Adding upstream version 124.0.1.upstream/124.0.1

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

39 files changed, 7317 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler.cc b/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler.cc
new file mode 100644
index 0000000000..13502a142b
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler.cc
@@ -0,0 +1,148 @@
+/*
+ *  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/video_coding/utility/bandwidth_quality_scaler.h"
+
+#include <algorithm>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "api/video/video_adaptation_reason.h"
+#include "api/video_codecs/video_encoder.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/experiments/bandwidth_quality_scaler_settings.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/exp_filter.h"
+#include "rtc_base/time_utils.h"
+#include "rtc_base/weak_ptr.h"
+
+namespace webrtc {
+
+namespace {
+
+constexpr int kDefaultMaxWindowSizeMs = 5000;
+constexpr float kHigherMaxBitrateTolerationFactor = 0.95;
+constexpr float kLowerMinBitrateTolerationFactor = 0.8;
+constexpr int kDefaultBitrateStateUpdateIntervalSeconds = 5;
+}  // namespace
+
+BandwidthQualityScaler::BandwidthQualityScaler(
+    BandwidthQualityScalerUsageHandlerInterface* handler)
+    : kBitrateStateUpdateInterval(TimeDelta::Seconds(
+          BandwidthQualityScalerSettings::ParseFromFieldTrials()
+              .BitrateStateUpdateInterval()
+              .value_or(kDefaultBitrateStateUpdateIntervalSeconds))),
+      handler_(handler),
+      encoded_bitrate_(kDefaultMaxWindowSizeMs, RateStatistics::kBpsScale),
+      weak_ptr_factory_(this) {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  RTC_DCHECK(handler_ != nullptr);
+
+  StartCheckForBitrate();
+}
+
+BandwidthQualityScaler::~BandwidthQualityScaler() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+}
+
+void BandwidthQualityScaler::StartCheckForBitrate() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  TaskQueueBase::Current()->PostDelayedTask(
+      [this_weak_ptr = weak_ptr_factory_.GetWeakPtr(), this] {
+        if (!this_weak_ptr) {
+          // The caller BandwidthQualityScaler has been deleted.
+          return;
+        }
+        RTC_DCHECK_RUN_ON(&task_checker_);
+        switch (CheckBitrate()) {
+          case BandwidthQualityScaler::CheckBitrateResult::kHighBitRate: {
+            handler_->OnReportUsageBandwidthHigh();
+            last_frame_size_pixels_.reset();
+            break;
+          }
+          case BandwidthQualityScaler::CheckBitrateResult::kLowBitRate: {
+            handler_->OnReportUsageBandwidthLow();
+            last_frame_size_pixels_.reset();
+            break;
+          }
+          case BandwidthQualityScaler::CheckBitrateResult::kNormalBitrate: {
+            break;
+          }
+          case BandwidthQualityScaler::CheckBitrateResult::
+              kInsufficientSamples: {
+            break;
+          }
+        }
+        StartCheckForBitrate();
+      },
+      kBitrateStateUpdateInterval);
+}
+
+void BandwidthQualityScaler::ReportEncodeInfo(int frame_size_bytes,
+                                              int64_t time_sent_in_ms,
+                                              uint32_t encoded_width,
+                                              uint32_t encoded_height) {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  last_time_sent_in_ms_ = time_sent_in_ms;
+  last_frame_size_pixels_ = encoded_width * encoded_height;
+  encoded_bitrate_.Update(frame_size_bytes, time_sent_in_ms);
+}
+
+void BandwidthQualityScaler::SetResolutionBitrateLimits(
+    const std::vector<VideoEncoder::ResolutionBitrateLimits>&
+        resolution_bitrate_limits) {
+  if (resolution_bitrate_limits.empty()) {
+    resolution_bitrate_limits_ = EncoderInfoSettings::
+        GetDefaultSinglecastBitrateLimitsWhenQpIsUntrusted();
+  } else {
+    resolution_bitrate_limits_ = resolution_bitrate_limits;
+  }
+}
+
+BandwidthQualityScaler::CheckBitrateResult
+BandwidthQualityScaler::CheckBitrate() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  if (!last_frame_size_pixels_.has_value() ||
+      !last_time_sent_in_ms_.has_value()) {
+    return BandwidthQualityScaler::CheckBitrateResult::kInsufficientSamples;
+  }
+
+  absl::optional<int64_t> current_bitrate_bps =
+      encoded_bitrate_.Rate(last_time_sent_in_ms_.value());
+  if (!current_bitrate_bps.has_value()) {
+    // We can't get a valid bitrate due to not enough data points.
+    return BandwidthQualityScaler::CheckBitrateResult::kInsufficientSamples;
+  }
+  absl::optional<VideoEncoder::ResolutionBitrateLimits> suitable_bitrate_limit =
+      EncoderInfoSettings::
+          GetSinglecastBitrateLimitForResolutionWhenQpIsUntrusted(
+              last_frame_size_pixels_, resolution_bitrate_limits_);
+
+  if (!suitable_bitrate_limit.has_value()) {
+    return BandwidthQualityScaler::CheckBitrateResult::kInsufficientSamples;
+  }
+
+  // Multiply by toleration factor to solve the frequent adaptation due to
+  // critical value.
+  if (current_bitrate_bps > suitable_bitrate_limit->max_bitrate_bps *
+                                kHigherMaxBitrateTolerationFactor) {
+    return BandwidthQualityScaler::CheckBitrateResult::kLowBitRate;
+  } else if (current_bitrate_bps <
+             suitable_bitrate_limit->min_start_bitrate_bps *
+                 kLowerMinBitrateTolerationFactor) {
+    return BandwidthQualityScaler::CheckBitrateResult::kHighBitRate;
+  }
+  return BandwidthQualityScaler::CheckBitrateResult::kNormalBitrate;
+}
+
+BandwidthQualityScalerUsageHandlerInterface::
+    ~BandwidthQualityScalerUsageHandlerInterface() {}
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler.h b/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler.h
new file mode 100644
index 0000000000..7cd1de0dd2
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler.h
@@ -0,0 +1,93 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_BANDWIDTH_QUALITY_SCALER_H_
+#define MODULES_VIDEO_CODING_UTILITY_BANDWIDTH_QUALITY_SCALER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "api/scoped_refptr.h"
+#include "api/sequence_checker.h"
+#include "api/video_codecs/video_encoder.h"
+#include "rtc_base/experiments/encoder_info_settings.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/exp_filter.h"
+#include "rtc_base/rate_statistics.h"
+#include "rtc_base/ref_count.h"
+#include "rtc_base/system/no_unique_address.h"
+#include "rtc_base/weak_ptr.h"
+
+namespace webrtc {
+
+class BandwidthQualityScalerUsageHandlerInterface {
+ public:
+  virtual ~BandwidthQualityScalerUsageHandlerInterface();
+
+  virtual void OnReportUsageBandwidthHigh() = 0;
+  virtual void OnReportUsageBandwidthLow() = 0;
+};
+
+// BandwidthQualityScaler runs asynchronously and monitors bandwidth values of
+// encoded frames. It holds a reference to a
+// BandwidthQualityScalerUsageHandlerInterface implementation to signal an
+// overuse or underuse of bandwidth (which indicate a desire to scale the video
+// stream down or up).
+class BandwidthQualityScaler {
+ public:
+  explicit BandwidthQualityScaler(
+      BandwidthQualityScalerUsageHandlerInterface* handler);
+  virtual ~BandwidthQualityScaler();
+
+  void ReportEncodeInfo(int frame_size_bytes,
+                        int64_t time_sent_in_ms,
+                        uint32_t encoded_width,
+                        uint32_t encoded_height);
+
+  // We prioritise to using the |resolution_bitrate_limits| provided by the
+  // current decoder. If not provided, we will use the default data by
+  // GetDefaultResolutionBitrateLimits().
+  void SetResolutionBitrateLimits(
+      const std::vector<VideoEncoder::ResolutionBitrateLimits>&
+          resolution_bitrate_limits);
+
+  const TimeDelta kBitrateStateUpdateInterval;
+
+ private:
+  enum class CheckBitrateResult {
+    kInsufficientSamples,
+    kNormalBitrate,
+    kHighBitRate,
+    kLowBitRate,
+  };
+
+  // We will periodically check encode bitrate, this function will make
+  // resolution up or down decisions and report the decision to the adapter.
+  void StartCheckForBitrate();
+  CheckBitrateResult CheckBitrate();
+
+  RTC_NO_UNIQUE_ADDRESS SequenceChecker task_checker_;
+  BandwidthQualityScalerUsageHandlerInterface* const handler_
+      RTC_GUARDED_BY(&task_checker_);
+
+  absl::optional<int64_t> last_time_sent_in_ms_ RTC_GUARDED_BY(&task_checker_);
+  RateStatistics encoded_bitrate_ RTC_GUARDED_BY(&task_checker_);
+  absl::optional<int> last_frame_size_pixels_ RTC_GUARDED_BY(&task_checker_);
+  rtc::WeakPtrFactory<BandwidthQualityScaler> weak_ptr_factory_;
+
+  std::vector<VideoEncoder::ResolutionBitrateLimits> resolution_bitrate_limits_;
+};
+
+}  // namespace webrtc
+#endif  // MODULES_VIDEO_CODING_UTILITY_BANDWIDTH_QUALITY_SCALER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler_unittest.cc
new file mode 100644
index 0000000000..4e2c759707
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/bandwidth_quality_scaler_unittest.cc
@@ -0,0 +1,275 @@
+/*
+ *  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/video_coding/utility/bandwidth_quality_scaler.h"
+
+#include <memory>
+#include <string>
+
+#include "api/units/time_delta.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/event.h"
+#include "rtc_base/experiments/encoder_info_settings.h"
+#include "rtc_base/task_queue_for_test.h"
+#include "rtc_base/time_utils.h"
+#include "test/field_trial.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+
+namespace {
+constexpr int kFramerateFps = 30;
+constexpr TimeDelta kDefaultBitrateStateUpdateInterval = TimeDelta::Seconds(5);
+constexpr TimeDelta kDefaultEncodeTime = TimeDelta::Seconds(1) / kFramerateFps;
+
+}  // namespace
+
+class FakeBandwidthQualityScalerHandler
+    : public BandwidthQualityScalerUsageHandlerInterface {
+ public:
+  ~FakeBandwidthQualityScalerHandler() override = default;
+  void OnReportUsageBandwidthHigh() override {
+    adapt_down_event_count_++;
+    event_.Set();
+  }
+
+  void OnReportUsageBandwidthLow() override {
+    adapt_up_event_count_++;
+    event_.Set();
+  }
+
+  rtc::Event event_;
+  int adapt_up_event_count_ = 0;
+  int adapt_down_event_count_ = 0;
+};
+
+class BandwidthQualityScalerUnderTest : public BandwidthQualityScaler {
+ public:
+  explicit BandwidthQualityScalerUnderTest(
+      BandwidthQualityScalerUsageHandlerInterface* handler)
+      : BandwidthQualityScaler(handler) {}
+
+  int GetBitrateStateUpdateIntervalMs() {
+    return this->kBitrateStateUpdateInterval.ms() + 200;
+  }
+};
+
+class BandwidthQualityScalerTest
+    : public ::testing::Test,
+      public ::testing::WithParamInterface<std::string> {
+ protected:
+  enum ScaleDirection {
+    kKeepScaleNormalBandwidth,
+    kKeepScaleAboveMaxBandwidth,
+    kKeepScaleUnderMinBandwidth,
+  };
+
+  enum FrameType {
+    kKeyFrame,
+    kNormalFrame,
+    kNormalFrame_Overuse,
+    kNormalFrame_Underuse,
+  };
+  struct FrameConfig {
+    FrameConfig(int frame_num,
+                FrameType frame_type,
+                int actual_width,
+                int actual_height)
+        : frame_num(frame_num),
+          frame_type(frame_type),
+          actual_width(actual_width),
+          actual_height(actual_height) {}
+
+    int frame_num;
+    FrameType frame_type;
+    int actual_width;
+    int actual_height;
+  };
+
+  BandwidthQualityScalerTest()
+      : scoped_field_trial_(GetParam()),
+        task_queue_("BandwidthQualityScalerTestQueue"),
+        handler_(std::make_unique<FakeBandwidthQualityScalerHandler>()) {
+    task_queue_.SendTask([this] {
+      bandwidth_quality_scaler_ =
+          std::unique_ptr<BandwidthQualityScalerUnderTest>(
+              new BandwidthQualityScalerUnderTest(handler_.get()));
+      bandwidth_quality_scaler_->SetResolutionBitrateLimits(
+          EncoderInfoSettings::
+              GetDefaultSinglecastBitrateLimitsWhenQpIsUntrusted());
+      // Only for testing. Set first_timestamp_ in RateStatistics to 0.
+      bandwidth_quality_scaler_->ReportEncodeInfo(0, 0, 0, 0);
+    });
+  }
+
+  ~BandwidthQualityScalerTest() {
+    task_queue_.SendTask([this] { bandwidth_quality_scaler_ = nullptr; });
+  }
+
+  int GetFrameSizeBytes(
+      const FrameConfig& config,
+      const VideoEncoder::ResolutionBitrateLimits& bitrate_limits) {
+    int scale = 8 * kFramerateFps;
+    switch (config.frame_type) {
+      case FrameType::kKeyFrame: {
+        // 4 is experimental value. Based on the test, the number of bytes of
+        // the key frame is about four times of the normal frame
+        return bitrate_limits.max_bitrate_bps * 4 / scale;
+      }
+      case FrameType::kNormalFrame_Overuse: {
+        return bitrate_limits.max_bitrate_bps * 3 / 2 / scale;
+      }
+      case FrameType::kNormalFrame_Underuse: {
+        return bitrate_limits.min_start_bitrate_bps * 3 / 4 / scale;
+      }
+      case FrameType::kNormalFrame: {
+        return (bitrate_limits.max_bitrate_bps +
+                bitrate_limits.min_start_bitrate_bps) /
+               2 / scale;
+      }
+    }
+    return -1;
+  }
+
+  absl::optional<VideoEncoder::ResolutionBitrateLimits>
+  GetDefaultSuitableBitrateLimit(int frame_size_pixels) {
+    return EncoderInfoSettings::
+        GetSinglecastBitrateLimitForResolutionWhenQpIsUntrusted(
+            frame_size_pixels,
+            EncoderInfoSettings::
+                GetDefaultSinglecastBitrateLimitsWhenQpIsUntrusted());
+  }
+
+  void TriggerBandwidthQualityScalerTest(
+      const std::vector<FrameConfig>& frame_configs) {
+    task_queue_.SendTask([frame_configs, this] {
+      RTC_CHECK(!frame_configs.empty());
+
+      int total_frame_nums = 0;
+      for (const FrameConfig& frame_config : frame_configs) {
+        total_frame_nums += frame_config.frame_num;
+      }
+
+      EXPECT_EQ(kFramerateFps * kDefaultBitrateStateUpdateInterval.seconds(),
+                total_frame_nums);
+
+      uint32_t time_send_to_scaler_ms_ = rtc::TimeMillis();
+      for (size_t i = 0; i < frame_configs.size(); ++i) {
+        const FrameConfig& config = frame_configs[i];
+        absl::optional<VideoEncoder::ResolutionBitrateLimits> suitable_bitrate =
+            GetDefaultSuitableBitrateLimit(config.actual_width *
+                                           config.actual_height);
+        EXPECT_TRUE(suitable_bitrate);
+        for (int j = 0; j <= config.frame_num; ++j) {
+          time_send_to_scaler_ms_ += kDefaultEncodeTime.ms();
+          int frame_size_bytes =
+              GetFrameSizeBytes(config, suitable_bitrate.value());
+          RTC_CHECK(frame_size_bytes > 0);
+          bandwidth_quality_scaler_->ReportEncodeInfo(
+              frame_size_bytes, time_send_to_scaler_ms_, config.actual_width,
+              config.actual_height);
+        }
+      }
+    });
+  }
+
+  test::ScopedFieldTrials scoped_field_trial_;
+  TaskQueueForTest task_queue_;
+  std::unique_ptr<BandwidthQualityScalerUnderTest> bandwidth_quality_scaler_;
+  std::unique_ptr<FakeBandwidthQualityScalerHandler> handler_;
+};
+
+INSTANTIATE_TEST_SUITE_P(
+    FieldTrials,
+    BandwidthQualityScalerTest,
+    ::testing::Values("WebRTC-Video-BandwidthQualityScalerSettings/"
+                      "bitrate_state_update_interval_s_:1/",
+                      "WebRTC-Video-BandwidthQualityScalerSettings/"
+                      "bitrate_state_update_interval_s_:2/"));
+
+TEST_P(BandwidthQualityScalerTest, AllNormalFrame_640x360) {
+  const std::vector<FrameConfig> frame_configs{
+      FrameConfig(150, FrameType::kNormalFrame, 640, 360)};
+  TriggerBandwidthQualityScalerTest(frame_configs);
+
+  // When resolution is 640*360, experimental working bitrate range is
+  // [500000,800000] bps. Encoded bitrate is 654253, so it falls in the range
+  // without any operation(up/down).
+  EXPECT_FALSE(handler_->event_.Wait(TimeDelta::Millis(
+      bandwidth_quality_scaler_->GetBitrateStateUpdateIntervalMs())));
+  EXPECT_EQ(0, handler_->adapt_down_event_count_);
+  EXPECT_EQ(0, handler_->adapt_up_event_count_);
+}
+
+TEST_P(BandwidthQualityScalerTest, AllNoramlFrame_AboveMaxBandwidth_640x360) {
+  const std::vector<FrameConfig> frame_configs{
+      FrameConfig(150, FrameType::kNormalFrame_Overuse, 640, 360)};
+  TriggerBandwidthQualityScalerTest(frame_configs);
+
+  // When resolution is 640*360, experimental working bitrate range is
+  // [500000,800000] bps. Encoded bitrate is 1208000 > 800000 * 0.95, so it
+  // triggers adapt_up_event_count_.
