaled
+  // auto-correlation.
+  PitchCandidate best;
+  PitchCandidate second_best;
+  second_best.period_inverted_lag = 1;
+  for (int inverted_lag = 0; inverted_lag < kNumLags12kHz; ++inverted_lag) {
+    // A pitch candidate must have positive correlation.
+    if (auto_correlation[inverted_lag] > 0.f) {
+      PitchCandidate candidate{
+          inverted_lag,
+          auto_correlation[inverted_lag] * auto_correlation[inverted_lag],
+          denominator};
+      if (candidate.HasStrongerPitchThan(second_best)) {
+        if (candidate.HasStrongerPitchThan(best)) {
+          second_best = best;
+          best = candidate;
+        } else {
+          second_best = candidate;
+        }
+      }
+    }
+    // Update `squared_energy_y` for the next inverted lag.
+    const float y_old = pitch_buffer[inverted_lag];
+    const float y_new = pitch_buffer[inverted_lag + kFrameSize20ms12kHz];
+    denominator -= y_old * y_old;
+    denominator += y_new * y_new;
+    denominator = std::max(0.f, denominator);
+  }
+  return {best.period_inverted_lag, second_best.period_inverted_lag};
+}
+
+int ComputePitchPeriod48kHz(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<const float, kRefineNumLags24kHz> y_energy,
+    CandidatePitchPeriods pitch_candidates,
+    AvailableCpuFeatures cpu_features) {
+  // Compute the auto-correlation terms only for neighbors of the two pitch
+  // candidates (best and second best).
+  std::array<float, kInitialNumLags24kHz> auto_correlation;
+  InvertedLagsIndex inverted_lags_index;
+  // Create two inverted lag ranges so that `r1` precedes `r2`.
+  const bool swap_candidates =
+      pitch_candidates.best > pitch_candidates.second_best;
+  const Range r1 = CreateInvertedLagRange(
+      swap_candidates ? pitch_candidates.second_best : pitch_candidates.best);
+  const Range r2 = CreateInvertedLagRange(
+      swap_candidates ? pitch_candidates.best : pitch_candidates.second_best);
+  // Check valid ranges.
+  RTC_DCHECK_LE(r1.min, r1.max);
+  RTC_DCHECK_LE(r2.min, r2.max);
+  // Check `r1` precedes `r2`.
+  RTC_DCHECK_LE(r1.min, r2.min);
+  RTC_DCHECK_LE(r1.max, r2.max);
+  VectorMath vector_math(cpu_features);
+  if (r1.max + 1 >= r2.min) {
+    // Overlapping or adjacent ranges.
+    ComputeAutoCorrelation({r1.min, r2.max}, pitch_buffer, auto_correlation,
+                           inverted_lags_index, vector_math);
+  } else {
+    // Disjoint ranges.
+    ComputeAutoCorrelation(r1, pitch_buffer, auto_correlation,
+                           inverted_lags_index, vector_math);
+    ComputeAutoCorrelation(r2, pitch_buffer, auto_correlation,
+                           inverted_lags_index, vector_math);
+  }
+  return ComputePitchPeriod48kHz(pitch_buffer, inverted_lags_index,
+                                 auto_correlation, y_energy, vector_math);
+}
+
+PitchInfo ComputeExtendedPitchPeriod48kHz(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<const float, kRefineNumLags24kHz> y_energy,
+    int initial_pitch_period_48kHz,
+    PitchInfo last_pitch_48kHz,
+    AvailableCpuFeatures cpu_features) {
+  RTC_DCHECK_LE(kMinPitch48kHz, initial_pitch_period_48kHz);
+  RTC_DCHECK_LE(initial_pitch_period_48kHz, kMaxPitch48kHz);
+
+  // Stores information for a refined pitch candidate.
+  struct RefinedPitchCandidate {
+    int period;
+    float strength;
+    // Additional strength data used for the final pitch estimation.
+    float xy;        // Auto-correlation.
+    float y_energy;  // Energy of the sliding frame `y`.
+  };
+
+  const float x_energy = y_energy[kMaxPitch24kHz];
+  const auto pitch_strength = [x_energy](float xy, float y_energy) {
+    RTC_DCHECK_GE(x_energy * y_energy, 0.f);
+    return xy / std::sqrt(1.f + x_energy * y_energy);
+  };
+  VectorMath vector_math(cpu_features);
+
+  // Initialize the best pitch candidate with `initial_pitch_period_48kHz`.
+  RefinedPitchCandidate best_pitch;
+  best_pitch.period =
+      std::min(initial_pitch_period_48kHz / 2, kMaxPitch24kHz - 1);
+  best_pitch.xy = ComputeAutoCorrelation(kMaxPitch24kHz - best_pitch.period,
+                                         pitch_buffer, vector_math);
+  best_pitch.y_energy = y_energy[kMaxPitch24kHz - best_pitch.period];
+  best_pitch.strength = pitch_strength(best_pitch.xy, best_pitch.y_energy);
+  // Keep a copy of the initial pitch candidate.
+  const PitchInfo initial_pitch{best_pitch.period, best_pitch.strength};
+  // 24 kHz version of the last estimated pitch.
+  const PitchInfo last_pitch{last_pitch_48kHz.period / 2,
+                             last_pitch_48kHz.strength};
+
+  // Find `max_period_divisor` such that the result of
+  // `GetAlternativePitchPeriod(initial_pitch_period, 1, max_period_divisor)`
+  // equals `kMinPitch24kHz`.
+  const int max_period_divisor =
+      (2 * initial_pitch.period) / (2 * kMinPitch24kHz - 1);
+  for (int period_divisor = 2; period_divisor <= max_period_divisor;
+       ++period_divisor) {
+    PitchInfo alternative_pitch;
+    alternative_pitch.period = GetAlternativePitchPeriod(
+        initial_pitch.period, /*multiplier=*/1, period_divisor);
+    RTC_DCHECK_GE(alternative_pitch.period, kMinPitch24kHz);
+    // When looking at `alternative_pitch.period`, we also look at one of its
+    // sub-harmonics. `kSubHarmonicMultipliers` is used to know where to look.
+    // `period_divisor` == 2 is a special case since `dual_alternative_period`
+    // might be greater than the maximum pitch period.
+    int dual_alternative_period = GetAlternativePitchPeriod(
+        initial_pitch.period, kSubHarmonicMultipliers[period_divisor - 2],
+        period_divisor);
+    RTC_DCHECK_GT(dual_alternative_period, 0);
+    if (period_divisor == 2 && dual_alternative_period > kMaxPitch24kHz) {
+      dual_alternative_period = initial_pitch.period;
+    }
+    RTC_DCHECK_NE(alternative_pitch.period, dual_alternative_period)
+        << "The lower pitch period and the additional sub-harmonic must not "
+           "coincide.";
+    // Compute an auto-correlation score for the primary pitch candidate
+    // `alternative_pitch.period` by also looking at its possible sub-harmonic
+    // `dual_alternative_period`.
+    const float xy_primary_period = ComputeAutoCorrelation(
+        kMaxPitch24kHz - alternative_pitch.period, pitch_buffer, vector_math);
+    // TODO(webrtc:10480): Copy `xy_primary_period` if the secondary period is
+    // equal to the primary one.
+    const float xy_secondary_period = ComputeAutoCorrelation(
+        kMaxPitch24kHz - dual_alternative_period, pitch_buffer, vector_math);
+    const float xy = 0.5f * (xy_primary_period + xy_secondary_period);
+    const float yy =
+        0.5f * (y_energy[kMaxPitch24kHz - alternative_pitch.period] +
+                y_energy[kMaxPitch24kHz - dual_alternative_period]);
+    alternative_pitch.strength = pitch_strength(xy, yy);
+
+    // Maybe update best period.
+    if (IsAlternativePitchStrongerThanInitial(
+            last_pitch, initial_pitch, alternative_pitch, period_divisor)) {
+      best_pitch = {alternative_pitch.period, alternative_pitch.strength, xy,
+                    yy};
+    }
+  }
+
+  // Final pitch strength and period.
+  best_pitch.xy = std::max(0.f, best_pitch.xy);
+  RTC_DCHECK_LE(0.f, best_pitch.y_energy);
+  float final_pitch_strength =
+      (best_pitch.y_energy <= best_pitch.xy)
+          ? 1.f
+          : best_pitch.xy / (best_pitch.y_energy + 1.f);
+  final_pitch_strength = std::min(best_pitch.strength, final_pitch_strength);
+  int final_pitch_period_48kHz = std::max(
+      kMinPitch48kHz, PitchPseudoInterpolationLagPitchBuf(
+                          best_pitch.period, pitch_buffer, vector_math));
+
+  return {final_pitch_period_48kHz, final_pitch_strength};
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal.h
new file mode 100644
index 0000000000..aa2dd13745
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal.h
@@ -0,0 +1,114 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_PITCH_SEARCH_INTERNAL_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_PITCH_SEARCH_INTERNAL_H_
+
+#include <stddef.h>
+
+#include <array>
+#include <utility>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Performs 2x decimation without any anti-aliasing filter.
+void Decimate2x(rtc::ArrayView<const float, kBufSize24kHz> src,
+                rtc::ArrayView<float, kBufSize12kHz> dst);
+
+// Key concepts and keywords used below in this file.
+//
+// The pitch estimation relies on a pitch buffer, which is an array-like data
+// structured designed as follows:
+//
+// |....A....|.....B.....|
+//
+// The part on the left, named `A` contains the oldest samples, whereas `B`
+// contains the most recent ones. The size of `A` corresponds to the maximum
+// pitch period, that of `B` to the analysis frame size (e.g., 16 ms and 20 ms
+// respectively).
+//
+// Pitch estimation is essentially based on the analysis of two 20 ms frames
+// extracted from the pitch buffer. One frame, called `x`, is kept fixed and
+// corresponds to `B` - i.e., the most recent 20 ms. The other frame, called
+// `y`, is extracted from different parts of the buffer instead.
+//
+// The offset between `x` and `y` corresponds to a specific pitch period.
+// For instance, if `y` is positioned at the beginning of the pitch buffer, then
+// the cross-correlation between `x` and `y` can be used as an indication of the
+// strength for the maximum pitch.
+//
+// Such an offset can be encoded in two ways:
+// - As a lag, which is the index in the pitch buffer for the first item in `y`
+// - As an inverted lag, which is the number of samples from the beginning of
+//   `x` and the end of `y`
+//
+// |---->| lag
+// |....A....|.....B.....|
+//       |<--| inverted lag
+//       |.....y.....| `y` 20 ms frame
+//
+// The inverted lag has the advantage of being directly proportional to the
+// corresponding pitch period.
+
+// Computes the sum of squared samples for every sliding frame `y` in the pitch
+// buffer. The indexes of `y_energy` are inverted lags.
+void ComputeSlidingFrameSquareEnergies24kHz(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<float, kRefineNumLags24kHz> y_energy,
+    AvailableCpuFeatures cpu_features);
+
+// Top-2 pitch period candidates. Unit: number of samples - i.e., inverted lags.
+struct CandidatePitchPeriods {
+  int best;
+  int second_best;
+};
+
+// Computes the candidate pitch periods at 12 kHz given a view on the 12 kHz
+// pitch buffer and the auto-correlation values (having inverted lags as
+// indexes).
+CandidatePitchPeriods ComputePitchPeriod12kHz(
+    rtc::ArrayView<const float, kBufSize12kHz> pitch_buffer,
+    rtc::ArrayView<const float, kNumLags12kHz> auto_correlation,
+    AvailableCpuFeatures cpu_features);
+
+// Computes the pitch period at 48 kHz given a view on the 24 kHz pitch buffer,
+// the energies for the sliding frames `y` at 24 kHz and the pitch period
+// candidates at 24 kHz (encoded as inverted lag).
+int ComputePitchPeriod48kHz(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<const float, kRefineNumLags24kHz> y_energy,
+    CandidatePitchPeriods pitch_candidates_24kHz,
+    AvailableCpuFeatures cpu_features);
+
+struct PitchInfo {
+  int period;
+  float strength;
+};
+
+// Computes the pitch period at 48 kHz searching in an extended pitch range
+// given a view on the 24 kHz pitch buffer, the energies for the sliding frames
+// `y` at 24 kHz, the initial 48 kHz estimation (computed by
+// `ComputePitchPeriod48kHz()`) and the last estimated pitch.
+PitchInfo ComputeExtendedPitchPeriod48kHz(
+    rtc::ArrayView<const float, kBufSize24kHz> pitch_buffer,
+    rtc::ArrayView<const float, kRefineNumLags24kHz> y_energy,
+    int initial_pitch_period_48kHz,
+    PitchInfo last_pitch_48kHz,
+    AvailableCpuFeatures cpu_features);
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_PITCH_SEARCH_INTERNAL_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal_unittest.cc
new file mode 100644
index 0000000000..2a6e68f157
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal_unittest.cc
@@ -0,0 +1,217 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/pitch_search_internal.h"
+
+#include <array>
+#include <string>
+#include <tuple>
+
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+#include "rtc_base/strings/string_builder.h"
+// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+// #include "test/fpe_observer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr int kTestPitchPeriodsLow = 3 * kMinPitch48kHz / 2;
+constexpr int kTestPitchPeriodsHigh = (3 * kMinPitch48kHz + kMaxPitch48kHz) / 2;
+
+constexpr float kTestPitchStrengthLow = 0.35f;
+constexpr float kTestPitchStrengthHigh = 0.75f;
+
+template <class T>
+std::string PrintTestIndexAndCpuFeatures(
+    const ::testing::TestParamInfo<T>& info) {
+  rtc::StringBuilder builder;
+  builder << info.index << "_" << info.param.cpu_features.ToString();
+  return builder.str();
+}
+
+// Finds the relevant CPU features combinations to test.
+std::vector<AvailableCpuFeatures> GetCpuFeaturesToTest() {
+  std::vector<AvailableCpuFeatures> v;
+  v.push_back(NoAvailableCpuFeatures());
+  AvailableCpuFeatures available = GetAvailableCpuFeatures();
+  if (available.avx2) {
+    v.push_back({/*sse2=*/false, /*avx2=*/true, /*neon=*/false});
+  }
+  if (available.sse2) {
+    v.push_back({/*sse2=*/true, /*avx2=*/false, /*neon=*/false});
+  }
+  return v;
+}
+
+// Checks that the frame-wise sliding square energy function produces output
+// within tolerance given test input data.
+TEST(RnnVadTest, ComputeSlidingFrameSquareEnergies24kHzWithinTolerance) {
+  const AvailableCpuFeatures cpu_features = GetAvailableCpuFeatures();
+
+  PitchTestData test_data;
+  std::array<float, kRefineNumLags24kHz> computed_output;
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+  ComputeSlidingFrameSquareEnergies24kHz(test_data.PitchBuffer24kHzView(),
+                                         computed_output, cpu_features);
+  auto square_energies_view = test_data.SquareEnergies24kHzView();
+  ExpectNearAbsolute({square_energies_view.data(), square_energies_view.size()},
+                     computed_output, 1e-3f);
+}
+
+// Checks that the estimated pitch period is bit-exact given test input data.
+TEST(RnnVadTest, ComputePitchPeriod12kHzBitExactness) {
+  const AvailableCpuFeatures cpu_features = GetAvailableCpuFeatures();
+
+  PitchTestData test_data;
+  std::array<float, kBufSize12kHz> pitch_buf_decimated;
+  Decimate2x(test_data.PitchBuffer24kHzView(), pitch_buf_decimated);
+  CandidatePitchPeriods pitch_candidates;
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+  pitch_candidates = ComputePitchPeriod12kHz(
+      pitch_buf_decimated, test_data.AutoCorrelation12kHzView(), cpu_features);
+  EXPECT_EQ(pitch_candidates.best, 140);
+  EXPECT_EQ(pitch_candidates.second_best, 142);
+}
+
+// Checks that the refined pitch period is bit-exact given test input data.
+TEST(RnnVadTest, ComputePitchPeriod48kHzBitExactness) {
+  const AvailableCpuFeatures cpu_features = GetAvailableCpuFeatures();
+
+  PitchTestData test_data;
+  std::vector<float> y_energy(kRefineNumLags24kHz);
+  rtc::ArrayView<float, kRefineNumLags24kHz> y_energy_view(y_energy.data(),
+                                                           kRefineNumLags24kHz);
+  ComputeSlidingFrameSquareEnergies24kHz(test_data.PitchBuffer24kHzView(),
+                                         y_energy_view, cpu_features);
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+  EXPECT_EQ(
+      ComputePitchPeriod48kHz(test_data.PitchBuffer24kHzView(), y_energy_view,
+                              /*pitch_candidates=*/{280, 284}, cpu_features),
+      560);
+  EXPECT_EQ(
+      ComputePitchPeriod48kHz(test_data.PitchBuffer24kHzView(), y_energy_view,
+                              /*pitch_candidates=*/{260, 284}, cpu_features),
+      568);
+}
+
+struct PitchCandidatesParameters {
+  CandidatePitchPeriods pitch_candidates;
+  AvailableCpuFeatures cpu_features;
+};
+
+class PitchCandidatesParametrization
+    : public ::testing::TestWithParam<PitchCandidatesParameters> {};
+
+// Checks that the result of `ComputePitchPeriod48kHz()` does not depend on the
+// order of the input pitch candidates.
+TEST_P(PitchCandidatesParametrization,
+       ComputePitchPeriod48kHzOrderDoesNotMatter) {
+  const PitchCandidatesParameters params = GetParam();
+  const CandidatePitchPeriods swapped_pitch_candidates{
+      params.pitch_candidates.second_best, params.pitch_candidates.best};
+
+  PitchTestData test_data;
+  std::vector<float> y_energy(kRefineNumLags24kHz);
+  rtc::ArrayView<float, kRefineNumLags24kHz> y_energy_view(y_energy.data(),
+                                                           kRefineNumLags24kHz);
+  ComputeSlidingFrameSquareEnergies24kHz(test_data.PitchBuffer24kHzView(),
+                                         y_energy_view, params.cpu_features);
+  EXPECT_EQ(
+      ComputePitchPeriod48kHz(test_data.PitchBuffer24kHzView(), y_energy_view,
+                              params.pitch_candidates, params.cpu_features),
+      ComputePitchPeriod48kHz(test_data.PitchBuffer24kHzView(), y_energy_view,
+                              swapped_pitch_candidates, params.cpu_features));
+}
+
+std::vector<PitchCandidatesParameters> CreatePitchCandidatesParameters() {
+  std::vector<PitchCandidatesParameters> v;
+  for (AvailableCpuFeatures cpu_features : GetCpuFeaturesToTest()) {
+    v.push_back({{0, 2}, cpu_features});
+    v.push_back({{260, 284}, cpu_features});
+    v.push_back({{280, 284}, cpu_features});
+    v.push_back(
+        {{kInitialNumLags24kHz - 2, kInitialNumLags24kHz - 1}, cpu_features});
+  }
+  return v;
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    RnnVadTest,
+    PitchCandidatesParametrization,
+    ::testing::ValuesIn(CreatePitchCandidatesParameters()),
+    PrintTestIndexAndCpuFeatures<PitchCandidatesParameters>);
+
+struct ExtendedPitchPeriodSearchParameters {
+  int initial_pitch_period;
+  PitchInfo last_pitch;
+  PitchInfo expected_pitch;
+  AvailableCpuFeatures cpu_features;
+};
+
+class ExtendedPitchPeriodSearchParametrizaion
+    : public ::testing::TestWithParam<ExtendedPitchPeriodSearchParameters> {};
+
+// Checks that the computed pitch period is bit-exact and that the computed
+// pitch strength is within tolerance given test input data.
+TEST_P(ExtendedPitchPeriodSearchParametrizaion,
+       PeriodBitExactnessGainWithinTolerance) {
+  const ExtendedPitchPeriodSearchParameters params = GetParam();
+
+  PitchTestData test_data;
+  std::vector<float> y_energy(kRefineNumLags24kHz);
+  rtc::ArrayView<float, kRefineNumLags24kHz> y_energy_view(y_energy.data(),
+                                                           kRefineNumLags24kHz);
+  ComputeSlidingFrameSquareEnergies24kHz(test_data.PitchBuffer24kHzView(),
+                                         y_energy_view, params.cpu_features);
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+  const auto computed_output = ComputeExtendedPitchPeriod48kHz(
+      test_data.PitchBuffer24kHzView(), y_energy_view,
+      params.initial_pitch_period, params.last_pitch, params.cpu_features);
+  EXPECT_EQ(params.expected_pitch.period, computed_output.period);
+  EXPECT_NEAR(params.expected_pitch.strength, computed_output.strength, 1e-6f);
+}
+
+std::vector<ExtendedPitchPeriodSearchParameters>
+CreateExtendedPitchPeriodSearchParameters() {
+  std::vector<ExtendedPitchPeriodSearchParameters> v;
+  for (AvailableCpuFeatures cpu_features : GetCpuFeaturesToTest()) {
+    for (int last_pitch_period :
+         {kTestPitchPeriodsLow, kTestPitchPeriodsHigh}) {
+      for (float last_pitch_strength :
+           {kTestPitchStrengthLow, kTestPitchStrengthHigh}) {
+        v.push_back({kTestPitchPeriodsLow,
+                     {last_pitch_period, last_pitch_strength},
+                     {91, -0.0188608f},
+                     cpu_features});
+        v.push_back({kTestPitchPeriodsHigh,
+                     {last_pitch_period, last_pitch_strength},
+                     {475, -0.0904344f},
+                     cpu_features});
+      }
+    }
+  }
+  return v;
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    RnnVadTest,
+    ExtendedPitchPeriodSearchParametrizaion,
+    ::testing::ValuesIn(CreateExtendedPitchPeriodSearchParameters()),
+    PrintTestIndexAndCpuFeatures<ExtendedPitchPeriodSearchParameters>);
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_unittest.cc
new file mode 100644
index 0000000000..79b44b995c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_unittest.cc
@@ -0,0 +1,53 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/pitch_search.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/pitch_search_internal.h"
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+// #include "test/fpe_observer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Checks that the computed pitch period is bit-exact and that the computed
+// pitch gain is within tolerance given test input data.
+TEST(RnnVadTest, PitchSearchWithinTolerance) {
+  ChunksFileReader reader = CreateLpResidualAndPitchInfoReader();
+  const int num_frames = std::min(reader.num_chunks, 300);  // Max 3 s.
+  std::vector<float> lp_residual(kBufSize24kHz);
+  float expected_pitch_period, expected_pitch_strength;
+  const AvailableCpuFeatures cpu_features = GetAvailableCpuFeatures();
+  PitchEstimator pitch_estimator(cpu_features);
+  {
+    // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+    // FloatingPointExceptionObserver fpe_observer;
+    for (int i = 0; i < num_frames; ++i) {
+      SCOPED_TRACE(i);
+      ASSERT_TRUE(reader.reader->ReadChunk(lp_residual));
+      ASSERT_TRUE(reader.reader->ReadValue(expected_pitch_period));
+      ASSERT_TRUE(reader.reader->ReadValue(expected_pitch_strength));
+      int pitch_period =
+          pitch_estimator.Estimate({lp_residual.data(), kBufSize24kHz});
+      EXPECT_EQ(expected_pitch_period, pitch_period);
+      EXPECT_NEAR(expected_pitch_strength,
+                  pitch_estimator.GetLastPitchStrengthForTesting(), 15e-6f);
+    }
+  }
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/ring_buffer.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/ring_buffer.h
new file mode 100644
index 0000000000..a6f7fdd1a6
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/ring_buffer.h
@@ -0,0 +1,65 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_RING_BUFFER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RING_BUFFER_H_
+
+#include <array>
+#include <cstring>
+#include <type_traits>
+
+#include "api/array_view.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Ring buffer for N arrays of type T each one with size S.
+template <typename T, int S, int N>
+class RingBuffer {
+  static_assert(S > 0, "");
+  static_assert(N > 0, "");
+  static_assert(std::is_arithmetic<T>::value,
+                "Integral or floating point required.");
+
+ public:
+  RingBuffer() : tail_(0) {}
+  RingBuffer(const RingBuffer&) = delete;
+  RingBuffer& operator=(const RingBuffer&) = delete;
+  ~RingBuffer() = default;
+  // Set the ring buffer values to zero.
+  void Reset() { buffer_.fill(0); }
+  // Replace the least recently pushed array in the buffer with `new_values`.
+  void Push(rtc::ArrayView<const T, S> new_values) {
+    std::memcpy(buffer_.data() + S * tail_, new_values.data(), S * sizeof(T));
+    tail_ += 1;
+    if (tail_ == N)
+      tail_ = 0;
+  }
+  // Return an array view onto the array with a given delay. A view on the last
+  // and least recently push array is returned when `delay` is 0 and N - 1
+  // respectively.
+  rtc::ArrayView<const T, S> GetArrayView(int delay) const {
+    RTC_DCHECK_LE(0, delay);
+    RTC_DCHECK_LT(delay, N);
+    int offset = tail_ - 1 - delay;
+    if (offset < 0)
+      offset += N;
+    return {buffer_.data() + S * offset, S};
+  }
+
+ private:
+  int tail_;  // Index of the least recently pushed sub-array.
+  std::array<T, S * N> buffer_{};
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RING_BUFFER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/ring_buffer_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/ring_buffer_unittest.cc
new file mode 100644
index 0000000000..d11d4eac3e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/ring_buffer_unittest.cc
@@ -0,0 +1,112 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/ring_buffer.h"
+
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// Compare the elements of two given array views.
+template <typename T, std::ptrdiff_t S>
+void ExpectEq(rtc::ArrayView<const T, S> a, rtc::ArrayView<const T, S> b) {
+  for (int i = 0; i < S; ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_EQ(a[i], b[i]);
+  }
+}
+
+// Test push/read sequences.
+template <typename T, int S, int N>
+void TestRingBuffer() {
+  SCOPED_TRACE(N);
+  SCOPED_TRACE(S);
+  std::array<T, S> prev_pushed_array;
+  std::array<T, S> pushed_array;
+  rtc::ArrayView<const T, S> pushed_array_view(pushed_array.data(), S);
+
+  // Init.
+  RingBuffer<T, S, N> ring_buf;
+  ring_buf.GetArrayView(0);
+  pushed_array.fill(0);
+  ring_buf.Push(pushed_array_view);
+  ExpectEq(pushed_array_view, ring_buf.GetArrayView(0));
+
+  // Push N times and check most recent and second most recent.
+  for (T v = 1; v <= static_cast<T>(N); ++v) {
+    SCOPED_TRACE(v);
+    prev_pushed_array = pushed_array;
+    pushed_array.fill(v);
+    ring_buf.Push(pushed_array_view);
+    ExpectEq(pushed_array_view, ring_buf.GetArrayView(0));
+    if (N > 1) {
+      pushed_array.fill(v - 1);
+      ExpectEq(pushed_array_view, ring_buf.GetArrayView(1));
+    }
+  }
+
+  // Check buffer.
+  for (int delay = 2; delay < N; ++delay) {
+    SCOPED_TRACE(delay);
+    T expected_value = N - static_cast<T>(delay);
+    pushed_array.fill(expected_value);
+    ExpectEq(pushed_array_view, ring_buf.GetArrayView(delay));
+  }
+}
+
+// Check that for different delays, different views are returned.
+TEST(RnnVadTest, RingBufferArrayViews) {
+  constexpr int s = 3;
+  constexpr int n = 4;
+  RingBuffer<int, s, n> ring_buf;
+  std::array<int, s> pushed_array;
+  pushed_array.fill(1);
+  for (int k = 0; k <= n; ++k) {  // Push data n + 1 times.
+    SCOPED_TRACE(k);
+    // Check array views.