+  EXPECT_TRUE(handler_->event_.Wait(TimeDelta::Millis(
+      bandwidth_quality_scaler_->GetBitrateStateUpdateIntervalMs())));
+  EXPECT_EQ(0, handler_->adapt_down_event_count_);
+  EXPECT_EQ(1, handler_->adapt_up_event_count_);
+}
+
+TEST_P(BandwidthQualityScalerTest, AllNormalFrame_Underuse_640x360) {
+  const std::vector<FrameConfig> frame_configs{
+      FrameConfig(150, FrameType::kNormalFrame_Underuse, 640, 360)};
+  TriggerBandwidthQualityScalerTest(frame_configs);
+
+  // When resolution is 640*360, experimental working bitrate range is
+  // [500000,800000] bps. Encoded bitrate is 377379 < 500000 * 0.8, so it
+  // triggers adapt_down_event_count_.
+  EXPECT_TRUE(handler_->event_.Wait(TimeDelta::Millis(
+      bandwidth_quality_scaler_->GetBitrateStateUpdateIntervalMs())));
+  EXPECT_EQ(1, handler_->adapt_down_event_count_);
+  EXPECT_EQ(0, handler_->adapt_up_event_count_);
+}
+
+TEST_P(BandwidthQualityScalerTest, FixedFrameTypeTest1_640x360) {
+  const std::vector<FrameConfig> frame_configs{
+      FrameConfig(5, FrameType::kNormalFrame_Underuse, 640, 360),
+      FrameConfig(110, FrameType::kNormalFrame, 640, 360),
+      FrameConfig(20, FrameType::kNormalFrame_Overuse, 640, 360),
+      FrameConfig(15, FrameType::kKeyFrame, 640, 360),
+  };
+  TriggerBandwidthQualityScalerTest(frame_configs);
+
+  // When resolution is 640*360, experimental working bitrate range is
+  // [500000,800000] bps. Encoded bitrate is 1059462 > 800000 * 0.95, so it
+  // triggers adapt_up_event_count_.
+  EXPECT_TRUE(handler_->event_.Wait(TimeDelta::Millis(
+      bandwidth_quality_scaler_->GetBitrateStateUpdateIntervalMs())));
+  EXPECT_EQ(0, handler_->adapt_down_event_count_);
+  EXPECT_EQ(1, handler_->adapt_up_event_count_);
+}
+
+TEST_P(BandwidthQualityScalerTest, FixedFrameTypeTest2_640x360) {
+  const std::vector<FrameConfig> frame_configs{
+      FrameConfig(10, FrameType::kNormalFrame_Underuse, 640, 360),
+      FrameConfig(50, FrameType::kNormalFrame, 640, 360),
+      FrameConfig(5, FrameType::kKeyFrame, 640, 360),
+      FrameConfig(85, FrameType::kNormalFrame_Overuse, 640, 360),
+  };
+  TriggerBandwidthQualityScalerTest(frame_configs);
+
+  // When resolution is 640*360, experimental working bitrate range is
+  // [500000,800000] bps. Encoded bitrate is 1059462 > 800000 * 0.95, so it
+  // triggers adapt_up_event_count_.
+  EXPECT_TRUE(handler_->event_.Wait(TimeDelta::Millis(
+      bandwidth_quality_scaler_->GetBitrateStateUpdateIntervalMs())));
+  EXPECT_EQ(0, handler_->adapt_down_event_count_);
+  EXPECT_EQ(1, handler_->adapt_up_event_count_);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.cc b/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.cc
new file mode 100644
index 0000000000..1138aa8448
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.cc
@@ -0,0 +1,92 @@
+/*
+ *  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/video_coding/utility/decoded_frames_history.h"
+
+#include <algorithm>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+namespace video_coding {
+
+DecodedFramesHistory::DecodedFramesHistory(size_t window_size)
+    : buffer_(window_size) {}
+
+DecodedFramesHistory::~DecodedFramesHistory() = default;
+
+void DecodedFramesHistory::InsertDecoded(int64_t frame_id, uint32_t timestamp) {
+  last_decoded_frame_ = frame_id;
+  last_decoded_frame_timestamp_ = timestamp;
+  int new_index = FrameIdToIndex(frame_id);
+
+  RTC_DCHECK(last_frame_id_ < frame_id);
+
+  // Clears expired values from the cyclic buffer_.
+  if (last_frame_id_) {
+    int64_t id_jump = frame_id - *last_frame_id_;
+    int last_index = FrameIdToIndex(*last_frame_id_);
+
+    if (id_jump >= static_cast<int64_t>(buffer_.size())) {
+      std::fill(buffer_.begin(), buffer_.end(), false);
+    } else if (new_index > last_index) {
+      std::fill(buffer_.begin() + last_index + 1, buffer_.begin() + new_index,
+                false);
+    } else {
+      std::fill(buffer_.begin() + last_index + 1, buffer_.end(), false);
+      std::fill(buffer_.begin(), buffer_.begin() + new_index, false);
+    }
+  }
+
+  buffer_[new_index] = true;
+  last_frame_id_ = frame_id;
+}
+
+bool DecodedFramesHistory::WasDecoded(int64_t frame_id) const {
+  if (!last_frame_id_)
+    return false;
+
+  // Reference to the picture_id out of the stored should happen.
+  if (frame_id <= *last_frame_id_ - static_cast<int64_t>(buffer_.size())) {
+    RTC_LOG(LS_WARNING) << "Referencing a frame out of the window. "
+                           "Assuming it was undecoded to avoid artifacts.";
+    return false;
+  }
+
+  if (frame_id > last_frame_id_)
+    return false;
+
+  return buffer_[FrameIdToIndex(frame_id)];
+}
+
+void DecodedFramesHistory::Clear() {
+  last_decoded_frame_timestamp_.reset();
+  last_decoded_frame_.reset();
+  std::fill(buffer_.begin(), buffer_.end(), false);
+  last_frame_id_.reset();
+}
+
+absl::optional<int64_t> DecodedFramesHistory::GetLastDecodedFrameId() const {
+  return last_decoded_frame_;
+}
+
+absl::optional<uint32_t> DecodedFramesHistory::GetLastDecodedFrameTimestamp()
+    const {
+  return last_decoded_frame_timestamp_;
+}
+
+int DecodedFramesHistory::FrameIdToIndex(int64_t frame_id) const {
+  int m = frame_id % buffer_.size();
+  return m >= 0 ? m : m + buffer_.size();
+}
+
+}  // namespace video_coding
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.h b/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.h
new file mode 100644
index 0000000000..9b8bf65821
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history.h
@@ -0,0 +1,52 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_DECODED_FRAMES_HISTORY_H_
+#define MODULES_VIDEO_CODING_UTILITY_DECODED_FRAMES_HISTORY_H_
+
+#include <stdint.h>
+
+#include <bitset>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "api/video/encoded_frame.h"
+
+namespace webrtc {
+namespace video_coding {
+
+class DecodedFramesHistory {
+ public:
+  // window_size - how much frames back to the past are actually remembered.
+  explicit DecodedFramesHistory(size_t window_size);
+  ~DecodedFramesHistory();
+  // Called for each decoded frame. Assumes frame id's are non-decreasing.
+  void InsertDecoded(int64_t frame_id, uint32_t timestamp);
+  // Query if the following (frame_id, spatial_id) pair was inserted before.
+  // Should be at most less by window_size-1 than the last inserted frame id.
+  bool WasDecoded(int64_t frame_id) const;
+
+  void Clear();
+
+  absl::optional<int64_t> GetLastDecodedFrameId() const;
+  absl::optional<uint32_t> GetLastDecodedFrameTimestamp() const;
+
+ private:
+  int FrameIdToIndex(int64_t frame_id) const;
+
+  std::vector<bool> buffer_;
+  absl::optional<int64_t> last_frame_id_;
+  absl::optional<int64_t> last_decoded_frame_;
+  absl::optional<uint32_t> last_decoded_frame_timestamp_;
+};
+
+}  // namespace video_coding
+}  // namespace webrtc
+#endif  // MODULES_VIDEO_CODING_UTILITY_DECODED_FRAMES_HISTORY_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history_unittest.cc
new file mode 100644
index 0000000000..ac09a42053
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/decoded_frames_history_unittest.cc
@@ -0,0 +1,114 @@
+/*
+ *  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/video_coding/utility/decoded_frames_history.h"
+
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace video_coding {
+namespace {
+
+constexpr int kHistorySize = 1 << 13;
+
+TEST(DecodedFramesHistory, RequestOnEmptyHistory) {
+  DecodedFramesHistory history(kHistorySize);
+  EXPECT_EQ(history.WasDecoded(1234), false);
+}
+
+TEST(DecodedFramesHistory, FindsLastDecodedFrame) {
+  DecodedFramesHistory history(kHistorySize);
+  history.InsertDecoded(1234, 0);
+  EXPECT_EQ(history.WasDecoded(1234), true);
+}
+
+TEST(DecodedFramesHistory, FindsPreviousFrame) {
+  DecodedFramesHistory history(kHistorySize);
+  history.InsertDecoded(1234, 0);
+  history.InsertDecoded(1235, 0);
+  EXPECT_EQ(history.WasDecoded(1234), true);
+}
+
+TEST(DecodedFramesHistory, ReportsMissingFrame) {
+  DecodedFramesHistory history(kHistorySize);
+  history.InsertDecoded(1234, 0);
+  history.InsertDecoded(1236, 0);
+  EXPECT_EQ(history.WasDecoded(1235), false);
+}
+
+TEST(DecodedFramesHistory, ClearsHistory) {
+  DecodedFramesHistory history(kHistorySize);
+  history.InsertDecoded(1234, 0);
+  history.Clear();
+  EXPECT_EQ(history.WasDecoded(1234), false);
+  EXPECT_EQ(history.GetLastDecodedFrameId(), absl::nullopt);
+  EXPECT_EQ(history.GetLastDecodedFrameTimestamp(), absl::nullopt);
+}
+
+TEST(DecodedFramesHistory, HandlesBigJumpInPictureId) {
+  DecodedFramesHistory history(kHistorySize);
+  history.InsertDecoded(1234, 0);
+  history.InsertDecoded(1235, 0);
+  history.InsertDecoded(1236, 0);
+  history.InsertDecoded(1236 + kHistorySize / 2, 0);
+  EXPECT_EQ(history.WasDecoded(1234), true);
+  EXPECT_EQ(history.WasDecoded(1237), false);
+}
+
+TEST(DecodedFramesHistory, ForgetsTooOldHistory) {
+  DecodedFramesHistory history(kHistorySize);
+  history.InsertDecoded(1234, 0);
+  history.InsertDecoded(1235, 0);
+  history.InsertDecoded(1236, 0);
+  history.InsertDecoded(1236 + kHistorySize * 2, 0);
+  EXPECT_EQ(history.WasDecoded(1234), false);
+  EXPECT_EQ(history.WasDecoded(1237), false);
+}
+
+TEST(DecodedFramesHistory, ReturnsLastDecodedFrameId) {
+  DecodedFramesHistory history(kHistorySize);
+  EXPECT_EQ(history.GetLastDecodedFrameId(), absl::nullopt);
+  history.InsertDecoded(1234, 0);
+  EXPECT_EQ(history.GetLastDecodedFrameId(), 1234);
+  history.InsertDecoded(1235, 0);
+  EXPECT_EQ(history.GetLastDecodedFrameId(), 1235);
+}
+
+TEST(DecodedFramesHistory, ReturnsLastDecodedFrameTimestamp) {
+  DecodedFramesHistory history(kHistorySize);
+  EXPECT_EQ(history.GetLastDecodedFrameTimestamp(), absl::nullopt);
+  history.InsertDecoded(1234, 12345);
+  EXPECT_EQ(history.GetLastDecodedFrameTimestamp(), 12345u);
+  history.InsertDecoded(1235, 12366);
+  EXPECT_EQ(history.GetLastDecodedFrameTimestamp(), 12366u);
+}
+
+TEST(DecodedFramesHistory, NegativePictureIds) {
+  DecodedFramesHistory history(kHistorySize);
+  history.InsertDecoded(-1234, 12345);
+  history.InsertDecoded(-1233, 12366);
+  EXPECT_EQ(*history.GetLastDecodedFrameId(), -1233);
+
+  history.InsertDecoded(-1, 12377);
+  history.InsertDecoded(0, 12388);
+  EXPECT_EQ(*history.GetLastDecodedFrameId(), 0);
+
+  history.InsertDecoded(1, 12399);
+  EXPECT_EQ(*history.GetLastDecodedFrameId(), 1);
+
+  EXPECT_EQ(history.WasDecoded(-1234), true);
+  EXPECT_EQ(history.WasDecoded(-1), true);
+  EXPECT_EQ(history.WasDecoded(0), true);
+  EXPECT_EQ(history.WasDecoded(1), true);
+}
+
+}  // namespace
+}  // namespace video_coding
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/frame_dropper.cc b/third_party/libwebrtc/modules/video_coding/utility/frame_dropper.cc
new file mode 100644
index 0000000000..8ea8a8e268
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/frame_dropper.cc
@@ -0,0 +1,268 @@
+/*
+ *  Copyright (c) 2011 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/video_coding/utility/frame_dropper.h"
+
+#include <algorithm>
+
+namespace webrtc {
+
+namespace {
+
+const float kDefaultFrameSizeAlpha = 0.9f;
+const float kDefaultKeyFrameRatioAlpha = 0.99f;
+// 1 key frame every 10th second in 30 fps.
+const float kDefaultKeyFrameRatioValue = 1 / 300.0f;
+
+const float kDefaultDropRatioAlpha = 0.9f;
+const float kDefaultDropRatioValue = 0.96f;
+// Maximum duration over which frames are continuously dropped.
+const float kDefaultMaxDropDurationSecs = 4.0f;
+
+// Default target bitrate.
+// TODO(isheriff): Should this be higher to avoid dropping too many packets when
+// the bandwidth is unknown at the start ?
+const float kDefaultTargetBitrateKbps = 300.0f;
+const float kDefaultIncomingFrameRate = 30;
+const float kLeakyBucketSizeSeconds = 0.5f;
+
+// A delta frame that is bigger than `kLargeDeltaFactor` times the average
+// delta frame is a large frame that is spread out for accumulation.
+const int kLargeDeltaFactor = 3;
+
+// Cap on the frame size accumulator to prevent excessive drops.
+const float kAccumulatorCapBufferSizeSecs = 3.0f;
+}  // namespace
+
+FrameDropper::FrameDropper()
+    : key_frame_ratio_(kDefaultKeyFrameRatioAlpha),
+      delta_frame_size_avg_kbits_(kDefaultFrameSizeAlpha),
+      drop_ratio_(kDefaultDropRatioAlpha, kDefaultDropRatioValue),
+      enabled_(true),
+      max_drop_duration_secs_(kDefaultMaxDropDurationSecs) {
+  Reset();
+}
+
+FrameDropper::~FrameDropper() = default;
+
+void FrameDropper::Reset() {
+  key_frame_ratio_.Reset(kDefaultKeyFrameRatioAlpha);
+  key_frame_ratio_.Apply(1.0f, kDefaultKeyFrameRatioValue);
+  delta_frame_size_avg_kbits_.Reset(kDefaultFrameSizeAlpha);
+
+  accumulator_ = 0.0f;
+  accumulator_max_ = kDefaultTargetBitrateKbps / 2;
+  target_bitrate_ = kDefaultTargetBitrateKbps;
+  incoming_frame_rate_ = kDefaultIncomingFrameRate;
+
+  large_frame_accumulation_count_ = 0;
+  large_frame_accumulation_chunk_size_ = 0;
+  large_frame_accumulation_spread_ = 0.5 * kDefaultIncomingFrameRate;
+
+  drop_next_ = false;
+  drop_ratio_.Reset(0.9f);
+  drop_ratio_.Apply(0.0f, 0.0f);
+  drop_count_ = 0;
+  was_below_max_ = true;
+}
+
+void FrameDropper::Enable(bool enable) {
+  enabled_ = enable;
+}
+
+void FrameDropper::Fill(size_t framesize_bytes, bool delta_frame) {
+  if (!enabled_) {
+    return;
+  }
+  float framesize_kbits = 8.0f * static_cast<float>(framesize_bytes) / 1000.0f;
+  if (!delta_frame) {
+    key_frame_ratio_.Apply(1.0, 1.0);
+    // Do not spread if we are already doing it (or we risk dropping bits that
+    // need accumulation). Given we compute the key frame ratio and spread
+    // based on that, this should not normally happen.
+    if (large_frame_accumulation_count_ == 0) {
+      if (key_frame_ratio_.filtered() > 1e-5 &&
+          1 / key_frame_ratio_.filtered() < large_frame_accumulation_spread_) {
+        large_frame_accumulation_count_ =
+            static_cast<int32_t>(1 / key_frame_ratio_.filtered() + 0.5);
+      } else {
+        large_frame_accumulation_count_ =
+            static_cast<int32_t>(large_frame_accumulation_spread_ + 0.5);
+      }
+      large_frame_accumulation_chunk_size_ =
+          framesize_kbits / large_frame_accumulation_count_;
+      framesize_kbits = 0;
+    }
+  } else {
+    // Identify if it is an unusually large delta frame and spread accumulation
+    // if that is the case.
+    if (delta_frame_size_avg_kbits_.filtered() != -1 &&
+        (framesize_kbits >
+         kLargeDeltaFactor * delta_frame_size_avg_kbits_.filtered()) &&
+        large_frame_accumulation_count_ == 0) {
+      large_frame_accumulation_count_ =
+          static_cast<int32_t>(large_frame_accumulation_spread_ + 0.5);
+      large_frame_accumulation_chunk_size_ =
+          framesize_kbits / large_frame_accumulation_count_;
+      framesize_kbits = 0;
+    } else {
+      delta_frame_size_avg_kbits_.Apply(1, framesize_kbits);
+    }
+    key_frame_ratio_.Apply(1.0, 0.0);
+  }
+  // Change the level of the accumulator (bucket)
+  accumulator_ += framesize_kbits;
+  CapAccumulator();
+}
+
+void FrameDropper::Leak(uint32_t input_framerate) {
+  if (!enabled_) {
+    return;
+  }
+  if (input_framerate < 1) {
+    return;
+  }
+  if (target_bitrate_ < 0.0f) {
+    return;
+  }
+  // Add lower bound for large frame accumulation spread.