+    for (int i = 0; i < n; ++i) {
+      SCOPED_TRACE(i);
+      auto view_i = ring_buf.GetArrayView(i);
+      for (int j = i + 1; j < n; ++j) {
+        SCOPED_TRACE(j);
+        auto view_j = ring_buf.GetArrayView(j);
+        EXPECT_NE(view_i, view_j);
+      }
+    }
+    ring_buf.Push(pushed_array);
+  }
+}
+
+TEST(RnnVadTest, RingBufferUnsigned) {
+  TestRingBuffer<uint8_t, 1, 1>();
+  TestRingBuffer<uint8_t, 2, 5>();
+  TestRingBuffer<uint8_t, 5, 2>();
+  TestRingBuffer<uint8_t, 5, 5>();
+}
+
+TEST(RnnVadTest, RingBufferSigned) {
+  TestRingBuffer<int, 1, 1>();
+  TestRingBuffer<int, 2, 5>();
+  TestRingBuffer<int, 5, 2>();
+  TestRingBuffer<int, 5, 5>();
+}
+
+TEST(RnnVadTest, RingBufferFloating) {
+  TestRingBuffer<float, 1, 1>();
+  TestRingBuffer<float, 2, 5>();
+  TestRingBuffer<float, 5, 2>();
+  TestRingBuffer<float, 5, 5>();
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn.cc
new file mode 100644
index 0000000000..475bef9775
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn.cc
@@ -0,0 +1,91 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/rnn.h"
+
+#include "rtc_base/checks.h"
+#include "third_party/rnnoise/src/rnn_vad_weights.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+using ::rnnoise::kInputLayerInputSize;
+static_assert(kFeatureVectorSize == kInputLayerInputSize, "");
+using ::rnnoise::kInputDenseBias;
+using ::rnnoise::kInputDenseWeights;
+using ::rnnoise::kInputLayerOutputSize;
+static_assert(kInputLayerOutputSize <= kFullyConnectedLayerMaxUnits, "");
+
+using ::rnnoise::kHiddenGruBias;
+using ::rnnoise::kHiddenGruRecurrentWeights;
+using ::rnnoise::kHiddenGruWeights;
+using ::rnnoise::kHiddenLayerOutputSize;
+static_assert(kHiddenLayerOutputSize <= kGruLayerMaxUnits, "");
+
+using ::rnnoise::kOutputDenseBias;
+using ::rnnoise::kOutputDenseWeights;
+using ::rnnoise::kOutputLayerOutputSize;
+static_assert(kOutputLayerOutputSize <= kFullyConnectedLayerMaxUnits, "");
+
+}  // namespace
+
+RnnVad::RnnVad(const AvailableCpuFeatures& cpu_features)
+    : input_(kInputLayerInputSize,
+             kInputLayerOutputSize,
+             kInputDenseBias,
+             kInputDenseWeights,
+             ActivationFunction::kTansigApproximated,
+             cpu_features,
+             /*layer_name=*/"FC1"),
+      hidden_(kInputLayerOutputSize,
+              kHiddenLayerOutputSize,
+              kHiddenGruBias,
+              kHiddenGruWeights,
+              kHiddenGruRecurrentWeights,
+              cpu_features,
+              /*layer_name=*/"GRU1"),
+      output_(kHiddenLayerOutputSize,
+              kOutputLayerOutputSize,
+              kOutputDenseBias,
+              kOutputDenseWeights,
+              ActivationFunction::kSigmoidApproximated,
+              // The output layer is just 24x1. The unoptimized code is faster.
+              NoAvailableCpuFeatures(),
+              /*layer_name=*/"FC2") {
+  // Input-output chaining size checks.
+  RTC_DCHECK_EQ(input_.size(), hidden_.input_size())
+      << "The input and the hidden layers sizes do not match.";
+  RTC_DCHECK_EQ(hidden_.size(), output_.input_size())
+      << "The hidden and the output layers sizes do not match.";
+}
+
+RnnVad::~RnnVad() = default;
+
+void RnnVad::Reset() {
+  hidden_.Reset();
+}
+
+float RnnVad::ComputeVadProbability(
+    rtc::ArrayView<const float, kFeatureVectorSize> feature_vector,
+    bool is_silence) {
+  if (is_silence) {
+    Reset();
+    return 0.f;
+  }
+  input_.ComputeOutput(feature_vector);
+  hidden_.ComputeOutput(input_);
+  output_.ComputeOutput(hidden_);
+  RTC_DCHECK_EQ(output_.size(), 1);
+  return output_.data()[0];
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn.h
new file mode 100644
index 0000000000..3148f1b3ff
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn.h
@@ -0,0 +1,53 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_RNN_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RNN_H_
+
+#include <stddef.h>
+#include <sys/types.h>
+
+#include <array>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/rnn_fc.h"
+#include "modules/audio_processing/agc2/rnn_vad/rnn_gru.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Recurrent network with hard-coded architecture and weights for voice activity
+// detection.
+class RnnVad {
+ public:
+  explicit RnnVad(const AvailableCpuFeatures& cpu_features);
+  RnnVad(const RnnVad&) = delete;
+  RnnVad& operator=(const RnnVad&) = delete;
+  ~RnnVad();
+  void Reset();
+  // Observes `feature_vector` and `is_silence`, updates the RNN and returns the
+  // current voice probability.
+  float ComputeVadProbability(
+      rtc::ArrayView<const float, kFeatureVectorSize> feature_vector,
+      bool is_silence);
+
+ private:
+  FullyConnectedLayer input_;
+  GatedRecurrentLayer hidden_;
+  FullyConnectedLayer output_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RNN_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc.cc
new file mode 100644
index 0000000000..91501fb6e3
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc.cc
@@ -0,0 +1,103 @@
+/*
+ *  Copyright (c) 2020 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 <algorithm>
+#include <numeric>
+
+#include "modules/audio_processing/agc2/rnn_vad/rnn_fc.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_conversions.h"
+#include "third_party/rnnoise/src/rnn_activations.h"
+#include "third_party/rnnoise/src/rnn_vad_weights.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+std::vector<float> GetScaledParams(rtc::ArrayView<const int8_t> params) {
+  std::vector<float> scaled_params(params.size());
+  std::transform(params.begin(), params.end(), scaled_params.begin(),
+                 [](int8_t x) -> float {
+                   return ::rnnoise::kWeightsScale * static_cast<float>(x);
+                 });
+  return scaled_params;
+}
+
+// TODO(bugs.chromium.org/10480): Hard-code optimized layout and remove this
+// function to improve setup time.
+// Casts and scales `weights` and re-arranges the layout.
+std::vector<float> PreprocessWeights(rtc::ArrayView<const int8_t> weights,
+                                     int output_size) {
+  if (output_size == 1) {
+    return GetScaledParams(weights);
+  }
+  // Transpose, scale and cast.
+  const int input_size = rtc::CheckedDivExact(
+      rtc::dchecked_cast<int>(weights.size()), output_size);
+  std::vector<float> w(weights.size());
+  for (int o = 0; o < output_size; ++o) {
+    for (int i = 0; i < input_size; ++i) {
+      w[o * input_size + i] = rnnoise::kWeightsScale *
+                              static_cast<float>(weights[i * output_size + o]);
+    }
+  }
+  return w;
+}
+
+rtc::FunctionView<float(float)> GetActivationFunction(
+    ActivationFunction activation_function) {
+  switch (activation_function) {
+    case ActivationFunction::kTansigApproximated:
+      return ::rnnoise::TansigApproximated;
+    case ActivationFunction::kSigmoidApproximated:
+      return ::rnnoise::SigmoidApproximated;
+  }
+}
+
+}  // namespace
+
+FullyConnectedLayer::FullyConnectedLayer(
+    const int input_size,
+    const int output_size,
+    const rtc::ArrayView<const int8_t> bias,
+    const rtc::ArrayView<const int8_t> weights,
+    ActivationFunction activation_function,
+    const AvailableCpuFeatures& cpu_features,
+    absl::string_view layer_name)
+    : input_size_(input_size),
+      output_size_(output_size),
+      bias_(GetScaledParams(bias)),
+      weights_(PreprocessWeights(weights, output_size)),
+      vector_math_(cpu_features),
+      activation_function_(GetActivationFunction(activation_function)) {
+  RTC_DCHECK_LE(output_size_, kFullyConnectedLayerMaxUnits)
+      << "Insufficient FC layer over-allocation (" << layer_name << ").";
+  RTC_DCHECK_EQ(output_size_, bias_.size())
+      << "Mismatching output size and bias terms array size (" << layer_name
+      << ").";
+  RTC_DCHECK_EQ(input_size_ * output_size_, weights_.size())
+      << "Mismatching input-output size and weight coefficients array size ("
+      << layer_name << ").";
+}
+
+FullyConnectedLayer::~FullyConnectedLayer() = default;
+
+void FullyConnectedLayer::ComputeOutput(rtc::ArrayView<const float> input) {
+  RTC_DCHECK_EQ(input.size(), input_size_);
+  rtc::ArrayView<const float> weights(weights_);
+  for (int o = 0; o < output_size_; ++o) {
+    output_[o] = activation_function_(
+        bias_[o] + vector_math_.DotProduct(
+                       input, weights.subview(o * input_size_, input_size_)));
+  }
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc.h
new file mode 100644
index 0000000000..d23957a6f2
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc.h
@@ -0,0 +1,72 @@
+/*
+ *  Copyright (c) 2020 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_AGC2_RNN_VAD_RNN_FC_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RNN_FC_H_
+
+#include <array>
+#include <vector>
+
+#include "absl/strings/string_view.h"
+#include "api/array_view.h"
+#include "api/function_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/vector_math.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Activation function for a neural network cell.
+enum class ActivationFunction { kTansigApproximated, kSigmoidApproximated };
+
+// Maximum number of units for an FC layer.
+constexpr int kFullyConnectedLayerMaxUnits = 24;
+
+// Fully-connected layer with a custom activation function which owns the output
+// buffer.
+class FullyConnectedLayer {
+ public:
+  // Ctor. `output_size` cannot be greater than `kFullyConnectedLayerMaxUnits`.
+  FullyConnectedLayer(int input_size,
+                      int output_size,
+                      rtc::ArrayView<const int8_t> bias,
+                      rtc::ArrayView<const int8_t> weights,
+                      ActivationFunction activation_function,
+                      const AvailableCpuFeatures& cpu_features,
+                      absl::string_view layer_name);
+  FullyConnectedLayer(const FullyConnectedLayer&) = delete;
+  FullyConnectedLayer& operator=(const FullyConnectedLayer&) = delete;
+  ~FullyConnectedLayer();
+
+  // Returns the size of the input vector.
+  int input_size() const { return input_size_; }
+  // Returns the pointer to the first element of the output buffer.
+  const float* data() const { return output_.data(); }
+  // Returns the size of the output buffer.
+  int size() const { return output_size_; }
+
+  // Computes the fully-connected layer output.
+  void ComputeOutput(rtc::ArrayView<const float> input);
+
+ private:
+  const int input_size_;
+  const int output_size_;
+  const std::vector<float> bias_;
+  const std::vector<float> weights_;
+  const VectorMath vector_math_;
+  rtc::FunctionView<float(float)> activation_function_;
+  // Over-allocated array with size equal to `output_size_`.
+  std::array<float, kFullyConnectedLayerMaxUnits> output_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RNN_FC_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc_unittest.cc
new file mode 100644
index 0000000000..ff9bb18bc2
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_fc_unittest.cc
@@ -0,0 +1,111 @@
+/*
+ *  Copyright (c) 2020 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/agc2/rnn_vad/rnn_fc.h"
+
+#include <array>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+#include "modules/audio_processing/test/performance_timer.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/system/arch.h"
+#include "test/gtest.h"
+#include "third_party/rnnoise/src/rnn_vad_weights.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+using ::rnnoise::kInputDenseBias;
+using ::rnnoise::kInputDenseWeights;
+using ::rnnoise::kInputLayerInputSize;
+using ::rnnoise::kInputLayerOutputSize;
+
+// Fully connected layer test data.
+constexpr std::array<float, 42> kFullyConnectedInputVector = {
+    -1.00131f,   -0.627069f, -7.81097f,  7.86285f,    -2.87145f,  3.32365f,
+    -0.653161f,  0.529839f,  -0.425307f, 0.25583f,    0.235094f,  0.230527f,
+    -0.144687f,  0.182785f,  0.57102f,   0.125039f,   0.479482f,  -0.0255439f,
+    -0.0073141f, -0.147346f, -0.217106f, -0.0846906f, -8.34943f,  3.09065f,
+    1.42628f,    -0.85235f,  -0.220207f, -0.811163f,  2.09032f,   -2.01425f,
+    -0.690268f,  -0.925327f, -0.541354f, 0.58455f,    -0.606726f, -0.0372358f,
+    0.565991f,   0.435854f,  0.420812f,  0.162198f,   -2.13f,     10.0089f};
+constexpr std::array<float, 24> kFullyConnectedExpectedOutput = {
+    -0.623293f, -0.988299f, 0.999378f,  0.967168f,  0.103087f,  -0.978545f,
+    -0.856347f, 0.346675f,  1.f,        -0.717442f, -0.544176f, 0.960363f,
+    0.983443f,  0.999991f,  -0.824335f, 0.984742f,  0.990208f,  0.938179f,
+    0.875092f,  0.999846f,  0.997707f,  -0.999382f, 0.973153f,  -0.966605f};
+
+class RnnFcParametrization
+    : public ::testing::TestWithParam<AvailableCpuFeatures> {};
+
+// Checks that the output of a fully connected layer is within tolerance given
+// test input data.
+TEST_P(RnnFcParametrization, CheckFullyConnectedLayerOutput) {
+  FullyConnectedLayer fc(kInputLayerInputSize, kInputLayerOutputSize,
+                         kInputDenseBias, kInputDenseWeights,
+                         ActivationFunction::kTansigApproximated,
+                         /*cpu_features=*/GetParam(),
+                         /*layer_name=*/"FC");
+  fc.ComputeOutput(kFullyConnectedInputVector);
+  ExpectNearAbsolute(kFullyConnectedExpectedOutput, fc, 1e-5f);
+}
+
+TEST_P(RnnFcParametrization, DISABLED_BenchmarkFullyConnectedLayer) {
+  const AvailableCpuFeatures cpu_features = GetParam();
+  FullyConnectedLayer fc(kInputLayerInputSize, kInputLayerOutputSize,
+                         kInputDenseBias, kInputDenseWeights,
+                         ActivationFunction::kTansigApproximated, cpu_features,
+                         /*layer_name=*/"FC");
+
+  constexpr int kNumTests = 10000;
+  ::webrtc::test::PerformanceTimer perf_timer(kNumTests);
+  for (int k = 0; k < kNumTests; ++k) {
+    perf_timer.StartTimer();
+    fc.ComputeOutput(kFullyConnectedInputVector);
+    perf_timer.StopTimer();
+  }
+  RTC_LOG(LS_INFO) << "CPU features: " << cpu_features.ToString() << " | "
+                   << (perf_timer.GetDurationAverage() / 1000) << " +/- "
+                   << (perf_timer.GetDurationStandardDeviation() / 1000)
+                   << " ms";
+}
+
+// Finds the relevant CPU features combinations to test.
+std::vector<AvailableCpuFeatures> GetCpuFeaturesToTest() {
+  std::vector<AvailableCpuFeatures> v;
+  v.push_back(NoAvailableCpuFeatures());
+  AvailableCpuFeatures available = GetAvailableCpuFeatures();
+  if (available.sse2) {
+    v.push_back({/*sse2=*/true, /*avx2=*/false, /*neon=*/false});
+  }
+  if (available.avx2) {
+    v.push_back({/*sse2=*/false, /*avx2=*/true, /*neon=*/false});
+  }
+  if (available.neon) {
+    v.push_back({/*sse2=*/false, /*avx2=*/false, /*neon=*/true});
+  }
+  return v;
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    RnnVadTest,
+    RnnFcParametrization,
+    ::testing::ValuesIn(GetCpuFeaturesToTest()),
+    [](const ::testing::TestParamInfo<AvailableCpuFeatures>& info) {
+      return info.param.ToString();
+    });
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru.cc
new file mode 100644
index 0000000000..ef37410caa
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru.cc
@@ -0,0 +1,198 @@
+/*
+ *  Copyright (c) 2020 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/agc2/rnn_vad/rnn_gru.h"
+
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_conversions.h"
+#include "third_party/rnnoise/src/rnn_activations.h"
+#include "third_party/rnnoise/src/rnn_vad_weights.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr int kNumGruGates = 3;  // Update, reset, output.
+
+std::vector<float> PreprocessGruTensor(rtc::ArrayView<const int8_t> tensor_src,
+                                       int output_size) {
+  // Transpose, cast and scale.
+  // `n` is the size of the first dimension of the 3-dim tensor `weights`.
+  const int n = rtc::CheckedDivExact(rtc::dchecked_cast<int>(tensor_src.size()),
+                                     output_size * kNumGruGates);
+  const int stride_src = kNumGruGates * output_size;
+  const int stride_dst = n * output_size;
+  std::vector<float> tensor_dst(tensor_src.size());
+  for (int g = 0; g < kNumGruGates; ++g) {
+    for (int o = 0; o < output_size; ++o) {
+      for (int i = 0; i < n; ++i) {
+        tensor_dst[g * stride_dst + o * n + i] =
+            ::rnnoise::kWeightsScale *
+            static_cast<float>(
+                tensor_src[i * stride_src + g * output_size + o]);
+      }
+    }
+  }
+  return tensor_dst;
+}
+
+// Computes the output for the update or the reset gate.
+// Operation: `g = sigmoid(W^T∙i + R^T∙s + b)` where
+// - `g`: output gate vector
+// - `W`: weights matrix
+// - `i`: input vector
+// - `R`: recurrent weights matrix
+// - `s`: state gate vector
+// - `b`: bias vector
+void ComputeUpdateResetGate(int input_size,
+                            int output_size,
+                            const VectorMath& vector_math,
+                            rtc::ArrayView<const float> input,
+                            rtc::ArrayView<const float> state,
+                            rtc::ArrayView<const float> bias,
+                            rtc::ArrayView<const float> weights,
+                            rtc::ArrayView<const float> recurrent_weights,
+                            rtc::ArrayView<float> gate) {
+  RTC_DCHECK_EQ(input.size(), input_size);
+  RTC_DCHECK_EQ(state.size(), output_size);
+  RTC_DCHECK_EQ(bias.size(), output_size);
+  RTC_DCHECK_EQ(weights.size(), input_size * output_size);
+  RTC_DCHECK_EQ(recurrent_weights.size(), output_size * output_size);
+  RTC_DCHECK_GE(gate.size(), output_size);  // `gate` is over-allocated.
+  for (int o = 0; o < output_size; ++o) {
+    float x = bias[o];
+    x += vector_math.DotProduct(input,
+                                weights.subview(o * input_size, input_size));
+    x += vector_math.DotProduct(
+        state, recurrent_weights.subview(o * output_size, output_size));
+    gate[o] = ::rnnoise::SigmoidApproximated(x);
+  }
+}
+
+// Computes the output for the state gate.
+// Operation: `s' = u .* s + (1 - u) .* ReLU(W^T∙i + R^T∙(s .* r) + b)` where
+// - `s'`: output state gate vector
+// - `s`: previous state gate vector
+// - `u`: update gate vector
+// - `W`: weights matrix
+// - `i`: input vector
+// - `R`: recurrent weights matrix
+// - `r`: reset gate vector
+// - `b`: bias vector
+// - `.*` element-wise product
+void ComputeStateGate(int input_size,
+                      int output_size,
+                      const VectorMath& vector_math,
+                      rtc::ArrayView<const float> input,
+                      rtc::ArrayView<const float> update,
+                      rtc::ArrayView<const float> reset,
+                      rtc::ArrayView<const float> bias,
+                      rtc::ArrayView<const float> weights,
+                      rtc::ArrayView<const float> recurrent_weights,
+                      rtc::ArrayView<float> state) {
+  RTC_DCHECK_EQ(input.size(), input_size);
+  RTC_DCHECK_GE(update.size(), output_size);  // `update` is over-allocated.
+  RTC_DCHECK_GE(reset.size(), output_size);   // `reset` is over-allocated.
+  RTC_DCHECK_EQ(bias.size(), output_size);
+  RTC_DCHECK_EQ(weights.size(), input_size * output_size);
+  RTC_DCHECK_EQ(recurrent_weights.size(), output_size * output_size);
+  RTC_DCHECK_EQ(state.size(), output_size);
+  std::array<float, kGruLayerMaxUnits> reset_x_state;
+  for (int o = 0; o < output_size; ++o) {
+    reset_x_state[o] = state[o] * reset[o];
+  }
+  for (int o = 0; o < output_size; ++o) {
+    float x = bias[o];
+    x += vector_math.DotProduct(input,
+                                weights.subview(o * input_size, input_size));
+    x += vector_math.DotProduct(
+        {reset_x_state.data(), static_cast<size_t>(output_size)},
+        recurrent_weights.subview(o * output_size, output_size));
+    state[o] = update[o] * state[o] + (1.f - update[o]) * std::max(0.f, x);
+  }
+}
+
+}  // namespace
+
+GatedRecurrentLayer::GatedRecurrentLayer(
+    const int input_size,
+    const int output_size,
+    const rtc::ArrayView<const int8_t> bias,
+    const rtc::ArrayView<const int8_t> weights,
+    const rtc::ArrayView<const int8_t> recurrent_weights,
+    const AvailableCpuFeatures& cpu_features,
+    absl::string_view layer_name)
+    : input_size_(input_size),
+      output_size_(output_size),
+      bias_(PreprocessGruTensor(bias, output_size)),
+      weights_(PreprocessGruTensor(weights, output_size)),
+      recurrent_weights_(PreprocessGruTensor(recurrent_weights, output_size)),
+      vector_math_(cpu_features) {
+  RTC_DCHECK_LE(output_size_, kGruLayerMaxUnits)
+      << "Insufficient GRU layer over-allocation (" << layer_name << ").";
+  RTC_DCHECK_EQ(kNumGruGates * output_size_, bias_.size())
+      << "Mismatching output size and bias terms array size (" << layer_name
+      << ").";
+  RTC_DCHECK_EQ(kNumGruGates * input_size_ * output_size_, weights_.size())
+      << "Mismatching input-output size and weight coefficients array size ("
+      << layer_name << ").";
+  RTC_DCHECK_EQ(kNumGruGates * output_size_ * output_size_,
+                recurrent_weights_.size())
+      << "Mismatching input-output size and recurrent weight coefficients array"
+         " size ("
+      << layer_name << ").";
+  Reset();
+}
+
+GatedRecurrentLayer::~GatedRecurrentLayer() = default;
+
+void GatedRecurrentLayer::Reset() {
+  state_.fill(0.f);
+}
+
+void GatedRecurrentLayer::ComputeOutput(rtc::ArrayView<const float> input) {
+  RTC_DCHECK_EQ(input.size(), input_size_);
+
+  // The tensors below are organized as a sequence of flattened tensors for the
+  // `update`, `reset` and `state` gates.
+  rtc::ArrayView<const float> bias(bias_);
+  rtc::ArrayView<const float> weights(weights_);
+  rtc::ArrayView<const float> recurrent_weights(recurrent_weights_);
+  // Strides to access to the flattened tensors for a specific gate.
+  const int stride_weights = input_size_ * output_size_;
+  const int stride_recurrent_weights = output_size_ * output_size_;
+
+  rtc::ArrayView<float> state(state_.data(), output_size_);
+
+  // Update gate.
+  std::array<float, kGruLayerMaxUnits> update;
+  ComputeUpdateResetGate(
+      input_size_, output_size_, vector_math_, input, state,
+      bias.subview(0, output_size_), weights.subview(0, stride_weights),
+      recurrent_weights.subview(0, stride_recurrent_weights), update);
+  // Reset gate.
+  std::array<float, kGruLayerMaxUnits> reset;
+  ComputeUpdateResetGate(input_size_, output_size_, vector_math_, input, state,
+                         bias.subview(output_size_, output_size_),
+                         weights.subview(stride_weights, stride_weights),
+                         recurrent_weights.subview(stride_recurrent_weights,
+                                                   stride_recurrent_weights),
+                         reset);
+  // State gate.
+  ComputeStateGate(input_size_, output_size_, vector_math_, input, update,
+                   reset, bias.subview(2 * output_size_, output_size_),
+                   weights.subview(2 * stride_weights, stride_weights),
+                   recurrent_weights.subview(2 * stride_recurrent_weights,
+                                             stride_recurrent_weights),
+                   state);
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru.h
new file mode 100644
index 0000000000..3407dfcdf1
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru.h
@@ -0,0 +1,70 @@
+/*
+ *  Copyright (c) 2020 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_AGC2_RNN_VAD_RNN_GRU_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RNN_GRU_H_
+
+#include <array>
+#include <vector>
+
+#include "absl/strings/string_view.h"
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/vector_math.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Maximum number of units for a GRU layer.
+constexpr int kGruLayerMaxUnits = 24;
+
+// Recurrent layer with gated recurrent units (GRUs) with sigmoid and ReLU as
+// activation functions for the update/reset and output gates respectively.
+class GatedRecurrentLayer {
+ public:
+  // Ctor. `output_size` cannot be greater than `kGruLayerMaxUnits`.
+  GatedRecurrentLayer(int input_size,
+                      int output_size,
+                      rtc::ArrayView<const int8_t> bias,
+                      rtc::ArrayView<const int8_t> weights,
+                      rtc::ArrayView<const int8_t> recurrent_weights,
+                      const AvailableCpuFeatures& cpu_features,
+                      absl::string_view layer_name);
+  GatedRecurrentLayer(const GatedRecurrentLayer&) = delete;
+  GatedRecurrentLayer& operator=(const GatedRecurrentLayer&) = delete;
+  ~GatedRecurrentLayer();
+
+  // Returns the size of the input vector.
+  int input_size() const { return input_size_; }
+  // Returns the pointer to the first element of the output buffer.
+  const float* data() const { return state_.data(); }
+  // Returns the size of the output buffer.
+  int size() const { return output_size_; }
+
+  // Resets the GRU state.
+  void Reset();
+  // Computes the recurrent layer output and updates the status.
+  void ComputeOutput(rtc::ArrayView<const float> input);
+
+ private:
+  const int input_size_;
+  const int output_size_;
+  const std::vector<float> bias_;
+  const std::vector<float> weights_;
+  const std::vector<float> recurrent_weights_;
+  const VectorMath vector_math_;
+  // Over-allocated array with size equal to `output_size_`.
+  std::array<float, kGruLayerMaxUnits> state_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_RNN_GRU_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru_unittest.cc
new file mode 100644
index 0000000000..88ae72803a
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru_unittest.cc
@@ -0,0 +1,186 @@
+/*
+ *  Copyright (c) 2020 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/agc2/rnn_vad/rnn_gru.h"
+
+#include <array>
+#include <memory>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+#include "modules/audio_processing/test/performance_timer.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "test/gtest.h"
+#include "third_party/rnnoise/src/rnn_vad_weights.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+void TestGatedRecurrentLayer(
+    GatedRecurrentLayer& gru,
+    rtc::ArrayView<const float> input_sequence,
+    rtc::ArrayView<const float> expected_output_sequence) {
+  const int input_sequence_length = rtc::CheckedDivExact(
+      rtc::dchecked_cast<int>(input_sequence.size()), gru.input_size());
+  const int output_sequence_length = rtc::CheckedDivExact(
+      rtc::dchecked_cast<int>(expected_output_sequence.size()), gru.size());
+  ASSERT_EQ(input_sequence_length, output_sequence_length)
+      << "The test data length is invalid.";
+  // Feed the GRU layer and check the output at every step.
+  gru.Reset();
+  for (int i = 0; i < input_sequence_length; ++i) {
+    SCOPED_TRACE(i);
+    gru.ComputeOutput(
+        input_sequence.subview(i * gru.input_size(), gru.input_size()));
+    const auto expected_output =
+        expected_output_sequence.subview(i * gru.size(), gru.size());
+    ExpectNearAbsolute(expected_output, gru, 3e-6f);
+  }
+}
+
+// Gated recurrent units layer test data.
+constexpr int kGruInputSize = 5;
+constexpr int kGruOutputSize = 4;
+constexpr std::array<int8_t, 12> kGruBias = {96,   -99, -81, -114, 49,  119,
+                                             -118, 68,  -76, 91,   121, 125};
+constexpr std::array<int8_t, 60> kGruWeights = {
+    // Input 0.
+    124, 9, 1, 116,        // Update.
+    -66, -21, -118, -110,  // Reset.
+    104, 75, -23, -51,     // Output.
+    // Input 1.
+    -72, -111, 47, 93,   // Update.
+    77, -98, 41, -8,     // Reset.
+    40, -23, -43, -107,  // Output.
+    // Input 2.
+    9, -73, 30, -32,      // Update.
+    -2, 64, -26, 91,      // Reset.
+    -48, -24, -28, -104,  // Output.
+    // Input 3.
+    74, -46, 116, 15,    // Update.
+    32, 52, -126, -38,   // Reset.
+    -121, 12, -16, 110,  // Output.
+    // Input 4.
+    -95, 66, -103, -35,  // Update.
+    -38, 3, -126, -61,   // Reset.
+    28, 98, -117, -43    // Output.
+};
+constexpr std::array<int8_t, 48> kGruRecurrentWeights = {
+    // Output 0.
+    -3, 87, 50, 51,     // Update.
+    -22, 27, -39, 62,   // Reset.
+    31, -83, -52, -48,  // Output.
+    // Output 1.