+  large_frame_accumulation_spread_ = std::max(0.5 * input_framerate, 5.0);
+  // Expected bits per frame based on current input frame rate.
+  float expected_bits_per_frame = target_bitrate_ / input_framerate;
+  if (large_frame_accumulation_count_ > 0) {
+    expected_bits_per_frame -= large_frame_accumulation_chunk_size_;
+    --large_frame_accumulation_count_;
+  }
+  accumulator_ -= expected_bits_per_frame;
+  if (accumulator_ < 0.0f) {
+    accumulator_ = 0.0f;
+  }
+  UpdateRatio();
+}
+
+void FrameDropper::UpdateRatio() {
+  if (accumulator_ > 1.3f * accumulator_max_) {
+    // Too far above accumulator max, react faster.
+    drop_ratio_.UpdateBase(0.8f);
+  } else {
+    // Go back to normal reaction.
+    drop_ratio_.UpdateBase(0.9f);
+  }
+  if (accumulator_ > accumulator_max_) {
+    // We are above accumulator max, and should ideally drop a frame. Increase
+    // the drop_ratio_ and drop the frame later.
+    if (was_below_max_) {
+      drop_next_ = true;
+    }
+    drop_ratio_.Apply(1.0f, 1.0f);
+    drop_ratio_.UpdateBase(0.9f);
+  } else {
+    drop_ratio_.Apply(1.0f, 0.0f);
+  }
+  was_below_max_ = accumulator_ < accumulator_max_;
+}
+
+// This function signals when to drop frames to the caller. It makes use of the
+// drop_ratio_ to smooth out the drops over time.
+bool FrameDropper::DropFrame() {
+  if (!enabled_) {
+    return false;
+  }
+  if (drop_next_) {
+    drop_next_ = false;
+    drop_count_ = 0;
+  }
+
+  if (drop_ratio_.filtered() >= 0.5f) {  // Drops per keep
+    // Limit is the number of frames we should drop between each kept frame
+    // to keep our drop ratio. limit is positive in this case.
+    float denom = 1.0f - drop_ratio_.filtered();
+    if (denom < 1e-5) {
+      denom = 1e-5f;
+    }
+    int32_t limit = static_cast<int32_t>(1.0f / denom - 1.0f + 0.5f);
+    // Put a bound on the max amount of dropped frames between each kept
+    // frame, in terms of frame rate and window size (secs).
+    int max_limit =
+        static_cast<int>(incoming_frame_rate_ * max_drop_duration_secs_);
+    if (limit > max_limit) {
+      limit = max_limit;
+    }
+    if (drop_count_ < 0) {
+      // Reset the drop_count_ since it was negative and should be positive.
+      drop_count_ = -drop_count_;
+    }
+    if (drop_count_ < limit) {
+      // As long we are below the limit we should drop frames.
+      drop_count_++;
+      return true;
+    } else {
+      // Only when we reset drop_count_ a frame should be kept.
+      drop_count_ = 0;
+      return false;
+    }
+  } else if (drop_ratio_.filtered() > 0.0f &&
+             drop_ratio_.filtered() < 0.5f) {  // Keeps per drop
+    // Limit is the number of frames we should keep between each drop
+    // in order to keep the drop ratio. limit is negative in this case,
+    // and the drop_count_ is also negative.
+    float denom = drop_ratio_.filtered();
+    if (denom < 1e-5) {
+      denom = 1e-5f;
+    }
+    int32_t limit = -static_cast<int32_t>(1.0f / denom - 1.0f + 0.5f);
+    if (drop_count_ > 0) {
+      // Reset the drop_count_ since we have a positive
+      // drop_count_, and it should be negative.
+      drop_count_ = -drop_count_;
+    }
+    if (drop_count_ > limit) {
+      if (drop_count_ == 0) {
+        // Drop frames when we reset drop_count_.
+        drop_count_--;
+        return true;
+      } else {
+        // Keep frames as long as we haven't reached limit.
+        drop_count_--;
+        return false;
+      }
+    } else {
+      drop_count_ = 0;
+      return false;
+    }
+  }
+  drop_count_ = 0;
+  return false;
+}
+
+void FrameDropper::SetRates(float bitrate, float incoming_frame_rate) {
+  // Bit rate of -1 means infinite bandwidth.
+  accumulator_max_ = bitrate * kLeakyBucketSizeSeconds;
+  if (target_bitrate_ > 0.0f && bitrate < target_bitrate_ &&
+      accumulator_ > accumulator_max_) {
+    // Rescale the accumulator level if the accumulator max decreases
+    accumulator_ = bitrate / target_bitrate_ * accumulator_;
+  }
+  target_bitrate_ = bitrate;
+  CapAccumulator();
+  incoming_frame_rate_ = incoming_frame_rate;
+}
+
+// Put a cap on the accumulator, i.e., don't let it grow beyond some level.
+// This is a temporary fix for screencasting where very large frames from
+// encoder will cause very slow response (too many frame drops).
+// TODO(isheriff): Remove this now that large delta frames are also spread out ?
+void FrameDropper::CapAccumulator() {
+  float max_accumulator = target_bitrate_ * kAccumulatorCapBufferSizeSecs;
+  if (accumulator_ > max_accumulator) {
+    accumulator_ = max_accumulator;
+  }
+}
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/frame_dropper.h b/third_party/libwebrtc/modules/video_coding/utility/frame_dropper.h
new file mode 100644
index 0000000000..b45b7fe27f
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/frame_dropper.h
@@ -0,0 +1,94 @@
+/*
+ *  Copyright (c) 2011 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_VIDEO_CODING_UTILITY_FRAME_DROPPER_H_
+#define MODULES_VIDEO_CODING_UTILITY_FRAME_DROPPER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "rtc_base/numerics/exp_filter.h"
+
+namespace webrtc {
+
+// The Frame Dropper implements a variant of the leaky bucket algorithm
+// for keeping track of when to drop frames to avoid bit rate
+// over use when the encoder can't keep its bit rate.
+class FrameDropper {
+ public:
+  FrameDropper();
+  ~FrameDropper();
+
+  // Resets the FrameDropper to its initial state.
+  void Reset();
+
+  void Enable(bool enable);
+
+  // Answers the question if it's time to drop a frame if we want to reach a
+  // given frame rate. Must be called for every frame.
+  //
+  // Return value     : True if we should drop the current frame.
+  bool DropFrame();
+
+  // Updates the FrameDropper with the size of the latest encoded frame.
+  // The FrameDropper calculates a new drop ratio (can be seen as the
+  // probability to drop a frame) and updates its internal statistics.
+  //
+  // Input:
+  //          - framesize_bytes    : The size of the latest frame returned
+  //                                 from the encoder.
+  //          - delta_frame        : True if the encoder returned a delta frame.
+  void Fill(size_t framesize_bytes, bool delta_frame);
+
+  void Leak(uint32_t input_framerate);
+
+  // Sets the target bit rate and the frame rate produced by the camera.
+  //
+  // Input:
+  //          - bitrate       : The target bit rate.
+  void SetRates(float bitrate, float incoming_frame_rate);
+
+ private:
+  void UpdateRatio();
+  void CapAccumulator();
+
+  rtc::ExpFilter key_frame_ratio_;
+  rtc::ExpFilter delta_frame_size_avg_kbits_;
+
+  // Key frames and large delta frames are not immediately accumulated in the
+  // bucket since they can immediately overflow the bucket leading to large
+  // drops on the following packets that may be much smaller. Instead these
+  // large frames are accumulated over several frames when the bucket leaks.
+
+  // `large_frame_accumulation_spread_` represents the number of frames over
+  // which a large frame is accumulated.
+  float large_frame_accumulation_spread_;
+  // `large_frame_accumulation_count_` represents the number of frames left
+  // to finish accumulating a large frame.
+  int large_frame_accumulation_count_;
+  // `large_frame_accumulation_chunk_size_` represents the size of a single
+  // chunk for large frame accumulation.
+  float large_frame_accumulation_chunk_size_;
+
+  float accumulator_;
+  float accumulator_max_;
+  float target_bitrate_;
+  bool drop_next_;
+  rtc::ExpFilter drop_ratio_;
+  int drop_count_;
+  float incoming_frame_rate_;
+  bool was_below_max_;
+  bool enabled_;
+  const float max_drop_duration_secs_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_FRAME_DROPPER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/frame_dropper_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/frame_dropper_unittest.cc
new file mode 100644
index 0000000000..066103a788
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/frame_dropper_unittest.cc
@@ -0,0 +1,160 @@
+/*
+ *  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/video_coding/utility/frame_dropper.h"
+
+#include "test/gtest.h"
+
+namespace webrtc {
+
+namespace {
+
+const float kTargetBitRateKbps = 300;
+const float kIncomingFrameRate = 30;
+const size_t kFrameSizeBytes = 1250;
+
+const size_t kLargeFrameSizeBytes = 25000;
+
+const bool kIncludeKeyFrame = true;
+const bool kDoNotIncludeKeyFrame = false;
+
+}  // namespace
+
+class FrameDropperTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    frame_dropper_.SetRates(kTargetBitRateKbps, kIncomingFrameRate);
+  }
+
+  void OverflowLeakyBucket() {
+    // Overflow bucket in frame dropper.
+    for (int i = 0; i < kIncomingFrameRate; ++i) {
+      frame_dropper_.Fill(kFrameSizeBytes, true);
+    }
+    frame_dropper_.Leak(kIncomingFrameRate);
+  }
+
+  void ValidateNoDropsAtTargetBitrate(int large_frame_size_bytes,
+                                      int large_frame_rate,
+                                      bool is_large_frame_delta) {
+    // Smaller frame size is computed to meet `kTargetBitRateKbps`.
+    int small_frame_size_bytes =
+        kFrameSizeBytes -
+        (large_frame_size_bytes * large_frame_rate) / kIncomingFrameRate;
+
+    for (int i = 1; i <= 5 * large_frame_rate; ++i) {
+      // Large frame. First frame is always a key frame.
+      frame_dropper_.Fill(large_frame_size_bytes,
+                          (i == 1) ? false : is_large_frame_delta);
+      frame_dropper_.Leak(kIncomingFrameRate);
+      EXPECT_FALSE(frame_dropper_.DropFrame());
+
+      // Smaller frames.
+      for (int j = 1; j < kIncomingFrameRate / large_frame_rate; ++j) {
+        frame_dropper_.Fill(small_frame_size_bytes, true);
+        frame_dropper_.Leak(kIncomingFrameRate);
+        EXPECT_FALSE(frame_dropper_.DropFrame());
+      }
+    }
+  }
+
+  void ValidateThroughputMatchesTargetBitrate(int bitrate_kbps,
+                                              bool include_keyframe) {
+    int delta_frame_size;
+    int total_bytes = 0;
+
+    if (include_keyframe) {
+      delta_frame_size = ((1000.0 / 8 * bitrate_kbps) - kLargeFrameSizeBytes) /
+                         (kIncomingFrameRate - 1);
+    } else {
+      delta_frame_size = bitrate_kbps * 1000.0 / (8 * kIncomingFrameRate);
+    }
+    const int kNumIterations = 1000;
+    for (int i = 1; i <= kNumIterations; ++i) {
+      int j = 0;
+      if (include_keyframe) {
+        if (!frame_dropper_.DropFrame()) {
+          frame_dropper_.Fill(kLargeFrameSizeBytes, false);
+          total_bytes += kLargeFrameSizeBytes;
+        }
+        frame_dropper_.Leak(kIncomingFrameRate);
+        j++;
+      }
+      for (; j < kIncomingFrameRate; ++j) {
+        if (!frame_dropper_.DropFrame()) {
+          frame_dropper_.Fill(delta_frame_size, true);
+          total_bytes += delta_frame_size;
+        }
+        frame_dropper_.Leak(kIncomingFrameRate);
+      }
+    }
+    float throughput_kbps = total_bytes * 8.0 / (1000 * kNumIterations);
+    float deviation_from_target =
+        (throughput_kbps - kTargetBitRateKbps) * 100.0 / kTargetBitRateKbps;
+    if (deviation_from_target < 0) {
+      deviation_from_target = -deviation_from_target;
+    }
+
+    // Variation is < 0.1%
+    EXPECT_LE(deviation_from_target, 0.1);
+  }
+
+  FrameDropper frame_dropper_;
+};
+
+TEST_F(FrameDropperTest, NoDropsWhenDisabled) {
+  frame_dropper_.Enable(false);
+  OverflowLeakyBucket();
+  EXPECT_FALSE(frame_dropper_.DropFrame());
+}
+
+TEST_F(FrameDropperTest, DropsByDefaultWhenBucketOverflows) {
+  OverflowLeakyBucket();
+  EXPECT_TRUE(frame_dropper_.DropFrame());
+}
+
+TEST_F(FrameDropperTest, NoDropsWhenFillRateMatchesLeakRate) {
+  for (int i = 0; i < 5 * kIncomingFrameRate; ++i) {
+    frame_dropper_.Fill(kFrameSizeBytes, true);
+    frame_dropper_.Leak(kIncomingFrameRate);
+    EXPECT_FALSE(frame_dropper_.DropFrame());
+  }
+}
+
+TEST_F(FrameDropperTest, LargeKeyFrames) {
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes, 1, false);
+  frame_dropper_.Reset();
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes / 2, 2, false);
+  frame_dropper_.Reset();
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes / 4, 4, false);
+  frame_dropper_.Reset();
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes / 8, 8, false);
+}
+
+TEST_F(FrameDropperTest, LargeDeltaFrames) {
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes, 1, true);
+  frame_dropper_.Reset();
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes / 2, 2, true);
+  frame_dropper_.Reset();
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes / 4, 4, true);
+  frame_dropper_.Reset();
+  ValidateNoDropsAtTargetBitrate(kLargeFrameSizeBytes / 8, 8, true);
+}
+
+TEST_F(FrameDropperTest, TrafficVolumeAboveAvailableBandwidth) {
+  ValidateThroughputMatchesTargetBitrate(700, kIncludeKeyFrame);
+  ValidateThroughputMatchesTargetBitrate(700, kDoNotIncludeKeyFrame);
+  ValidateThroughputMatchesTargetBitrate(600, kIncludeKeyFrame);
+  ValidateThroughputMatchesTargetBitrate(600, kDoNotIncludeKeyFrame);
+  ValidateThroughputMatchesTargetBitrate(500, kIncludeKeyFrame);
+  ValidateThroughputMatchesTargetBitrate(500, kDoNotIncludeKeyFrame);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated.cc b/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated.cc
new file mode 100644
index 0000000000..5978adc3c4
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated.cc
@@ -0,0 +1,85 @@
+/*
+ *  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/video_coding/utility/framerate_controller_deprecated.h"
+
+#include <stddef.h>
+
+#include <cstdint>
+
+namespace webrtc {
+
+FramerateControllerDeprecated::FramerateControllerDeprecated(
+    float target_framerate_fps)
+    : min_frame_interval_ms_(0), framerate_estimator_(1000.0, 1000.0) {
+  SetTargetRate(target_framerate_fps);
+}
+
+void FramerateControllerDeprecated::SetTargetRate(float target_framerate_fps) {
+  if (target_framerate_fps_ != target_framerate_fps) {
+    framerate_estimator_.Reset();
+    if (last_timestamp_ms_) {
+      framerate_estimator_.Update(1, *last_timestamp_ms_);
+    }
+
+    const size_t target_frame_interval_ms = 1000 / target_framerate_fps;
+    target_framerate_fps_ = target_framerate_fps;
+    min_frame_interval_ms_ = 85 * target_frame_interval_ms / 100;
+  }
+}
+
+float FramerateControllerDeprecated::GetTargetRate() {
+  return *target_framerate_fps_;
+}
+
+void FramerateControllerDeprecated::Reset() {
+  framerate_estimator_.Reset();
+  last_timestamp_ms_.reset();
+}
+
+bool FramerateControllerDeprecated::DropFrame(uint32_t timestamp_ms) const {
+  if (timestamp_ms < last_timestamp_ms_) {
+    // Timestamp jumps backward. We can't make adequate drop decision. Don't
+    // drop this frame. Stats will be reset in AddFrame().
+    return false;
+  }
+
+  if (Rate(timestamp_ms).value_or(*target_framerate_fps_) >
+      target_framerate_fps_) {
+    return true;
+  }
+
+  if (last_timestamp_ms_) {
+    const int64_t diff_ms =
+        static_cast<int64_t>(timestamp_ms) - *last_timestamp_ms_;
+    if (diff_ms < min_frame_interval_ms_) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+void FramerateControllerDeprecated::AddFrame(uint32_t timestamp_ms) {
+  if (timestamp_ms < last_timestamp_ms_) {
+    // Timestamp jumps backward.
+    Reset();
+  }
+
+  framerate_estimator_.Update(1, timestamp_ms);
+  last_timestamp_ms_ = timestamp_ms;
+}
+
+absl::optional<float> FramerateControllerDeprecated::Rate(
+    uint32_t timestamp_ms) const {
+  return framerate_estimator_.Rate(timestamp_ms);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated.h b/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated.h
new file mode 100644
index 0000000000..ca0cbea053
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated.h
@@ -0,0 +1,47 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_FRAMERATE_CONTROLLER_DEPRECATED_H_
+#define MODULES_VIDEO_CODING_UTILITY_FRAMERATE_CONTROLLER_DEPRECATED_H_
+
+#include <stdint.h>
+
+#include "absl/types/optional.h"
+#include "rtc_base/rate_statistics.h"
+
+namespace webrtc {
+
+// Please use webrtc::FramerateController instead.
+class FramerateControllerDeprecated {
+ public:
+  explicit FramerateControllerDeprecated(float target_framerate_fps);
+
+  void SetTargetRate(float target_framerate_fps);
+  float GetTargetRate();
+
+  // Advices user to drop next frame in order to reach target framerate.