+    -6, 83, -19, 104,  // Update.
+    105, 48, 23, 68,   // Reset.
+    23, 40, 7, -120,   // Output.
+    // Output 2.
+    64, -62, 117, 85,     // Update.
+    51, -43, 54, -105,    // Reset.
+    120, 56, -128, -107,  // Output.
+    // Output 3.
+    39, 50, -17, -47,   // Update.
+    -117, 14, 108, 12,  // Reset.
+    -7, -72, 103, -87,  // Output.
+};
+constexpr std::array<float, 20> kGruInputSequence = {
+    0.89395463f, 0.93224651f, 0.55788344f, 0.32341808f, 0.93355054f,
+    0.13475326f, 0.97370994f, 0.14253306f, 0.93710381f, 0.76093364f,
+    0.65780413f, 0.41657975f, 0.49403164f, 0.46843281f, 0.75138855f,
+    0.24517593f, 0.47657707f, 0.57064998f, 0.435184f,   0.19319285f};
+constexpr std::array<float, 16> kGruExpectedOutputSequence = {
+    0.0239123f,  0.5773077f,  0.f,         0.f,
+    0.01282811f, 0.64330572f, 0.f,         0.04863098f,
+    0.00781069f, 0.75267816f, 0.f,         0.02579715f,
+    0.00471378f, 0.59162533f, 0.11087593f, 0.01334511f};
+
+class RnnGruParametrization
+    : public ::testing::TestWithParam<AvailableCpuFeatures> {};
+
+// Checks that the output of a GRU layer is within tolerance given test input
+// data.
+TEST_P(RnnGruParametrization, CheckGatedRecurrentLayer) {
+  GatedRecurrentLayer gru(kGruInputSize, kGruOutputSize, kGruBias, kGruWeights,
+                          kGruRecurrentWeights,
+                          /*cpu_features=*/GetParam(),
+                          /*layer_name=*/"GRU");
+  TestGatedRecurrentLayer(gru, kGruInputSequence, kGruExpectedOutputSequence);
+}
+
+TEST_P(RnnGruParametrization, DISABLED_BenchmarkGatedRecurrentLayer) {
+  // Prefetch test data.
+  std::unique_ptr<FileReader> reader = CreateGruInputReader();
+  std::vector<float> gru_input_sequence(reader->size());
+  reader->ReadChunk(gru_input_sequence);
+
+  using ::rnnoise::kHiddenGruBias;
+  using ::rnnoise::kHiddenGruRecurrentWeights;
+  using ::rnnoise::kHiddenGruWeights;
+  using ::rnnoise::kHiddenLayerOutputSize;
+  using ::rnnoise::kInputLayerOutputSize;
+
+  GatedRecurrentLayer gru(kInputLayerOutputSize, kHiddenLayerOutputSize,
+                          kHiddenGruBias, kHiddenGruWeights,
+                          kHiddenGruRecurrentWeights,
+                          /*cpu_features=*/GetParam(),
+                          /*layer_name=*/"GRU");
+
+  rtc::ArrayView<const float> input_sequence(gru_input_sequence);
+  ASSERT_EQ(input_sequence.size() % kInputLayerOutputSize,
+            static_cast<size_t>(0));
+  const int input_sequence_length =
+      input_sequence.size() / kInputLayerOutputSize;
+
+  constexpr int kNumTests = 100;
+  ::webrtc::test::PerformanceTimer perf_timer(kNumTests);
+  for (int k = 0; k < kNumTests; ++k) {
+    perf_timer.StartTimer();
+    for (int i = 0; i < input_sequence_length; ++i) {
+      gru.ComputeOutput(
+          input_sequence.subview(i * gru.input_size(), gru.input_size()));
+    }
+    perf_timer.StopTimer();
+  }
+  RTC_LOG(LS_INFO) << (perf_timer.GetDurationAverage() / 1000) << " +/- "
+                   << (perf_timer.GetDurationStandardDeviation() / 1000)
+                   << " ms";
+}
+
+// Finds the relevant CPU features combinations to test.
+std::vector<AvailableCpuFeatures> GetCpuFeaturesToTest() {
+  std::vector<AvailableCpuFeatures> v;
+  v.push_back(NoAvailableCpuFeatures());
+  AvailableCpuFeatures available = GetAvailableCpuFeatures();
+  if (available.sse2) {
+    v.push_back({/*sse2=*/true, /*avx2=*/false, /*neon=*/false});
+  }
+  if (available.avx2) {
+    v.push_back({/*sse2=*/false, /*avx2=*/true, /*neon=*/false});
+  }
+  if (available.neon) {
+    v.push_back({/*sse2=*/false, /*avx2=*/false, /*neon=*/true});
+  }
+  return v;
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    RnnVadTest,
+    RnnGruParametrization,
+    ::testing::ValuesIn(GetCpuFeaturesToTest()),
+    [](const ::testing::TestParamInfo<AvailableCpuFeatures>& info) {
+      return info.param.ToString();
+    });
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_unittest.cc
new file mode 100644
index 0000000000..4c5409a14e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_unittest.cc
@@ -0,0 +1,70 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/rnn.h"
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr std::array<float, kFeatureVectorSize> kFeatures = {
+    -1.00131f,   -0.627069f, -7.81097f,  7.86285f,    -2.87145f,  3.32365f,
+    -0.653161f,  0.529839f,  -0.425307f, 0.25583f,    0.235094f,  0.230527f,
+    -0.144687f,  0.182785f,  0.57102f,   0.125039f,   0.479482f,  -0.0255439f,
+    -0.0073141f, -0.147346f, -0.217106f, -0.0846906f, -8.34943f,  3.09065f,
+    1.42628f,    -0.85235f,  -0.220207f, -0.811163f,  2.09032f,   -2.01425f,
+    -0.690268f,  -0.925327f, -0.541354f, 0.58455f,    -0.606726f, -0.0372358f,
+    0.565991f,   0.435854f,  0.420812f,  0.162198f,   -2.13f,     10.0089f};
+
+void WarmUpRnnVad(RnnVad& rnn_vad) {
+  for (int i = 0; i < 10; ++i) {
+    rnn_vad.ComputeVadProbability(kFeatures, /*is_silence=*/false);
+  }
+}
+
+// Checks that the speech probability is zero with silence.
+TEST(RnnVadTest, CheckZeroProbabilityWithSilence) {
+  RnnVad rnn_vad(GetAvailableCpuFeatures());
+  WarmUpRnnVad(rnn_vad);
+  EXPECT_EQ(rnn_vad.ComputeVadProbability(kFeatures, /*is_silence=*/true), 0.f);
+}
+
+// Checks that the same output is produced after reset given the same input
+// sequence.
+TEST(RnnVadTest, CheckRnnVadReset) {
+  RnnVad rnn_vad(GetAvailableCpuFeatures());
+  WarmUpRnnVad(rnn_vad);
+  float pre = rnn_vad.ComputeVadProbability(kFeatures, /*is_silence=*/false);
+  rnn_vad.Reset();
+  WarmUpRnnVad(rnn_vad);
+  float post = rnn_vad.ComputeVadProbability(kFeatures, /*is_silence=*/false);
+  EXPECT_EQ(pre, post);
+}
+
+// Checks that the same output is produced after silence is observed given the
+// same input sequence.
+TEST(RnnVadTest, CheckRnnVadSilence) {
+  RnnVad rnn_vad(GetAvailableCpuFeatures());
+  WarmUpRnnVad(rnn_vad);
+  float pre = rnn_vad.ComputeVadProbability(kFeatures, /*is_silence=*/false);
+  rnn_vad.ComputeVadProbability(kFeatures, /*is_silence=*/true);
+  WarmUpRnnVad(rnn_vad);
+  float post = rnn_vad.ComputeVadProbability(kFeatures, /*is_silence=*/false);
+  EXPECT_EQ(pre, post);
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_auto_correlation_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_auto_correlation_gn/moz.build
new file mode 100644
index 0000000000..3f00e43e7c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_auto_correlation_gn/moz.build
@@ -0,0 +1,232 @@
+# 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_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/agc2/rnn_vad/auto_correlation.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("rnn_vad_auto_correlation_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_common_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_common_gn/moz.build
new file mode 100644
index 0000000000..64d3371d81
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_common_gn/moz.build
@@ -0,0 +1,216 @@
+# 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_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"
+]
+
+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":
+
+    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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("rnn_vad_common_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_gn/moz.build
new file mode 100644
index 0000000000..82e5302312
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_gn/moz.build
@@ -0,0 +1,233 @@
+# 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_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/agc2/rnn_vad/features_extraction.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn.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("rnn_vad_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_layers_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_layers_gn/moz.build
new file mode 100644
index 0000000000..7dd4619965
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_layers_gn/moz.build
@@ -0,0 +1,233 @@
+# 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_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/agc2/rnn_vad/rnn_fc.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_gru.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("rnn_vad_layers_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_lp_residual_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_lp_residual_gn/moz.build
new file mode 100644
index 0000000000..1fcbbbe408
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_lp_residual_gn/moz.build
@@ -0,0 +1,221 @@
+# 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_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/agc2/rnn_vad/lp_residual.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
+
+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
+
+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("rnn_vad_lp_residual_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_pitch_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_pitch_gn/moz.build
new file mode 100644
index 0000000000..6a69de9e29
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_pitch_gn/moz.build
@@ -0,0 +1,233 @@
+# 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_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/agc2/rnn_vad/pitch_search.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/pitch_search_internal.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("rnn_vad_pitch_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_ring_buffer_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_ring_buffer_gn/moz.build
new file mode 100644
index 0000000000..d2a4eb7261
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_ring_buffer_gn/moz.build
@@ -0,0 +1,205 @@
+# 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_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"
+]
+
+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
+
+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
+
+if CONFIG["CPU_ARCH"] == "aarch64":
+
+    DEFINES["WEBRTC_ARCH_ARM64"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["CPU_ARCH"] == "arm":
+
+    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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("rnn_vad_ring_buffer_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_sequence_buffer_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_sequence_buffer_gn/moz.build
new file mode 100644
index 0000000000..c6913470c3
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_sequence_buffer_gn/moz.build
@@ -0,0 +1,205 @@
+# 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_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"
+]
+
+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
+
+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
+
+if CONFIG["CPU_ARCH"] == "aarch64":
+
+    DEFINES["WEBRTC_ARCH_ARM64"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["CPU_ARCH"] == "arm":
+
+    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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("rnn_vad_sequence_buffer_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_spectral_features_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_spectral_features_gn/moz.build
new file mode 100644
index 0000000000..8298c7e091
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_spectral_features_gn/moz.build
@@ -0,0 +1,233 @@
+# 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_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/agc2/rnn_vad/spectral_features.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal.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("rnn_vad_spectral_features_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_symmetric_matrix_buffer_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_symmetric_matrix_buffer_gn/moz.build
new file mode 100644
index 0000000000..acb9330454
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_symmetric_matrix_buffer_gn/moz.build
@@ -0,0 +1,205 @@
+# 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_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"
+]
+
+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
+
+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
+
+if CONFIG["CPU_ARCH"] == "aarch64":
+
+    DEFINES["WEBRTC_ARCH_ARM64"] = True
+    DEFINES["WEBRTC_HAS_NEON"] = True
+
+if CONFIG["CPU_ARCH"] == "arm":
+
+    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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("rnn_vad_symmetric_matrix_buffer_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_tool.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_tool.cc
new file mode 100644
index 0000000000..a0e1242eb4
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_tool.cc
@@ -0,0 +1,123 @@
+/*
+ *  Copyright (c) 2018 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 <array>
+#include <string>
+#include <vector>
+
+#include "absl/flags/flag.h"
+#include "absl/flags/parse.h"
+#include "common_audio/resampler/push_sinc_resampler.h"
+#include "common_audio/wav_file.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/features_extraction.h"
+#include "modules/audio_processing/agc2/rnn_vad/rnn.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/safe_compare.h"
+
+ABSL_FLAG(std::string, i, "", "Path to the input wav file");
+ABSL_FLAG(std::string, f, "", "Path to the output features file");
+ABSL_FLAG(std::string, o, "", "Path to the output VAD probabilities file");
+
+namespace webrtc {
+namespace rnn_vad {
+namespace test {
+
+int main(int argc, char* argv[]) {
+  absl::ParseCommandLine(argc, argv);
+  rtc::LogMessage::LogToDebug(rtc::LS_INFO);
+
+  // Open wav input file and check properties.
+  const std::string input_wav_file = absl::GetFlag(FLAGS_i);
+  WavReader wav_reader(input_wav_file);
+  if (wav_reader.num_channels() != 1) {
+    RTC_LOG(LS_ERROR) << "Only mono wav files are supported";
+    return 1;
+  }
+  if (wav_reader.sample_rate() % 100 != 0) {
+    RTC_LOG(LS_ERROR) << "The sample rate rate must allow 10 ms frames.";
+    return 1;
+  }
+  RTC_LOG(LS_INFO) << "Input sample rate: " << wav_reader.sample_rate();
+
+  // Init output files.
+  const std::string output_vad_probs_file = absl::GetFlag(FLAGS_o);
+  FILE* vad_probs_file = fopen(output_vad_probs_file.c_str(), "wb");
+  FILE* features_file = nullptr;
+  const std::string output_feature_file = absl::GetFlag(FLAGS_f);
+  if (!output_feature_file.empty()) {
+    features_file = fopen(output_feature_file.c_str(), "wb");
+  }
+
+  // Initialize.
+  const int frame_size_10ms =
+      rtc::CheckedDivExact(wav_reader.sample_rate(), 100);
+  std::vector<float> samples_10ms;
+  samples_10ms.resize(frame_size_10ms);
+  std::array<float, kFrameSize10ms24kHz> samples_10ms_24kHz;
+  PushSincResampler resampler(frame_size_10ms, kFrameSize10ms24kHz);
+  const AvailableCpuFeatures cpu_features = GetAvailableCpuFeatures();
+  FeaturesExtractor features_extractor(cpu_features);
+  std::array<float, kFeatureVectorSize> feature_vector;
+  RnnVad rnn_vad(cpu_features);
+
+  // Compute VAD probabilities.
+  while (true) {
+    // Read frame at the input sample rate.
+    const size_t read_samples =
+        wav_reader.ReadSamples(frame_size_10ms, samples_10ms.data());
+    if (rtc::SafeLt(read_samples, frame_size_10ms)) {
+      break;  // EOF.
+    }
+    // Resample input.
+    resampler.Resample(samples_10ms.data(), samples_10ms.size(),
+                       samples_10ms_24kHz.data(), samples_10ms_24kHz.size());
+
+    // Extract features and feed the RNN.
+    bool is_silence = features_extractor.CheckSilenceComputeFeatures(
+        samples_10ms_24kHz, feature_vector);
+    float vad_probability =
+        rnn_vad.ComputeVadProbability(feature_vector, is_silence);
+    // Write voice probability.
+    RTC_DCHECK_GE(vad_probability, 0.f);
+    RTC_DCHECK_GE(1.f, vad_probability);
+    fwrite(&vad_probability, sizeof(float), 1, vad_probs_file);
+    // Write features.
+    if (features_file) {
+      const float float_is_silence = is_silence ? 1.f : 0.f;
+      fwrite(&float_is_silence, sizeof(float), 1, features_file);
+      if (is_silence) {
+        // Do not write uninitialized values.
+        feature_vector.fill(0.f);
+      }
+      fwrite(feature_vector.data(), sizeof(float), kFeatureVectorSize,
+             features_file);
+    }
+  }
+
+  // Close output file(s).
+  fclose(vad_probs_file);
+  RTC_LOG(LS_INFO) << "VAD probabilities written to " << output_vad_probs_file;
+  if (features_file) {
+    fclose(features_file);
+    RTC_LOG(LS_INFO) << "features written to " << output_feature_file;
+  }
+
+  return 0;
+}
+
+}  // namespace test
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+int main(int argc, char* argv[]) {
+  return webrtc::rnn_vad::test::main(argc, argv);
+}
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_unittest.cc
new file mode 100644
index 0000000000..f33cd14a8a
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/rnn_vad_unittest.cc
@@ -0,0 +1,185 @@
+/*
+ *  Copyright (c) 2018 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 <array>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "common_audio/resampler/push_sinc_resampler.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/agc2/rnn_vad/features_extraction.h"
+#include "modules/audio_processing/agc2/rnn_vad/rnn.h"
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+#include "modules/audio_processing/test/performance_timer.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "test/gtest.h"
+#include "third_party/rnnoise/src/rnn_activations.h"
+#include "third_party/rnnoise/src/rnn_vad_weights.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr int kFrameSize10ms48kHz = 480;
+
+void DumpPerfStats(int num_samples,
+                   int sample_rate,
+                   double average_us,
+                   double standard_deviation) {
+  float audio_track_length_ms =
+      1e3f * static_cast<float>(num_samples) / static_cast<float>(sample_rate);
+  float average_ms = static_cast<float>(average_us) / 1e3f;
+  float speed = audio_track_length_ms / average_ms;
+  RTC_LOG(LS_INFO) << "track duration (ms): " << audio_track_length_ms;
+  RTC_LOG(LS_INFO) << "average processing time (ms): " << average_ms << " +/- "
+                   << (standard_deviation / 1e3);
+  RTC_LOG(LS_INFO) << "speed: " << speed << "x";
+}
+
+// When the RNN VAD model is updated and the expected output changes, set the
+// constant below to true in order to write new expected output binary files.
+constexpr bool kWriteComputedOutputToFile = false;
+
+// Avoids that one forgets to set `kWriteComputedOutputToFile` back to false
+// when the expected output files are re-exported.
+TEST(RnnVadTest, CheckWriteComputedOutputIsFalse) {
+  ASSERT_FALSE(kWriteComputedOutputToFile)
+      << "Cannot land if kWriteComputedOutput is true.";
+}
+
+class RnnVadProbabilityParametrization
+    : public ::testing::TestWithParam<AvailableCpuFeatures> {};
+
+// Checks that the computed VAD probability for a test input sequence sampled at
+// 48 kHz is within tolerance.
+TEST_P(RnnVadProbabilityParametrization, RnnVadProbabilityWithinTolerance) {
+  // Init resampler, feature extractor and RNN.
+  PushSincResampler decimator(kFrameSize10ms48kHz, kFrameSize10ms24kHz);
+  const AvailableCpuFeatures cpu_features = GetParam();
+  FeaturesExtractor features_extractor(cpu_features);
+  RnnVad rnn_vad(cpu_features);
+
+  // Init input samples and expected output readers.
+  std::unique_ptr<FileReader> samples_reader = CreatePcmSamplesReader();
+  std::unique_ptr<FileReader> expected_vad_prob_reader = CreateVadProbsReader();
+
+  // Input length. The last incomplete frame is ignored.
+  const int num_frames = samples_reader->size() / kFrameSize10ms48kHz;
+
+  // Init buffers.
+  std::vector<float> samples_48k(kFrameSize10ms48kHz);
+  std::vector<float> samples_24k(kFrameSize10ms24kHz);
+  std::vector<float> feature_vector(kFeatureVectorSize);
+  std::vector<float> computed_vad_prob(num_frames);
+  std::vector<float> expected_vad_prob(num_frames);
+
+  // Read expected output.
+  ASSERT_TRUE(expected_vad_prob_reader->ReadChunk(expected_vad_prob));
+
+  // Compute VAD probabilities on the downsampled input.
+  float cumulative_error = 0.f;
+  for (int i = 0; i < num_frames; ++i) {
+    ASSERT_TRUE(samples_reader->ReadChunk(samples_48k));
+    decimator.Resample(samples_48k.data(), samples_48k.size(),
+                       samples_24k.data(), samples_24k.size());
+    bool is_silence = features_extractor.CheckSilenceComputeFeatures(
+        {samples_24k.data(), kFrameSize10ms24kHz},
+        {feature_vector.data(), kFeatureVectorSize});
+    computed_vad_prob[i] = rnn_vad.ComputeVadProbability(
+        {feature_vector.data(), kFeatureVectorSize}, is_silence);
+    EXPECT_NEAR(computed_vad_prob[i], expected_vad_prob[i], 1e-3f);
+    cumulative_error += std::abs(computed_vad_prob[i] - expected_vad_prob[i]);
+  }
+  // Check average error.
+  EXPECT_LT(cumulative_error / num_frames, 1e-4f);
+
+  if (kWriteComputedOutputToFile) {
+    FileWriter vad_prob_writer("new_vad_prob.dat");
+    vad_prob_writer.WriteChunk(computed_vad_prob);
+  }
+}
+
+// Performance test for the RNN VAD (pre-fetching and downsampling are
+// excluded). Keep disabled and only enable locally to measure performance as
+// follows:
+// - on desktop: run the this unit test adding "--logs";
+// - on android: run the this unit test adding "--logcat-output-file".
+TEST_P(RnnVadProbabilityParametrization, DISABLED_RnnVadPerformance) {
+  // PCM samples reader and buffers.
+  std::unique_ptr<FileReader> samples_reader = CreatePcmSamplesReader();
+  // The last incomplete frame is ignored.
+  const int num_frames = samples_reader->size() / kFrameSize10ms48kHz;
+  std::array<float, kFrameSize10ms48kHz> samples;
+  // Pre-fetch and decimate samples.
+  PushSincResampler decimator(kFrameSize10ms48kHz, kFrameSize10ms24kHz);
+  std::vector<float> prefetched_decimated_samples;
+  prefetched_decimated_samples.resize(num_frames * kFrameSize10ms24kHz);
+  for (int i = 0; i < num_frames; ++i) {
+    ASSERT_TRUE(samples_reader->ReadChunk(samples));
+    decimator.Resample(samples.data(), samples.size(),
+                       &prefetched_decimated_samples[i * kFrameSize10ms24kHz],
+                       kFrameSize10ms24kHz);
+  }
+  // Initialize.
+  const AvailableCpuFeatures cpu_features = GetParam();
+  FeaturesExtractor features_extractor(cpu_features);
+  std::array<float, kFeatureVectorSize> feature_vector;
+  RnnVad rnn_vad(cpu_features);
+  constexpr int number_of_tests = 100;
+  ::webrtc::test::PerformanceTimer perf_timer(number_of_tests);
+  for (int k = 0; k < number_of_tests; ++k) {
+    features_extractor.Reset();
+    rnn_vad.Reset();
+    // Process frames.
+    perf_timer.StartTimer();
+    for (int i = 0; i < num_frames; ++i) {
+      bool is_silence = features_extractor.CheckSilenceComputeFeatures(
+          {&prefetched_decimated_samples[i * kFrameSize10ms24kHz],
+           kFrameSize10ms24kHz},
+          feature_vector);
+      rnn_vad.ComputeVadProbability(feature_vector, is_silence);
+    }
+    perf_timer.StopTimer();
+  }
+  DumpPerfStats(num_frames * kFrameSize10ms24kHz, kSampleRate24kHz,
+                perf_timer.GetDurationAverage(),
+                perf_timer.GetDurationStandardDeviation());
+}
+
+// Finds the relevant CPU features combinations to test.
+std::vector<AvailableCpuFeatures> GetCpuFeaturesToTest() {
+  std::vector<AvailableCpuFeatures> v;
+  v.push_back(NoAvailableCpuFeatures());
+  AvailableCpuFeatures available = GetAvailableCpuFeatures();
+  if (available.avx2 && available.sse2) {
+    v.push_back({/*sse2=*/true, /*avx2=*/true, /*neon=*/false});
+  }
+  if (available.sse2) {
+    v.push_back({/*sse2=*/true, /*avx2=*/false, /*neon=*/false});
+  }
+  if (available.neon) {
+    v.push_back({/*sse2=*/false, /*avx2=*/false, /*neon=*/true});
+  }
+  return v;
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    RnnVadTest,
+    RnnVadProbabilityParametrization,
+    ::testing::ValuesIn(GetCpuFeaturesToTest()),
+    [](const ::testing::TestParamInfo<AvailableCpuFeatures>& info) {
+      return info.param.ToString();
+    });
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/sequence_buffer.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/sequence_buffer.h
new file mode 100644
index 0000000000..a7402788c8
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/sequence_buffer.h
@@ -0,0 +1,79 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_SEQUENCE_BUFFER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SEQUENCE_BUFFER_H_
+
+#include <algorithm>
+#include <cstring>
+#include <type_traits>
+#include <vector>
+
+#include "api/array_view.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Linear buffer implementation to (i) push fixed size chunks of sequential data
+// and (ii) view contiguous parts of the buffer. The buffer and the pushed
+// chunks have size S and N respectively. For instance, when S = 2N the first
+// half of the sequence buffer is replaced with its second half, and the new N
+// values are written at the end of the buffer.
+// The class also provides a view on the most recent M values, where 0 < M <= S
+// and by default M = N.
+template <typename T, int S, int N, int M = N>
+class SequenceBuffer {
+  static_assert(N <= S,
+                "The new chunk size cannot be larger than the sequence buffer "
+                "size.");
+  static_assert(std::is_arithmetic<T>::value,
+                "Integral or floating point required.");
+
+ public:
+  SequenceBuffer() : buffer_(S) {
+    RTC_DCHECK_EQ(S, buffer_.size());
+    Reset();
+  }
+  SequenceBuffer(const SequenceBuffer&) = delete;
+  SequenceBuffer& operator=(const SequenceBuffer&) = delete;
+  ~SequenceBuffer() = default;
+  int size() const { return S; }
+  int chunks_size() const { return N; }
+  // Sets the sequence buffer values to zero.
+  void Reset() { std::fill(buffer_.begin(), buffer_.end(), 0); }
+  // Returns a view on the whole buffer.
+  rtc::ArrayView<const T, S> GetBufferView() const {
+    return {buffer_.data(), S};
+  }
+  // Returns a view on the M most recent values of the buffer.
+  rtc::ArrayView<const T, M> GetMostRecentValuesView() const {
+    static_assert(M <= S,
+                  "The number of most recent values cannot be larger than the "
+                  "sequence buffer size.");
+    return {buffer_.data() + S - M, M};
+  }
+  // Shifts left the buffer by N items and add new N items at the end.
+  void Push(rtc::ArrayView<const T, N> new_values) {
+    // Make space for the new values.
+    if (S > N)
+      std::memmove(buffer_.data(), buffer_.data() + N, (S - N) * sizeof(T));
+    // Copy the new values at the end of the buffer.
+    std::memcpy(buffer_.data() + S - N, new_values.data(), N * sizeof(T));
+  }
+
+ private:
+  std::vector<T> buffer_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SEQUENCE_BUFFER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/sequence_buffer_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/sequence_buffer_unittest.cc
new file mode 100644
index 0000000000..af005833c1
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/sequence_buffer_unittest.cc
@@ -0,0 +1,102 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/sequence_buffer.h"
+
+#include <algorithm>
+#include <array>
+
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+template <typename T, int S, int N>
+void TestSequenceBufferPushOp() {
+  SCOPED_TRACE(S);
+  SCOPED_TRACE(N);
+  SequenceBuffer<T, S, N> seq_buf;
+  auto seq_buf_view = seq_buf.GetBufferView();
+  std::array<T, N> chunk;
+
+  // Check that a chunk is fully gone after ceil(S / N) push ops.
+  chunk.fill(1);
+  seq_buf.Push(chunk);
+  chunk.fill(0);
+  constexpr int required_push_ops = (S % N) ? S / N + 1 : S / N;
+  for (int i = 0; i < required_push_ops - 1; ++i) {
+    SCOPED_TRACE(i);
+    seq_buf.Push(chunk);
+    // Still in the buffer.
+    const auto* m = std::max_element(seq_buf_view.begin(), seq_buf_view.end());
+    EXPECT_EQ(1, *m);
+  }
+  // Gone after another push.
+  seq_buf.Push(chunk);
+  const auto* m = std::max_element(seq_buf_view.begin(), seq_buf_view.end());
+  EXPECT_EQ(0, *m);
+
+  // Check that the last item moves left by N positions after a push op.
+  if (S > N) {
+    // Fill in with non-zero values.
+    for (int i = 0; i < N; ++i)
+      chunk[i] = static_cast<T>(i + 1);
+    seq_buf.Push(chunk);
+    // With the next Push(), `last` will be moved left by N positions.
+    const T last = chunk[N - 1];
+    for (int i = 0; i < N; ++i)
+      chunk[i] = static_cast<T>(last + i + 1);
+    seq_buf.Push(chunk);
+    EXPECT_EQ(last, seq_buf_view[S - N - 1]);
+  }
+}
+
+TEST(RnnVadTest, SequenceBufferGetters) {
+  constexpr int buffer_size = 8;
+  constexpr int chunk_size = 8;
+  SequenceBuffer<int, buffer_size, chunk_size> seq_buf;
+  EXPECT_EQ(buffer_size, seq_buf.size());
+  EXPECT_EQ(chunk_size, seq_buf.chunks_size());
+  // Test view.