+  bool DropFrame(uint32_t timestamp_ms) const;
+
+  void AddFrame(uint32_t timestamp_ms);
+
+  void Reset();
+
+ private:
+  absl::optional<float> Rate(uint32_t timestamp_ms) const;
+
+  absl::optional<float> target_framerate_fps_;
+  absl::optional<uint32_t> last_timestamp_ms_;
+  uint32_t min_frame_interval_ms_;
+  RateStatistics framerate_estimator_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_FRAMERATE_CONTROLLER_DEPRECATED_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated_unittest.cc
new file mode 100644
index 0000000000..eabf0529db
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/framerate_controller_deprecated_unittest.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/video_coding/utility/framerate_controller_deprecated.h"
+
+#include <stddef.h>
+
+#include "test/gtest.h"
+
+namespace webrtc {
+
+TEST(FramerateControllerDeprecated, KeepTargetFramerate) {
+  const float input_framerate_fps = 20;
+  const float target_framerate_fps = 5;
+  const float max_abs_framerate_error_fps = target_framerate_fps * 0.1f;
+  const size_t input_duration_secs = 3;
+  const size_t num_input_frames = input_duration_secs * input_framerate_fps;
+
+  FramerateControllerDeprecated framerate_controller(target_framerate_fps);
+  size_t num_dropped_frames = 0;
+  for (size_t frame_num = 0; frame_num < num_input_frames; ++frame_num) {
+    const uint32_t timestamp_ms =
+        static_cast<uint32_t>(1000 * frame_num / input_framerate_fps);
+    if (framerate_controller.DropFrame(timestamp_ms)) {
+      ++num_dropped_frames;
+    } else {
+      framerate_controller.AddFrame(timestamp_ms);
+    }
+  }
+
+  const float output_framerate_fps =
+      static_cast<float>(num_input_frames - num_dropped_frames) /
+      input_duration_secs;
+  EXPECT_NEAR(output_framerate_fps, target_framerate_fps,
+              max_abs_framerate_error_fps);
+}
+
+TEST(FramerateControllerDeprecated, DoNotDropAnyFramesIfTargerEqualsInput) {
+  const float input_framerate_fps = 30;
+  const size_t input_duration_secs = 3;
+  const size_t num_input_frames = input_duration_secs * input_framerate_fps;
+
+  FramerateControllerDeprecated framerate_controller(input_framerate_fps);
+  size_t num_dropped_frames = 0;
+  for (size_t frame_num = 0; frame_num < num_input_frames; ++frame_num) {
+    const uint32_t timestamp_ms =
+        static_cast<uint32_t>(1000 * frame_num / input_framerate_fps);
+    if (framerate_controller.DropFrame(timestamp_ms)) {
+      ++num_dropped_frames;
+    } else {
+      framerate_controller.AddFrame(timestamp_ms);
+    }
+  }
+
+  EXPECT_EQ(num_dropped_frames, 0U);
+}
+
+TEST(FramerateControllerDeprecated, DoNotDropFrameWhenTimestampJumpsBackward) {
+  FramerateControllerDeprecated framerate_controller(30);
+  ASSERT_FALSE(framerate_controller.DropFrame(66));
+  framerate_controller.AddFrame(66);
+  EXPECT_FALSE(framerate_controller.DropFrame(33));
+}
+
+TEST(FramerateControllerDeprecated, DropFrameIfItIsTooCloseToPreviousFrame) {
+  FramerateControllerDeprecated framerate_controller(30);
+  ASSERT_FALSE(framerate_controller.DropFrame(33));
+  framerate_controller.AddFrame(33);
+  EXPECT_TRUE(framerate_controller.DropFrame(34));
+}
+
+TEST(FramerateControllerDeprecated, FrameDroppingStartsFromSecondInputFrame) {
+  const float input_framerate_fps = 23;
+  const float target_framerate_fps = 19;
+  const uint32_t input_frame_duration_ms =
+      static_cast<uint32_t>(1000 / input_framerate_fps);
+  FramerateControllerDeprecated framerate_controller(target_framerate_fps);
+  ASSERT_FALSE(framerate_controller.DropFrame(1 * input_frame_duration_ms));
+  framerate_controller.AddFrame(1 * input_frame_duration_ms);
+  EXPECT_TRUE(framerate_controller.DropFrame(2 * input_frame_duration_ms));
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/ivf_defines.h b/third_party/libwebrtc/modules/video_coding/utility/ivf_defines.h
new file mode 100644
index 0000000000..212d381e70
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/ivf_defines.h
@@ -0,0 +1,25 @@
+/*
+ *  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.
+ */
+
+/*
+ * This file contains definitions that are common to the IvfFileReader and
+ * IvfFileWriter classes.
+ */
+
+#ifndef MODULES_VIDEO_CODING_UTILITY_IVF_DEFINES_H_
+#define MODULES_VIDEO_CODING_UTILITY_IVF_DEFINES_H_
+
+#include <stddef.h>
+
+namespace webrtc {
+constexpr size_t kIvfHeaderSize = 32;
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_IVF_DEFINES_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader.cc b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader.cc
new file mode 100644
index 0000000000..4c08ca613a
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader.cc
@@ -0,0 +1,242 @@
+/*
+ *  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/video_coding/utility/ivf_file_reader.h"
+
+#include <string>
+#include <vector>
+
+#include "api/video_codecs/video_codec.h"
+#include "modules/rtp_rtcp/source/byte_io.h"
+#include "modules/video_coding/utility/ivf_defines.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+namespace {
+
+constexpr size_t kIvfFrameHeaderSize = 12;
+constexpr int kCodecTypeBytesCount = 4;
+
+constexpr uint8_t kFileHeaderStart[kCodecTypeBytesCount] = {'D', 'K', 'I', 'F'};
+constexpr uint8_t kVp8Header[kCodecTypeBytesCount] = {'V', 'P', '8', '0'};
+constexpr uint8_t kVp9Header[kCodecTypeBytesCount] = {'V', 'P', '9', '0'};
+constexpr uint8_t kAv1Header[kCodecTypeBytesCount] = {'A', 'V', '0', '1'};
+constexpr uint8_t kH264Header[kCodecTypeBytesCount] = {'H', '2', '6', '4'};
+constexpr uint8_t kH265Header[kCodecTypeBytesCount] = {'H', '2', '6', '5'};
+
+// RTP standard required 90kHz clock rate.
+constexpr int32_t kRtpClockRateHz = 90000;
+
+}  // namespace
+
+std::unique_ptr<IvfFileReader> IvfFileReader::Create(FileWrapper file) {
+  auto reader =
+      std::unique_ptr<IvfFileReader>(new IvfFileReader(std::move(file)));
+  if (!reader->Reset()) {
+    return nullptr;
+  }
+  return reader;
+}
+IvfFileReader::~IvfFileReader() {
+  Close();
+}
+
+bool IvfFileReader::Reset() {
+  // Set error to true while initialization.
+  has_error_ = true;
+  if (!file_.Rewind()) {
+    RTC_LOG(LS_ERROR) << "Failed to rewind IVF file";
+    return false;
+  }
+
+  uint8_t ivf_header[kIvfHeaderSize] = {0};
+  size_t read = file_.Read(&ivf_header, kIvfHeaderSize);
+  if (read != kIvfHeaderSize) {
+    RTC_LOG(LS_ERROR) << "Failed to read IVF header";
+    return false;
+  }
+
+  if (memcmp(&ivf_header[0], kFileHeaderStart, 4) != 0) {
+    RTC_LOG(LS_ERROR) << "File is not in IVF format: DKIF header expected";
+    return false;
+  }
+
+  absl::optional<VideoCodecType> codec_type = ParseCodecType(ivf_header, 8);
+  if (!codec_type) {
+    return false;
+  }
+  codec_type_ = *codec_type;
+
+  width_ = ByteReader<uint16_t>::ReadLittleEndian(&ivf_header[12]);
+  height_ = ByteReader<uint16_t>::ReadLittleEndian(&ivf_header[14]);
+  if (width_ == 0 || height_ == 0) {
+    RTC_LOG(LS_ERROR) << "Invalid IVF header: width or height is 0";
+    return false;
+  }
+
+  time_scale_ = ByteReader<uint32_t>::ReadLittleEndian(&ivf_header[16]);
+  if (time_scale_ == 0) {
+    RTC_LOG(LS_ERROR) << "Invalid IVF header: time scale can't be 0";
+    return false;
+  }
+
+  num_frames_ = static_cast<size_t>(
+      ByteReader<uint32_t>::ReadLittleEndian(&ivf_header[24]));
+  if (num_frames_ <= 0) {
+    RTC_LOG(LS_ERROR) << "Invalid IVF header: number of frames 0 or negative";
+    return false;
+  }
+
+  num_read_frames_ = 0;
+  next_frame_header_ = ReadNextFrameHeader();
+  if (!next_frame_header_) {
+    RTC_LOG(LS_ERROR) << "Failed to read 1st frame header";
+    return false;
+  }
+  // Initialization succeed: reset error.
+  has_error_ = false;
+
+  const char* codec_name = CodecTypeToPayloadString(codec_type_);
+  RTC_LOG(LS_INFO) << "Opened IVF file with codec data of type " << codec_name
+                   << " at resolution " << width_ << " x " << height_
+                   << ", using " << time_scale_ << "Hz clock resolution.";
+
+  return true;
+}
+
+absl::optional<EncodedImage> IvfFileReader::NextFrame() {
+  if (has_error_ || !HasMoreFrames()) {
+    return absl::nullopt;
+  }
+
+  rtc::scoped_refptr<EncodedImageBuffer> payload = EncodedImageBuffer::Create();
+  std::vector<size_t> layer_sizes;
+  // next_frame_header_ have to be presented by the way how it was loaded. If it
+  // is missing it means there is a bug in error handling.
+  RTC_DCHECK(next_frame_header_);
+  int64_t current_timestamp = next_frame_header_->timestamp;
+  // The first frame from the file should be marked as Key frame.
+  bool is_first_frame = num_read_frames_ == 0;
+  while (next_frame_header_ &&
+         current_timestamp == next_frame_header_->timestamp) {
+    // Resize payload to fit next spatial layer.
+    size_t current_layer_size = next_frame_header_->frame_size;
+    size_t current_layer_start_pos = payload->size();
+    payload->Realloc(payload->size() + current_layer_size);
+    layer_sizes.push_back(current_layer_size);
+
+    // Read next layer into payload
+    size_t read = file_.Read(&payload->data()[current_layer_start_pos],
+                             current_layer_size);
+    if (read != current_layer_size) {
+      RTC_LOG(LS_ERROR) << "Frame #" << num_read_frames_
+                        << ": failed to read frame payload";
+      has_error_ = true;
+      return absl::nullopt;
+    }
+    num_read_frames_++;
+
+    current_timestamp = next_frame_header_->timestamp;
+    next_frame_header_ = ReadNextFrameHeader();
+  }
+  if (!next_frame_header_) {
+    // If EOF was reached, we need to check that all frames were met.
+    if (!has_error_ && num_read_frames_ != num_frames_) {
+      RTC_LOG(LS_ERROR) << "Unexpected EOF";
+      has_error_ = true;
+      return absl::nullopt;
+    }
+  }
+
+  EncodedImage image;
+  image.capture_time_ms_ = current_timestamp;
+  image.SetRtpTimestamp(
+      static_cast<uint32_t>(current_timestamp * kRtpClockRateHz / time_scale_));
+  image.SetEncodedData(payload);
+  image.SetSpatialIndex(static_cast<int>(layer_sizes.size()) - 1);
+  for (size_t i = 0; i < layer_sizes.size(); ++i) {
+    image.SetSpatialLayerFrameSize(static_cast<int>(i), layer_sizes[i]);
+  }
+  if (is_first_frame) {
+    image._frameType = VideoFrameType::kVideoFrameKey;
+  }
+
+  return image;
+}
+
+bool IvfFileReader::Close() {
+  if (!file_.is_open())
+    return false;
+
+  file_.Close();
+  return true;
+}
+
+absl::optional<VideoCodecType> IvfFileReader::ParseCodecType(uint8_t* buffer,
+                                                             size_t start_pos) {
+  if (memcmp(&buffer[start_pos], kVp8Header, kCodecTypeBytesCount) == 0) {
+    return VideoCodecType::kVideoCodecVP8;
+  }
+  if (memcmp(&buffer[start_pos], kVp9Header, kCodecTypeBytesCount) == 0) {
+    return VideoCodecType::kVideoCodecVP9;
+  }
+  if (memcmp(&buffer[start_pos], kAv1Header, kCodecTypeBytesCount) == 0) {
+    return VideoCodecType::kVideoCodecAV1;
+  }
+  if (memcmp(&buffer[start_pos], kH264Header, kCodecTypeBytesCount) == 0) {
+    return VideoCodecType::kVideoCodecH264;
+  }
+  if (memcmp(&buffer[start_pos], kH265Header, kCodecTypeBytesCount) == 0) {
+    return VideoCodecType::kVideoCodecH265;
+  }
+  has_error_ = true;
+  RTC_LOG(LS_ERROR) << "Unknown codec type: "
+                    << std::string(
+                           reinterpret_cast<char const*>(&buffer[start_pos]),
+                           kCodecTypeBytesCount);
+  return absl::nullopt;
+}
+
+absl::optional<IvfFileReader::FrameHeader>
+IvfFileReader::ReadNextFrameHeader() {
+  uint8_t ivf_frame_header[kIvfFrameHeaderSize] = {0};
+  size_t read = file_.Read(&ivf_frame_header, kIvfFrameHeaderSize);
+  if (read != kIvfFrameHeaderSize) {
+    if (read != 0 || !file_.ReadEof()) {
+      has_error_ = true;
+      RTC_LOG(LS_ERROR) << "Frame #" << num_read_frames_
+                        << ": failed to read IVF frame header";
+    }
+    return absl::nullopt;
+  }
+  FrameHeader header;
+  header.frame_size = static_cast<size_t>(
+      ByteReader<uint32_t>::ReadLittleEndian(&ivf_frame_header[0]));
+  header.timestamp =
+      ByteReader<uint64_t>::ReadLittleEndian(&ivf_frame_header[4]);
+
+  if (header.frame_size == 0) {
+    has_error_ = true;
+    RTC_LOG(LS_ERROR) << "Frame #" << num_read_frames_
+                      << ": invalid frame size";
+    return absl::nullopt;
+  }
+
+  if (header.timestamp < 0) {
+    has_error_ = true;
+    RTC_LOG(LS_ERROR) << "Frame #" << num_read_frames_
+                      << ": negative timestamp";
+    return absl::nullopt;
+  }
+
+  return header;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader.h b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader.h
new file mode 100644
index 0000000000..db4fc25575
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader.h
@@ -0,0 +1,82 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_IVF_FILE_READER_H_
+#define MODULES_VIDEO_CODING_UTILITY_IVF_FILE_READER_H_
+
+#include <memory>
+#include <utility>
+
+#include "absl/types/optional.h"
+#include "api/video/encoded_image.h"
+#include "api/video_codecs/video_codec.h"
+#include "rtc_base/system/file_wrapper.h"
+
+namespace webrtc {
+
+class IvfFileReader {
+ public:
+  // Creates IvfFileReader. Returns nullptr if error acquired.
+  static std::unique_ptr<IvfFileReader> Create(FileWrapper file);
+  ~IvfFileReader();
+
+  IvfFileReader(const IvfFileReader&) = delete;
+  IvfFileReader& operator=(const IvfFileReader&) = delete;
+
+  // Reinitializes reader. Returns false if any error acquired.
+  bool Reset();
+
+  // Returns codec type which was used to create this IVF file and which should
+  // be used to decode EncodedImages from this file.
+  VideoCodecType GetVideoCodecType() const { return codec_type_; }
+  // Returns count of frames in this file.
+  size_t GetFramesCount() const { return num_frames_; }
+
+  // Returns next frame or absl::nullopt if any error acquired. Always returns
+  // absl::nullopt after first error was spotted.
+  absl::optional<EncodedImage> NextFrame();
+  bool HasMoreFrames() const { return num_read_frames_ < num_frames_; }
+  bool HasError() const { return has_error_; }
+
+  uint16_t GetFrameWidth() const { return width_; }
+  uint16_t GetFrameHeight() const { return height_; }
+
+  bool Close();
+
+ private:
+  struct FrameHeader {
+    size_t frame_size;
+    int64_t timestamp;
+  };
+
+  explicit IvfFileReader(FileWrapper file) : file_(std::move(file)) {}
+
+  // Parses codec type from specified position of the buffer. Codec type
+  // contains kCodecTypeBytesCount bytes and caller has to ensure that buffer
+  // won't overflow.