+  auto seq_buf_view = seq_buf.GetBufferView();
+  EXPECT_EQ(0, seq_buf_view[0]);
+  EXPECT_EQ(0, seq_buf_view[seq_buf_view.size() - 1]);
+  constexpr std::array<int, chunk_size> chunk = {10, 20, 30, 40,
+                                                 50, 60, 70, 80};
+  seq_buf.Push(chunk);
+  EXPECT_EQ(10, *seq_buf_view.begin());
+  EXPECT_EQ(80, *(seq_buf_view.end() - 1));
+}
+
+TEST(RnnVadTest, SequenceBufferPushOpsUnsigned) {
+  TestSequenceBufferPushOp<uint8_t, 32, 8>();   // Chunk size: 25%.
+  TestSequenceBufferPushOp<uint8_t, 32, 16>();  // Chunk size: 50%.
+  TestSequenceBufferPushOp<uint8_t, 32, 32>();  // Chunk size: 100%.
+  TestSequenceBufferPushOp<uint8_t, 23, 7>();   // Non-integer ratio.
+}
+
+TEST(RnnVadTest, SequenceBufferPushOpsSigned) {
+  TestSequenceBufferPushOp<int, 32, 8>();   // Chunk size: 25%.
+  TestSequenceBufferPushOp<int, 32, 16>();  // Chunk size: 50%.
+  TestSequenceBufferPushOp<int, 32, 32>();  // Chunk size: 100%.
+  TestSequenceBufferPushOp<int, 23, 7>();   // Non-integer ratio.
+}
+
+TEST(RnnVadTest, SequenceBufferPushOpsFloating) {
+  TestSequenceBufferPushOp<float, 32, 8>();   // Chunk size: 25%.
+  TestSequenceBufferPushOp<float, 32, 16>();  // Chunk size: 50%.
+  TestSequenceBufferPushOp<float, 32, 32>();  // Chunk size: 100%.
+  TestSequenceBufferPushOp<float, 23, 7>();   // Non-integer ratio.
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features.cc
new file mode 100644
index 0000000000..96086babb6
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features.cc
@@ -0,0 +1,214 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/spectral_features.h"
+
+#include <algorithm>
+#include <cmath>
+#include <limits>
+#include <numeric>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr float kSilenceThreshold = 0.04f;
+
+// Computes the new cepstral difference stats and pushes them into the passed
+// symmetric matrix buffer.
+void UpdateCepstralDifferenceStats(
+    rtc::ArrayView<const float, kNumBands> new_cepstral_coeffs,
+    const RingBuffer<float, kNumBands, kCepstralCoeffsHistorySize>& ring_buf,
+    SymmetricMatrixBuffer<float, kCepstralCoeffsHistorySize>* sym_matrix_buf) {
+  RTC_DCHECK(sym_matrix_buf);
+  // Compute the new cepstral distance stats.
+  std::array<float, kCepstralCoeffsHistorySize - 1> distances;
+  for (int i = 0; i < kCepstralCoeffsHistorySize - 1; ++i) {
+    const int delay = i + 1;
+    auto old_cepstral_coeffs = ring_buf.GetArrayView(delay);
+    distances[i] = 0.f;
+    for (int k = 0; k < kNumBands; ++k) {
+      const float c = new_cepstral_coeffs[k] - old_cepstral_coeffs[k];
+      distances[i] += c * c;
+    }
+  }
+  // Push the new spectral distance stats into the symmetric matrix buffer.
+  sym_matrix_buf->Push(distances);
+}
+
+// Computes the first half of the Vorbis window.
+std::array<float, kFrameSize20ms24kHz / 2> ComputeScaledHalfVorbisWindow(
+    float scaling = 1.f) {
+  constexpr int kHalfSize = kFrameSize20ms24kHz / 2;
+  std::array<float, kHalfSize> half_window{};
+  for (int i = 0; i < kHalfSize; ++i) {
+    half_window[i] =
+        scaling *
+        std::sin(0.5 * kPi * std::sin(0.5 * kPi * (i + 0.5) / kHalfSize) *
+                 std::sin(0.5 * kPi * (i + 0.5) / kHalfSize));
+  }
+  return half_window;
+}
+
+// Computes the forward FFT on a 20 ms frame to which a given window function is
+// applied. The Fourier coefficient corresponding to the Nyquist frequency is
+// set to zero (it is never used and this allows to simplify the code).
+void ComputeWindowedForwardFft(
+    rtc::ArrayView<const float, kFrameSize20ms24kHz> frame,
+    const std::array<float, kFrameSize20ms24kHz / 2>& half_window,
+    Pffft::FloatBuffer* fft_input_buffer,
+    Pffft::FloatBuffer* fft_output_buffer,
+    Pffft* fft) {
+  RTC_DCHECK_EQ(frame.size(), 2 * half_window.size());
+  // Apply windowing.
+  auto in = fft_input_buffer->GetView();
+  for (int i = 0, j = kFrameSize20ms24kHz - 1;
+       rtc::SafeLt(i, half_window.size()); ++i, --j) {
+    in[i] = frame[i] * half_window[i];
+    in[j] = frame[j] * half_window[i];
+  }
+  fft->ForwardTransform(*fft_input_buffer, fft_output_buffer, /*ordered=*/true);
+  // Set the Nyquist frequency coefficient to zero.
+  auto out = fft_output_buffer->GetView();
+  out[1] = 0.f;
+}
+
+}  // namespace
+
+SpectralFeaturesExtractor::SpectralFeaturesExtractor()
+    : half_window_(ComputeScaledHalfVorbisWindow(
+          1.f / static_cast<float>(kFrameSize20ms24kHz))),
+      fft_(kFrameSize20ms24kHz, Pffft::FftType::kReal),
+      fft_buffer_(fft_.CreateBuffer()),
+      reference_frame_fft_(fft_.CreateBuffer()),
+      lagged_frame_fft_(fft_.CreateBuffer()),
+      dct_table_(ComputeDctTable()) {}
+
+SpectralFeaturesExtractor::~SpectralFeaturesExtractor() = default;
+
+void SpectralFeaturesExtractor::Reset() {
+  cepstral_coeffs_ring_buf_.Reset();
+  cepstral_diffs_buf_.Reset();
+}
+
+bool SpectralFeaturesExtractor::CheckSilenceComputeFeatures(
+    rtc::ArrayView<const float, kFrameSize20ms24kHz> reference_frame,
+    rtc::ArrayView<const float, kFrameSize20ms24kHz> lagged_frame,
+    rtc::ArrayView<float, kNumBands - kNumLowerBands> higher_bands_cepstrum,
+    rtc::ArrayView<float, kNumLowerBands> average,
+    rtc::ArrayView<float, kNumLowerBands> first_derivative,
+    rtc::ArrayView<float, kNumLowerBands> second_derivative,
+    rtc::ArrayView<float, kNumLowerBands> bands_cross_corr,
+    float* variability) {
+  // Compute the Opus band energies for the reference frame.
+  ComputeWindowedForwardFft(reference_frame, half_window_, fft_buffer_.get(),
+                            reference_frame_fft_.get(), &fft_);
+  spectral_correlator_.ComputeAutoCorrelation(
+      reference_frame_fft_->GetConstView(), reference_frame_bands_energy_);
+  // Check if the reference frame has silence.
+  const float tot_energy =
+      std::accumulate(reference_frame_bands_energy_.begin(),
+                      reference_frame_bands_energy_.end(), 0.f);
+  if (tot_energy < kSilenceThreshold) {
+    return true;
+  }
+  // Compute the Opus band energies for the lagged frame.
+  ComputeWindowedForwardFft(lagged_frame, half_window_, fft_buffer_.get(),
+                            lagged_frame_fft_.get(), &fft_);
+  spectral_correlator_.ComputeAutoCorrelation(lagged_frame_fft_->GetConstView(),
+                                              lagged_frame_bands_energy_);
+  // Log of the band energies for the reference frame.
+  std::array<float, kNumBands> log_bands_energy;
+  ComputeSmoothedLogMagnitudeSpectrum(reference_frame_bands_energy_,
+                                      log_bands_energy);
+  // Reference frame cepstrum.
+  std::array<float, kNumBands> cepstrum;
+  ComputeDct(log_bands_energy, dct_table_, cepstrum);
+  // Ad-hoc correction terms for the first two cepstral coefficients.
+  cepstrum[0] -= 12.f;
+  cepstrum[1] -= 4.f;
+  // Update the ring buffer and the cepstral difference stats.
+  cepstral_coeffs_ring_buf_.Push(cepstrum);
+  UpdateCepstralDifferenceStats(cepstrum, cepstral_coeffs_ring_buf_,
+                                &cepstral_diffs_buf_);
+  // Write the higher bands cepstral coefficients.
+  RTC_DCHECK_EQ(cepstrum.size() - kNumLowerBands, higher_bands_cepstrum.size());
+  std::copy(cepstrum.begin() + kNumLowerBands, cepstrum.end(),
+            higher_bands_cepstrum.begin());
+  // Compute and write remaining features.
+  ComputeAvgAndDerivatives(average, first_derivative, second_derivative);
+  ComputeNormalizedCepstralCorrelation(bands_cross_corr);
+  RTC_DCHECK(variability);
+  *variability = ComputeVariability();
+  return false;
+}
+
+void SpectralFeaturesExtractor::ComputeAvgAndDerivatives(
+    rtc::ArrayView<float, kNumLowerBands> average,
+    rtc::ArrayView<float, kNumLowerBands> first_derivative,
+    rtc::ArrayView<float, kNumLowerBands> second_derivative) const {
+  auto curr = cepstral_coeffs_ring_buf_.GetArrayView(0);
+  auto prev1 = cepstral_coeffs_ring_buf_.GetArrayView(1);
+  auto prev2 = cepstral_coeffs_ring_buf_.GetArrayView(2);
+  RTC_DCHECK_EQ(average.size(), first_derivative.size());
+  RTC_DCHECK_EQ(first_derivative.size(), second_derivative.size());
+  RTC_DCHECK_LE(average.size(), curr.size());
+  for (int i = 0; rtc::SafeLt(i, average.size()); ++i) {
+    // Average, kernel: [1, 1, 1].
+    average[i] = curr[i] + prev1[i] + prev2[i];
+    // First derivative, kernel: [1, 0, - 1].
+    first_derivative[i] = curr[i] - prev2[i];
+    // Second derivative, Laplacian kernel: [1, -2, 1].
+    second_derivative[i] = curr[i] - 2 * prev1[i] + prev2[i];
+  }
+}
+
+void SpectralFeaturesExtractor::ComputeNormalizedCepstralCorrelation(
+    rtc::ArrayView<float, kNumLowerBands> bands_cross_corr) {
+  spectral_correlator_.ComputeCrossCorrelation(
+      reference_frame_fft_->GetConstView(), lagged_frame_fft_->GetConstView(),
+      bands_cross_corr_);
+  // Normalize.
+  for (int i = 0; rtc::SafeLt(i, bands_cross_corr_.size()); ++i) {
+    bands_cross_corr_[i] =
+        bands_cross_corr_[i] /
+        std::sqrt(0.001f + reference_frame_bands_energy_[i] *
+                               lagged_frame_bands_energy_[i]);
+  }
+  // Cepstrum.
+  ComputeDct(bands_cross_corr_, dct_table_, bands_cross_corr);
+  // Ad-hoc correction terms for the first two cepstral coefficients.
+  bands_cross_corr[0] -= 1.3f;
+  bands_cross_corr[1] -= 0.9f;
+}
+
+float SpectralFeaturesExtractor::ComputeVariability() const {
+  // Compute cepstral variability score.
+  float variability = 0.f;
+  for (int delay1 = 0; delay1 < kCepstralCoeffsHistorySize; ++delay1) {
+    float min_dist = std::numeric_limits<float>::max();
+    for (int delay2 = 0; delay2 < kCepstralCoeffsHistorySize; ++delay2) {
+      if (delay1 == delay2)  // The distance would be 0.
+        continue;
+      min_dist =
+          std::min(min_dist, cepstral_diffs_buf_.GetValue(delay1, delay2));
+    }
+    variability += min_dist;
+  }
+  // Normalize (based on training set stats).
+  // TODO(bugs.webrtc.org/10480): Isolate normalization from feature extraction.
+  return variability / kCepstralCoeffsHistorySize - 2.1f;
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features.h
new file mode 100644
index 0000000000..d327ef8e01
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features.h
@@ -0,0 +1,79 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_SPECTRAL_FEATURES_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SPECTRAL_FEATURES_H_
+
+#include <array>
+#include <cstddef>
+#include <memory>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/ring_buffer.h"
+#include "modules/audio_processing/agc2/rnn_vad/spectral_features_internal.h"
+#include "modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer.h"
+#include "modules/audio_processing/utility/pffft_wrapper.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Class to compute spectral features.
+class SpectralFeaturesExtractor {
+ public:
+  SpectralFeaturesExtractor();
+  SpectralFeaturesExtractor(const SpectralFeaturesExtractor&) = delete;
+  SpectralFeaturesExtractor& operator=(const SpectralFeaturesExtractor&) =
+      delete;
+  ~SpectralFeaturesExtractor();
+  // Resets the internal state of the feature extractor.
+  void Reset();
+  // Analyzes a pair of reference and lagged frames from the pitch buffer,
+  // detects silence and computes features. If silence is detected, the output
+  // is neither computed nor written.
+  bool CheckSilenceComputeFeatures(
+      rtc::ArrayView<const float, kFrameSize20ms24kHz> reference_frame,
+      rtc::ArrayView<const float, kFrameSize20ms24kHz> lagged_frame,
+      rtc::ArrayView<float, kNumBands - kNumLowerBands> higher_bands_cepstrum,
+      rtc::ArrayView<float, kNumLowerBands> average,
+      rtc::ArrayView<float, kNumLowerBands> first_derivative,
+      rtc::ArrayView<float, kNumLowerBands> second_derivative,
+      rtc::ArrayView<float, kNumLowerBands> bands_cross_corr,
+      float* variability);
+
+ private:
+  void ComputeAvgAndDerivatives(
+      rtc::ArrayView<float, kNumLowerBands> average,
+      rtc::ArrayView<float, kNumLowerBands> first_derivative,
+      rtc::ArrayView<float, kNumLowerBands> second_derivative) const;
+  void ComputeNormalizedCepstralCorrelation(
+      rtc::ArrayView<float, kNumLowerBands> bands_cross_corr);
+  float ComputeVariability() const;
+
+  const std::array<float, kFrameSize20ms24kHz / 2> half_window_;
+  Pffft fft_;
+  std::unique_ptr<Pffft::FloatBuffer> fft_buffer_;
+  std::unique_ptr<Pffft::FloatBuffer> reference_frame_fft_;
+  std::unique_ptr<Pffft::FloatBuffer> lagged_frame_fft_;
+  SpectralCorrelator spectral_correlator_;
+  std::array<float, kOpusBands24kHz> reference_frame_bands_energy_;
+  std::array<float, kOpusBands24kHz> lagged_frame_bands_energy_;
+  std::array<float, kOpusBands24kHz> bands_cross_corr_;
+  const std::array<float, kNumBands * kNumBands> dct_table_;
+  RingBuffer<float, kNumBands, kCepstralCoeffsHistorySize>
+      cepstral_coeffs_ring_buf_;
+  SymmetricMatrixBuffer<float, kCepstralCoeffsHistorySize> cepstral_diffs_buf_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SPECTRAL_FEATURES_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal.cc
new file mode 100644
index 0000000000..a10b0f7ec9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal.cc
@@ -0,0 +1,188 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/spectral_features_internal.h"
+
+#include <algorithm>
+#include <cmath>
+#include <cstddef>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// Weights for each FFT coefficient for each Opus band (Nyquist frequency
+// excluded). The size of each band is specified in
+// `kOpusScaleNumBins24kHz20ms`.
+constexpr std::array<float, kFrameSize20ms24kHz / 2> kOpusBandWeights24kHz20ms =
+    {{
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 0
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 1
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 2
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 3
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 4
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 5
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 6
+        0.f,       0.25f,      0.5f,       0.75f,  // Band 7
+        0.f,       0.125f,     0.25f,      0.375f,    0.5f,
+        0.625f,    0.75f,      0.875f,  // Band 8
+        0.f,       0.125f,     0.25f,      0.375f,    0.5f,
+        0.625f,    0.75f,      0.875f,  // Band 9
+        0.f,       0.125f,     0.25f,      0.375f,    0.5f,
+        0.625f,    0.75f,      0.875f,  // Band 10
+        0.f,       0.125f,     0.25f,      0.375f,    0.5f,
+        0.625f,    0.75f,      0.875f,  // Band 11
+        0.f,       0.0625f,    0.125f,     0.1875f,   0.25f,
+        0.3125f,   0.375f,     0.4375f,    0.5f,      0.5625f,
+        0.625f,    0.6875f,    0.75f,      0.8125f,   0.875f,
+        0.9375f,  // Band 12
+        0.f,       0.0625f,    0.125f,     0.1875f,   0.25f,
+        0.3125f,   0.375f,     0.4375f,    0.5f,      0.5625f,
+        0.625f,    0.6875f,    0.75f,      0.8125f,   0.875f,
+        0.9375f,  // Band 13
+        0.f,       0.0625f,    0.125f,     0.1875f,   0.25f,
+        0.3125f,   0.375f,     0.4375f,    0.5f,      0.5625f,
+        0.625f,    0.6875f,    0.75f,      0.8125f,   0.875f,
+        0.9375f,  // Band 14
+        0.f,       0.0416667f, 0.0833333f, 0.125f,    0.166667f,
+        0.208333f, 0.25f,      0.291667f,  0.333333f, 0.375f,
+        0.416667f, 0.458333f,  0.5f,       0.541667f, 0.583333f,
+        0.625f,    0.666667f,  0.708333f,  0.75f,     0.791667f,
+        0.833333f, 0.875f,     0.916667f,  0.958333f,  // Band 15
+        0.f,       0.0416667f, 0.0833333f, 0.125f,    0.166667f,
+        0.208333f, 0.25f,      0.291667f,  0.333333f, 0.375f,
+        0.416667f, 0.458333f,  0.5f,       0.541667f, 0.583333f,
+        0.625f,    0.666667f,  0.708333f,  0.75f,     0.791667f,
+        0.833333f, 0.875f,     0.916667f,  0.958333f,  // Band 16
+        0.f,       0.03125f,   0.0625f,    0.09375f,  0.125f,
+        0.15625f,  0.1875f,    0.21875f,   0.25f,     0.28125f,
+        0.3125f,   0.34375f,   0.375f,     0.40625f,  0.4375f,
+        0.46875f,  0.5f,       0.53125f,   0.5625f,   0.59375f,
+        0.625f,    0.65625f,   0.6875f,    0.71875f,  0.75f,
+        0.78125f,  0.8125f,    0.84375f,   0.875f,    0.90625f,
+        0.9375f,   0.96875f,  // Band 17
+        0.f,       0.0208333f, 0.0416667f, 0.0625f,   0.0833333f,
+        0.104167f, 0.125f,     0.145833f,  0.166667f, 0.1875f,
+        0.208333f, 0.229167f,  0.25f,      0.270833f, 0.291667f,
+        0.3125f,   0.333333f,  0.354167f,  0.375f,    0.395833f,
+        0.416667f, 0.4375f,    0.458333f,  0.479167f, 0.5f,
+        0.520833f, 0.541667f,  0.5625f,    0.583333f, 0.604167f,
+        0.625f,    0.645833f,  0.666667f,  0.6875f,   0.708333f,
+        0.729167f, 0.75f,      0.770833f,  0.791667f, 0.8125f,
+        0.833333f, 0.854167f,  0.875f,     0.895833f, 0.916667f,
+        0.9375f,   0.958333f,  0.979167f  // Band 18
+    }};
+
+}  // namespace
+
+SpectralCorrelator::SpectralCorrelator()
+    : weights_(kOpusBandWeights24kHz20ms.begin(),
+               kOpusBandWeights24kHz20ms.end()) {}
+
+SpectralCorrelator::~SpectralCorrelator() = default;
+
+void SpectralCorrelator::ComputeAutoCorrelation(
+    rtc::ArrayView<const float> x,
+    rtc::ArrayView<float, kOpusBands24kHz> auto_corr) const {
+  ComputeCrossCorrelation(x, x, auto_corr);
+}
+
+void SpectralCorrelator::ComputeCrossCorrelation(
+    rtc::ArrayView<const float> x,
+    rtc::ArrayView<const float> y,
+    rtc::ArrayView<float, kOpusBands24kHz> cross_corr) const {
+  RTC_DCHECK_EQ(x.size(), kFrameSize20ms24kHz);
+  RTC_DCHECK_EQ(x.size(), y.size());
+  RTC_DCHECK_EQ(x[1], 0.f) << "The Nyquist coefficient must be zeroed.";
+  RTC_DCHECK_EQ(y[1], 0.f) << "The Nyquist coefficient must be zeroed.";
+  constexpr auto kOpusScaleNumBins24kHz20ms = GetOpusScaleNumBins24kHz20ms();
+  int k = 0;  // Next Fourier coefficient index.
+  cross_corr[0] = 0.f;
+  for (int i = 0; i < kOpusBands24kHz - 1; ++i) {
+    cross_corr[i + 1] = 0.f;
+    for (int j = 0; j < kOpusScaleNumBins24kHz20ms[i]; ++j) {  // Band size.
+      const float v = x[2 * k] * y[2 * k] + x[2 * k + 1] * y[2 * k + 1];
+      const float tmp = weights_[k] * v;
+      cross_corr[i] += v - tmp;
+      cross_corr[i + 1] += tmp;
+      k++;
+    }
+  }
+  cross_corr[0] *= 2.f;  // The first band only gets half contribution.
+  RTC_DCHECK_EQ(k, kFrameSize20ms24kHz / 2);  // Nyquist coefficient never used.
+}
+
+void ComputeSmoothedLogMagnitudeSpectrum(
+    rtc::ArrayView<const float> bands_energy,
+    rtc::ArrayView<float, kNumBands> log_bands_energy) {
+  RTC_DCHECK_LE(bands_energy.size(), kNumBands);
+  constexpr float kOneByHundred = 1e-2f;
+  constexpr float kLogOneByHundred = -2.f;
+  // Init.
+  float log_max = kLogOneByHundred;
+  float follow = kLogOneByHundred;
+  const auto smooth = [&log_max, &follow](float x) {
+    x = std::max(log_max - 7.f, std::max(follow - 1.5f, x));
+    log_max = std::max(log_max, x);
+    follow = std::max(follow - 1.5f, x);
+    return x;
+  };
+  // Smoothing over the bands for which the band energy is defined.
+  for (int i = 0; rtc::SafeLt(i, bands_energy.size()); ++i) {
+    log_bands_energy[i] = smooth(std::log10(kOneByHundred + bands_energy[i]));
+  }
+  // Smoothing over the remaining bands (zero energy).
+  for (int i = bands_energy.size(); i < kNumBands; ++i) {
+    log_bands_energy[i] = smooth(kLogOneByHundred);
+  }
+}
+
+std::array<float, kNumBands * kNumBands> ComputeDctTable() {
+  std::array<float, kNumBands * kNumBands> dct_table;
+  const double k = std::sqrt(0.5);
+  for (int i = 0; i < kNumBands; ++i) {
+    for (int j = 0; j < kNumBands; ++j)
+      dct_table[i * kNumBands + j] = std::cos((i + 0.5) * j * kPi / kNumBands);
+    dct_table[i * kNumBands] *= k;
+  }
+  return dct_table;
+}
+
+void ComputeDct(rtc::ArrayView<const float> in,
+                rtc::ArrayView<const float, kNumBands * kNumBands> dct_table,
+                rtc::ArrayView<float> out) {
+  // DCT scaling factor - i.e., sqrt(2 / kNumBands).
+  constexpr float kDctScalingFactor = 0.301511345f;
+  constexpr float kDctScalingFactorError =
+      kDctScalingFactor * kDctScalingFactor -
+      2.f / static_cast<float>(kNumBands);
+  static_assert(
+      (kDctScalingFactorError >= 0.f && kDctScalingFactorError < 1e-1f) ||
+          (kDctScalingFactorError < 0.f && kDctScalingFactorError > -1e-1f),
+      "kNumBands changed and kDctScalingFactor has not been updated.");
+  RTC_DCHECK_NE(in.data(), out.data()) << "In-place DCT is not supported.";
+  RTC_DCHECK_LE(in.size(), kNumBands);
+  RTC_DCHECK_LE(1, out.size());
+  RTC_DCHECK_LE(out.size(), in.size());
+  for (int i = 0; rtc::SafeLt(i, out.size()); ++i) {
+    out[i] = 0.f;
+    for (int j = 0; rtc::SafeLt(j, in.size()); ++j) {
+      out[i] += in[j] * dct_table[j * kNumBands + i];
+    }
+    // TODO(bugs.webrtc.org/10480): Scaling factor in the DCT table.
+    out[i] *= kDctScalingFactor;
+  }
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal.h
new file mode 100644
index 0000000000..f4b293a567
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal.h
@@ -0,0 +1,100 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_SPECTRAL_FEATURES_INTERNAL_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SPECTRAL_FEATURES_INTERNAL_H_
+
+#include <stddef.h>
+
+#include <array>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// At a sample rate of 24 kHz, the last 3 Opus bands are beyond the Nyquist
+// frequency. However, band #19 gets the contributions from band #18 because
+// of the symmetric triangular filter with peak response at 12 kHz.
+constexpr int kOpusBands24kHz = 20;
+static_assert(kOpusBands24kHz < kNumBands,
+              "The number of bands at 24 kHz must be less than those defined "
+              "in the Opus scale at 48 kHz.");
+
+// Number of FFT frequency bins covered by each band in the Opus scale at a
+// sample rate of 24 kHz for 20 ms frames.
+// Declared here for unit testing.
+constexpr std::array<int, kOpusBands24kHz - 1> GetOpusScaleNumBins24kHz20ms() {
+  return {4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 16, 16, 16, 24, 24, 32, 48};
+}
+
+// TODO(bugs.webrtc.org/10480): Move to a separate file.
+// Class to compute band-wise spectral features in the Opus perceptual scale
+// for 20 ms frames sampled at 24 kHz. The analysis methods apply triangular
+// filters with peak response at the each band boundary.
+class SpectralCorrelator {
+ public:
+  // Ctor.
+  SpectralCorrelator();
+  SpectralCorrelator(const SpectralCorrelator&) = delete;
+  SpectralCorrelator& operator=(const SpectralCorrelator&) = delete;
+  ~SpectralCorrelator();
+
+  // Computes the band-wise spectral auto-correlations.
+  // `x` must:
+  //  - have size equal to `kFrameSize20ms24kHz`;
+  //  - be encoded as vectors of interleaved real-complex FFT coefficients
+  //    where x[1] = y[1] = 0 (the Nyquist frequency coefficient is omitted).
+  void ComputeAutoCorrelation(
+      rtc::ArrayView<const float> x,
+      rtc::ArrayView<float, kOpusBands24kHz> auto_corr) const;
+
+  // Computes the band-wise spectral cross-correlations.
+  // `x` and `y` must:
+  //  - have size equal to `kFrameSize20ms24kHz`;
+  //  - be encoded as vectors of interleaved real-complex FFT coefficients where
+  //    x[1] = y[1] = 0 (the Nyquist frequency coefficient is omitted).
+  void ComputeCrossCorrelation(
+      rtc::ArrayView<const float> x,
+      rtc::ArrayView<const float> y,
+      rtc::ArrayView<float, kOpusBands24kHz> cross_corr) const;
+
+ private:
+  const std::vector<float> weights_;  // Weights for each Fourier coefficient.
+};
+
+// TODO(bugs.webrtc.org/10480): Move to anonymous namespace in
+// spectral_features.cc. Given a vector of Opus-bands energy coefficients,
+// computes the log magnitude spectrum applying smoothing both over time and
+// over frequency. Declared here for unit testing.
+void ComputeSmoothedLogMagnitudeSpectrum(
+    rtc::ArrayView<const float> bands_energy,
+    rtc::ArrayView<float, kNumBands> log_bands_energy);
+
+// TODO(bugs.webrtc.org/10480): Move to anonymous namespace in
+// spectral_features.cc. Creates a DCT table for arrays having size equal to
+// `kNumBands`. Declared here for unit testing.
+std::array<float, kNumBands * kNumBands> ComputeDctTable();
+
+// TODO(bugs.webrtc.org/10480): Move to anonymous namespace in
+// spectral_features.cc. Computes DCT for `in` given a pre-computed DCT table.