+  absl::optional<VideoCodecType> ParseCodecType(uint8_t* buffer,
+                                                size_t start_pos);
+  absl::optional<FrameHeader> ReadNextFrameHeader();
+
+  VideoCodecType codec_type_;
+  size_t num_frames_;
+  size_t num_read_frames_;
+  uint16_t width_;
+  uint16_t height_;
+  uint32_t time_scale_;
+  FileWrapper file_;
+
+  absl::optional<FrameHeader> next_frame_header_;
+  bool has_error_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_IVF_FILE_READER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader_unittest.cc
new file mode 100644
index 0000000000..14bfdcae14
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_reader_unittest.cc
@@ -0,0 +1,188 @@
+/*
+ *  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/video_coding/utility/ivf_file_reader.h"
+
+#include <memory>
+#include <string>
+
+#include "modules/video_coding/utility/ivf_file_writer.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+namespace {
+
+constexpr int kWidth = 320;
+constexpr int kHeight = 240;
+constexpr int kNumFrames = 3;
+constexpr uint8_t kDummyPayload[4] = {'0', '1', '2', '3'};
+
+}  // namespace
+
+class IvfFileReaderTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    file_name_ =
+        webrtc::test::TempFilename(webrtc::test::OutputPath(), "test_file.ivf");
+  }
+  void TearDown() override { webrtc::test::RemoveFile(file_name_); }
+
+  bool WriteDummyTestFrames(IvfFileWriter* file_writer,
+                            VideoCodecType codec_type,
+                            int width,
+                            int height,
+                            int num_frames,
+                            bool use_capture_tims_ms,
+                            int spatial_layers_count) {
+    EncodedImage frame;
+    frame.SetSpatialIndex(spatial_layers_count);
+    rtc::scoped_refptr<EncodedImageBuffer> payload = EncodedImageBuffer::Create(
+        sizeof(kDummyPayload) * spatial_layers_count);
+    for (int i = 0; i < spatial_layers_count; ++i) {
+      memcpy(&payload->data()[i * sizeof(kDummyPayload)], kDummyPayload,
+             sizeof(kDummyPayload));
+      frame.SetSpatialLayerFrameSize(i, sizeof(kDummyPayload));
+    }
+    frame.SetEncodedData(payload);
+    frame._encodedWidth = width;
+    frame._encodedHeight = height;
+    for (int i = 1; i <= num_frames; ++i) {
+      if (use_capture_tims_ms) {
+        frame.capture_time_ms_ = i;
+      } else {
+        frame.SetRtpTimestamp(i);
+      }
+      if (!file_writer->WriteFrame(frame, codec_type))
+        return false;
+    }
+    return true;
+  }
+
+  void CreateTestFile(VideoCodecType codec_type,
+                      bool use_capture_tims_ms,
+                      int spatial_layers_count) {
+    std::unique_ptr<IvfFileWriter> file_writer =
+        IvfFileWriter::Wrap(FileWrapper::OpenWriteOnly(file_name_), 0);
+    ASSERT_TRUE(file_writer.get());
+    ASSERT_TRUE(WriteDummyTestFrames(file_writer.get(), codec_type, kWidth,
+                                     kHeight, kNumFrames, use_capture_tims_ms,
+                                     spatial_layers_count));
+    ASSERT_TRUE(file_writer->Close());
+  }
+
+  void ValidateFrame(absl::optional<EncodedImage> frame,
+                     int frame_index,
+                     bool use_capture_tims_ms,
+                     int spatial_layers_count) {
+    ASSERT_TRUE(frame);
+    EXPECT_EQ(frame->SpatialIndex(), spatial_layers_count - 1);
+    if (use_capture_tims_ms) {
+      EXPECT_EQ(frame->capture_time_ms_, static_cast<int64_t>(frame_index));
+      EXPECT_EQ(frame->RtpTimestamp(), static_cast<int64_t>(90 * frame_index));
+    } else {
+      EXPECT_EQ(frame->RtpTimestamp(), static_cast<int64_t>(frame_index));
+    }
+    ASSERT_EQ(frame->size(), sizeof(kDummyPayload) * spatial_layers_count);
+    for (int i = 0; i < spatial_layers_count; ++i) {
+      EXPECT_EQ(memcmp(&frame->data()[i * sizeof(kDummyPayload)], kDummyPayload,
+                       sizeof(kDummyPayload)),
+                0)
+          << std::string(reinterpret_cast<char const*>(
+                             &frame->data()[i * sizeof(kDummyPayload)]),
+                         sizeof(kDummyPayload));
+    }
+  }
+
+  void ValidateContent(VideoCodecType codec_type,
+                       bool use_capture_tims_ms,
+                       int spatial_layers_count) {
+    std::unique_ptr<IvfFileReader> reader =
+        IvfFileReader::Create(FileWrapper::OpenReadOnly(file_name_));
+    ASSERT_TRUE(reader.get());
+    EXPECT_EQ(reader->GetVideoCodecType(), codec_type);
+    EXPECT_EQ(reader->GetFramesCount(),
+              spatial_layers_count * static_cast<size_t>(kNumFrames));
+    for (int i = 1; i <= kNumFrames; ++i) {
+      ASSERT_TRUE(reader->HasMoreFrames());
+      ValidateFrame(reader->NextFrame(), i, use_capture_tims_ms,
+                    spatial_layers_count);
+      EXPECT_FALSE(reader->HasError());
+    }
+    EXPECT_FALSE(reader->HasMoreFrames());
+    EXPECT_FALSE(reader->NextFrame());
+    EXPECT_FALSE(reader->HasError());
+    ASSERT_TRUE(reader->Close());
+  }
+
+  std::string file_name_;
+};
+
+TEST_F(IvfFileReaderTest, BasicVp8FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecVP8, false, 1);
+  ValidateContent(kVideoCodecVP8, false, 1);
+}
+
+TEST_F(IvfFileReaderTest, BasicVP8FileMsTimestamp) {
+  CreateTestFile(kVideoCodecVP8, true, 1);
+  ValidateContent(kVideoCodecVP8, true, 1);
+}
+
+TEST_F(IvfFileReaderTest, BasicVP9FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecVP9, false, 1);
+  ValidateContent(kVideoCodecVP9, false, 1);
+}
+
+TEST_F(IvfFileReaderTest, BasicVP9FileMsTimestamp) {
+  CreateTestFile(kVideoCodecVP9, true, 1);
+  ValidateContent(kVideoCodecVP9, true, 1);
+}
+
+TEST_F(IvfFileReaderTest, BasicAv1FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecAV1, false, 1);
+  ValidateContent(kVideoCodecAV1, false, 1);
+}
+
+TEST_F(IvfFileReaderTest, BasicAv1FileMsTimestamp) {
+  CreateTestFile(kVideoCodecAV1, true, 1);
+  ValidateContent(kVideoCodecAV1, true, 1);
+}
+
+TEST_F(IvfFileReaderTest, BasicH264FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecH264, false, 1);
+  ValidateContent(kVideoCodecH264, false, 1);
+}
+
+TEST_F(IvfFileReaderTest, BasicH264FileMsTimestamp) {
+  CreateTestFile(kVideoCodecH264, true, 1);
+  ValidateContent(kVideoCodecH264, true, 1);
+}
+
+TEST_F(IvfFileReaderTest, MultilayerVp8FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecVP8, false, 3);
+  ValidateContent(kVideoCodecVP8, false, 3);
+}
+
+TEST_F(IvfFileReaderTest, MultilayerVP9FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecVP9, false, 3);
+  ValidateContent(kVideoCodecVP9, false, 3);
+}
+
+TEST_F(IvfFileReaderTest, MultilayerAv1FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecAV1, false, 3);
+  ValidateContent(kVideoCodecAV1, false, 3);
+}
+
+TEST_F(IvfFileReaderTest, MultilayerH264FileNtpTimestamp) {
+  CreateTestFile(kVideoCodecH264, false, 3);
+  ValidateContent(kVideoCodecH264, false, 3);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer.cc b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer.cc
new file mode 100644
index 0000000000..422e4585a8
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer.cc
@@ -0,0 +1,255 @@
+/*
+ *  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/video_coding/utility/ivf_file_writer.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <utility>
+
+#include "absl/strings/string_view.h"
+#include "api/video/encoded_image.h"
+#include "api/video/video_codec_type.h"
+#include "api/video_codecs/video_codec.h"
+#include "modules/rtp_rtcp/source/byte_io.h"
+#include "modules/video_coding/utility/ivf_defines.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/system/file_wrapper.h"
+
+// TODO(palmkvist): make logging more informative in the absence of a file name
+// (or get one)
+
+namespace webrtc {
+
+namespace {
+
+constexpr int kDefaultWidth = 1280;
+constexpr int kDefaultHeight = 720;
+}  // namespace
+
+IvfFileWriter::IvfFileWriter(FileWrapper file, size_t byte_limit)
+    : codec_type_(kVideoCodecGeneric),
+      bytes_written_(0),
+      byte_limit_(byte_limit),
+      num_frames_(0),
+      width_(0),
+      height_(0),
+      last_timestamp_(-1),
+      using_capture_timestamps_(false),
+      file_(std::move(file)) {
+  RTC_DCHECK(byte_limit == 0 || kIvfHeaderSize <= byte_limit)
+      << "The byte_limit is too low, not even the header will fit.";
+}
+
+IvfFileWriter::~IvfFileWriter() {
+  Close();
+}
+
+std::unique_ptr<IvfFileWriter> IvfFileWriter::Wrap(FileWrapper file,
+                                                   size_t byte_limit) {
+  return std::unique_ptr<IvfFileWriter>(
+      new IvfFileWriter(std::move(file), byte_limit));
+}
+
+std::unique_ptr<IvfFileWriter> IvfFileWriter::Wrap(absl::string_view filename,
+                                                   size_t byte_limit) {
+  return std::unique_ptr<IvfFileWriter>(
+      new IvfFileWriter(FileWrapper::OpenWriteOnly(filename), byte_limit));
+}
+
+bool IvfFileWriter::WriteHeader() {
+  if (!file_.Rewind()) {
+    RTC_LOG(LS_WARNING) << "Unable to rewind ivf output file.";
+    return false;
+  }
+
+  uint8_t ivf_header[kIvfHeaderSize] = {0};
+  ivf_header[0] = 'D';
+  ivf_header[1] = 'K';
+  ivf_header[2] = 'I';
+  ivf_header[3] = 'F';
+  ByteWriter<uint16_t>::WriteLittleEndian(&ivf_header[4], 0);   // Version.
+  ByteWriter<uint16_t>::WriteLittleEndian(&ivf_header[6], 32);  // Header size.
+
+  switch (codec_type_) {
+    case kVideoCodecVP8:
+      ivf_header[8] = 'V';
+      ivf_header[9] = 'P';
+      ivf_header[10] = '8';
+      ivf_header[11] = '0';
+      break;
+    case kVideoCodecVP9:
+      ivf_header[8] = 'V';
+      ivf_header[9] = 'P';
+      ivf_header[10] = '9';
+      ivf_header[11] = '0';
+      break;
+    case kVideoCodecAV1:
+      ivf_header[8] = 'A';
+      ivf_header[9] = 'V';
+      ivf_header[10] = '0';
+      ivf_header[11] = '1';
+      break;
+    case kVideoCodecH264:
+      ivf_header[8] = 'H';
+      ivf_header[9] = '2';
+      ivf_header[10] = '6';
+      ivf_header[11] = '4';
+      break;
+    case kVideoCodecH265:
+      ivf_header[8] = 'H';
+      ivf_header[9] = '2';
+      ivf_header[10] = '6';
+      ivf_header[11] = '5';
+      break;
+    default:
+      // For unknown codec type use **** code. You can specify actual payload
+      // format when playing the video with ffplay: ffplay -f H263 file.ivf
+      ivf_header[8] = '*';
+      ivf_header[9] = '*';
+      ivf_header[10] = '*';
+      ivf_header[11] = '*';
+      break;
+  }
+
+  ByteWriter<uint16_t>::WriteLittleEndian(&ivf_header[12], width_);
+  ByteWriter<uint16_t>::WriteLittleEndian(&ivf_header[14], height_);
+  // Render timestamps are in ms (1/1000 scale), while RTP timestamps use a
+  // 90kHz clock.
+  ByteWriter<uint32_t>::WriteLittleEndian(
+      &ivf_header[16], using_capture_timestamps_ ? 1000 : 90000);
+  ByteWriter<uint32_t>::WriteLittleEndian(&ivf_header[20], 1);
+  ByteWriter<uint32_t>::WriteLittleEndian(&ivf_header[24],
+                                          static_cast<uint32_t>(num_frames_));
+  ByteWriter<uint32_t>::WriteLittleEndian(&ivf_header[28], 0);  // Reserved.
+
+  if (!file_.Write(ivf_header, kIvfHeaderSize)) {
+    RTC_LOG(LS_ERROR) << "Unable to write IVF header for ivf output file.";
+    return false;
+  }
+
+  if (bytes_written_ < kIvfHeaderSize) {
+    bytes_written_ = kIvfHeaderSize;
+  }
+
+  return true;
+}
+
+bool IvfFileWriter::InitFromFirstFrame(const EncodedImage& encoded_image,
+                                       VideoCodecType codec_type) {
+  if (encoded_image._encodedWidth == 0 || encoded_image._encodedHeight == 0) {
+    width_ = kDefaultWidth;
+    height_ = kDefaultHeight;
+  } else {
+    width_ = encoded_image._encodedWidth;
+    height_ = encoded_image._encodedHeight;
+  }
+
+  using_capture_timestamps_ = encoded_image.RtpTimestamp() == 0;
+
+  codec_type_ = codec_type;
+
+  if (!WriteHeader())
+    return false;
+
+  const char* codec_name = CodecTypeToPayloadString(codec_type_);
+  RTC_LOG(LS_WARNING) << "Created IVF file for codec data of type "
+                      << codec_name << " at resolution " << width_ << " x "
+                      << height_ << ", using "
+                      << (using_capture_timestamps_ ? "1" : "90")
+                      << "kHz clock resolution.";
+  return true;
+}
+
+bool IvfFileWriter::WriteFrame(const EncodedImage& encoded_image,
+                               VideoCodecType codec_type) {
+  if (!file_.is_open())
+    return false;
+
+  if (num_frames_ == 0 && !InitFromFirstFrame(encoded_image, codec_type))
+    return false;
+  RTC_DCHECK_EQ(codec_type_, codec_type);
+
+  int64_t timestamp = using_capture_timestamps_
+                          ? encoded_image.capture_time_ms_
+                          : wrap_handler_.Unwrap(encoded_image.RtpTimestamp());
+  if (last_timestamp_ != -1 && timestamp < last_timestamp_) {
+    RTC_LOG(LS_WARNING) << "Timestamp not increasing: " << last_timestamp_
+                        << " -> " << timestamp;
+  }
+  last_timestamp_ = timestamp;
+
+  bool written_frames = false;
+  size_t max_sl_index = encoded_image.SpatialIndex().value_or(0);
+  const uint8_t* data = encoded_image.data();
+  for (size_t sl_idx = 0; sl_idx <= max_sl_index; ++sl_idx) {
+    size_t cur_size = encoded_image.SpatialLayerFrameSize(sl_idx).value_or(0);
+    if (cur_size > 0) {
+      written_frames = true;
+      if (!WriteOneSpatialLayer(timestamp, data, cur_size)) {
+        return false;
+      }
+      data += cur_size;
+    }
+  }
+
+  // If frame has only one spatial layer it won't have any spatial layers'
+  // sizes. Therefore this case should be addressed separately.
+  if (!written_frames) {
+    return WriteOneSpatialLayer(timestamp, data, encoded_image.size());
+  } else {
+    return true;
+  }
+}
+
+bool IvfFileWriter::WriteOneSpatialLayer(int64_t timestamp,
+                                         const uint8_t* data,
+                                         size_t size) {
+  const size_t kFrameHeaderSize = 12;
+  if (byte_limit_ != 0 &&
+      bytes_written_ + kFrameHeaderSize + size > byte_limit_) {
+    RTC_LOG(LS_WARNING) << "Closing IVF file due to reaching size limit: "
+                        << byte_limit_ << " bytes.";
+    Close();
+    return false;
+  }
+  uint8_t frame_header[kFrameHeaderSize] = {};
+  ByteWriter<uint32_t>::WriteLittleEndian(&frame_header[0],
+                                          static_cast<uint32_t>(size));
+  ByteWriter<uint64_t>::WriteLittleEndian(&frame_header[4], timestamp);
+  if (!file_.Write(frame_header, kFrameHeaderSize) ||
+      !file_.Write(data, size)) {
+    RTC_LOG(LS_ERROR) << "Unable to write frame to file.";
+    return false;
+  }
+
+  bytes_written_ += kFrameHeaderSize + size;
+
+  ++num_frames_;
+  return true;
+}
+
+bool IvfFileWriter::Close() {
+  if (!file_.is_open())
+    return false;
+
+  if (num_frames_ == 0) {
+    file_.Close();
+    return true;
+  }
+
+  bool ret = WriteHeader();
+  file_.Close();
+  return ret;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer.h b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer.h
new file mode 100644
index 0000000000..c1c088690b
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer.h
@@ -0,0 +1,69 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_IVF_FILE_WRITER_H_
+#define MODULES_VIDEO_CODING_UTILITY_IVF_FILE_WRITER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+
+#include "absl/strings/string_view.h"
+#include "api/video/encoded_image.h"
+#include "api/video/video_codec_type.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
+#include "rtc_base/system/file_wrapper.h"
+
+namespace webrtc {
+
+class IvfFileWriter {
+ public:
+  // Takes ownership of the file, which will be closed either through
+  // Close or ~IvfFileWriter. If writing a frame would take the file above the
+  // `byte_limit` the file will be closed, the write (and all future writes)
+  // will fail. A `byte_limit` of 0 is equivalent to no limit.