+// In-place computation is not allowed and `out` can be smaller than `in` in
+// order to only compute the first DCT coefficients. Declared here for unit
+// testing.
+void ComputeDct(rtc::ArrayView<const float> in,
+                rtc::ArrayView<const float, kNumBands * kNumBands> dct_table,
+                rtc::ArrayView<float> out);
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SPECTRAL_FEATURES_INTERNAL_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal_unittest.cc
new file mode 100644
index 0000000000..ece4eb5024
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_internal_unittest.cc
@@ -0,0 +1,160 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/spectral_features_internal.h"
+
+#include <algorithm>
+#include <array>
+#include <complex>
+#include <numeric>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+#include "modules/audio_processing/utility/pffft_wrapper.h"
+#include "rtc_base/numerics/safe_compare.h"
+// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+// #include "test/fpe_observer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// Generates the values for the array named `kOpusBandWeights24kHz20ms` in the
+// anonymous namespace of the .cc file, which is the array of FFT coefficient
+// weights for the Opus scale triangular filters.
+std::vector<float> ComputeTriangularFiltersWeights() {
+  constexpr auto kOpusScaleNumBins24kHz20ms = GetOpusScaleNumBins24kHz20ms();
+  const auto& v = kOpusScaleNumBins24kHz20ms;  // Alias.
+  const int num_weights = std::accumulate(kOpusScaleNumBins24kHz20ms.begin(),
+                                          kOpusScaleNumBins24kHz20ms.end(), 0);
+  std::vector<float> weights(num_weights);
+  int next_fft_coeff_index = 0;
+  for (int band = 0; rtc::SafeLt(band, v.size()); ++band) {
+    const int band_size = v[band];
+    for (int j = 0; rtc::SafeLt(j, band_size); ++j) {
+      weights[next_fft_coeff_index + j] = static_cast<float>(j) / band_size;
+    }
+    next_fft_coeff_index += band_size;
+  }
+  return weights;
+}
+
+// Checks that the values returned by GetOpusScaleNumBins24kHz20ms() match the
+// Opus scale frequency boundaries.
+TEST(RnnVadTest, TestOpusScaleBoundaries) {
+  constexpr int kBandFrequencyBoundariesHz[kNumBands - 1] = {
+      200,  400,  600,  800,  1000, 1200, 1400, 1600,  2000,  2400, 2800,
+      3200, 4000, 4800, 5600, 6800, 8000, 9600, 12000, 15600, 20000};
+  constexpr auto kOpusScaleNumBins24kHz20ms = GetOpusScaleNumBins24kHz20ms();
+  int prev = 0;
+  for (int i = 0; rtc::SafeLt(i, kOpusScaleNumBins24kHz20ms.size()); ++i) {
+    int boundary =
+        kBandFrequencyBoundariesHz[i] * kFrameSize20ms24kHz / kSampleRate24kHz;
+    EXPECT_EQ(kOpusScaleNumBins24kHz20ms[i], boundary - prev);
+    prev = boundary;
+  }
+}
+
+// Checks that the computed triangular filters weights for the Opus scale are
+// monotonic withing each Opus band. This test should only be enabled when
+// ComputeTriangularFiltersWeights() is changed and `kOpusBandWeights24kHz20ms`
+// is updated accordingly.
+TEST(RnnVadTest, DISABLED_TestOpusScaleWeights) {
+  auto weights = ComputeTriangularFiltersWeights();
+  int i = 0;
+  for (int band_size : GetOpusScaleNumBins24kHz20ms()) {
+    SCOPED_TRACE(band_size);
+    rtc::ArrayView<float> band_weights(weights.data() + i, band_size);
+    float prev = -1.f;
+    for (float weight : band_weights) {
+      EXPECT_LT(prev, weight);
+      prev = weight;
+    }
+    i += band_size;
+  }
+}
+
+// Checks that the computed band-wise auto-correlation is non-negative for a
+// simple input vector of FFT coefficients.
+TEST(RnnVadTest, SpectralCorrelatorValidOutput) {
+  // Input: vector of (1, 1j) values.
+  Pffft fft(kFrameSize20ms24kHz, Pffft::FftType::kReal);
+  auto in = fft.CreateBuffer();
+  std::array<float, kOpusBands24kHz> out;
+  auto in_view = in->GetView();
+  std::fill(in_view.begin(), in_view.end(), 1.f);
+  in_view[1] = 0.f;  // Nyquist frequency.
+  // Compute and check output.
+  SpectralCorrelator e;
+  e.ComputeAutoCorrelation(in_view, out);
+  for (int i = 0; i < kOpusBands24kHz; ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_GT(out[i], 0.f);
+  }
+}
+
+// Checks that the computed smoothed log magnitude spectrum is within tolerance
+// given hard-coded test input data.
+TEST(RnnVadTest, ComputeSmoothedLogMagnitudeSpectrumWithinTolerance) {
+  constexpr std::array<float, kNumBands> input = {
+      {86.060539245605f, 275.668334960938f, 43.406528472900f, 6.541896820068f,
+       17.964015960693f, 8.090919494629f,   1.261920094490f,  1.212702631950f,
+       1.619154453278f,  0.508935272694f,   0.346316039562f,  0.237035423517f,
+       0.172424271703f,  0.271657168865f,   0.126088857651f,  0.139967113733f,
+       0.207200810313f,  0.155893072486f,   0.091090843081f,  0.033391401172f,
+       0.013879744336f,  0.011973354965f}};
+  constexpr std::array<float, kNumBands> expected_output = {
+      {1.934854507446f,  2.440402746201f,  1.637655138969f,  0.816367030144f,
+       1.254645109177f,  0.908534288406f,  0.104459829628f,  0.087320849299f,
+       0.211962252855f,  -0.284886807203f, -0.448164641857f, -0.607240796089f,
+       -0.738917350769f, -0.550279200077f, -0.866177439690f, -0.824003994465f,
+       -0.663138568401f, -0.780171751976f, -0.995288193226f, -1.362596273422f,
+       -1.621970295906f, -1.658103585243f}};
+  std::array<float, kNumBands> computed_output;
+  {
+    // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+    // FloatingPointExceptionObserver fpe_observer;
+    ComputeSmoothedLogMagnitudeSpectrum(input, computed_output);
+    ExpectNearAbsolute(expected_output, computed_output, 1e-5f);
+  }
+}
+
+// Checks that the computed DCT is within tolerance given hard-coded test input
+// data.
+TEST(RnnVadTest, ComputeDctWithinTolerance) {
+  constexpr std::array<float, kNumBands> input = {
+      {0.232155621052f,  0.678957760334f, 0.220818966627f,  -0.077363930643f,
+       -0.559227049351f, 0.432545185089f, 0.353900641203f,  0.398993015289f,
+       0.409774333239f,  0.454977899790f, 0.300520688295f,  -0.010286616161f,
+       0.272525429726f,  0.098067551851f, 0.083649002016f,  0.046226885170f,
+       -0.033228103071f, 0.144773483276f, -0.117661058903f, -0.005628800020f,
+       -0.009547689930f, -0.045382082462f}};
+  constexpr std::array<float, kNumBands> expected_output = {
+      {0.697072803974f,  0.442710995674f,  -0.293156713247f, -0.060711503029f,
+       0.292050391436f,  0.489301353693f,  0.402255415916f,  0.134404733777f,
+       -0.086305990815f, -0.199605688453f, -0.234511867166f, -0.413774639368f,
+       -0.388507157564f, -0.032798115164f, 0.044605545700f,  0.112466648221f,
+       -0.050096966326f, 0.045971218497f,  -0.029815061018f, -0.410366982222f,
+       -0.209233760834f, -0.128037497401f}};
+  auto dct_table = ComputeDctTable();
+  std::array<float, kNumBands> computed_output;
+  {
+    // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+    // FloatingPointExceptionObserver fpe_observer;
+    ComputeDct(input, dct_table, computed_output);
+    ExpectNearAbsolute(expected_output, computed_output, 1e-5f);
+  }
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_unittest.cc
new file mode 100644
index 0000000000..324d694957
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_unittest.cc
@@ -0,0 +1,160 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/spectral_features.h"
+
+#include <algorithm>
+
+#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+// #include "test/fpe_observer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr int kTestFeatureVectorSize = kNumBands + 3 * kNumLowerBands + 1;
+
+// Writes non-zero sample values.
+void WriteTestData(rtc::ArrayView<float> samples) {
+  for (int i = 0; rtc::SafeLt(i, samples.size()); ++i) {
+    samples[i] = i % 100;
+  }
+}
+
+rtc::ArrayView<float, kNumBands - kNumLowerBands> GetHigherBandsSpectrum(
+    std::array<float, kTestFeatureVectorSize>* feature_vector) {
+  return {feature_vector->data() + kNumLowerBands, kNumBands - kNumLowerBands};
+}
+
+rtc::ArrayView<float, kNumLowerBands> GetAverage(
+    std::array<float, kTestFeatureVectorSize>* feature_vector) {
+  return {feature_vector->data(), kNumLowerBands};
+}
+
+rtc::ArrayView<float, kNumLowerBands> GetFirstDerivative(
+    std::array<float, kTestFeatureVectorSize>* feature_vector) {
+  return {feature_vector->data() + kNumBands, kNumLowerBands};
+}
+
+rtc::ArrayView<float, kNumLowerBands> GetSecondDerivative(
+    std::array<float, kTestFeatureVectorSize>* feature_vector) {
+  return {feature_vector->data() + kNumBands + kNumLowerBands, kNumLowerBands};
+}
+
+rtc::ArrayView<float, kNumLowerBands> GetCepstralCrossCorrelation(
+    std::array<float, kTestFeatureVectorSize>* feature_vector) {
+  return {feature_vector->data() + kNumBands + 2 * kNumLowerBands,
+          kNumLowerBands};
+}
+
+float* GetCepstralVariability(
+    std::array<float, kTestFeatureVectorSize>* feature_vector) {
+  return feature_vector->data() + kNumBands + 3 * kNumLowerBands;
+}
+
+constexpr float kInitialFeatureVal = -9999.f;
+
+// Checks that silence is detected when the input signal is 0 and that the
+// feature vector is written only if the input signal is not tagged as silence.
+TEST(RnnVadTest, SpectralFeaturesWithAndWithoutSilence) {
+  // Initialize.
+  SpectralFeaturesExtractor sfe;
+  std::array<float, kFrameSize20ms24kHz> samples;
+  rtc::ArrayView<float, kFrameSize20ms24kHz> samples_view(samples);
+  bool is_silence;
+  std::array<float, kTestFeatureVectorSize> feature_vector;
+
+  // Write an initial value in the feature vector to detect changes.
+  std::fill(feature_vector.begin(), feature_vector.end(), kInitialFeatureVal);
+
+  // TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
+  // FloatingPointExceptionObserver fpe_observer;
+
+  // With silence.
+  std::fill(samples.begin(), samples.end(), 0.f);
+  is_silence = sfe.CheckSilenceComputeFeatures(
+      samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector),
+      GetAverage(&feature_vector), GetFirstDerivative(&feature_vector),
+      GetSecondDerivative(&feature_vector),
+      GetCepstralCrossCorrelation(&feature_vector),
+      GetCepstralVariability(&feature_vector));
+  // Silence is expected, the output won't be overwritten.
+  EXPECT_TRUE(is_silence);
+  EXPECT_TRUE(std::all_of(feature_vector.begin(), feature_vector.end(),
+                          [](float x) { return x == kInitialFeatureVal; }));
+
+  // With no silence.
+  WriteTestData(samples);
+  is_silence = sfe.CheckSilenceComputeFeatures(
+      samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector),
+      GetAverage(&feature_vector), GetFirstDerivative(&feature_vector),
+      GetSecondDerivative(&feature_vector),
+      GetCepstralCrossCorrelation(&feature_vector),
+      GetCepstralVariability(&feature_vector));
+  // Silence is not expected, the output will be overwritten.
+  EXPECT_FALSE(is_silence);
+  EXPECT_FALSE(std::all_of(feature_vector.begin(), feature_vector.end(),
+                           [](float x) { return x == kInitialFeatureVal; }));
+}
+
+// Feeds a constant input signal and checks that:
+// - the cepstral coefficients average does not change;
+// - the derivatives are zero;
+// - the cepstral variability score does not change.
+TEST(RnnVadTest, CepstralFeaturesConstantAverageZeroDerivative) {
+  // Initialize.
+  SpectralFeaturesExtractor sfe;
+  std::array<float, kFrameSize20ms24kHz> samples;
+  rtc::ArrayView<float, kFrameSize20ms24kHz> samples_view(samples);
+  WriteTestData(samples);
+
+  // Fill the spectral features with test data.
+  std::array<float, kTestFeatureVectorSize> feature_vector;
+  for (int i = 0; i < kCepstralCoeffsHistorySize; ++i) {
+    sfe.CheckSilenceComputeFeatures(
+        samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector),
+        GetAverage(&feature_vector), GetFirstDerivative(&feature_vector),
+        GetSecondDerivative(&feature_vector),
+        GetCepstralCrossCorrelation(&feature_vector),
+        GetCepstralVariability(&feature_vector));
+  }
+
+  // Feed the test data one last time but using a different output vector.
+  std::array<float, kTestFeatureVectorSize> feature_vector_last;
+  sfe.CheckSilenceComputeFeatures(
+      samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector_last),
+      GetAverage(&feature_vector_last),
+      GetFirstDerivative(&feature_vector_last),
+      GetSecondDerivative(&feature_vector_last),
+      GetCepstralCrossCorrelation(&feature_vector_last),
+      GetCepstralVariability(&feature_vector_last));
+
+  // Average is unchanged.
+  ExpectEqualFloatArray({feature_vector.data(), kNumLowerBands},
+                        {feature_vector_last.data(), kNumLowerBands});
+  // First and second derivatives are zero.
+  constexpr std::array<float, kNumLowerBands> zeros{};
+  ExpectEqualFloatArray(
+      {feature_vector_last.data() + kNumBands, kNumLowerBands}, zeros);
+  ExpectEqualFloatArray(
+      {feature_vector_last.data() + kNumBands + kNumLowerBands, kNumLowerBands},
+      zeros);
+  // Variability is unchanged.
+  EXPECT_FLOAT_EQ(feature_vector[kNumBands + 3 * kNumLowerBands],
+                  feature_vector_last[kNumBands + 3 * kNumLowerBands]);
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer.h
new file mode 100644
index 0000000000..d186479551
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer.h
@@ -0,0 +1,95 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_SYMMETRIC_MATRIX_BUFFER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SYMMETRIC_MATRIX_BUFFER_H_
+
+#include <algorithm>
+#include <array>
+#include <cstring>
+#include <utility>
+
+#include "api/array_view.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Data structure to buffer the results of pair-wise comparisons between items
+// stored in a ring buffer. Every time that the oldest item is replaced in the
+// ring buffer, the new one is compared to the remaining items in the ring
+// buffer. The results of such comparisons need to be buffered and automatically
+// removed when one of the two corresponding items that have been compared is
+// removed from the ring buffer. It is assumed that the comparison is symmetric
+// and that comparing an item with itself is not needed.
+template <typename T, int S>
+class SymmetricMatrixBuffer {
+  static_assert(S > 2, "");
+
+ public:
+  SymmetricMatrixBuffer() = default;
+  SymmetricMatrixBuffer(const SymmetricMatrixBuffer&) = delete;
+  SymmetricMatrixBuffer& operator=(const SymmetricMatrixBuffer&) = delete;
+  ~SymmetricMatrixBuffer() = default;
+  // Sets the buffer values to zero.
+  void Reset() {
+    static_assert(std::is_arithmetic<T>::value,
+                  "Integral or floating point required.");
+    buf_.fill(0);
+  }
+  // Pushes the results from the comparison between the most recent item and
+  // those that are still in the ring buffer. The first element in `values` must
+  // correspond to the comparison between the most recent item and the second
+  // most recent one in the ring buffer, whereas the last element in `values`
+  // must correspond to the comparison between the most recent item and the
+  // oldest one in the ring buffer.
+  void Push(rtc::ArrayView<T, S - 1> values) {
+    // Move the lower-right sub-matrix of size (S-2) x (S-2) one row up and one
+    // column left.
+    std::memmove(buf_.data(), buf_.data() + S, (buf_.size() - S) * sizeof(T));
+    // Copy new values in the last column in the right order.
+    for (int i = 0; rtc::SafeLt(i, values.size()); ++i) {
+      const int index = (S - 1 - i) * (S - 1) - 1;
+      RTC_DCHECK_GE(index, 0);
+      RTC_DCHECK_LT(index, buf_.size());
+      buf_[index] = values[i];
+    }
+  }
+  // Reads the value that corresponds to comparison of two items in the ring
+  // buffer having delay `delay1` and `delay2`. The two arguments must not be
+  // equal and both must be in {0, ..., S - 1}.
+  T GetValue(int delay1, int delay2) const {
+    int row = S - 1 - delay1;
+    int col = S - 1 - delay2;
+    RTC_DCHECK_NE(row, col) << "The diagonal cannot be accessed.";
+    if (row > col)
+      std::swap(row, col);  // Swap to access the upper-right triangular part.
+    RTC_DCHECK_LE(0, row);
+    RTC_DCHECK_LT(row, S - 1) << "Not enforcing row < col and row != col.";
+    RTC_DCHECK_LE(1, col) << "Not enforcing row < col and row != col.";
+    RTC_DCHECK_LT(col, S);
+    const int index = row * (S - 1) + (col - 1);
+    RTC_DCHECK_LE(0, index);
+    RTC_DCHECK_LT(index, buf_.size());
+    return buf_[index];
+  }
+
+ private:
+  // Encode an upper-right triangular matrix (excluding its diagonal) using a
+  // square matrix. This allows to move the data in Push() with one single
+  // operation.
+  std::array<T, (S - 1) * (S - 1)> buf_{};
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SYMMETRIC_MATRIX_BUFFER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer_unittest.cc
new file mode 100644
index 0000000000..1509ca5ac1
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer_unittest.cc
@@ -0,0 +1,107 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/symmetric_matrix_buffer.h"
+
+#include "modules/audio_processing/agc2/rnn_vad/ring_buffer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+template <typename T, int S>
+void CheckSymmetry(const SymmetricMatrixBuffer<T, S>* sym_matrix_buf) {
+  for (int row = 0; row < S - 1; ++row)
+    for (int col = row + 1; col < S; ++col)
+      EXPECT_EQ(sym_matrix_buf->GetValue(row, col),
+                sym_matrix_buf->GetValue(col, row));
+}
+
+using PairType = std::pair<int, int>;
+
+// Checks that the symmetric matrix buffer contains any pair with a value equal
+// to the given one.
+template <int S>
+bool CheckPairsWithValueExist(
+    const SymmetricMatrixBuffer<PairType, S>* sym_matrix_buf,
+    const int value) {
+  for (int row = 0; row < S - 1; ++row) {
+    for (int col = row + 1; col < S; ++col) {
+      auto p = sym_matrix_buf->GetValue(row, col);
+      if (p.first == value || p.second == value)
+        return true;
+    }
+  }
+  return false;
+}
+
+// Test that shows how to combine RingBuffer and SymmetricMatrixBuffer to
+// efficiently compute pair-wise scores. This test verifies that the evolution
+// of a SymmetricMatrixBuffer instance follows that of RingBuffer.
+TEST(RnnVadTest, SymmetricMatrixBufferUseCase) {
+  // Instance a ring buffer which will be fed with a series of integer values.
+  constexpr int kRingBufSize = 10;
+  RingBuffer<int, 1, kRingBufSize> ring_buf;
+  // Instance a symmetric matrix buffer for the ring buffer above. It stores
+  // pairs of integers with which this test can easily check that the evolution
+  // of RingBuffer and SymmetricMatrixBuffer match.
+  SymmetricMatrixBuffer<PairType, kRingBufSize> sym_matrix_buf;
+  for (int t = 1; t <= 100; ++t) {  // Evolution steps.
+    SCOPED_TRACE(t);
+    const int t_removed = ring_buf.GetArrayView(kRingBufSize - 1)[0];
+    ring_buf.Push({&t, 1});
+    // The head of the ring buffer is `t`.
+    ASSERT_EQ(t, ring_buf.GetArrayView(0)[0]);
+    // Create the comparisons between `t` and the older elements in the ring
+    // buffer.
+    std::array<PairType, kRingBufSize - 1> new_comparions;
+    for (int i = 0; i < kRingBufSize - 1; ++i) {
+      // Start comparing `t` to the second newest element in the ring buffer.
+      const int delay = i + 1;
+      const auto t_prev = ring_buf.GetArrayView(delay)[0];
+      ASSERT_EQ(std::max(0, t - delay), t_prev);
+      // Compare the last element `t` with `t_prev`.
+      new_comparions[i].first = t_prev;
+      new_comparions[i].second = t;
+    }
+    // Push the new comparisons in the symmetric matrix buffer.
+    sym_matrix_buf.Push({new_comparions.data(), new_comparions.size()});
+    // Tests.
+    CheckSymmetry(&sym_matrix_buf);
+    // Check that the pairs resulting from the content in the ring buffer are
+    // in the right position.
+    for (int delay1 = 0; delay1 < kRingBufSize - 1; ++delay1) {
+      for (int delay2 = delay1 + 1; delay2 < kRingBufSize; ++delay2) {
+        const auto t1 = ring_buf.GetArrayView(delay1)[0];
+        const auto t2 = ring_buf.GetArrayView(delay2)[0];
+        ASSERT_LE(t2, t1);
+        const auto p = sym_matrix_buf.GetValue(delay1, delay2);
+        EXPECT_EQ(p.first, t2);
+        EXPECT_EQ(p.second, t1);
+      }
+    }
+    // Check that every older element in the ring buffer still has a
+    // corresponding pair in the symmetric matrix buffer.
+    for (int delay = 1; delay < kRingBufSize; ++delay) {
+      const auto t_prev = ring_buf.GetArrayView(delay)[0];
+      EXPECT_TRUE(CheckPairsWithValueExist(&sym_matrix_buf, t_prev));
+    }
+    // Check that the element removed from the ring buffer has no corresponding
+    // pairs in the symmetric matrix buffer.
+    if (t > kRingBufSize - 1) {
+      EXPECT_FALSE(CheckPairsWithValueExist(&sym_matrix_buf, t_removed));
+    }
+  }
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/test_utils.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/test_utils.cc
new file mode 100644
index 0000000000..857a9f2706
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/test_utils.cc
@@ -0,0 +1,143 @@
+/*
+ *  Copyright (c) 2018 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/agc2/rnn_vad/test_utils.h"
+
+#include <algorithm>
+#include <fstream>
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+// File reader for binary files that contain a sequence of values with
+// arithmetic type `T`. The values of type `T` that are read are cast to float.
+template <typename T>
+class FloatFileReader : public FileReader {
+ public:
+  static_assert(std::is_arithmetic<T>::value, "");
+  explicit FloatFileReader(absl::string_view filename)
+      : is_(std::string(filename), std::ios::binary | std::ios::ate),
+        size_(is_.tellg() / sizeof(T)) {
+    RTC_CHECK(is_);
+    SeekBeginning();
+  }
+  FloatFileReader(const FloatFileReader&) = delete;
+  FloatFileReader& operator=(const FloatFileReader&) = delete;
+  ~FloatFileReader() = default;
+
+  int size() const override { return size_; }
+  bool ReadChunk(rtc::ArrayView<float> dst) override {
+    const std::streamsize bytes_to_read = dst.size() * sizeof(T);
+    if (std::is_same<T, float>::value) {
+      is_.read(reinterpret_cast<char*>(dst.data()), bytes_to_read);
+    } else {
+      buffer_.resize(dst.size());
+      is_.read(reinterpret_cast<char*>(buffer_.data()), bytes_to_read);
+      std::transform(buffer_.begin(), buffer_.end(), dst.begin(),
+                     [](const T& v) -> float { return static_cast<float>(v); });
+    }
+    return is_.gcount() == bytes_to_read;
+  }
+  bool ReadValue(float& dst) override { return ReadChunk({&dst, 1}); }
+  void SeekForward(int hop) override { is_.seekg(hop * sizeof(T), is_.cur); }
+  void SeekBeginning() override { is_.seekg(0, is_.beg); }
+
+ private:
+  std::ifstream is_;
+  const int size_;
+  std::vector<T> buffer_;
+};
+
+}  // namespace
+
+using webrtc::test::ResourcePath;
+
+void ExpectEqualFloatArray(rtc::ArrayView<const float> expected,
+                           rtc::ArrayView<const float> computed) {
+  ASSERT_EQ(expected.size(), computed.size());
+  for (int i = 0; rtc::SafeLt(i, expected.size()); ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_FLOAT_EQ(expected[i], computed[i]);
+  }
+}
+
+void ExpectNearAbsolute(rtc::ArrayView<const float> expected,
+                        rtc::ArrayView<const float> computed,
+                        float tolerance) {
+  ASSERT_EQ(expected.size(), computed.size());
+  for (int i = 0; rtc::SafeLt(i, expected.size()); ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_NEAR(expected[i], computed[i], tolerance);
+  }
+}
+
+std::unique_ptr<FileReader> CreatePcmSamplesReader() {
+  return std::make_unique<FloatFileReader<int16_t>>(
+      /*filename=*/test::ResourcePath("audio_processing/agc2/rnn_vad/samples",
+                                      "pcm"));
+}
+
+ChunksFileReader CreatePitchBuffer24kHzReader() {
+  auto reader = std::make_unique<FloatFileReader<float>>(
+      /*filename=*/test::ResourcePath(
+          "audio_processing/agc2/rnn_vad/pitch_buf_24k", "dat"));
+  const int num_chunks = rtc::CheckedDivExact(reader->size(), kBufSize24kHz);
+  return {/*chunk_size=*/kBufSize24kHz, num_chunks, std::move(reader)};
+}
+
+ChunksFileReader CreateLpResidualAndPitchInfoReader() {
+  constexpr int kPitchInfoSize = 2;  // Pitch period and strength.
+  constexpr int kChunkSize = kBufSize24kHz + kPitchInfoSize;
+  auto reader = std::make_unique<FloatFileReader<float>>(
+      /*filename=*/test::ResourcePath(
+          "audio_processing/agc2/rnn_vad/pitch_lp_res", "dat"));
+  const int num_chunks = rtc::CheckedDivExact(reader->size(), kChunkSize);
+  return {kChunkSize, num_chunks, std::move(reader)};
+}
+
+std::unique_ptr<FileReader> CreateGruInputReader() {
+  return std::make_unique<FloatFileReader<float>>(
+      /*filename=*/test::ResourcePath("audio_processing/agc2/rnn_vad/gru_in",
+                                      "dat"));
+}
+
+std::unique_ptr<FileReader> CreateVadProbsReader() {
+  return std::make_unique<FloatFileReader<float>>(
+      /*filename=*/test::ResourcePath("audio_processing/agc2/rnn_vad/vad_prob",
+                                      "dat"));
+}
+
+PitchTestData::PitchTestData() {
+  FloatFileReader<float> reader(
+      /*filename=*/ResourcePath(
+          "audio_processing/agc2/rnn_vad/pitch_search_int", "dat"));
+  reader.ReadChunk(pitch_buffer_24k_);
+  reader.ReadChunk(square_energies_24k_);
+  reader.ReadChunk(auto_correlation_12k_);
+  // Reverse the order of the squared energy values.
+  // Required after the WebRTC CL 191703 which switched to forward computation.
+  std::reverse(square_energies_24k_.begin(), square_energies_24k_.end());
+}
+
+PitchTestData::~PitchTestData() = default;
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/test_utils.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/test_utils.h
new file mode 100644
index 0000000000..e64b7b7ecd
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/test_utils.h
@@ -0,0 +1,130 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_RNN_VAD_TEST_UTILS_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_TEST_UTILS_H_
+
+#include <array>
+#include <fstream>
+#include <memory>
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+constexpr float kFloatMin = std::numeric_limits<float>::min();
+
+// Fails for every pair from two equally sized rtc::ArrayView<float> views such
+// that the values in the pair do not match.
+void ExpectEqualFloatArray(rtc::ArrayView<const float> expected,
+                           rtc::ArrayView<const float> computed);
+
+// Fails for every pair from two equally sized rtc::ArrayView<float> views such
+// that their absolute error is above a given threshold.
+void ExpectNearAbsolute(rtc::ArrayView<const float> expected,
+                        rtc::ArrayView<const float> computed,
+                        float tolerance);
+
+// File reader interface.
+class FileReader {
+ public:
+  virtual ~FileReader() = default;
+  // Number of values in the file.