+  static std::unique_ptr<IvfFileWriter> Wrap(FileWrapper file,
+                                             size_t byte_limit);
+  static std::unique_ptr<IvfFileWriter> Wrap(absl::string_view filename,
+                                             size_t byte_limit);
+  ~IvfFileWriter();
+
+  IvfFileWriter(const IvfFileWriter&) = delete;
+  IvfFileWriter& operator=(const IvfFileWriter&) = delete;
+
+  bool WriteFrame(const EncodedImage& encoded_image, VideoCodecType codec_type);
+  bool Close();
+
+ private:
+  explicit IvfFileWriter(FileWrapper file, size_t byte_limit);
+
+  bool WriteHeader();
+  bool InitFromFirstFrame(const EncodedImage& encoded_image,
+                          VideoCodecType codec_type);
+  bool WriteOneSpatialLayer(int64_t timestamp,
+                            const uint8_t* data,
+                            size_t size);
+
+  VideoCodecType codec_type_;
+  size_t bytes_written_;
+  size_t byte_limit_;
+  size_t num_frames_;
+  uint16_t width_;
+  uint16_t height_;
+  int64_t last_timestamp_;
+  bool using_capture_timestamps_;
+  RtpTimestampUnwrapper wrap_handler_;
+  FileWrapper file_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_IVF_FILE_WRITER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc
new file mode 100644
index 0000000000..bc6ab65b34
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc
@@ -0,0 +1,311 @@
+/*
+ *  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/video_coding/utility/ivf_file_writer.h"
+
+#include <string.h>
+
+#include <memory>
+#include <string>
+
+#include "modules/rtp_rtcp/source/byte_io.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+namespace {
+static const int kHeaderSize = 32;
+static const int kFrameHeaderSize = 12;
+static uint8_t dummy_payload[4] = {0, 1, 2, 3};
+// As the default parameter when the width and height of encodedImage are 0,
+// the values are copied from ivf_file_writer.cc
+constexpr int kDefaultWidth = 1280;
+constexpr int kDefaultHeight = 720;
+}  // namespace
+
+class IvfFileWriterTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    file_name_ =
+        webrtc::test::TempFilename(webrtc::test::OutputPath(), "test_file");
+  }
+  void TearDown() override { webrtc::test::RemoveFile(file_name_); }
+
+  bool WriteDummyTestFrames(VideoCodecType codec_type,
+                            int width,
+                            int height,
+                            int num_frames,
+                            bool use_capture_tims_ms) {
+    EncodedImage frame;
+    frame.SetEncodedData(
+        EncodedImageBuffer::Create(dummy_payload, sizeof(dummy_payload)));
+    frame._encodedWidth = width;
+    frame._encodedHeight = height;
+    for (int i = 1; i <= num_frames; ++i) {
+      frame.set_size(i % sizeof(dummy_payload));
+      if (use_capture_tims_ms) {
+        frame.capture_time_ms_ = i;
+      } else {
+        frame.SetRtpTimestamp(i);
+      }
+      if (!file_writer_->WriteFrame(frame, codec_type))
+        return false;
+    }
+    return true;
+  }
+
+  void VerifyIvfHeader(FileWrapper* file,
+                       const uint8_t fourcc[4],
+                       int width,
+                       int height,
+                       uint32_t num_frames,
+                       bool use_capture_tims_ms) {
+    ASSERT_TRUE(file->is_open());
+    uint8_t data[kHeaderSize];
+    ASSERT_EQ(static_cast<size_t>(kHeaderSize), file->Read(data, kHeaderSize));
+
+    uint8_t dkif[4] = {'D', 'K', 'I', 'F'};
+    EXPECT_EQ(0, memcmp(dkif, data, 4));
+    EXPECT_EQ(0u, ByteReader<uint16_t>::ReadLittleEndian(&data[4]));
+    EXPECT_EQ(32u, ByteReader<uint16_t>::ReadLittleEndian(&data[6]));
+    EXPECT_EQ(0, memcmp(fourcc, &data[8], 4));
+    EXPECT_EQ(width, ByteReader<uint16_t>::ReadLittleEndian(&data[12]));
+    EXPECT_EQ(height, ByteReader<uint16_t>::ReadLittleEndian(&data[14]));
+    EXPECT_EQ(use_capture_tims_ms ? 1000u : 90000u,
+              ByteReader<uint32_t>::ReadLittleEndian(&data[16]));
+    EXPECT_EQ(1u, ByteReader<uint32_t>::ReadLittleEndian(&data[20]));
+    EXPECT_EQ(num_frames, ByteReader<uint32_t>::ReadLittleEndian(&data[24]));
+    EXPECT_EQ(0u, ByteReader<uint32_t>::ReadLittleEndian(&data[28]));
+  }
+
+  void VerifyDummyTestFrames(FileWrapper* file, uint32_t num_frames) {
+    const int kMaxFrameSize = 4;
+    for (uint32_t i = 1; i <= num_frames; ++i) {
+      uint8_t frame_header[kFrameHeaderSize];
+      ASSERT_EQ(static_cast<unsigned int>(kFrameHeaderSize),
+                file->Read(frame_header, kFrameHeaderSize));
+      uint32_t frame_length =
+          ByteReader<uint32_t>::ReadLittleEndian(&frame_header[0]);
+      EXPECT_EQ(i % 4, frame_length);
+      uint64_t timestamp =
+          ByteReader<uint64_t>::ReadLittleEndian(&frame_header[4]);
+      EXPECT_EQ(i, timestamp);
+
+      uint8_t data[kMaxFrameSize] = {};
+      ASSERT_EQ(frame_length,
+                static_cast<uint32_t>(file->Read(data, frame_length)));
+      EXPECT_EQ(0, memcmp(data, dummy_payload, frame_length));
+    }
+  }
+
+  void RunBasicFileStructureTest(VideoCodecType codec_type,
+                                 const uint8_t fourcc[4],
+                                 bool use_capture_tims_ms) {
+    file_writer_ =
+        IvfFileWriter::Wrap(FileWrapper::OpenWriteOnly(file_name_), 0);
+    ASSERT_TRUE(file_writer_.get());
+    const int kWidth = 320;
+    const int kHeight = 240;
+    const int kNumFrames = 257;
+    ASSERT_TRUE(WriteDummyTestFrames(codec_type, kWidth, kHeight, kNumFrames,
+                                     use_capture_tims_ms));
+    EXPECT_TRUE(file_writer_->Close());
+
+    FileWrapper out_file = FileWrapper::OpenReadOnly(file_name_);
+    VerifyIvfHeader(&out_file, fourcc, kWidth, kHeight, kNumFrames,
+                    use_capture_tims_ms);
+    VerifyDummyTestFrames(&out_file, kNumFrames);
+
+    out_file.Close();
+  }
+
+  std::string file_name_;
+  std::unique_ptr<IvfFileWriter> file_writer_;
+};
+
+TEST_F(IvfFileWriterTest, WritesBasicVP8FileNtpTimestamp) {
+  const uint8_t fourcc[4] = {'V', 'P', '8', '0'};
+  RunBasicFileStructureTest(kVideoCodecVP8, fourcc, false);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicVP8FileMsTimestamp) {
+  const uint8_t fourcc[4] = {'V', 'P', '8', '0'};
+  RunBasicFileStructureTest(kVideoCodecVP8, fourcc, true);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicVP9FileNtpTimestamp) {
+  const uint8_t fourcc[4] = {'V', 'P', '9', '0'};
+  RunBasicFileStructureTest(kVideoCodecVP9, fourcc, false);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicVP9FileMsTimestamp) {
+  const uint8_t fourcc[4] = {'V', 'P', '9', '0'};
+  RunBasicFileStructureTest(kVideoCodecVP9, fourcc, true);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicAv1FileNtpTimestamp) {
+  const uint8_t fourcc[4] = {'A', 'V', '0', '1'};
+  RunBasicFileStructureTest(kVideoCodecAV1, fourcc, false);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicAv1FileMsTimestamp) {
+  const uint8_t fourcc[4] = {'A', 'V', '0', '1'};
+  RunBasicFileStructureTest(kVideoCodecAV1, fourcc, true);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicH264FileNtpTimestamp) {
+  const uint8_t fourcc[4] = {'H', '2', '6', '4'};
+  RunBasicFileStructureTest(kVideoCodecH264, fourcc, false);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicH264FileMsTimestamp) {
+  const uint8_t fourcc[4] = {'H', '2', '6', '4'};
+  RunBasicFileStructureTest(kVideoCodecH264, fourcc, true);
+}
+
+TEST_F(IvfFileWriterTest, WritesBasicUnknownCodecFileMsTimestamp) {
+  const uint8_t fourcc[4] = {'*', '*', '*', '*'};
+  RunBasicFileStructureTest(kVideoCodecGeneric, fourcc, true);
+}
+
+TEST_F(IvfFileWriterTest, ClosesWhenReachesLimit) {
+  const uint8_t fourcc[4] = {'V', 'P', '8', '0'};
+  const int kWidth = 320;
+  const int kHeight = 240;
+  const int kNumFramesToWrite = 2;
+  const int kNumFramesToFit = 1;
+
+  file_writer_ = IvfFileWriter::Wrap(
+      FileWrapper::OpenWriteOnly(file_name_),
+      kHeaderSize +
+          kNumFramesToFit * (kFrameHeaderSize + sizeof(dummy_payload)));
+  ASSERT_TRUE(file_writer_.get());
+
+  ASSERT_FALSE(WriteDummyTestFrames(kVideoCodecVP8, kWidth, kHeight,
+                                    kNumFramesToWrite, true));
+  ASSERT_FALSE(file_writer_->Close());
+
+  FileWrapper out_file = FileWrapper::OpenReadOnly(file_name_);
+  VerifyIvfHeader(&out_file, fourcc, kWidth, kHeight, kNumFramesToFit, true);
+  VerifyDummyTestFrames(&out_file, kNumFramesToFit);
+
+  out_file.Close();
+}
+
+TEST_F(IvfFileWriterTest, UseDefaultValueWhenWidthAndHeightAreZero) {
+  const uint8_t fourcc[4] = {'V', 'P', '8', '0'};
+  const int kWidth = 0;
+  const int kHeight = 0;
+  const int kNumFramesToWrite = 2;
+  const int kNumFramesToFit = 1;
+
+  file_writer_ = IvfFileWriter::Wrap(
+      FileWrapper::OpenWriteOnly(file_name_),
+      kHeaderSize +
+          kNumFramesToFit * (kFrameHeaderSize + sizeof(dummy_payload)));
+  ASSERT_TRUE(file_writer_.get());
+
+  ASSERT_FALSE(WriteDummyTestFrames(kVideoCodecVP8, kWidth, kHeight,
+                                    kNumFramesToWrite, true));
+  ASSERT_FALSE(file_writer_->Close());
+
+  FileWrapper out_file = FileWrapper::OpenReadOnly(file_name_);
+  // When the width and height are zero, we should expect the width and height
+  // in IvfHeader to be kDefaultWidth and kDefaultHeight instead of kWidth and
+  // kHeight.
+  VerifyIvfHeader(&out_file, fourcc, kDefaultWidth, kDefaultHeight,
+                  kNumFramesToFit, true);
+  VerifyDummyTestFrames(&out_file, kNumFramesToFit);
+
+  out_file.Close();
+}
+
+TEST_F(IvfFileWriterTest, UseDefaultValueWhenOnlyWidthIsZero) {
+  const uint8_t fourcc[4] = {'V', 'P', '8', '0'};
+  const int kWidth = 0;
+  const int kHeight = 360;
+  const int kNumFramesToWrite = 2;
+  const int kNumFramesToFit = 1;
+
+  file_writer_ = IvfFileWriter::Wrap(
+      FileWrapper::OpenWriteOnly(file_name_),
+      kHeaderSize +
+          kNumFramesToFit * (kFrameHeaderSize + sizeof(dummy_payload)));
+  ASSERT_TRUE(file_writer_.get());
+
+  ASSERT_FALSE(WriteDummyTestFrames(kVideoCodecVP8, kWidth, kHeight,
+                                    kNumFramesToWrite, true));
+  ASSERT_FALSE(file_writer_->Close());
+
+  FileWrapper out_file = FileWrapper::OpenReadOnly(file_name_);
+  // When the width and height are zero, we should expect the width and height
+  // in IvfHeader to be kDefaultWidth and kDefaultHeight instead of kWidth and
+  // kHeight.
+  VerifyIvfHeader(&out_file, fourcc, kDefaultWidth, kDefaultHeight,
+                  kNumFramesToFit, true);
+  VerifyDummyTestFrames(&out_file, kNumFramesToFit);
+
+  out_file.Close();
+}
+
+TEST_F(IvfFileWriterTest, UseDefaultValueWhenOnlyHeightIsZero) {
+  const uint8_t fourcc[4] = {'V', 'P', '8', '0'};
+  const int kWidth = 240;
+  const int kHeight = 0;
+  const int kNumFramesToWrite = 2;
+  const int kNumFramesToFit = 1;
+
+  file_writer_ = IvfFileWriter::Wrap(
+      FileWrapper::OpenWriteOnly(file_name_),
+      kHeaderSize +
+          kNumFramesToFit * (kFrameHeaderSize + sizeof(dummy_payload)));
+  ASSERT_TRUE(file_writer_.get());
+
+  ASSERT_FALSE(WriteDummyTestFrames(kVideoCodecVP8, kWidth, kHeight,
+                                    kNumFramesToWrite, true));
+  ASSERT_FALSE(file_writer_->Close());
+
+  FileWrapper out_file = FileWrapper::OpenReadOnly(file_name_);
+  // When the width and height are zero, we should expect the width and height
+  // in IvfHeader to be kDefaultWidth and kDefaultHeight instead of kWidth and
+  // kHeight.
+  VerifyIvfHeader(&out_file, fourcc, kDefaultWidth, kDefaultHeight,
+                  kNumFramesToFit, true);
+  VerifyDummyTestFrames(&out_file, kNumFramesToFit);
+
+  out_file.Close();
+}
+
+TEST_F(IvfFileWriterTest, UseDefaultValueWhenHeightAndWidthAreNotZero) {
+  const uint8_t fourcc[4] = {'V', 'P', '8', '0'};
+  const int kWidth = 360;
+  const int kHeight = 240;
+  const int kNumFramesToWrite = 2;
+  const int kNumFramesToFit = 1;
+
+  file_writer_ = IvfFileWriter::Wrap(
+      FileWrapper::OpenWriteOnly(file_name_),
+      kHeaderSize +
+          kNumFramesToFit * (kFrameHeaderSize + sizeof(dummy_payload)));
+  ASSERT_TRUE(file_writer_.get());
+
+  ASSERT_FALSE(WriteDummyTestFrames(kVideoCodecVP8, kWidth, kHeight,
+                                    kNumFramesToWrite, true));
+  ASSERT_FALSE(file_writer_->Close());
+
+  FileWrapper out_file = FileWrapper::OpenReadOnly(file_name_);
+  VerifyIvfHeader(&out_file, fourcc, kWidth, kHeight, kNumFramesToFit, true);
+  VerifyDummyTestFrames(&out_file, kNumFramesToFit);
+
+  out_file.Close();
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/qp_parser.cc b/third_party/libwebrtc/modules/video_coding/utility/qp_parser.cc
new file mode 100644
index 0000000000..3b9aaa377e
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/qp_parser.cc
@@ -0,0 +1,55 @@
+/*
+ *  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/video_coding/utility/qp_parser.h"
+
+#include "modules/video_coding/utility/vp8_header_parser.h"
+#include "modules/video_coding/utility/vp9_uncompressed_header_parser.h"
+
+namespace webrtc {
+
+absl::optional<uint32_t> QpParser::Parse(VideoCodecType codec_type,
+                                         size_t spatial_idx,
+                                         const uint8_t* frame_data,
+                                         size_t frame_size) {
+  if (frame_data == nullptr || frame_size == 0 ||
+      spatial_idx >= kMaxSimulcastStreams) {
+    return absl::nullopt;
+  }
+
+  if (codec_type == kVideoCodecVP8) {
+    int qp = -1;
+    if (vp8::GetQp(frame_data, frame_size, &qp)) {
+      return qp;
+    }
+  } else if (codec_type == kVideoCodecVP9) {
+    int qp = -1;
+    if (vp9::GetQp(frame_data, frame_size, &qp)) {
+      return qp;
+    }
+  } else if (codec_type == kVideoCodecH264) {
+    return h264_parsers_[spatial_idx].Parse(frame_data, frame_size);
+  } else if (codec_type == kVideoCodecH265) {
+    // TODO(bugs.webrtc.org/13485)
+  }
+
+  return absl::nullopt;
+}
+
+absl::optional<uint32_t> QpParser::H264QpParser::Parse(
+    const uint8_t* frame_data,
+    size_t frame_size) {
+  MutexLock lock(&mutex_);
+  bitstream_parser_.ParseBitstream(
+      rtc::ArrayView<const uint8_t>(frame_data, frame_size));
+  return bitstream_parser_.GetLastSliceQp();
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/qp_parser.h b/third_party/libwebrtc/modules/video_coding/utility/qp_parser.h
new file mode 100644
index 0000000000..f132ff9337
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/qp_parser.h
@@ -0,0 +1,45 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_QP_PARSER_H_
+#define MODULES_VIDEO_CODING_UTILITY_QP_PARSER_H_
+
+#include "absl/types/optional.h"
+#include "api/video/video_codec_constants.h"
+#include "api/video/video_codec_type.h"
+#include "common_video/h264/h264_bitstream_parser.h"
+#include "rtc_base/synchronization/mutex.h"
+
+namespace webrtc {
+class QpParser {
+ public:
+  absl::optional<uint32_t> Parse(VideoCodecType codec_type,
+                                 size_t spatial_idx,
+                                 const uint8_t* frame_data,
+                                 size_t frame_size);
+
+ private:
+  // A thread safe wrapper for H264 bitstream parser.