+  virtual int size() const = 0;
+  // Reads `dst.size()` float values into `dst`, advances the internal file
+  // position according to the number of read bytes and returns true if the
+  // values are correctly read. If the number of remaining bytes in the file is
+  // not sufficient to read `dst.size()` float values, `dst` is partially
+  // modified and false is returned.
+  virtual bool ReadChunk(rtc::ArrayView<float> dst) = 0;
+  // Reads a single float value, advances the internal file position according
+  // to the number of read bytes and returns true if the value is correctly
+  // read. If the number of remaining bytes in the file is not sufficient to
+  // read one float, `dst` is not modified and false is returned.
+  virtual bool ReadValue(float& dst) = 0;
+  // Advances the internal file position by `hop` float values.
+  virtual void SeekForward(int hop) = 0;
+  // Resets the internal file position to BOF.
+  virtual void SeekBeginning() = 0;
+};
+
+// File reader for files that contain `num_chunks` chunks with size equal to
+// `chunk_size`.
+struct ChunksFileReader {
+  const int chunk_size;
+  const int num_chunks;
+  std::unique_ptr<FileReader> reader;
+};
+
+// Creates a reader for the PCM S16 samples file.
+std::unique_ptr<FileReader> CreatePcmSamplesReader();
+
+// Creates a reader for the 24 kHz pitch buffer test data.
+ChunksFileReader CreatePitchBuffer24kHzReader();
+
+// Creates a reader for the LP residual and pitch information test data.
+ChunksFileReader CreateLpResidualAndPitchInfoReader();
+
+// Creates a reader for the sequence of GRU input vectors.
+std::unique_ptr<FileReader> CreateGruInputReader();
+
+// Creates a reader for the VAD probabilities test data.
+std::unique_ptr<FileReader> CreateVadProbsReader();
+
+// Class to retrieve a test pitch buffer content and the expected output for the
+// analysis steps.
+class PitchTestData {
+ public:
+  PitchTestData();
+  ~PitchTestData();
+  rtc::ArrayView<const float, kBufSize24kHz> PitchBuffer24kHzView() const {
+    return pitch_buffer_24k_;
+  }
+  rtc::ArrayView<const float, kRefineNumLags24kHz> SquareEnergies24kHzView()
+      const {
+    return square_energies_24k_;
+  }
+  rtc::ArrayView<const float, kNumLags12kHz> AutoCorrelation12kHzView() const {
+    return auto_correlation_12k_;
+  }
+
+ private:
+  std::array<float, kBufSize24kHz> pitch_buffer_24k_;
+  std::array<float, kRefineNumLags24kHz> square_energies_24k_;
+  std::array<float, kNumLags12kHz> auto_correlation_12k_;
+};
+
+// Writer for binary files.
+class FileWriter {
+ public:
+  explicit FileWriter(absl::string_view file_path)
+      : os_(std::string(file_path), std::ios::binary) {}
+  FileWriter(const FileWriter&) = delete;
+  FileWriter& operator=(const FileWriter&) = delete;
+  ~FileWriter() = default;
+  void WriteChunk(rtc::ArrayView<const float> value) {
+    const std::streamsize bytes_to_write = value.size() * sizeof(float);
+    os_.write(reinterpret_cast<const char*>(value.data()), bytes_to_write);
+  }
+
+ private:
+  std::ofstream os_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_TEST_UTILS_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math.h b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math.h
new file mode 100644
index 0000000000..47f681196a
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math.h
@@ -0,0 +1,114 @@
+/*
+ *  Copyright (c) 2020 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_AGC2_RNN_VAD_VECTOR_MATH_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_VECTOR_MATH_H_
+
+// Defines WEBRTC_ARCH_X86_FAMILY, used below.
+#include "rtc_base/system/arch.h"
+
+#if defined(WEBRTC_HAS_NEON)
+#include <arm_neon.h>
+#endif
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+#include <emmintrin.h>
+#endif
+
+#include <numeric>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_conversions.h"
+#include "rtc_base/system/arch.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+// Provides optimizations for mathematical operations having vectors as
+// operand(s).
+class VectorMath {
+ public:
+  explicit VectorMath(AvailableCpuFeatures cpu_features)
+      : cpu_features_(cpu_features) {}
+
+  // Computes the dot product between two equally sized vectors.
+  float DotProduct(rtc::ArrayView<const float> x,
+                   rtc::ArrayView<const float> y) const {
+    RTC_DCHECK_EQ(x.size(), y.size());
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+    if (cpu_features_.avx2) {
+      return DotProductAvx2(x, y);
+    } else if (cpu_features_.sse2) {
+      __m128 accumulator = _mm_setzero_ps();
+      constexpr int kBlockSizeLog2 = 2;
+      constexpr int kBlockSize = 1 << kBlockSizeLog2;
+      const int incomplete_block_index = (x.size() >> kBlockSizeLog2)
+                                         << kBlockSizeLog2;
+      for (int i = 0; i < incomplete_block_index; i += kBlockSize) {
+        RTC_DCHECK_LE(i + kBlockSize, x.size());
+        const __m128 x_i = _mm_loadu_ps(&x[i]);
+        const __m128 y_i = _mm_loadu_ps(&y[i]);
+        // Multiply-add.
+        const __m128 z_j = _mm_mul_ps(x_i, y_i);
+        accumulator = _mm_add_ps(accumulator, z_j);
+      }
+      // Reduce `accumulator` by addition.
+      __m128 high = _mm_movehl_ps(accumulator, accumulator);
+      accumulator = _mm_add_ps(accumulator, high);
+      high = _mm_shuffle_ps(accumulator, accumulator, 1);
+      accumulator = _mm_add_ps(accumulator, high);
+      float dot_product = _mm_cvtss_f32(accumulator);
+      // Add the result for the last block if incomplete.
+      for (int i = incomplete_block_index;
+           i < rtc::dchecked_cast<int>(x.size()); ++i) {
+        dot_product += x[i] * y[i];
+      }
+      return dot_product;
+    }
+#elif defined(WEBRTC_HAS_NEON) && defined(WEBRTC_ARCH_ARM64)
+    if (cpu_features_.neon) {
+      float32x4_t accumulator = vdupq_n_f32(0.f);
+      constexpr int kBlockSizeLog2 = 2;
+      constexpr int kBlockSize = 1 << kBlockSizeLog2;
+      const int incomplete_block_index = (x.size() >> kBlockSizeLog2)
+                                         << kBlockSizeLog2;
+      for (int i = 0; i < incomplete_block_index; i += kBlockSize) {
+        RTC_DCHECK_LE(i + kBlockSize, x.size());
+        const float32x4_t x_i = vld1q_f32(&x[i]);
+        const float32x4_t y_i = vld1q_f32(&y[i]);
+        accumulator = vfmaq_f32(accumulator, x_i, y_i);
+      }
+      // Reduce `accumulator` by addition.
+      const float32x2_t tmp =
+          vpadd_f32(vget_low_f32(accumulator), vget_high_f32(accumulator));
+      float dot_product = vget_lane_f32(vpadd_f32(tmp, vrev64_f32(tmp)), 0);
+      // Add the result for the last block if incomplete.
+      for (int i = incomplete_block_index;
+           i < rtc::dchecked_cast<int>(x.size()); ++i) {
+        dot_product += x[i] * y[i];
+      }
+      return dot_product;
+    }
+#endif
+    return std::inner_product(x.begin(), x.end(), y.begin(), 0.f);
+  }
+
+ private:
+  float DotProductAvx2(rtc::ArrayView<const float> x,
+                       rtc::ArrayView<const float> y) const;
+
+  const AvailableCpuFeatures cpu_features_;
+};
+
+}  // namespace rnn_vad
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_VECTOR_MATH_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_avx2.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_avx2.cc
new file mode 100644
index 0000000000..e4d246d9ab
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_avx2.cc
@@ -0,0 +1,55 @@
+/*
+ *  Copyright (c) 2020 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/agc2/rnn_vad/vector_math.h"
+
+#include <immintrin.h>
+
+#include "api/array_view.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_conversions.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+float VectorMath::DotProductAvx2(rtc::ArrayView<const float> x,
+                                 rtc::ArrayView<const float> y) const {
+  RTC_DCHECK(cpu_features_.avx2);
+  RTC_DCHECK_EQ(x.size(), y.size());
+  __m256 accumulator = _mm256_setzero_ps();
+  constexpr int kBlockSizeLog2 = 3;
+  constexpr int kBlockSize = 1 << kBlockSizeLog2;
+  const int incomplete_block_index = (x.size() >> kBlockSizeLog2)
+                                     << kBlockSizeLog2;
+  for (int i = 0; i < incomplete_block_index; i += kBlockSize) {
+    RTC_DCHECK_LE(i + kBlockSize, x.size());
+    const __m256 x_i = _mm256_loadu_ps(&x[i]);
+    const __m256 y_i = _mm256_loadu_ps(&y[i]);
+    accumulator = _mm256_fmadd_ps(x_i, y_i, accumulator);
+  }
+  // Reduce `accumulator` by addition.
+  __m128 high = _mm256_extractf128_ps(accumulator, 1);
+  __m128 low = _mm256_extractf128_ps(accumulator, 0);
+  low = _mm_add_ps(high, low);
+  high = _mm_movehl_ps(high, low);
+  low = _mm_add_ps(high, low);
+  high = _mm_shuffle_ps(low, low, 1);
+  low = _mm_add_ss(high, low);
+  float dot_product = _mm_cvtss_f32(low);
+  // Add the result for the last block if incomplete.
+  for (int i = incomplete_block_index; i < rtc::dchecked_cast<int>(x.size());
+       ++i) {
+    dot_product += x[i] * y[i];
+  }
+  return dot_product;
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_avx2_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_avx2_gn/moz.build
new file mode 100644
index 0000000000..275c512cf6
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_avx2_gn/moz.build
@@ -0,0 +1,185 @@
+# 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()
+
+CXXFLAGS += [
+    "-mavx2",
+    "-mfma"
+]
+
+DEFINES["ABSL_ALLOCATOR_NOTHROW"] = "1"
+DEFINES["RTC_DAV1D_IN_INTERNAL_DECODER_FACTORY"] = True
+DEFINES["RTC_ENABLE_VP9"] = True
+DEFINES["WEBRTC_ENABLE_AVX2"] = True
+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/agc2/rnn_vad/vector_math_avx2.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["_GNU_SOURCE"] = True
+    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["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"] == "x86" and CONFIG["OS_TARGET"] == "Android":
+
+    CXXFLAGS += [
+        "-msse2"
+    ]
+
+    OS_LIBS += [
+        "android_support"
+    ]
+
+if CONFIG["CPU_ARCH"] == "x86" and CONFIG["OS_TARGET"] == "Linux":
+
+    CXXFLAGS += [
+        "-msse2"
+    ]
+
+Library("vector_math_avx2_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_gn/moz.build
new file mode 100644
index 0000000000..263ec679e3
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_gn/moz.build
@@ -0,0 +1,216 @@
+# 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_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"
+]
+
+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":
+
+    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":
+
+    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":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+if CONFIG["CPU_ARCH"] == "x86_64" and CONFIG["OS_TARGET"] == "Linux":
+
+    DEFINES["_GNU_SOURCE"] = True
+
+Library("vector_math_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_unittest.cc
new file mode 100644
index 0000000000..45fd65d61e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/vector_math_unittest.cc
@@ -0,0 +1,71 @@
+/*
+ *  Copyright (c) 2020 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/agc2/rnn_vad/vector_math.h"
+
+#include <vector>
+
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+constexpr int kSizeOfX = 19;
+constexpr float kX[kSizeOfX] = {
+    0.31593041f, 0.9350786f,   -0.25252445f, -0.86956251f, -0.9673632f,
+    0.54571901f, -0.72504495f, -0.79509912f, -0.25525012f, -0.73340473f,
+    0.15747377f, -0.04370565f, 0.76135145f,  -0.57239645f, 0.68616848f,
+    0.3740298f,  0.34710799f,  -0.92207423f, 0.10738454f};
+constexpr int kSizeOfXSubSpan = 16;
+static_assert(kSizeOfXSubSpan < kSizeOfX, "");
+constexpr float kEnergyOfX = 7.315563958160327f;
+constexpr float kEnergyOfXSubspan = 6.333327669592963f;
+
+class VectorMathParametrization
+    : public ::testing::TestWithParam<AvailableCpuFeatures> {};
+
+TEST_P(VectorMathParametrization, TestDotProduct) {
+  VectorMath vector_math(/*cpu_features=*/GetParam());
+  EXPECT_FLOAT_EQ(vector_math.DotProduct(kX, kX), kEnergyOfX);
+  EXPECT_FLOAT_EQ(
+      vector_math.DotProduct({kX, kSizeOfXSubSpan}, {kX, kSizeOfXSubSpan}),
+      kEnergyOfXSubspan);
+}
+
+// Finds the relevant CPU features combinations to test.
+std::vector<AvailableCpuFeatures> GetCpuFeaturesToTest() {
+  std::vector<AvailableCpuFeatures> v;
+  v.push_back({/*sse2=*/false, /*avx2=*/false, /*neon=*/false});
+  AvailableCpuFeatures available = GetAvailableCpuFeatures();
+  if (available.avx2) {
+    v.push_back({/*sse2=*/false, /*avx2=*/true, /*neon=*/false});
+  }
+  if (available.sse2) {
+    v.push_back({/*sse2=*/true, /*avx2=*/false, /*neon=*/false});
+  }
+  if (available.neon) {
+    v.push_back({/*sse2=*/false, /*avx2=*/false, /*neon=*/true});
+  }
+  return v;
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    RnnVadTest,
+    VectorMathParametrization,
+    ::testing::ValuesIn(GetCpuFeaturesToTest()),
+    [](const ::testing::TestParamInfo<AvailableCpuFeatures>& info) {
+      return info.param.ToString();
+    });
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector.cc b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector.cc
new file mode 100644
index 0000000000..961baf4cd3
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector.cc
@@ -0,0 +1,183 @@
+/*
+ *  Copyright (c) 2018 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/agc2/saturation_protector.h"
+
+#include <memory>
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/agc2/saturation_protector_buffer.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_minmax.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kPeakEnveloperSuperFrameLengthMs = 400;
+constexpr float kMinMarginDb = 12.0f;
+constexpr float kMaxMarginDb = 25.0f;
+constexpr float kAttack = 0.9988493699365052f;
+constexpr float kDecay = 0.9997697679981565f;
+
+// Saturation protector state. Defined outside of `SaturationProtectorImpl` to
+// implement check-point and restore ops.
+struct SaturationProtectorState {
+  bool operator==(const SaturationProtectorState& s) const {
+    return headroom_db == s.headroom_db &&
+           peak_delay_buffer == s.peak_delay_buffer &&
+           max_peaks_dbfs == s.max_peaks_dbfs &&
+           time_since_push_ms == s.time_since_push_ms;
+  }
+  inline bool operator!=(const SaturationProtectorState& s) const {
+    return !(*this == s);
+  }
+
+  float headroom_db;
+  SaturationProtectorBuffer peak_delay_buffer;
+  float max_peaks_dbfs;
+  int time_since_push_ms;  // Time since the last ring buffer push operation.
+};
+
+// Resets the saturation protector state.
+void ResetSaturationProtectorState(float initial_headroom_db,
+                                   SaturationProtectorState& state) {
+  state.headroom_db = initial_headroom_db;
+  state.peak_delay_buffer.Reset();
+  state.max_peaks_dbfs = kMinLevelDbfs;
+  state.time_since_push_ms = 0;
+}
+
+// Updates `state` by analyzing the estimated speech level `speech_level_dbfs`
+// and the peak level `peak_dbfs` for an observed frame. `state` must not be
+// modified without calling this function.
+void UpdateSaturationProtectorState(float peak_dbfs,
+                                    float speech_level_dbfs,
+                                    SaturationProtectorState& state) {
+  // Get the max peak over `kPeakEnveloperSuperFrameLengthMs` ms.
+  state.max_peaks_dbfs = std::max(state.max_peaks_dbfs, peak_dbfs);
+  state.time_since_push_ms += kFrameDurationMs;
+  if (rtc::SafeGt(state.time_since_push_ms, kPeakEnveloperSuperFrameLengthMs)) {
+    // Push `max_peaks_dbfs` back into the ring buffer.
+    state.peak_delay_buffer.PushBack(state.max_peaks_dbfs);
+    // Reset.
+    state.max_peaks_dbfs = kMinLevelDbfs;
+    state.time_since_push_ms = 0;
+  }
+
+  // Update the headroom by comparing the estimated speech level and the delayed
+  // max speech peak.
+  const float delayed_peak_dbfs =
+      state.peak_delay_buffer.Front().value_or(state.max_peaks_dbfs);
+  const float difference_db = delayed_peak_dbfs - speech_level_dbfs;
+  if (difference_db > state.headroom_db) {
+    // Attack.
+    state.headroom_db =
+        state.headroom_db * kAttack + difference_db * (1.0f - kAttack);
+  } else {
+    // Decay.
+    state.headroom_db =
+        state.headroom_db * kDecay + difference_db * (1.0f - kDecay);
+  }
+
+  state.headroom_db =
+      rtc::SafeClamp<float>(state.headroom_db, kMinMarginDb, kMaxMarginDb);
+}
+
+// Saturation protector which recommends a headroom based on the recent peaks.
+class SaturationProtectorImpl : public SaturationProtector {
+ public:
+  explicit SaturationProtectorImpl(float initial_headroom_db,
+                                   int adjacent_speech_frames_threshold,
+                                   ApmDataDumper* apm_data_dumper)
+      : apm_data_dumper_(apm_data_dumper),
+        initial_headroom_db_(initial_headroom_db),
+        adjacent_speech_frames_threshold_(adjacent_speech_frames_threshold) {
+    Reset();
+  }
+  SaturationProtectorImpl(const SaturationProtectorImpl&) = delete;
+  SaturationProtectorImpl& operator=(const SaturationProtectorImpl&) = delete;
+  ~SaturationProtectorImpl() = default;
+
+  float HeadroomDb() override { return headroom_db_; }
+
+  void Analyze(float speech_probability,
+               float peak_dbfs,
+               float speech_level_dbfs) override {
+    if (speech_probability < kVadConfidenceThreshold) {
+      // Not a speech frame.
+      if (adjacent_speech_frames_threshold_ > 1) {
+        // When two or more adjacent speech frames are required in order to
+        // update the state, we need to decide whether to discard or confirm the
+        // updates based on the speech sequence length.
+        if (num_adjacent_speech_frames_ >= adjacent_speech_frames_threshold_) {
+          // First non-speech frame after a long enough sequence of speech
+          // frames. Update the reliable state.
+          reliable_state_ = preliminary_state_;
+        } else if (num_adjacent_speech_frames_ > 0) {
+          // First non-speech frame after a too short sequence of speech frames.
+          // Reset to the last reliable state.
+          preliminary_state_ = reliable_state_;
+        }
+      }
+      num_adjacent_speech_frames_ = 0;
+    } else {
+      // Speech frame observed.
+      num_adjacent_speech_frames_++;
+
+      // Update preliminary level estimate.
+      UpdateSaturationProtectorState(peak_dbfs, speech_level_dbfs,
+                                     preliminary_state_);
+
+      if (num_adjacent_speech_frames_ >= adjacent_speech_frames_threshold_) {
+        // `preliminary_state_` is now reliable. Update the headroom.
+        headroom_db_ = preliminary_state_.headroom_db;
+      }
+    }
+    DumpDebugData();
+  }
+
+  void Reset() override {
+    num_adjacent_speech_frames_ = 0;
+    headroom_db_ = initial_headroom_db_;
+    ResetSaturationProtectorState(initial_headroom_db_, preliminary_state_);
+    ResetSaturationProtectorState(initial_headroom_db_, reliable_state_);
+  }
+
+ private:
+  void DumpDebugData() {
+    apm_data_dumper_->DumpRaw(
+        "agc2_saturation_protector_preliminary_max_peak_dbfs",
+        preliminary_state_.max_peaks_dbfs);
+    apm_data_dumper_->DumpRaw(
+        "agc2_saturation_protector_reliable_max_peak_dbfs",
+        reliable_state_.max_peaks_dbfs);
+  }
+
+  ApmDataDumper* const apm_data_dumper_;
+  const float initial_headroom_db_;
+  const int adjacent_speech_frames_threshold_;
+  int num_adjacent_speech_frames_;
+  float headroom_db_;
+  SaturationProtectorState preliminary_state_;
+  SaturationProtectorState reliable_state_;
+};
+
+}  // namespace
+
+std::unique_ptr<SaturationProtector> CreateSaturationProtector(
+    float initial_headroom_db,
+    int adjacent_speech_frames_threshold,
+    ApmDataDumper* apm_data_dumper) {
+  return std::make_unique<SaturationProtectorImpl>(
+      initial_headroom_db, adjacent_speech_frames_threshold, apm_data_dumper);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector.h b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector.h
new file mode 100644
index 0000000000..ef22145d5f
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector.h
@@ -0,0 +1,46 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_SATURATION_PROTECTOR_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_SATURATION_PROTECTOR_H_
+
+#include <memory>
+
+namespace webrtc {
+class ApmDataDumper;
+
+// Saturation protector. Analyzes peak levels and recommends a headroom to
+// reduce the chances of clipping.
+class SaturationProtector {
+ public:
+  virtual ~SaturationProtector() = default;
+
+  // Returns the recommended headroom in dB.
+  virtual float HeadroomDb() = 0;
+
+  // Analyzes the peak level of a 10 ms frame along with its speech probability
+  // and the current speech level estimate to update the recommended headroom.
+  virtual void Analyze(float speech_probability,
+                       float peak_dbfs,
+                       float speech_level_dbfs) = 0;
+
+  // Resets the internal state.
+  virtual void Reset() = 0;
+};
+
+// Creates a saturation protector that starts at `initial_headroom_db`.
+std::unique_ptr<SaturationProtector> CreateSaturationProtector(
+    float initial_headroom_db,
+    int adjacent_speech_frames_threshold,
+    ApmDataDumper* apm_data_dumper);
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_SATURATION_PROTECTOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer.cc b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer.cc
new file mode 100644
index 0000000000..41efdad2c8
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer.cc
@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2021 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/agc2/saturation_protector_buffer.h"
+
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_compare.h"
+
+namespace webrtc {
+
+SaturationProtectorBuffer::SaturationProtectorBuffer() = default;
+
+SaturationProtectorBuffer::~SaturationProtectorBuffer() = default;
+
+bool SaturationProtectorBuffer::operator==(
+    const SaturationProtectorBuffer& b) const {
+  RTC_DCHECK_LE(size_, buffer_.size());
+  RTC_DCHECK_LE(b.size_, b.buffer_.size());
+  if (size_ != b.size_) {
+    return false;
+  }
+  for (int i = 0, i0 = FrontIndex(), i1 = b.FrontIndex(); i < size_;
+       ++i, ++i0, ++i1) {
+    if (buffer_[i0 % buffer_.size()] != b.buffer_[i1 % b.buffer_.size()]) {
+      return false;
+    }
+  }
+  return true;
+}
+
+int SaturationProtectorBuffer::Capacity() const {
+  return buffer_.size();
+}
+
+int SaturationProtectorBuffer::Size() const {
+  return size_;
+}
+
+void SaturationProtectorBuffer::Reset() {
+  next_ = 0;
+  size_ = 0;
+}
+
+void SaturationProtectorBuffer::PushBack(float v) {
+  RTC_DCHECK_GE(next_, 0);
+  RTC_DCHECK_GE(size_, 0);
+  RTC_DCHECK_LT(next_, buffer_.size());
+  RTC_DCHECK_LE(size_, buffer_.size());
+  buffer_[next_++] = v;
+  if (rtc::SafeEq(next_, buffer_.size())) {
+    next_ = 0;
+  }
+  if (rtc::SafeLt(size_, buffer_.size())) {
+    size_++;
+  }
+}
+
+absl::optional<float> SaturationProtectorBuffer::Front() const {
+  if (size_ == 0) {
+    return absl::nullopt;
+  }
+  RTC_DCHECK_LT(FrontIndex(), buffer_.size());
+  return buffer_[FrontIndex()];
+}
+
+int SaturationProtectorBuffer::FrontIndex() const {
+  return rtc::SafeEq(size_, buffer_.size()) ? next_ : 0;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer.h b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer.h
new file mode 100644
index 0000000000..e17d0998c4
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer.h
@@ -0,0 +1,59 @@
+/*
+ *  Copyright (c) 2021 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_AGC2_SATURATION_PROTECTOR_BUFFER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_SATURATION_PROTECTOR_BUFFER_H_
+
+#include <array>
+
+#include "absl/types/optional.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+
+namespace webrtc {
+
+// Ring buffer for the saturation protector which only supports (i) push back
+// and (ii) read oldest item.
+class SaturationProtectorBuffer {
+ public:
+  SaturationProtectorBuffer();
+  ~SaturationProtectorBuffer();
+
+  bool operator==(const SaturationProtectorBuffer& b) const;
+  inline bool operator!=(const SaturationProtectorBuffer& b) const {
+    return !(*this == b);
+  }
+
+  // Maximum number of values that the buffer can contain.
+  int Capacity() const;
+
+  // Number of values in the buffer.
+  int Size() const;
+
+  void Reset();
+
+  // Pushes back `v`. If the buffer is full, the oldest value is replaced.
+  void PushBack(float v);
+
+  // Returns the oldest item in the buffer. Returns an empty value if the
+  // buffer is empty.
+  absl::optional<float> Front() const;
+
+ private:
+  int FrontIndex() const;
+  // `buffer_` has `size_` elements (up to the size of `buffer_`) and `next_` is
+  // the position where the next new value is written in `buffer_`.
+  std::array<float, kSaturationProtectorBufferSize> buffer_;
+  int next_ = 0;
+  int size_ = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_SATURATION_PROTECTOR_BUFFER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer_unittest.cc
new file mode 100644
index 0000000000..22187bf027
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer_unittest.cc
@@ -0,0 +1,73 @@
+/*
+ *  Copyright (c) 2021 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/agc2/saturation_protector_buffer.h"
+
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+using ::testing::Eq;
+using ::testing::Optional;
+
+TEST(GainController2SaturationProtectorBuffer, Init) {
+  SaturationProtectorBuffer b;
+  EXPECT_EQ(b.Size(), 0);
+  EXPECT_FALSE(b.Front().has_value());
+}
+
+TEST(GainController2SaturationProtectorBuffer, PushBack) {
+  SaturationProtectorBuffer b;
+  constexpr float kValue = 123.0f;
+  b.PushBack(kValue);
+  EXPECT_EQ(b.Size(), 1);
+  EXPECT_THAT(b.Front(), Optional(Eq(kValue)));
+}
+
+TEST(GainController2SaturationProtectorBuffer, Reset) {
+  SaturationProtectorBuffer b;
+  b.PushBack(123.0f);
+  b.Reset();
+  EXPECT_EQ(b.Size(), 0);
+  EXPECT_FALSE(b.Front().has_value());
+}
+
+// Checks that the front value does not change until the ring buffer gets full.
+TEST(GainController2SaturationProtectorBuffer, FrontUntilBufferIsFull) {
+  SaturationProtectorBuffer b;
+  constexpr float kValue = 123.0f;
+  b.PushBack(kValue);
+  for (int i = 1; i < b.Capacity(); ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_THAT(b.Front(), Optional(Eq(kValue)));
+    b.PushBack(kValue + i);
+  }
+}
+
+// Checks that when the buffer is full it behaves as a shift register.
+TEST(GainController2SaturationProtectorBuffer, FrontIsDelayed) {
+  SaturationProtectorBuffer b;
+  // Fill the buffer.
+  for (int i = 0; i < b.Capacity(); ++i) {
+    b.PushBack(i);
+  }
+  // The ring buffer should now behave as a shift register with a delay equal to
+  // its capacity.
+  for (int i = b.Capacity(); i < 2 * b.Capacity() + 1; ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_THAT(b.Front(), Optional(Eq(i - b.Capacity())));
+    b.PushBack(i);
+  }
+}
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_gn/moz.build
new file mode 100644
index 0000000000..a1e6f309bf
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_gn/moz.build
@@ -0,0 +1,234 @@
+# 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/agc2/saturation_protector.cc",
+    "/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_buffer.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("saturation_protector_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_unittest.cc
new file mode 100644
index 0000000000..3b104be8cd
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/saturation_protector_unittest.cc
@@ -0,0 +1,140 @@
+/*
+ *  Copyright (c) 2018 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/agc2/saturation_protector.h"
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+
+constexpr float kInitialHeadroomDb = 20.0f;
+constexpr int kNoAdjacentSpeechFramesRequired = 1;
+constexpr float kMaxSpeechProbability = 1.0f;
+
+// Calls `Analyze(speech_probability, peak_dbfs, speech_level_dbfs)`
+// `num_iterations` times on `saturation_protector` and return the largest
+// headroom difference between two consecutive calls.
+float RunOnConstantLevel(int num_iterations,
+                         float speech_probability,
+                         float peak_dbfs,
+                         float speech_level_dbfs,
+                         SaturationProtector& saturation_protector) {
+  float last_headroom = saturation_protector.HeadroomDb();
+  float max_difference = 0.0f;
+  for (int i = 0; i < num_iterations; ++i) {
+    saturation_protector.Analyze(speech_probability, peak_dbfs,
+                                 speech_level_dbfs);
+    const float new_headroom = saturation_protector.HeadroomDb();
+    max_difference =
+        std::max(max_difference, std::fabs(new_headroom - last_headroom));
+    last_headroom = new_headroom;
+  }
+  return max_difference;
+}
+
+// Checks that the returned headroom value is correctly reset.
+TEST(GainController2SaturationProtector, Reset) {
+  ApmDataDumper apm_data_dumper(0);
+  auto saturation_protector = CreateSaturationProtector(
+      kInitialHeadroomDb, kNoAdjacentSpeechFramesRequired, &apm_data_dumper);
+  const float initial_headroom_db = saturation_protector->HeadroomDb();
+  RunOnConstantLevel(/*num_iterations=*/10, kMaxSpeechProbability,
+                     /*peak_dbfs=*/0.0f,
+                     /*speech_level_dbfs=*/-10.0f, *saturation_protector);
+  // Make sure that there are side-effects.
+  ASSERT_NE(initial_headroom_db, saturation_protector->HeadroomDb());
+  saturation_protector->Reset();
+  EXPECT_EQ(initial_headroom_db, saturation_protector->HeadroomDb());
+}
+
+// Checks that the estimate converges to the ratio between peaks and level
+// estimator values after a while.
+TEST(GainController2SaturationProtector, EstimatesCrestRatio) {
+  constexpr int kNumIterations = 2000;
+  constexpr float kPeakLevelDbfs = -20.0f;
+  constexpr float kCrestFactorDb = kInitialHeadroomDb + 1.0f;
+  constexpr float kSpeechLevelDbfs = kPeakLevelDbfs - kCrestFactorDb;
+  const float kMaxDifferenceDb =
+      0.5f * std::fabs(kInitialHeadroomDb - kCrestFactorDb);
+
+  ApmDataDumper apm_data_dumper(0);
+  auto saturation_protector = CreateSaturationProtector(
+      kInitialHeadroomDb, kNoAdjacentSpeechFramesRequired, &apm_data_dumper);
+  RunOnConstantLevel(kNumIterations, kMaxSpeechProbability, kPeakLevelDbfs,
+                     kSpeechLevelDbfs, *saturation_protector);
+  EXPECT_NEAR(saturation_protector->HeadroomDb(), kCrestFactorDb,
+              kMaxDifferenceDb);
+}
+
+// Checks that the headroom does not change too quickly.
+TEST(GainController2SaturationProtector, ChangeSlowly) {
+  constexpr int kNumIterations = 1000;
+  constexpr float kPeakLevelDbfs = -20.f;
+  constexpr float kCrestFactorDb = kInitialHeadroomDb - 5.f;
+  constexpr float kOtherCrestFactorDb = kInitialHeadroomDb;
+  constexpr float kSpeechLevelDbfs = kPeakLevelDbfs - kCrestFactorDb;
+  constexpr float kOtherSpeechLevelDbfs = kPeakLevelDbfs - kOtherCrestFactorDb;
+
+  ApmDataDumper apm_data_dumper(0);
+  auto saturation_protector = CreateSaturationProtector(
+      kInitialHeadroomDb, kNoAdjacentSpeechFramesRequired, &apm_data_dumper);
+  float max_difference_db =
+      RunOnConstantLevel(kNumIterations, kMaxSpeechProbability, kPeakLevelDbfs,
+                         kSpeechLevelDbfs, *saturation_protector);
+  max_difference_db = std::max(
+      RunOnConstantLevel(kNumIterations, kMaxSpeechProbability, kPeakLevelDbfs,
+                         kOtherSpeechLevelDbfs, *saturation_protector),
+      max_difference_db);
+  constexpr float kMaxChangeSpeedDbPerSecond = 0.5f;  // 1 db / 2 seconds.
+  EXPECT_LE(max_difference_db,
+            kMaxChangeSpeedDbPerSecond / 1000 * kFrameDurationMs);
+}
+
+class SaturationProtectorParametrization
+    : public ::testing::TestWithParam<int> {
+ protected:
+  int adjacent_speech_frames_threshold() const { return GetParam(); }
+};
+
+TEST_P(SaturationProtectorParametrization, DoNotAdaptToShortSpeechSegments) {
+  ApmDataDumper apm_data_dumper(0);
+  auto saturation_protector = CreateSaturationProtector(
+      kInitialHeadroomDb, adjacent_speech_frames_threshold(), &apm_data_dumper);
+  const float initial_headroom_db = saturation_protector->HeadroomDb();
+  RunOnConstantLevel(/*num_iterations=*/adjacent_speech_frames_threshold() - 1,
+                     kMaxSpeechProbability,
+                     /*peak_dbfs=*/0.0f,
+                     /*speech_level_dbfs=*/-10.0f, *saturation_protector);
+  // No adaptation expected.
+  EXPECT_EQ(initial_headroom_db, saturation_protector->HeadroomDb());
+}
+
+TEST_P(SaturationProtectorParametrization, AdaptToEnoughSpeechSegments) {
+  ApmDataDumper apm_data_dumper(0);
+  auto saturation_protector = CreateSaturationProtector(
+      kInitialHeadroomDb, adjacent_speech_frames_threshold(), &apm_data_dumper);
+  const float initial_headroom_db = saturation_protector->HeadroomDb();
+  RunOnConstantLevel(/*num_iterations=*/adjacent_speech_frames_threshold() + 1,
+                     kMaxSpeechProbability,
+                     /*peak_dbfs=*/0.0f,
+                     /*speech_level_dbfs=*/-10.0f, *saturation_protector);
+  // Adaptation expected.
+  EXPECT_NE(initial_headroom_db, saturation_protector->HeadroomDb());
+}
+
+INSTANTIATE_TEST_SUITE_P(GainController2,
+                         SaturationProtectorParametrization,
+                         ::testing::Values(2, 9, 17));
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator.cc b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator.cc
new file mode 100644
index 0000000000..7bf3252116
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator.cc
@@ -0,0 +1,174 @@
+/*
+ *  Copyright (c) 2018 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/agc2/speech_level_estimator.h"
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/safe_minmax.h"
+
+namespace webrtc {
+namespace {
+
+float ClampLevelEstimateDbfs(float level_estimate_dbfs) {
+  return rtc::SafeClamp<float>(level_estimate_dbfs, -90.0f, 30.0f);
+}
+
+// Returns the initial speech level estimate needed to apply the initial gain.
+float GetInitialSpeechLevelEstimateDbfs(
+    const AudioProcessing::Config::GainController2::AdaptiveDigital& config) {
+  return ClampLevelEstimateDbfs(-kSaturationProtectorInitialHeadroomDb -
+                                config.initial_gain_db - config.headroom_db);
+}
+
+}  // namespace
+
+bool SpeechLevelEstimator::LevelEstimatorState::operator==(
+    const SpeechLevelEstimator::LevelEstimatorState& b) const {
+  return time_to_confidence_ms == b.time_to_confidence_ms &&
+         level_dbfs.numerator == b.level_dbfs.numerator &&
+         level_dbfs.denominator == b.level_dbfs.denominator;
+}
+
+float SpeechLevelEstimator::LevelEstimatorState::Ratio::GetRatio() const {
+  RTC_DCHECK_NE(denominator, 0.f);
+  return numerator / denominator;
+}
+
+SpeechLevelEstimator::SpeechLevelEstimator(
+    ApmDataDumper* apm_data_dumper,
+    const AudioProcessing::Config::GainController2::AdaptiveDigital& config,
+    int adjacent_speech_frames_threshold)
+    : apm_data_dumper_(apm_data_dumper),
+      initial_speech_level_dbfs_(GetInitialSpeechLevelEstimateDbfs(config)),
+      adjacent_speech_frames_threshold_(adjacent_speech_frames_threshold),
+      level_dbfs_(initial_speech_level_dbfs_),
+      // TODO(bugs.webrtc.org/7494): Remove init below when AGC2 input volume
+      // controller temporal dependency removed.
+      is_confident_(false) {
+  RTC_DCHECK(apm_data_dumper_);
+  RTC_DCHECK_GE(adjacent_speech_frames_threshold_, 1);
+  Reset();
+}
+
+void SpeechLevelEstimator::Update(float rms_dbfs,
+                                  float peak_dbfs,
+                                  float speech_probability) {
+  RTC_DCHECK_GT(rms_dbfs, -150.0f);
+  RTC_DCHECK_LT(rms_dbfs, 50.0f);
+  RTC_DCHECK_GT(peak_dbfs, -150.0f);
+  RTC_DCHECK_LT(peak_dbfs, 50.0f);
+  RTC_DCHECK_GE(speech_probability, 0.0f);
+  RTC_DCHECK_LE(speech_probability, 1.0f);
+  if (speech_probability < kVadConfidenceThreshold) {
+    // Not a speech frame.
+    if (adjacent_speech_frames_threshold_ > 1) {
+      // When two or more adjacent speech frames are required in order to update
+      // the state, we need to decide whether to discard or confirm the updates
+      // based on the speech sequence length.
+      if (num_adjacent_speech_frames_ >= adjacent_speech_frames_threshold_) {
+        // First non-speech frame after a long enough sequence of speech frames.
+        // Update the reliable state.
+        reliable_state_ = preliminary_state_;
+      } else if (num_adjacent_speech_frames_ > 0) {
+        // First non-speech frame after a too short sequence of speech frames.
+        // Reset to the last reliable state.
+        preliminary_state_ = reliable_state_;
+      }
+    }
+    num_adjacent_speech_frames_ = 0;
+  } else {
+    // Speech frame observed.
+    num_adjacent_speech_frames_++;
+
+    // Update preliminary level estimate.
+    RTC_DCHECK_GE(preliminary_state_.time_to_confidence_ms, 0);
+    const bool buffer_is_full = preliminary_state_.time_to_confidence_ms == 0;
+    if (!buffer_is_full) {
+      preliminary_state_.time_to_confidence_ms -= kFrameDurationMs;
+    }
+    // Weighted average of levels with speech probability as weight.
+    RTC_DCHECK_GT(speech_probability, 0.0f);
+    const float leak_factor = buffer_is_full ? kLevelEstimatorLeakFactor : 1.0f;
+    preliminary_state_.level_dbfs.numerator =
+        preliminary_state_.level_dbfs.numerator * leak_factor +
+        rms_dbfs * speech_probability;
+    preliminary_state_.level_dbfs.denominator =
+        preliminary_state_.level_dbfs.denominator * leak_factor +
+        speech_probability;
+
+    const float level_dbfs = preliminary_state_.level_dbfs.GetRatio();
+
+    if (num_adjacent_speech_frames_ >= adjacent_speech_frames_threshold_) {
+      // `preliminary_state_` is now reliable. Update the last level estimation.
+      level_dbfs_ = ClampLevelEstimateDbfs(level_dbfs);
+    }
+  }
+  UpdateIsConfident();
+  DumpDebugData();
+}
+
+void SpeechLevelEstimator::UpdateIsConfident() {
+  if (adjacent_speech_frames_threshold_ == 1) {
+    // Ignore `reliable_state_` when a single frame is enough to update the
+    // level estimate (because it is not used).
+    is_confident_ = preliminary_state_.time_to_confidence_ms == 0;
+    return;
+  }
+  // Once confident, it remains confident.
+  RTC_DCHECK(reliable_state_.time_to_confidence_ms != 0 ||
+             preliminary_state_.time_to_confidence_ms == 0);
+  // During the first long enough speech sequence, `reliable_state_` must be
+  // ignored since `preliminary_state_` is used.
+  is_confident_ =
+      reliable_state_.time_to_confidence_ms == 0 ||
+      (num_adjacent_speech_frames_ >= adjacent_speech_frames_threshold_ &&
+       preliminary_state_.time_to_confidence_ms == 0);
+}
+
+void SpeechLevelEstimator::Reset() {
+  ResetLevelEstimatorState(preliminary_state_);
+  ResetLevelEstimatorState(reliable_state_);
+  level_dbfs_ = initial_speech_level_dbfs_;
+  num_adjacent_speech_frames_ = 0;
+}
+
+void SpeechLevelEstimator::ResetLevelEstimatorState(
+    LevelEstimatorState& state) const {
+  state.time_to_confidence_ms = kLevelEstimatorTimeToConfidenceMs;
+  state.level_dbfs.numerator = initial_speech_level_dbfs_;
+  state.level_dbfs.denominator = 1.0f;
+}
+
+void SpeechLevelEstimator::DumpDebugData() const {
+  if (!apm_data_dumper_)
+    return;
+  apm_data_dumper_->DumpRaw("agc2_speech_level_dbfs", level_dbfs_);
+  apm_data_dumper_->DumpRaw("agc2_speech_level_is_confident", is_confident_);
+  apm_data_dumper_->DumpRaw(
+      "agc2_adaptive_level_estimator_num_adjacent_speech_frames",
+      num_adjacent_speech_frames_);
+  apm_data_dumper_->DumpRaw(
+      "agc2_adaptive_level_estimator_preliminary_level_estimate_num",
+      preliminary_state_.level_dbfs.numerator);
+  apm_data_dumper_->DumpRaw(
+      "agc2_adaptive_level_estimator_preliminary_level_estimate_den",
+      preliminary_state_.level_dbfs.denominator);
+  apm_data_dumper_->DumpRaw(
+      "agc2_adaptive_level_estimator_preliminary_time_to_confidence_ms",
+      preliminary_state_.time_to_confidence_ms);
+  apm_data_dumper_->DumpRaw(
+      "agc2_adaptive_level_estimator_reliable_time_to_confidence_ms",
+      reliable_state_.time_to_confidence_ms);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator.h b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator.h
new file mode 100644
index 0000000000..4d9f106ba9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator.h
@@ -0,0 +1,81 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_SPEECH_LEVEL_ESTIMATOR_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_SPEECH_LEVEL_ESTIMATOR_H_
+
+#include <stddef.h>
+
+#include <type_traits>
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/include/audio_processing.h"
+
+namespace webrtc {
+class ApmDataDumper;
+
+// Active speech level estimator based on the analysis of the following
+// framewise properties: RMS level (dBFS), peak level (dBFS), speech
+// probability.
+class SpeechLevelEstimator {
+ public:
+  SpeechLevelEstimator(
+      ApmDataDumper* apm_data_dumper,
+      const AudioProcessing::Config::GainController2::AdaptiveDigital& config,
+      int adjacent_speech_frames_threshold);
+  SpeechLevelEstimator(const SpeechLevelEstimator&) = delete;
+  SpeechLevelEstimator& operator=(const SpeechLevelEstimator&) = delete;
+
+  // Updates the level estimation.
+  void Update(float rms_dbfs, float peak_dbfs, float speech_probability);
+  // Returns the estimated speech plus noise level.
+  float level_dbfs() const { return level_dbfs_; }
+  // Returns true if the estimator is confident on its current estimate.
+  bool is_confident() const { return is_confident_; }
+
+  void Reset();
+
+ private:
+  // Part of the level estimator state used for check-pointing and restore ops.
+  struct LevelEstimatorState {
+    bool operator==(const LevelEstimatorState& s) const;
+    inline bool operator!=(const LevelEstimatorState& s) const {
+      return !(*this == s);
+    }
+    // TODO(bugs.webrtc.org/7494): Remove `time_to_confidence_ms` if redundant.
+    int time_to_confidence_ms;
+    struct Ratio {
+      float numerator;
+      float denominator;
+      float GetRatio() const;
+    } level_dbfs;
+  };
+  static_assert(std::is_trivially_copyable<LevelEstimatorState>::value, "");
+
+  void UpdateIsConfident();
+
+  void ResetLevelEstimatorState(LevelEstimatorState& state) const;
+
+  void DumpDebugData() const;
+
+  ApmDataDumper* const apm_data_dumper_;
+
+  const float initial_speech_level_dbfs_;
+  const int adjacent_speech_frames_threshold_;
+  LevelEstimatorState preliminary_state_;
+  LevelEstimatorState reliable_state_;
+  float level_dbfs_;
+  bool is_confident_;
+  int num_adjacent_speech_frames_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_SPEECH_LEVEL_ESTIMATOR_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator_gn/moz.build
new file mode 100644
index 0000000000..bb1dbc67b8
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator_gn/moz.build
@@ -0,0 +1,233 @@
+# 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/agc2/speech_level_estimator.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("speech_level_estimator_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator_unittest.cc
new file mode 100644
index 0000000000..e1c5f85434
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/speech_level_estimator_unittest.cc
@@ -0,0 +1,207 @@
+/*
+ *  Copyright (c) 2018 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/agc2/speech_level_estimator.h"
+
+#include <memory>
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/include/audio_processing.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+
+using AdaptiveDigitalConfig =
+    AudioProcessing::Config::GainController2::AdaptiveDigital;
+
+// Number of speech frames that the level estimator must observe in order to
+// become confident about the estimated level.
+constexpr int kNumFramesToConfidence =
+    kLevelEstimatorTimeToConfidenceMs / kFrameDurationMs;
+static_assert(kNumFramesToConfidence > 0, "");
+
+constexpr float kConvergenceSpeedTestsLevelTolerance = 0.5f;
+
+// Provides the `vad_level` value `num_iterations` times to `level_estimator`.
+void RunOnConstantLevel(int num_iterations,
+                        float rms_dbfs,
+                        float peak_dbfs,
+                        float speech_probability,
+                        SpeechLevelEstimator& level_estimator) {
+  for (int i = 0; i < num_iterations; ++i) {
+    level_estimator.Update(rms_dbfs, peak_dbfs, speech_probability);
+  }
+}
+
+constexpr float kNoSpeechProbability = 0.0f;
+constexpr float kLowSpeechProbability = kVadConfidenceThreshold / 2.0f;
+constexpr float kMaxSpeechProbability = 1.0f;
+
+// Level estimator with data dumper.
+struct TestLevelEstimator {
+  explicit TestLevelEstimator(int adjacent_speech_frames_threshold)
+      : data_dumper(0),
+        estimator(std::make_unique<SpeechLevelEstimator>(
+            &data_dumper,
+            AdaptiveDigitalConfig{},
+            adjacent_speech_frames_threshold)),
+        initial_speech_level_dbfs(estimator->level_dbfs()),
+        level_rms_dbfs(initial_speech_level_dbfs / 2.0f),
+        level_peak_dbfs(initial_speech_level_dbfs / 3.0f) {
+    RTC_DCHECK_LT(level_rms_dbfs, level_peak_dbfs);
+    RTC_DCHECK_LT(initial_speech_level_dbfs, level_rms_dbfs);
+    RTC_DCHECK_GT(level_rms_dbfs - initial_speech_level_dbfs, 5.0f)
+        << "Adjust `level_rms_dbfs` so that the difference from the initial "
+           "level is wide enough for the tests";
+  }
+  ApmDataDumper data_dumper;
+  std::unique_ptr<SpeechLevelEstimator> estimator;
+  const float initial_speech_level_dbfs;
+  const float level_rms_dbfs;
+  const float level_peak_dbfs;
+};
+
+// Checks that the level estimator converges to a constant input speech level.
+TEST(GainController2SpeechLevelEstimator, LevelStabilizes) {
+  TestLevelEstimator level_estimator(/*adjacent_speech_frames_threshold=*/1);
+  RunOnConstantLevel(/*num_iterations=*/kNumFramesToConfidence,
+                     level_estimator.level_rms_dbfs,
+                     level_estimator.level_peak_dbfs, kMaxSpeechProbability,
+                     *level_estimator.estimator);
+  const float estimated_level_dbfs = level_estimator.estimator->level_dbfs();
+  RunOnConstantLevel(/*num_iterations=*/1, level_estimator.level_rms_dbfs,
+                     level_estimator.level_peak_dbfs, kMaxSpeechProbability,
+                     *level_estimator.estimator);
+  EXPECT_NEAR(level_estimator.estimator->level_dbfs(), estimated_level_dbfs,
+              0.1f);
+}
+
+// Checks that the level controller does not become confident when too few
+// speech frames are observed.
+TEST(GainController2SpeechLevelEstimator, IsNotConfident) {
+  TestLevelEstimator level_estimator(/*adjacent_speech_frames_threshold=*/1);
+  RunOnConstantLevel(/*num_iterations=*/kNumFramesToConfidence / 2,
+                     level_estimator.level_rms_dbfs,
+                     level_estimator.level_peak_dbfs, kMaxSpeechProbability,
+                     *level_estimator.estimator);
+  EXPECT_FALSE(level_estimator.estimator->is_confident());
+}
+
+// Checks that the level controller becomes confident when enough speech frames
+// are observed.
+TEST(GainController2SpeechLevelEstimator, IsConfident) {
+  TestLevelEstimator level_estimator(/*adjacent_speech_frames_threshold=*/1);
+  RunOnConstantLevel(/*num_iterations=*/kNumFramesToConfidence,
+                     level_estimator.level_rms_dbfs,
+                     level_estimator.level_peak_dbfs, kMaxSpeechProbability,
+                     *level_estimator.estimator);
+  EXPECT_TRUE(level_estimator.estimator->is_confident());
+}
+
+// Checks that the estimated level is not affected by the level of non-speech
+// frames.
+TEST(GainController2SpeechLevelEstimator, EstimatorIgnoresNonSpeechFrames) {
+  TestLevelEstimator level_estimator(/*adjacent_speech_frames_threshold=*/1);
+  // Simulate speech.
+  RunOnConstantLevel(/*num_iterations=*/kNumFramesToConfidence,
+                     level_estimator.level_rms_dbfs,
+                     level_estimator.level_peak_dbfs, kMaxSpeechProbability,
+                     *level_estimator.estimator);
+  const float estimated_level_dbfs = level_estimator.estimator->level_dbfs();
+  // Simulate full-scale non-speech.
+  RunOnConstantLevel(/*num_iterations=*/kNumFramesToConfidence,
+                     /*rms_dbfs=*/0.0f, /*peak_dbfs=*/0.0f,
+                     kNoSpeechProbability, *level_estimator.estimator);
+  // No estimated level change is expected.
+  EXPECT_FLOAT_EQ(level_estimator.estimator->level_dbfs(),
+                  estimated_level_dbfs);
+}
+
+// Checks the convergence speed of the estimator before it becomes confident.
+TEST(GainController2SpeechLevelEstimator, ConvergenceSpeedBeforeConfidence) {
+  TestLevelEstimator level_estimator(/*adjacent_speech_frames_threshold=*/1);
+  RunOnConstantLevel(/*num_iterations=*/kNumFramesToConfidence,
+                     level_estimator.level_rms_dbfs,
+                     level_estimator.level_peak_dbfs, kMaxSpeechProbability,
+                     *level_estimator.estimator);
+  EXPECT_NEAR(level_estimator.estimator->level_dbfs(),
+              level_estimator.level_rms_dbfs,
+              kConvergenceSpeedTestsLevelTolerance);
+}
+
+// Checks the convergence speed of the estimator after it becomes confident.
+TEST(GainController2SpeechLevelEstimator, ConvergenceSpeedAfterConfidence) {
+  TestLevelEstimator level_estimator(/*adjacent_speech_frames_threshold=*/1);
+  // Reach confidence using the initial level estimate.
+  RunOnConstantLevel(
+      /*num_iterations=*/kNumFramesToConfidence,
+      /*rms_dbfs=*/level_estimator.initial_speech_level_dbfs,
+      /*peak_dbfs=*/level_estimator.initial_speech_level_dbfs + 6.0f,
+      kMaxSpeechProbability, *level_estimator.estimator);
+  // No estimate change should occur, but confidence is achieved.
+  ASSERT_FLOAT_EQ(level_estimator.estimator->level_dbfs(),
+                  level_estimator.initial_speech_level_dbfs);
+  ASSERT_TRUE(level_estimator.estimator->is_confident());
+  // After confidence.
+  constexpr float kConvergenceTimeAfterConfidenceNumFrames = 600;  // 6 seconds.
+  static_assert(
+      kConvergenceTimeAfterConfidenceNumFrames > kNumFramesToConfidence, "");
+  RunOnConstantLevel(
+      /*num_iterations=*/kConvergenceTimeAfterConfidenceNumFrames,
+      level_estimator.level_rms_dbfs, level_estimator.level_peak_dbfs,
+      kMaxSpeechProbability, *level_estimator.estimator);
+  EXPECT_NEAR(level_estimator.estimator->level_dbfs(),
+              level_estimator.level_rms_dbfs,
+              kConvergenceSpeedTestsLevelTolerance);
+}
+
+class SpeechLevelEstimatorParametrization
+    : public ::testing::TestWithParam<int> {
+ protected:
+  int adjacent_speech_frames_threshold() const { return GetParam(); }
+};
+
+TEST_P(SpeechLevelEstimatorParametrization, DoNotAdaptToShortSpeechSegments) {
+  TestLevelEstimator level_estimator(adjacent_speech_frames_threshold());
+  const float initial_level = level_estimator.estimator->level_dbfs();
+  ASSERT_LT(initial_level, level_estimator.level_peak_dbfs);
+  for (int i = 0; i < adjacent_speech_frames_threshold() - 1; ++i) {
+    SCOPED_TRACE(i);
+    level_estimator.estimator->Update(level_estimator.level_rms_dbfs,
+                                      level_estimator.level_peak_dbfs,
+                                      kMaxSpeechProbability);
+    EXPECT_EQ(initial_level, level_estimator.estimator->level_dbfs());
+  }
+  level_estimator.estimator->Update(level_estimator.level_rms_dbfs,
+                                    level_estimator.level_peak_dbfs,
+                                    kLowSpeechProbability);
+  EXPECT_EQ(initial_level, level_estimator.estimator->level_dbfs());
+}
+
+TEST_P(SpeechLevelEstimatorParametrization, AdaptToEnoughSpeechSegments) {
+  TestLevelEstimator level_estimator(adjacent_speech_frames_threshold());
+  const float initial_level = level_estimator.estimator->level_dbfs();
+  ASSERT_LT(initial_level, level_estimator.level_peak_dbfs);
+  for (int i = 0; i < adjacent_speech_frames_threshold(); ++i) {
+    level_estimator.estimator->Update(level_estimator.level_rms_dbfs,
+                                      level_estimator.level_peak_dbfs,
+                                      kMaxSpeechProbability);
+  }
+  EXPECT_LT(initial_level, level_estimator.estimator->level_dbfs());
+}
+
+INSTANTIATE_TEST_SUITE_P(GainController2,
+                         SpeechLevelEstimatorParametrization,
+                         ::testing::Values(1, 9, 17));
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer.cc b/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer.cc
new file mode 100644
index 0000000000..7746f6c000
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer.cc
@@ -0,0 +1,105 @@
+/*
+ *  Copyright (c) 2022 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/agc2/speech_probability_buffer.h"
+
+#include <algorithm>
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace {
+
+constexpr float kActivityThreshold = 0.9f;
+constexpr int kNumAnalysisFrames = 100;
+// We use 12 in AGC2 adaptive digital, but with a slightly different logic.
+constexpr int kTransientWidthThreshold = 7;
+
+}  // namespace
+
+SpeechProbabilityBuffer::SpeechProbabilityBuffer(
+    float low_probability_threshold)
+    : low_probability_threshold_(low_probability_threshold),
+      probabilities_(kNumAnalysisFrames) {
+  RTC_DCHECK_GE(low_probability_threshold, 0.0f);
+  RTC_DCHECK_LE(low_probability_threshold, 1.0f);
+  RTC_DCHECK(!probabilities_.empty());
+}
+
+void SpeechProbabilityBuffer::Update(float probability) {
+  // Remove the oldest entry if the circular buffer is full.
+  if (buffer_is_full_) {
+    const float oldest_probability = probabilities_[buffer_index_];
+    sum_probabilities_ -= oldest_probability;
+  }
+
+  // Check for transients.
+  if (probability <= low_probability_threshold_) {
+    // Set a probability lower than the threshold to zero.
+    probability = 0.0f;
+
+    // Check if this has been a transient.