+  class H264QpParser {
+   public:
+    absl::optional<uint32_t> Parse(const uint8_t* frame_data,
+                                   size_t frame_size);
+
+   private:
+    Mutex mutex_;
+    H264BitstreamParser bitstream_parser_ RTC_GUARDED_BY(mutex_);
+  };
+
+  H264QpParser h264_parsers_[kMaxSimulcastStreams];
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_QP_PARSER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/qp_parser_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/qp_parser_unittest.cc
new file mode 100644
index 0000000000..1131288f26
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/qp_parser_unittest.cc
@@ -0,0 +1,118 @@
+/*
+ *  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/video_coding/utility/qp_parser.h"
+
+#include <stddef.h>
+
+#include "test/gtest.h"
+
+namespace webrtc {
+
+namespace {
+// ffmpeg -s 16x16 -f rawvideo -pix_fmt rgb24 -r 30 -i /dev/zero -c:v libvpx
+// -qmin 20 -qmax 20 -crf 20 -frames:v 1 -y out.ivf
+const uint8_t kCodedFrameVp8Qp25[] = {
+    0x10, 0x02, 0x00, 0x9d, 0x01, 0x2a, 0x10, 0x00, 0x10, 0x00,
+    0x02, 0x47, 0x08, 0x85, 0x85, 0x88, 0x85, 0x84, 0x88, 0x0c,
+    0x82, 0x00, 0x0c, 0x0d, 0x60, 0x00, 0xfe, 0xfc, 0x5c, 0xd0};
+
+// ffmpeg -s 16x16 -f rawvideo -pix_fmt rgb24 -r 30 -i /dev/zero -c:v libvpx-vp9
+// -qmin 24 -qmax 24 -crf 24 -frames:v 1 -y out.ivf
+const uint8_t kCodedFrameVp9Qp96[] = {
+    0xa2, 0x49, 0x83, 0x42, 0xe0, 0x00, 0xf0, 0x00, 0xf6, 0x00,
+    0x38, 0x24, 0x1c, 0x18, 0xc0, 0x00, 0x00, 0x30, 0x70, 0x00,
+    0x00, 0x4a, 0xa7, 0xff, 0xfc, 0xb9, 0x01, 0xbf, 0xff, 0xff,
+    0x97, 0x20, 0xdb, 0xff, 0xff, 0xcb, 0x90, 0x5d, 0x40};
+
+// ffmpeg -s 16x16 -f rawvideo -pix_fmt yuv420p -r 30 -i /dev/zero -c:v libx264
+// -qmin 38 -qmax 38 -crf 38 -profile:v baseline -frames:v 2 -y out.264
+const uint8_t kCodedFrameH264SpsPpsIdrQp38[] = {
+    0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0xc0, 0x0a, 0xd9, 0x1e, 0x84,
+    0x00, 0x00, 0x03, 0x00, 0x04, 0x00, 0x00, 0x03, 0x00, 0xf0, 0x3c,
+    0x48, 0x99, 0x20, 0x00, 0x00, 0x00, 0x01, 0x68, 0xcb, 0x80, 0xc4,
+    0xb2, 0x00, 0x00, 0x01, 0x65, 0x88, 0x84, 0xf1, 0x18, 0xa0, 0x00,
+    0x20, 0x5b, 0x1c, 0x00, 0x04, 0x07, 0xe3, 0x80, 0x00, 0x80, 0xfe};
+
+const uint8_t kCodedFrameH264SpsPpsIdrQp49[] = {
+    0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0xc0, 0x0a, 0xd9, 0x1e, 0x84,
+    0x00, 0x00, 0x03, 0x00, 0x04, 0x00, 0x00, 0x03, 0x00, 0xf0, 0x3c,
+    0x48, 0x99, 0x20, 0x00, 0x00, 0x00, 0x01, 0x68, 0xcb, 0x80, 0x5d,
+    0x2c, 0x80, 0x00, 0x00, 0x01, 0x65, 0x88, 0x84, 0xf1, 0x18, 0xa0,
+    0x00, 0x5e, 0x38, 0x00, 0x08, 0x03, 0xc7, 0x00, 0x01, 0x00, 0x7c};
+
+const uint8_t kCodedFrameH264InterSliceQpDelta0[] = {0x00, 0x00, 0x00, 0x01,
+                                                     0x41, 0x9a, 0x39, 0xea};
+
+}  // namespace
+
+TEST(QpParserTest, ParseQpVp8) {
+  QpParser parser;
+  absl::optional<uint32_t> qp = parser.Parse(
+      kVideoCodecVP8, 0, kCodedFrameVp8Qp25, sizeof(kCodedFrameVp8Qp25));
+  EXPECT_EQ(qp, 25u);
+}
+
+TEST(QpParserTest, ParseQpVp9) {
+  QpParser parser;
+  absl::optional<uint32_t> qp = parser.Parse(
+      kVideoCodecVP9, 0, kCodedFrameVp9Qp96, sizeof(kCodedFrameVp9Qp96));
+  EXPECT_EQ(qp, 96u);
+}
+
+TEST(QpParserTest, ParseQpH264) {
+  QpParser parser;
+  absl::optional<uint32_t> qp = parser.Parse(
+      VideoCodecType::kVideoCodecH264, 0, kCodedFrameH264SpsPpsIdrQp38,
+      sizeof(kCodedFrameH264SpsPpsIdrQp38));
+  EXPECT_EQ(qp, 38u);
+
+  qp = parser.Parse(kVideoCodecH264, 1, kCodedFrameH264SpsPpsIdrQp49,
+                    sizeof(kCodedFrameH264SpsPpsIdrQp49));
+  EXPECT_EQ(qp, 49u);
+
+  qp = parser.Parse(kVideoCodecH264, 0, kCodedFrameH264InterSliceQpDelta0,
+                    sizeof(kCodedFrameH264InterSliceQpDelta0));
+  EXPECT_EQ(qp, 38u);
+
+  qp = parser.Parse(kVideoCodecH264, 1, kCodedFrameH264InterSliceQpDelta0,
+                    sizeof(kCodedFrameH264InterSliceQpDelta0));
+  EXPECT_EQ(qp, 49u);
+}
+
+TEST(QpParserTest, ParseQpUnsupportedCodecType) {
+  QpParser parser;
+  absl::optional<uint32_t> qp = parser.Parse(
+      kVideoCodecGeneric, 0, kCodedFrameVp8Qp25, sizeof(kCodedFrameVp8Qp25));
+  EXPECT_FALSE(qp.has_value());
+}
+
+TEST(QpParserTest, ParseQpNullData) {
+  QpParser parser;
+  absl::optional<uint32_t> qp = parser.Parse(kVideoCodecVP8, 0, nullptr, 100);
+  EXPECT_FALSE(qp.has_value());
+}
+
+TEST(QpParserTest, ParseQpEmptyData) {
+  QpParser parser;
+  absl::optional<uint32_t> qp =
+      parser.Parse(kVideoCodecVP8, 0, kCodedFrameVp8Qp25, 0);
+  EXPECT_FALSE(qp.has_value());
+}
+
+TEST(QpParserTest, ParseQpSpatialIdxExceedsMax) {
+  QpParser parser;
+  absl::optional<uint32_t> qp =
+      parser.Parse(kVideoCodecVP8, kMaxSimulcastStreams, kCodedFrameVp8Qp25,
+                   sizeof(kCodedFrameVp8Qp25));
+  EXPECT_FALSE(qp.has_value());
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/quality_scaler.cc b/third_party/libwebrtc/modules/video_coding/utility/quality_scaler.cc
new file mode 100644
index 0000000000..7ecb340ea4
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/quality_scaler.cc
@@ -0,0 +1,336 @@
+/*
+ *  Copyright (c) 2014 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/video_coding/utility/quality_scaler.h"
+
+#include <memory>
+#include <utility>
+
+#include "api/field_trials_view.h"
+#include "api/units/time_delta.h"
+#include "api/video/video_adaptation_reason.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/experiments/quality_scaler_settings.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/exp_filter.h"
+#include "rtc_base/weak_ptr.h"
+
+namespace webrtc {
+
+namespace {
+// Threshold constant used until first downscale (to permit fast rampup).
+static const int kMeasureMs = 2000;
+static const float kSamplePeriodScaleFactor = 2.5;
+static const int kFramedropPercentThreshold = 60;
+static const size_t kMinFramesNeededToScale = 2 * 30;
+
+}  // namespace
+
+class QualityScaler::QpSmoother {
+ public:
+  explicit QpSmoother(float alpha)
+      : alpha_(alpha),
+        // The initial value of last_sample_ms doesn't matter since the smoother
+        // will ignore the time delta for the first update.
+        last_sample_ms_(0),
+        smoother_(alpha) {}
+
+  absl::optional<int> GetAvg() const {
+    float value = smoother_.filtered();
+    if (value == rtc::ExpFilter::kValueUndefined) {
+      return absl::nullopt;
+    }
+    return static_cast<int>(value);
+  }
+
+  void Add(float sample, int64_t time_sent_us) {
+    int64_t now_ms = time_sent_us / 1000;
+    smoother_.Apply(static_cast<float>(now_ms - last_sample_ms_), sample);
+    last_sample_ms_ = now_ms;
+  }
+
+  void Reset() { smoother_.Reset(alpha_); }
+
+ private:
+  const float alpha_;
+  int64_t last_sample_ms_;
+  rtc::ExpFilter smoother_;
+};
+
+// The QualityScaler checks for QP periodically by queuing CheckQpTasks. The
+// task will either run to completion and trigger a new task being queued, or it
+// will be destroyed because the QualityScaler is destroyed.
+//
+// When high or low QP is reported, the task will be pending until a callback is
+// invoked. This lets the QualityScalerQpUsageHandlerInterface react to QP usage
+// asynchronously and prevents checking for QP until the stream has potentially
+// been reconfigured.
+class QualityScaler::CheckQpTask {
+ public:
+  // The result of one CheckQpTask may influence the delay of the next
+  // CheckQpTask.
+  struct Result {
+    bool observed_enough_frames = false;
+    bool qp_usage_reported = false;
+  };
+
+  CheckQpTask(QualityScaler* quality_scaler, Result previous_task_result)
+      : quality_scaler_(quality_scaler),
+        state_(State::kNotStarted),
+        previous_task_result_(previous_task_result),
+        weak_ptr_factory_(this) {}
+
+  void StartDelayedTask() {
+    RTC_DCHECK_EQ(state_, State::kNotStarted);
+    state_ = State::kCheckingQp;
+    TaskQueueBase::Current()->PostDelayedTask(
+        [this_weak_ptr = weak_ptr_factory_.GetWeakPtr(), this] {
+          if (!this_weak_ptr) {
+            // The task has been cancelled through destruction.
+            return;
+          }
+          RTC_DCHECK_EQ(state_, State::kCheckingQp);
+          RTC_DCHECK_RUN_ON(&quality_scaler_->task_checker_);
+          switch (quality_scaler_->CheckQp()) {
+            case QualityScaler::CheckQpResult::kInsufficientSamples: {
+              result_.observed_enough_frames = false;
+              // After this line, `this` may be deleted.
+              break;
+            }
+            case QualityScaler::CheckQpResult::kNormalQp: {
+              result_.observed_enough_frames = true;
+              break;
+            }
+            case QualityScaler::CheckQpResult::kHighQp: {
+              result_.observed_enough_frames = true;
+              result_.qp_usage_reported = true;
+              quality_scaler_->fast_rampup_ = false;
+              quality_scaler_->handler_->OnReportQpUsageHigh();
+              quality_scaler_->ClearSamples();
+              break;
+            }
+            case QualityScaler::CheckQpResult::kLowQp: {
+              result_.observed_enough_frames = true;
+              result_.qp_usage_reported = true;
+              quality_scaler_->handler_->OnReportQpUsageLow();
+              quality_scaler_->ClearSamples();
+              break;
+            }
+          }
+          state_ = State::kCompleted;
+          // Starting the next task deletes the pending task. After this line,
+          // `this` has been deleted.
+          quality_scaler_->StartNextCheckQpTask();
+        },
+        TimeDelta::Millis(GetCheckingQpDelayMs()));
+  }
+
+  bool HasCompletedTask() const { return state_ == State::kCompleted; }
+
+  Result result() const {
+    RTC_DCHECK(HasCompletedTask());
+    return result_;
+  }
+
+ private:
+  enum class State {
+    kNotStarted,
+    kCheckingQp,
+    kCompleted,
+  };
+
+  // Determines the sampling period of CheckQpTasks.
+  int64_t GetCheckingQpDelayMs() const {
+    RTC_DCHECK_RUN_ON(&quality_scaler_->task_checker_);
+    if (quality_scaler_->fast_rampup_) {
+      return quality_scaler_->sampling_period_ms_;
+    }
+    if (quality_scaler_->experiment_enabled_ &&
+        !previous_task_result_.observed_enough_frames) {
+      // Use half the interval while waiting for enough frames.
+      return quality_scaler_->sampling_period_ms_ / 2;
+    }
+    if (quality_scaler_->scale_factor_ &&
+        !previous_task_result_.qp_usage_reported) {
+      // Last CheckQp did not call AdaptDown/Up, possibly reduce interval.
+      return quality_scaler_->sampling_period_ms_ *
+             quality_scaler_->scale_factor_.value();
+    }
+    return quality_scaler_->sampling_period_ms_ *
+           quality_scaler_->initial_scale_factor_;
+  }
+
+  QualityScaler* const quality_scaler_;
+  State state_;
+  const Result previous_task_result_;
+  Result result_;
+
+  rtc::WeakPtrFactory<CheckQpTask> weak_ptr_factory_;
+};
+
+QualityScaler::QualityScaler(QualityScalerQpUsageHandlerInterface* handler,
+                             VideoEncoder::QpThresholds thresholds,
+                             const FieldTrialsView& field_trials)
+    : QualityScaler(handler, thresholds, field_trials, kMeasureMs) {}
+
+// Protected ctor, should not be called directly.
+QualityScaler::QualityScaler(QualityScalerQpUsageHandlerInterface* handler,
+                             VideoEncoder::QpThresholds thresholds,
+                             const FieldTrialsView& field_trials,
+                             int64_t default_sampling_period_ms)
+    : handler_(handler),
+      thresholds_(thresholds),
+      sampling_period_ms_(QualityScalerSettings(field_trials)
+                              .SamplingPeriodMs()
+                              .value_or(default_sampling_period_ms)),
+      fast_rampup_(true),
+      // Arbitrarily choose size based on 30 fps for 5 seconds.
+      average_qp_(QualityScalerSettings(field_trials)
+                      .AverageQpWindow()
+                      .value_or(5 * 30)),
+      framedrop_percent_media_opt_(5 * 30),
+      framedrop_percent_all_(5 * 30),
+      experiment_enabled_(QualityScalingExperiment::Enabled(field_trials)),
+      min_frames_needed_(QualityScalerSettings(field_trials)
+                             .MinFrames()
+                             .value_or(kMinFramesNeededToScale)),
+      initial_scale_factor_(QualityScalerSettings(field_trials)
+                                .InitialScaleFactor()
+                                .value_or(kSamplePeriodScaleFactor)),
+      scale_factor_(QualityScalerSettings(field_trials).ScaleFactor()) {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  if (experiment_enabled_) {
+    config_ = QualityScalingExperiment::GetConfig(field_trials);
+    qp_smoother_high_.reset(new QpSmoother(config_.alpha_high));
+    qp_smoother_low_.reset(new QpSmoother(config_.alpha_low));
+  }
+  RTC_DCHECK(handler_ != nullptr);
+  StartNextCheckQpTask();
+  RTC_LOG(LS_INFO) << "QP thresholds: low: " << thresholds_.low
+                   << ", high: " << thresholds_.high;
+}
+
+QualityScaler::~QualityScaler() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+}
+
+void QualityScaler::StartNextCheckQpTask() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  RTC_DCHECK(!pending_qp_task_ || pending_qp_task_->HasCompletedTask())
+      << "A previous CheckQpTask has not completed yet!";
+  CheckQpTask::Result previous_task_result;
+  if (pending_qp_task_) {
+    previous_task_result = pending_qp_task_->result();
+  }
+  pending_qp_task_ = std::make_unique<CheckQpTask>(this, previous_task_result);
+  pending_qp_task_->StartDelayedTask();
+}
+
+void QualityScaler::SetQpThresholds(VideoEncoder::QpThresholds thresholds) {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  thresholds_ = thresholds;
+}
+
+void QualityScaler::ReportDroppedFrameByMediaOpt() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  framedrop_percent_media_opt_.AddSample(100);
+  framedrop_percent_all_.AddSample(100);
+}
+
+void QualityScaler::ReportDroppedFrameByEncoder() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  framedrop_percent_all_.AddSample(100);
+}
+
+void QualityScaler::ReportQp(int qp, int64_t time_sent_us) {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  framedrop_percent_media_opt_.AddSample(0);
+  framedrop_percent_all_.AddSample(0);
+  average_qp_.AddSample(qp);
+  if (qp_smoother_high_)
+    qp_smoother_high_->Add(qp, time_sent_us);
+  if (qp_smoother_low_)
+    qp_smoother_low_->Add(qp, time_sent_us);
+}
+
+bool QualityScaler::QpFastFilterLow() const {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  size_t num_frames = config_.use_all_drop_reasons
+                          ? framedrop_percent_all_.Size()
+                          : framedrop_percent_media_opt_.Size();
+  const size_t kMinNumFrames = 10;
+  if (num_frames < kMinNumFrames) {
+    return false;  // Wait for more frames before making a decision.
+  }
+  absl::optional<int> avg_qp_high = qp_smoother_high_
+                                        ? qp_smoother_high_->GetAvg()
+                                        : average_qp_.GetAverageRoundedDown();
+  return (avg_qp_high) ? (avg_qp_high.value() <= thresholds_.low) : false;
+}
+
+QualityScaler::CheckQpResult QualityScaler::CheckQp() const {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  // Should be set through InitEncode -> Should be set by now.
+  RTC_DCHECK_GE(thresholds_.low, 0);
+
+  // If we have not observed at least this many frames we can't make a good
+  // scaling decision.
+  const size_t frames = config_.use_all_drop_reasons
+                            ? framedrop_percent_all_.Size()
+                            : framedrop_percent_media_opt_.Size();
+  if (frames < min_frames_needed_) {
+    return CheckQpResult::kInsufficientSamples;
+  }
+
+  // Check if we should scale down due to high frame drop.
+  const absl::optional<int> drop_rate =
+      config_.use_all_drop_reasons
+          ? framedrop_percent_all_.GetAverageRoundedDown()
+          : framedrop_percent_media_opt_.GetAverageRoundedDown();
+  if (drop_rate && *drop_rate >= kFramedropPercentThreshold) {
+    RTC_LOG(LS_INFO) << "Reporting high QP, framedrop percent " << *drop_rate;
+    return CheckQpResult::kHighQp;
+  }
+
+  // Check if we should scale up or down based on QP.
+  const absl::optional<int> avg_qp_high =
+      qp_smoother_high_ ? qp_smoother_high_->GetAvg()
+                        : average_qp_.GetAverageRoundedDown();
+  const absl::optional<int> avg_qp_low =
+      qp_smoother_low_ ? qp_smoother_low_->GetAvg()
+                       : average_qp_.GetAverageRoundedDown();
+  if (avg_qp_high && avg_qp_low) {
+    RTC_LOG(LS_INFO) << "Checking average QP " << *avg_qp_high << " ("
+                     << *avg_qp_low << ").";
+    if (*avg_qp_high > thresholds_.high) {
+      return CheckQpResult::kHighQp;
+    }
+    if (*avg_qp_low <= thresholds_.low) {
+      // QP has been low. We want to try a higher resolution.