+    if (num_high_probability_observations_ <= kTransientWidthThreshold) {
+      RemoveTransient();
+    }
+    num_high_probability_observations_ = 0;
+  } else if (num_high_probability_observations_ <= kTransientWidthThreshold) {
+    ++num_high_probability_observations_;
+  }
+
+  // Update the circular buffer and the current sum.
+  probabilities_[buffer_index_] = probability;
+  sum_probabilities_ += probability;
+
+  // Increment the buffer index and check for wrap-around.
+  if (++buffer_index_ >= kNumAnalysisFrames) {
+    buffer_index_ = 0;
+    buffer_is_full_ = true;
+  }
+}
+
+void SpeechProbabilityBuffer::RemoveTransient() {
+  // Don't expect to be here if high-activity region is longer than
+  // `kTransientWidthThreshold` or there has not been any transient.
+  RTC_DCHECK_LE(num_high_probability_observations_, kTransientWidthThreshold);
+
+  // Replace previously added probabilities with zero.
+  int index =
+      (buffer_index_ > 0) ? (buffer_index_ - 1) : (kNumAnalysisFrames - 1);
+
+  while (num_high_probability_observations_-- > 0) {
+    sum_probabilities_ -= probabilities_[index];
+    probabilities_[index] = 0.0f;
+
+    // Update the circular buffer index.
+    index = (index > 0) ? (index - 1) : (kNumAnalysisFrames - 1);
+  }
+}
+
+bool SpeechProbabilityBuffer::IsActiveSegment() const {
+  if (!buffer_is_full_) {
+    return false;
+  }
+  if (sum_probabilities_ < kActivityThreshold * kNumAnalysisFrames) {
+    return false;
+  }
+  return true;
+}
+
+void SpeechProbabilityBuffer::Reset() {
+  sum_probabilities_ = 0.0f;
+
+  // Empty the circular buffer.
+  buffer_index_ = 0;
+  buffer_is_full_ = false;
+  num_high_probability_observations_ = 0;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer.h b/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer.h
new file mode 100644
index 0000000000..3056a3eeab
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer.h
@@ -0,0 +1,80 @@
+/*
+ *  Copyright (c) 2022 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_AGC2_SPEECH_PROBABILITY_BUFFER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_SPEECH_PROBABILITY_BUFFER_H_
+
+#include <vector>
+
+#include "rtc_base/gtest_prod_util.h"
+
+namespace webrtc {
+
+// This class implements a circular buffer that stores speech probabilities
+// for a speech segment and estimates speech activity for that segment.
+class SpeechProbabilityBuffer {
+ public:
+  // Ctor. The value of `low_probability_threshold` is required to be on the
+  // range [0.0f, 1.0f].
+  explicit SpeechProbabilityBuffer(float low_probability_threshold);
+  ~SpeechProbabilityBuffer() {}
+  SpeechProbabilityBuffer(const SpeechProbabilityBuffer&) = delete;
+  SpeechProbabilityBuffer& operator=(const SpeechProbabilityBuffer&) = delete;
+
+  // Adds `probability` in the buffer and computes an updatds sum of the buffer
+  // probabilities. Value of `probability` is required to be on the range
+  // [0.0f, 1.0f].
+  void Update(float probability);
+
+  // Resets the histogram, forgets the past.
+  void Reset();
+
+  // Returns true if the segment is active (a long enough segment with an
+  // average speech probability above `low_probability_threshold`).
+  bool IsActiveSegment() const;
+
+ private:
+  void RemoveTransient();
+
+  // Use only for testing.
+  float GetSumProbabilities() const { return sum_probabilities_; }
+
+  FRIEND_TEST_ALL_PREFIXES(SpeechProbabilityBufferTest,
+                           CheckSumAfterInitialization);
+  FRIEND_TEST_ALL_PREFIXES(SpeechProbabilityBufferTest, CheckSumAfterUpdate);
+  FRIEND_TEST_ALL_PREFIXES(SpeechProbabilityBufferTest, CheckSumAfterReset);
+  FRIEND_TEST_ALL_PREFIXES(SpeechProbabilityBufferTest,
+                           CheckSumAfterTransientNotRemoved);
+  FRIEND_TEST_ALL_PREFIXES(SpeechProbabilityBufferTest,
+                           CheckSumAfterTransientRemoved);
+
+  const float low_probability_threshold_;
+
+  // Sum of probabilities stored in `probabilities_`. Must be updated if
+  // `probabilities_` is updated.
+  float sum_probabilities_ = 0.0f;
+
+  // Circular buffer for probabilities.
+  std::vector<float> probabilities_;
+
+  // Current index of the circular buffer, where the newest data will be written
+  // to, therefore, pointing to the oldest data if buffer is full.
+  int buffer_index_ = 0;
+
+  // Indicates if the buffer is full and adding a new value removes the oldest
+  // value.
+  int buffer_is_full_ = false;
+
+  int num_high_probability_observations_ = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_SPEECH_PROBABILITY_BUFFER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer_unittest.cc
new file mode 100644
index 0000000000..89cc209d9d
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/speech_probability_buffer_unittest.cc
@@ -0,0 +1,346 @@
+/*
+ *  Copyright (c) 2022 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/agc2/speech_probability_buffer.h"
+
+#include <algorithm>
+
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+constexpr float kAbsError = 0.001f;
+constexpr float kActivityThreshold = 0.9f;
+constexpr float kLowProbabilityThreshold = 0.2f;
+constexpr int kNumAnalysisFrames = 100;
+
+}  // namespace
+
+TEST(SpeechProbabilityBufferTest, CheckSumAfterInitialization) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  EXPECT_EQ(buffer.GetSumProbabilities(), 0.0f);
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSumAfterUpdate) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  buffer.Update(0.7f);
+
+  EXPECT_NEAR(buffer.GetSumProbabilities(), 0.7f, kAbsError);
+
+  buffer.Update(0.6f);
+
+  EXPECT_NEAR(buffer.GetSumProbabilities(), 1.3f, kAbsError);
+
+  for (int i = 0; i < kNumAnalysisFrames - 1; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  EXPECT_NEAR(buffer.GetSumProbabilities(), 99.6f, kAbsError);
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSumAfterReset) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  buffer.Update(0.7f);
+  buffer.Update(0.6f);
+  buffer.Update(0.3f);
+
+  EXPECT_GT(buffer.GetSumProbabilities(), 0.0f);
+
+  buffer.Reset();
+
+  EXPECT_EQ(buffer.GetSumProbabilities(), 0.0f);
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSumAfterTransientNotRemoved) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+
+  buffer.Update(0.0f);
+
+  EXPECT_NEAR(buffer.GetSumProbabilities(), 9.0f, kAbsError);
+
+  buffer.Update(0.0f);
+
+  EXPECT_NEAR(buffer.GetSumProbabilities(), 9.0f, kAbsError);
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSumAfterTransientRemoved) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  buffer.Update(0.0f);
+  buffer.Update(0.0f);
+  buffer.Update(0.0f);
+  buffer.Update(0.0f);
+  buffer.Update(0.0f);
+  buffer.Update(0.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+  buffer.Update(1.0f);
+
+  EXPECT_NEAR(buffer.GetSumProbabilities(), 3.0f, kAbsError);
+
+  buffer.Update(0.0f);
+
+  EXPECT_NEAR(buffer.GetSumProbabilities(), 0.0f, kAbsError);
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSegmentIsNotActiveAfterNoUpdates) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSegmentIsActiveChangesFromFalseToTrue) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  // Add low probabilities until the buffer is full. That's not enough
+  // to make `IsActiveSegment()` to return true.
+  for (int i = 0; i < kNumAnalysisFrames; ++i) {
+    buffer.Update(0.0f);
+  }
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  // Add high probabilities until `IsActiveSegment()` returns true.
+  for (int i = 0; i < kActivityThreshold * kNumAnalysisFrames - 1; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(1.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSegmentIsActiveChangesFromTrueToFalse) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  // Add high probabilities until the buffer is full. That's enough to
+  // make `IsActiveSegment()` to return true.
+  for (int i = 0; i < kNumAnalysisFrames; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  // Add low probabilities until `IsActiveSegment()` returns false.
+  for (int i = 0; i < (1.0f - kActivityThreshold) * kNumAnalysisFrames - 1;
+       ++i) {
+    buffer.Update(0.0f);
+  }
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  buffer.Update(1.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest,
+     CheckSegmentIsActiveAfterUpdatesWithHighProbabilities) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames - 1; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(1.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest,
+     CheckSegmentIsNotActiveAfterUpdatesWithLowProbabilities) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames - 1; ++i) {
+    buffer.Update(0.3f);
+  }
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(0.3f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSegmentIsActiveAfterBufferIsFull) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames - 1; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(1.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  buffer.Update(1.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSegmentIsNotActiveAfterBufferIsFull) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames - 1; ++i) {
+    buffer.Update(0.29f);
+  }
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(0.29f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(0.29f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSegmentIsNotActiveAfterReset) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  buffer.Reset();
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest,
+     CheckSegmentIsNotActiveAfterTransientRemovedAfterFewUpdates) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  buffer.Update(0.4f);
+  buffer.Update(0.4f);
+  buffer.Update(0.0f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest,
+     CheckSegmentIsActiveAfterTransientNotRemoved) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  buffer.Update(0.7f);
+  buffer.Update(0.8f);
+  buffer.Update(0.9f);
+  buffer.Update(1.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  buffer.Update(0.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  buffer.Update(0.7f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest,
+     CheckSegmentIsNotActiveAfterTransientNotRemoved) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames; ++i) {
+    buffer.Update(0.1f);
+  }
+
+  buffer.Update(0.7f);
+  buffer.Update(0.8f);
+  buffer.Update(0.9f);
+  buffer.Update(1.0f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(0.0f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(0.7f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest,
+     CheckSegmentIsNotActiveAfterTransientRemoved) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames; ++i) {
+    buffer.Update(0.1f);
+  }
+
+  buffer.Update(0.7f);
+  buffer.Update(0.8f);
+  buffer.Update(0.9f);
+  buffer.Update(1.0f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(0.0f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+
+  buffer.Update(0.7f);
+
+  EXPECT_FALSE(buffer.IsActiveSegment());
+}
+
+TEST(SpeechProbabilityBufferTest, CheckSegmentIsActiveAfterTransientRemoved) {
+  SpeechProbabilityBuffer buffer(kLowProbabilityThreshold);
+
+  for (int i = 0; i < kNumAnalysisFrames; ++i) {
+    buffer.Update(1.0f);
+  }
+
+  buffer.Update(0.7f);
+  buffer.Update(0.8f);
+  buffer.Update(0.9f);
+  buffer.Update(1.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  buffer.Update(0.0f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+
+  buffer.Update(0.7f);
+
+  EXPECT_TRUE(buffer.IsActiveSegment());
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper.cc b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper.cc
new file mode 100644
index 0000000000..af6325dea7
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper.cc
@@ -0,0 +1,113 @@
+/*
+ *  Copyright (c) 2018 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/agc2/vad_wrapper.h"
+
+#include <array>
+#include <utility>
+
+#include "api/array_view.h"
+#include "common_audio/resampler/include/push_resampler.h"
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/agc2/rnn_vad/common.h"
+#include "modules/audio_processing/agc2/rnn_vad/features_extraction.h"
+#include "modules/audio_processing/agc2/rnn_vad/rnn.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kNumFramesPerSecond = 100;
+
+class MonoVadImpl : public VoiceActivityDetectorWrapper::MonoVad {
+ public:
+  explicit MonoVadImpl(const AvailableCpuFeatures& cpu_features)
+      : features_extractor_(cpu_features), rnn_vad_(cpu_features) {}
+  MonoVadImpl(const MonoVadImpl&) = delete;
+  MonoVadImpl& operator=(const MonoVadImpl&) = delete;
+  ~MonoVadImpl() = default;
+
+  int SampleRateHz() const override { return rnn_vad::kSampleRate24kHz; }
+  void Reset() override { rnn_vad_.Reset(); }
+  float Analyze(rtc::ArrayView<const float> frame) override {
+    RTC_DCHECK_EQ(frame.size(), rnn_vad::kFrameSize10ms24kHz);
+    std::array<float, rnn_vad::kFeatureVectorSize> feature_vector;
+    const bool is_silence = features_extractor_.CheckSilenceComputeFeatures(
+        /*samples=*/{frame.data(), rnn_vad::kFrameSize10ms24kHz},
+        feature_vector);
+    return rnn_vad_.ComputeVadProbability(feature_vector, is_silence);
+  }
+
+ private:
+  rnn_vad::FeaturesExtractor features_extractor_;
+  rnn_vad::RnnVad rnn_vad_;
+};
+
+}  // namespace
+
+VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
+    const AvailableCpuFeatures& cpu_features,
+    int sample_rate_hz)
+    : VoiceActivityDetectorWrapper(kVadResetPeriodMs,
+                                   cpu_features,
+                                   sample_rate_hz) {}
+
+VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
+    int vad_reset_period_ms,
+    const AvailableCpuFeatures& cpu_features,
+    int sample_rate_hz)
+    : VoiceActivityDetectorWrapper(vad_reset_period_ms,
+                                   std::make_unique<MonoVadImpl>(cpu_features),
+                                   sample_rate_hz) {}
+
+VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
+    int vad_reset_period_ms,
+    std::unique_ptr<MonoVad> vad,
+    int sample_rate_hz)
+    : vad_reset_period_frames_(
+          rtc::CheckedDivExact(vad_reset_period_ms, kFrameDurationMs)),
+      time_to_vad_reset_(vad_reset_period_frames_),
+      vad_(std::move(vad)) {
+  RTC_DCHECK(vad_);
+  RTC_DCHECK_GT(vad_reset_period_frames_, 1);
+  resampled_buffer_.resize(
+      rtc::CheckedDivExact(vad_->SampleRateHz(), kNumFramesPerSecond));
+  Initialize(sample_rate_hz);
+}
+
+VoiceActivityDetectorWrapper::~VoiceActivityDetectorWrapper() = default;
+
+void VoiceActivityDetectorWrapper::Initialize(int sample_rate_hz) {
+  RTC_DCHECK_GT(sample_rate_hz, 0);
+  frame_size_ = rtc::CheckedDivExact(sample_rate_hz, kNumFramesPerSecond);
+  int status =
+      resampler_.InitializeIfNeeded(sample_rate_hz, vad_->SampleRateHz(),
+                                    /*num_channels=*/1);
+  constexpr int kStatusOk = 0;
+  RTC_DCHECK_EQ(status, kStatusOk);
+  vad_->Reset();
+}
+
+float VoiceActivityDetectorWrapper::Analyze(AudioFrameView<const float> frame) {
+  // Periodically reset the VAD.
+  time_to_vad_reset_--;
+  if (time_to_vad_reset_ <= 0) {
+    vad_->Reset();
+    time_to_vad_reset_ = vad_reset_period_frames_;
+  }
+  // Resample the first channel of `frame`.
+  RTC_DCHECK_EQ(frame.samples_per_channel(), frame_size_);
+  resampler_.Resample(frame.channel(0).data(), frame_size_,
+                      resampled_buffer_.data(), resampled_buffer_.size());
+
+  return vad_->Analyze(resampled_buffer_);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper.h b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper.h
new file mode 100644
index 0000000000..459c471630
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper.h
@@ -0,0 +1,82 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_VAD_WRAPPER_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_VAD_WRAPPER_H_
+
+#include <memory>
+#include <vector>
+
+#include "api/array_view.h"
+#include "common_audio/resampler/include/push_resampler.h"
+#include "modules/audio_processing/agc2/cpu_features.h"
+#include "modules/audio_processing/include/audio_frame_view.h"
+
+namespace webrtc {
+
+// Wraps a single-channel Voice Activity Detector (VAD) which is used to analyze
+// the first channel of the input audio frames. Takes care of resampling the
+// input frames to match the sample rate of the wrapped VAD and periodically
+// resets the VAD.
+class VoiceActivityDetectorWrapper {
+ public:
+  // Single channel VAD interface.
+  class MonoVad {
+   public:
+    virtual ~MonoVad() = default;
+    // Returns the sample rate (Hz) required for the input frames analyzed by
+    // `ComputeProbability`.
+    virtual int SampleRateHz() const = 0;
+    // Resets the internal state.
+    virtual void Reset() = 0;
+    // Analyzes an audio frame and returns the speech probability.
+    virtual float Analyze(rtc::ArrayView<const float> frame) = 0;
+  };
+
+  // Ctor. Uses `cpu_features` to instantiate the default VAD.
+  VoiceActivityDetectorWrapper(const AvailableCpuFeatures& cpu_features,
+                               int sample_rate_hz);
+
+  // Ctor. `vad_reset_period_ms` indicates the period in milliseconds to call
+  // `MonoVad::Reset()`; it must be equal to or greater than the duration of two
+  // frames. Uses `cpu_features` to instantiate the default VAD.
+  VoiceActivityDetectorWrapper(int vad_reset_period_ms,
+                               const AvailableCpuFeatures& cpu_features,
+                               int sample_rate_hz);
+  // Ctor. Uses a custom `vad`.
+  VoiceActivityDetectorWrapper(int vad_reset_period_ms,
+                               std::unique_ptr<MonoVad> vad,
+                               int sample_rate_hz);
+
+  VoiceActivityDetectorWrapper(const VoiceActivityDetectorWrapper&) = delete;
+  VoiceActivityDetectorWrapper& operator=(const VoiceActivityDetectorWrapper&) =
+      delete;
+  ~VoiceActivityDetectorWrapper();
+
+  // Initializes the VAD wrapper.
+  void Initialize(int sample_rate_hz);
+
+  // Analyzes the first channel of `frame` and returns the speech probability.
+  // `frame` must be a 10 ms frame with the sample rate specified in the last
+  // `Initialize()` call.
+  float Analyze(AudioFrameView<const float> frame);
+
+ private:
+  const int vad_reset_period_frames_;
+  int frame_size_;
+  int time_to_vad_reset_;
+  PushResampler<float> resampler_;
+  std::unique_ptr<MonoVad> vad_;
+  std::vector<float> resampled_buffer_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_VAD_WRAPPER_H_
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper_gn/moz.build b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper_gn/moz.build
new file mode 100644
index 0000000000..dfa2765108
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper_gn/moz.build
@@ -0,0 +1,232 @@
+# 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_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/agc2/vad_wrapper.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("vad_wrapper_gn")
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper_unittest.cc
new file mode 100644
index 0000000000..91efdb566e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/vad_wrapper_unittest.cc
@@ -0,0 +1,181 @@
+/*
+ *  Copyright (c) 2018 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/agc2/vad_wrapper.h"
+
+#include <limits>
+#include <memory>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "modules/audio_processing/agc2/agc2_common.h"
+#include "modules/audio_processing/include/audio_frame_view.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/gunit.h"
+#include "rtc_base/numerics/safe_compare.h"
+#include "test/gmock.h"
+
+namespace webrtc {
+namespace {
+
+using ::testing::AnyNumber;
+using ::testing::Return;
+using ::testing::ReturnRoundRobin;
+using ::testing::Truly;
+
+constexpr int kNumFramesPerSecond = 100;
+
+constexpr int kNoVadPeriodicReset =
+    kFrameDurationMs * (std::numeric_limits<int>::max() / kFrameDurationMs);
+
+constexpr int kSampleRate8kHz = 8000;
+
+class MockVad : public VoiceActivityDetectorWrapper::MonoVad {
+ public:
+  MOCK_METHOD(int, SampleRateHz, (), (const, override));
+  MOCK_METHOD(void, Reset, (), (override));
+  MOCK_METHOD(float, Analyze, (rtc::ArrayView<const float> frame), (override));
+};
+
+// Checks that the ctor and `Initialize()` read the sample rate of the wrapped
+// VAD.
+TEST(GainController2VoiceActivityDetectorWrapper, CtorAndInitReadSampleRate) {
+  auto vad = std::make_unique<MockVad>();
+  EXPECT_CALL(*vad, SampleRateHz)
+      .Times(2)
+      .WillRepeatedly(Return(kSampleRate8kHz));
+  EXPECT_CALL(*vad, Reset).Times(AnyNumber());
+  auto vad_wrapper = std::make_unique<VoiceActivityDetectorWrapper>(
+      kNoVadPeriodicReset, std::move(vad), kSampleRate8kHz);
+}
+
+// Creates a `VoiceActivityDetectorWrapper` injecting a mock VAD that
+// repeatedly returns the next value from `speech_probabilities` and that
+// restarts from the beginning when after the last element is returned.
+std::unique_ptr<VoiceActivityDetectorWrapper> CreateMockVadWrapper(
+    int vad_reset_period_ms,
+    int sample_rate_hz,
+    const std::vector<float>& speech_probabilities,
+    int expected_vad_reset_calls) {
+  auto vad = std::make_unique<MockVad>();
+  EXPECT_CALL(*vad, SampleRateHz)
+      .Times(AnyNumber())
+      .WillRepeatedly(Return(sample_rate_hz));
+  if (expected_vad_reset_calls >= 0) {
+    EXPECT_CALL(*vad, Reset).Times(expected_vad_reset_calls);
+  }
+  EXPECT_CALL(*vad, Analyze)
+      .Times(AnyNumber())
+      .WillRepeatedly(ReturnRoundRobin(speech_probabilities));
+  return std::make_unique<VoiceActivityDetectorWrapper>(
+      vad_reset_period_ms, std::move(vad), kSampleRate8kHz);
+}
+
+// 10 ms mono frame.
+struct FrameWithView {
+  // Ctor. Initializes the frame samples with `value`.
+  explicit FrameWithView(int sample_rate_hz)
+      : samples(rtc::CheckedDivExact(sample_rate_hz, kNumFramesPerSecond),
+                0.0f),
+        channel0(samples.data()),
+        view(&channel0, /*num_channels=*/1, samples.size()) {}
+  std::vector<float> samples;
+  const float* const channel0;
+  const AudioFrameView<const float> view;
+};
+
+// Checks that the expected speech probabilities are returned.
+TEST(GainController2VoiceActivityDetectorWrapper, CheckSpeechProbabilities) {
+  const std::vector<float> speech_probabilities{0.709f, 0.484f, 0.882f, 0.167f,
+                                                0.44f,  0.525f, 0.858f, 0.314f,
+                                                0.653f, 0.965f, 0.413f, 0.0f};
+  auto vad_wrapper = CreateMockVadWrapper(kNoVadPeriodicReset, kSampleRate8kHz,
+                                          speech_probabilities,
+                                          /*expected_vad_reset_calls=*/1);
+  FrameWithView frame(kSampleRate8kHz);
+  for (int i = 0; rtc::SafeLt(i, speech_probabilities.size()); ++i) {
+    SCOPED_TRACE(i);
+    EXPECT_EQ(speech_probabilities[i], vad_wrapper->Analyze(frame.view));
+  }
+}
+
+// Checks that the VAD is not periodically reset.
+TEST(GainController2VoiceActivityDetectorWrapper, VadNoPeriodicReset) {
+  constexpr int kNumFrames = 19;
+  auto vad_wrapper = CreateMockVadWrapper(kNoVadPeriodicReset, kSampleRate8kHz,
+                                          /*speech_probabilities=*/{1.0f},
+                                          /*expected_vad_reset_calls=*/1);
+  FrameWithView frame(kSampleRate8kHz);
+  for (int i = 0; i < kNumFrames; ++i) {
+    vad_wrapper->Analyze(frame.view);
+  }
+}
+
+class VadPeriodResetParametrization
+    : public ::testing::TestWithParam<std::tuple<int, int>> {
+ protected:
+  int num_frames() const { return std::get<0>(GetParam()); }
+  int vad_reset_period_frames() const { return std::get<1>(GetParam()); }
+};
+
+// Checks that the VAD is periodically reset with the expected period.
+TEST_P(VadPeriodResetParametrization, VadPeriodicReset) {
+  auto vad_wrapper = CreateMockVadWrapper(
+      /*vad_reset_period_ms=*/vad_reset_period_frames() * kFrameDurationMs,
+      kSampleRate8kHz,
+      /*speech_probabilities=*/{1.0f},
+      /*expected_vad_reset_calls=*/1 +
+          num_frames() / vad_reset_period_frames());
+  FrameWithView frame(kSampleRate8kHz);
+  for (int i = 0; i < num_frames(); ++i) {
+    vad_wrapper->Analyze(frame.view);
+  }
+}
+
+INSTANTIATE_TEST_SUITE_P(GainController2VoiceActivityDetectorWrapper,
+                         VadPeriodResetParametrization,
+                         ::testing::Combine(::testing::Values(1, 19, 123),
+                                            ::testing::Values(2, 5, 20, 53)));
+
+class VadResamplingParametrization
+    : public ::testing::TestWithParam<std::tuple<int, int>> {
+ protected:
+  int input_sample_rate_hz() const { return std::get<0>(GetParam()); }
+  int vad_sample_rate_hz() const { return std::get<1>(GetParam()); }
+};
+
+// Checks that regardless of the input audio sample rate, the wrapped VAD
+// analyzes frames having the expected size, that is according to its internal
+// sample rate.
+TEST_P(VadResamplingParametrization, CheckResampledFrameSize) {
+  auto vad = std::make_unique<MockVad>();
+  EXPECT_CALL(*vad, SampleRateHz)
+      .Times(AnyNumber())
+      .WillRepeatedly(Return(vad_sample_rate_hz()));
+  EXPECT_CALL(*vad, Reset).Times(1);
+  EXPECT_CALL(*vad, Analyze(Truly([this](rtc::ArrayView<const float> frame) {
+    return rtc::SafeEq(frame.size(), rtc::CheckedDivExact(vad_sample_rate_hz(),
+                                                          kNumFramesPerSecond));
+  }))).Times(1);
+  auto vad_wrapper = std::make_unique<VoiceActivityDetectorWrapper>(
+      kNoVadPeriodicReset, std::move(vad), input_sample_rate_hz());
+  FrameWithView frame(input_sample_rate_hz());
+  vad_wrapper->Analyze(frame.view);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    GainController2VoiceActivityDetectorWrapper,
+    VadResamplingParametrization,
+    ::testing::Combine(::testing::Values(8000, 16000, 44100, 48000),
+                       ::testing::Values(6000, 8000, 12000, 16000, 24000)));
+
+}  // namespace
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/vector_float_frame.cc b/third_party/libwebrtc/modules/audio_processing/agc2/vector_float_frame.cc
new file mode 100644
index 0000000000..a70d815196
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/vector_float_frame.cc
@@ -0,0 +1,39 @@
+/*
+ *  Copyright (c) 2018 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/agc2/vector_float_frame.h"
+
+namespace webrtc {
+
+namespace {
+
+std::vector<float*> ConstructChannelPointers(
+    std::vector<std::vector<float>>* x) {
+  std::vector<float*> channel_ptrs;
+  for (auto& v : *x) {
+    channel_ptrs.push_back(v.data());
+  }
+  return channel_ptrs;
+}
+}  // namespace
+
+VectorFloatFrame::VectorFloatFrame(int num_channels,
+                                   int samples_per_channel,
+                                   float start_value)
+    : channels_(num_channels,
+                std::vector<float>(samples_per_channel, start_value)),
+      channel_ptrs_(ConstructChannelPointers(&channels_)),
+      float_frame_view_(channel_ptrs_.data(),
+                        channels_.size(),
+                        samples_per_channel) {}
+
+VectorFloatFrame::~VectorFloatFrame() = default;
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/vector_float_frame.h b/third_party/libwebrtc/modules/audio_processing/agc2/vector_float_frame.h
new file mode 100644
index 0000000000..b521f346f9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/vector_float_frame.h
@@ -0,0 +1,42 @@
+/*
+ *  Copyright (c) 2018 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_AGC2_VECTOR_FLOAT_FRAME_H_
+#define MODULES_AUDIO_PROCESSING_AGC2_VECTOR_FLOAT_FRAME_H_
+
+#include <vector>
+
+#include "modules/audio_processing/include/audio_frame_view.h"
+
+namespace webrtc {
+
+// A construct consisting of a multi-channel audio frame, and a FloatFrame view
+// of it.
+class VectorFloatFrame {
+ public:
+  VectorFloatFrame(int num_channels,
+                   int samples_per_channel,
+                   float start_value);
+  const AudioFrameView<float>& float_frame_view() { return float_frame_view_; }
+  AudioFrameView<const float> float_frame_view() const {
+    return float_frame_view_;
+  }
+
+  ~VectorFloatFrame();
+
+ private:
+  std::vector<std::vector<float>> channels_;
+  std::vector<float*> channel_ptrs_;
+  AudioFrameView<float> float_frame_view_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AGC2_VECTOR_FLOAT_FRAME_H_