+      return CheckQpResult::kLowQp;
+    }
+  }
+  return CheckQpResult::kNormalQp;
+}
+
+void QualityScaler::ClearSamples() {
+  RTC_DCHECK_RUN_ON(&task_checker_);
+  framedrop_percent_media_opt_.Reset();
+  framedrop_percent_all_.Reset();
+  average_qp_.Reset();
+  if (qp_smoother_high_)
+    qp_smoother_high_->Reset();
+  if (qp_smoother_low_)
+    qp_smoother_low_->Reset();
+}
+
+QualityScalerQpUsageHandlerInterface::~QualityScalerQpUsageHandlerInterface() {}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/quality_scaler.h b/third_party/libwebrtc/modules/video_coding/utility/quality_scaler.h
new file mode 100644
index 0000000000..14623ff1f3
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/quality_scaler.h
@@ -0,0 +1,123 @@
+/*
+ *  Copyright (c) 2014 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_VIDEO_CODING_UTILITY_QUALITY_SCALER_H_
+#define MODULES_VIDEO_CODING_UTILITY_QUALITY_SCALER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+
+#include "absl/types/optional.h"
+#include "api/field_trials_view.h"
+#include "api/scoped_refptr.h"
+#include "api/sequence_checker.h"
+#include "api/video_codecs/video_encoder.h"
+#include "rtc_base/experiments/quality_scaling_experiment.h"
+#include "rtc_base/numerics/moving_average.h"
+#include "rtc_base/ref_count.h"
+#include "rtc_base/system/no_unique_address.h"
+
+namespace webrtc {
+
+class QualityScalerQpUsageHandlerCallbackInterface;
+class QualityScalerQpUsageHandlerInterface;
+
+// QualityScaler runs asynchronously and monitors QP values of encoded frames.
+// It holds a reference to a QualityScalerQpUsageHandlerInterface implementation
+// to signal an overuse or underuse of QP (which indicate a desire to scale the
+// video stream down or up).
+class QualityScaler {
+ public:
+  // Construct a QualityScaler with given `thresholds` and `handler`.
+  // This starts the quality scaler periodically checking what the average QP
+  // has been recently.
+  QualityScaler(QualityScalerQpUsageHandlerInterface* handler,
+                VideoEncoder::QpThresholds thresholds,
+                const FieldTrialsView& field_trials);
+  virtual ~QualityScaler();
+  // Should be called each time a frame is dropped at encoding.
+  void ReportDroppedFrameByMediaOpt();
+  void ReportDroppedFrameByEncoder();
+  // Inform the QualityScaler of the last seen QP.
+  void ReportQp(int qp, int64_t time_sent_us);
+
+  void SetQpThresholds(VideoEncoder::QpThresholds thresholds);
+  bool QpFastFilterLow() const;
+
+  // The following members declared protected for testing purposes.
+ protected:
+  QualityScaler(QualityScalerQpUsageHandlerInterface* handler,
+                VideoEncoder::QpThresholds thresholds,
+                const FieldTrialsView& field_trials,
+                int64_t sampling_period_ms);
+
+ private:
+  class QpSmoother;
+  class CheckQpTask;
+  class CheckQpTaskHandlerCallback;
+
+  enum class CheckQpResult {
+    kInsufficientSamples,
+    kNormalQp,
+    kHighQp,
+    kLowQp,
+  };
+
+  // Starts checking for QP in a delayed task. When the resulting CheckQpTask
+  // completes, it will invoke this method again, ensuring that we always
+  // periodically check for QP. See CheckQpTask for more details. We never run
+  // more than one CheckQpTask at a time.
+  void StartNextCheckQpTask();
+
+  CheckQpResult CheckQp() const;
+  void ClearSamples();
+
+  std::unique_ptr<CheckQpTask> pending_qp_task_ RTC_GUARDED_BY(&task_checker_);
+  QualityScalerQpUsageHandlerInterface* const handler_
+      RTC_GUARDED_BY(&task_checker_);
+  RTC_NO_UNIQUE_ADDRESS SequenceChecker task_checker_;
+
+  VideoEncoder::QpThresholds thresholds_ RTC_GUARDED_BY(&task_checker_);
+  const int64_t sampling_period_ms_;
+  bool fast_rampup_ RTC_GUARDED_BY(&task_checker_);
+  rtc::MovingAverage average_qp_ RTC_GUARDED_BY(&task_checker_);
+  rtc::MovingAverage framedrop_percent_media_opt_
+      RTC_GUARDED_BY(&task_checker_);
+  rtc::MovingAverage framedrop_percent_all_ RTC_GUARDED_BY(&task_checker_);
+
+  // Used by QualityScalingExperiment.
+  const bool experiment_enabled_;
+  QualityScalingExperiment::Config config_ RTC_GUARDED_BY(&task_checker_);
+  std::unique_ptr<QpSmoother> qp_smoother_high_ RTC_GUARDED_BY(&task_checker_);
+  std::unique_ptr<QpSmoother> qp_smoother_low_ RTC_GUARDED_BY(&task_checker_);
+
+  const size_t min_frames_needed_;
+  const double initial_scale_factor_;
+  const absl::optional<double> scale_factor_;
+};
+
+// Reacts to QP being too high or too low. For best quality, when QP is high it
+// is desired to decrease the resolution or frame rate of the stream and when QP
+// is low it is desired to increase the resolution or frame rate of the stream.
+// Whether to reconfigure the stream is ultimately up to the handler, which is
+// able to respond asynchronously.
+class QualityScalerQpUsageHandlerInterface {
+ public:
+  virtual ~QualityScalerQpUsageHandlerInterface();
+
+  virtual void OnReportQpUsageHigh() = 0;
+  virtual void OnReportQpUsageLow() = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_QUALITY_SCALER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/quality_scaler_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/quality_scaler_unittest.cc
new file mode 100644
index 0000000000..1142947d54
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/quality_scaler_unittest.cc
@@ -0,0 +1,256 @@
+/*
+ *  Copyright (c) 2014 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/video_coding/utility/quality_scaler.h"
+
+#include <memory>
+#include <string>
+
+#include "api/field_trials_view.h"
+#include "api/units/time_delta.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/event.h"
+#include "rtc_base/task_queue_for_test.h"
+#include "test/gtest.h"
+#include "test/scoped_key_value_config.h"
+
+namespace webrtc {
+namespace {
+static const int kFramerate = 30;
+static const int kLowQp = 15;
+static const int kHighQp = 40;
+static const int kMinFramesNeededToScale = 60;  // From quality_scaler.cc.
+static constexpr TimeDelta kDefaultTimeout = TimeDelta::Millis(150);
+}  // namespace
+
+class FakeQpUsageHandler : public QualityScalerQpUsageHandlerInterface {
+ public:
+  ~FakeQpUsageHandler() override = default;
+
+  // QualityScalerQpUsageHandlerInterface implementation.
+  void OnReportQpUsageHigh() override {
+    adapt_down_events_++;
+    event.Set();
+  }
+
+  void OnReportQpUsageLow() override {
+    adapt_up_events_++;
+    event.Set();
+  }
+
+  rtc::Event event;
+  int adapt_up_events_ = 0;
+  int adapt_down_events_ = 0;
+};
+
+// Pass a lower sampling period to speed up the tests.
+class QualityScalerUnderTest : public QualityScaler {
+ public:
+  explicit QualityScalerUnderTest(QualityScalerQpUsageHandlerInterface* handler,
+                                  VideoEncoder::QpThresholds thresholds,
+                                  const FieldTrialsView& field_trials)
+      : QualityScaler(handler, thresholds, field_trials, 5) {}
+};
+
+class QualityScalerTest : public ::testing::Test,
+                          public ::testing::WithParamInterface<std::string> {
+ protected:
+  enum ScaleDirection {
+    kKeepScaleAboveLowQp,
+    kKeepScaleAtHighQp,
+    kScaleDown,
+    kScaleDownAboveHighQp,
+    kScaleUp
+  };
+
+  QualityScalerTest()
+      : scoped_field_trial_(GetParam()),
+        task_queue_("QualityScalerTestQueue"),
+        handler_(std::make_unique<FakeQpUsageHandler>()) {
+    task_queue_.SendTask([this] {
+      qs_ = std::unique_ptr<QualityScaler>(new QualityScalerUnderTest(
+          handler_.get(), VideoEncoder::QpThresholds(kLowQp, kHighQp),
+          scoped_field_trial_));
+    });
+  }
+
+  ~QualityScalerTest() override {
+    task_queue_.SendTask([this] { qs_ = nullptr; });
+  }
+
+  void TriggerScale(ScaleDirection scale_direction) {
+    for (int i = 0; i < kFramerate * 5; ++i) {
+      switch (scale_direction) {
+        case kKeepScaleAboveLowQp:
+          qs_->ReportQp(kLowQp + 1, 0);
+          break;
+        case kScaleUp:
+          qs_->ReportQp(kLowQp, 0);
+          break;
+        case kScaleDown:
+          qs_->ReportDroppedFrameByMediaOpt();
+          break;
+        case kKeepScaleAtHighQp:
+          qs_->ReportQp(kHighQp, 0);
+          break;
+        case kScaleDownAboveHighQp:
+          qs_->ReportQp(kHighQp + 1, 0);
+          break;
+      }
+    }
+  }
+
+  test::ScopedKeyValueConfig scoped_field_trial_;
+  TaskQueueForTest task_queue_;
+  std::unique_ptr<QualityScaler> qs_;
+  std::unique_ptr<FakeQpUsageHandler> handler_;
+};
+
+INSTANTIATE_TEST_SUITE_P(
+    FieldTrials,
+    QualityScalerTest,
+    ::testing::Values(
+        "WebRTC-Video-QualityScaling/Enabled-1,2,3,4,5,6,7,8,0.9,0.99,1/",
+        "WebRTC-Video-QualityScaling/Disabled/"));
+
+TEST_P(QualityScalerTest, DownscalesAfterContinuousFramedrop) {
+  task_queue_.SendTask([this] { TriggerScale(kScaleDown); });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(1, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, KeepsScaleAtHighQp) {
+  task_queue_.SendTask([this] { TriggerScale(kKeepScaleAtHighQp); });
+  EXPECT_FALSE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(0, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, DownscalesAboveHighQp) {
+  task_queue_.SendTask([this] { TriggerScale(kScaleDownAboveHighQp); });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(1, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, DownscalesAfterTwoThirdsFramedrop) {
+  task_queue_.SendTask([this] {
+    for (int i = 0; i < kFramerate * 5; ++i) {
+      qs_->ReportDroppedFrameByMediaOpt();
+      qs_->ReportDroppedFrameByMediaOpt();
+      qs_->ReportQp(kHighQp, 0);
+    }
+  });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(1, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, DoesNotDownscaleAfterHalfFramedrop) {
+  task_queue_.SendTask([this] {
+    for (int i = 0; i < kFramerate * 5; ++i) {
+      qs_->ReportDroppedFrameByMediaOpt();
+      qs_->ReportQp(kHighQp, 0);
+    }
+  });
+  EXPECT_FALSE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(0, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, DownscalesAfterTwoThirdsIfFieldTrialEnabled) {
+  const bool kDownScaleExpected =
+      GetParam().find("Enabled") != std::string::npos;
+  task_queue_.SendTask([this] {
+    for (int i = 0; i < kFramerate * 5; ++i) {
+      qs_->ReportDroppedFrameByMediaOpt();
+      qs_->ReportDroppedFrameByEncoder();
+      qs_->ReportQp(kHighQp, 0);
+    }
+  });
+  EXPECT_EQ(kDownScaleExpected, handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(kDownScaleExpected ? 1 : 0, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, KeepsScaleOnNormalQp) {
+  task_queue_.SendTask([this] { TriggerScale(kKeepScaleAboveLowQp); });
+  EXPECT_FALSE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(0, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, UpscalesAfterLowQp) {
+  task_queue_.SendTask([this] { TriggerScale(kScaleUp); });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(0, handler_->adapt_down_events_);
+  EXPECT_EQ(1, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, ScalesDownAndBackUp) {
+  task_queue_.SendTask([this] { TriggerScale(kScaleDown); });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(1, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+  task_queue_.SendTask([this] { TriggerScale(kScaleUp); });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(1, handler_->adapt_down_events_);
+  EXPECT_EQ(1, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, DoesNotScaleUntilEnoughFramesObserved) {
+  task_queue_.SendTask([this] {
+    // Not enough frames to make a decision.
+    for (int i = 0; i < kMinFramesNeededToScale - 1; ++i) {
+      qs_->ReportQp(kLowQp, 0);
+    }
+  });
+  EXPECT_FALSE(handler_->event.Wait(kDefaultTimeout));
+  task_queue_.SendTask([this] {
+    // Send 1 more. Enough frames observed, should result in an adapt
+    // request.
+    qs_->ReportQp(kLowQp, 0);
+  });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(0, handler_->adapt_down_events_);
+  EXPECT_EQ(1, handler_->adapt_up_events_);
+
+  // Samples should be cleared after an adapt request.
+  task_queue_.SendTask([this] {
+    // Not enough frames to make a decision.
+    qs_->ReportQp(kLowQp, 0);
+  });
+  EXPECT_FALSE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(0, handler_->adapt_down_events_);
+  EXPECT_EQ(1, handler_->adapt_up_events_);
+}
+
+TEST_P(QualityScalerTest, ScalesDownAndBackUpWithMinFramesNeeded) {
+  task_queue_.SendTask([this] {
+    for (int i = 0; i < kMinFramesNeededToScale; ++i) {
+      qs_->ReportQp(kHighQp + 1, 0);
+    }
+  });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(1, handler_->adapt_down_events_);
+  EXPECT_EQ(0, handler_->adapt_up_events_);
+  // Samples cleared.
+  task_queue_.SendTask([this] {
+    for (int i = 0; i < kMinFramesNeededToScale; ++i) {
+      qs_->ReportQp(kLowQp, 0);
+    }
+  });
+  EXPECT_TRUE(handler_->event.Wait(kDefaultTimeout));
+  EXPECT_EQ(1, handler_->adapt_down_events_);
+  EXPECT_EQ(1, handler_->adapt_up_events_);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator.cc b/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator.cc
new file mode 100644
index 0000000000..1496934e1c
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator.cc
@@ -0,0 +1,343 @@
+/*
+ *  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/video_coding/utility/simulcast_rate_allocator.h"
+
+#include <stdio.h>
+
+#include <algorithm>
+#include <cmath>
+#include <cstdint>
+#include <numeric>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "rtc_base/checks.h"
+#include "rtc_base/experiments/rate_control_settings.h"
+#include "system_wrappers/include/field_trial.h"
+
+namespace webrtc {
+namespace {
+// Ratio allocation between temporal streams:
+// Values as required for the VP8 codec (accumulating).
+static const float
+    kLayerRateAllocation[kMaxTemporalStreams][kMaxTemporalStreams] = {
+        {1.0f, 1.0f, 1.0f, 1.0f},  // 1 layer
+        {0.6f, 1.0f, 1.0f, 1.0f},  // 2 layers {60%, 40%}
+        {0.4f, 0.6f, 1.0f, 1.0f},  // 3 layers {40%, 20%, 40%}
+        {0.25f, 0.4f, 0.6f, 1.0f}  // 4 layers {25%, 15%, 20%, 40%}
+};
+
+static const float kBaseHeavy3TlRateAllocation[kMaxTemporalStreams] = {
+    0.6f, 0.8f, 1.0f, 1.0f  // 3 layers {60%, 20%, 20%}
+};
+
+const uint32_t kLegacyScreenshareTl0BitrateKbps = 200;
+const uint32_t kLegacyScreenshareTl1BitrateKbps = 1000;
+}  // namespace
+
+float SimulcastRateAllocator::GetTemporalRateAllocation(
+    int num_layers,
+    int temporal_id,
+    bool base_heavy_tl3_alloc) {
+  RTC_CHECK_GT(num_layers, 0);
+  RTC_CHECK_LE(num_layers, kMaxTemporalStreams);
+  RTC_CHECK_GE(temporal_id, 0);
+  RTC_CHECK_LT(temporal_id, num_layers);
+  if (num_layers == 3 && base_heavy_tl3_alloc) {
+    return kBaseHeavy3TlRateAllocation[temporal_id];
+  }
+  return kLayerRateAllocation[num_layers - 1][temporal_id];
+}
+
+SimulcastRateAllocator::SimulcastRateAllocator(const VideoCodec& codec)
+    : codec_(codec),
+      stable_rate_settings_(StableTargetRateExperiment::ParseFromFieldTrials()),
+      rate_control_settings_(RateControlSettings::ParseFromFieldTrials()),
+      legacy_conference_mode_(false) {}
+
+SimulcastRateAllocator::~SimulcastRateAllocator() = default;
+
+VideoBitrateAllocation SimulcastRateAllocator::Allocate(
+    VideoBitrateAllocationParameters parameters) {
+  VideoBitrateAllocation allocated_bitrates;
+  DataRate stable_rate = parameters.total_bitrate;
+  if (stable_rate_settings_.IsEnabled() &&
+      parameters.stable_bitrate > DataRate::Zero()) {
+    stable_rate = std::min(parameters.stable_bitrate, parameters.total_bitrate);
+  }
+  DistributeAllocationToSimulcastLayers(parameters.total_bitrate, stable_rate,
+                                        &allocated_bitrates);
+  DistributeAllocationToTemporalLayers(&allocated_bitrates);
+  return allocated_bitrates;
+}
+
+void SimulcastRateAllocator::DistributeAllocationToSimulcastLayers(
+    DataRate total_bitrate,
+    DataRate stable_bitrate,
+    VideoBitrateAllocation* allocated_bitrates) {
+  DataRate left_in_total_allocation = total_bitrate;
+  DataRate left_in_stable_allocation = stable_bitrate;
+
+  if (codec_.maxBitrate) {
+    DataRate max_rate = DataRate::KilobitsPerSec(codec_.maxBitrate);
+    left_in_total_allocation = std::min(left_in_total_allocation, max_rate);
+    left_in_stable_allocation = std::min(left_in_stable_allocation, max_rate);
+  }
+
+  if (codec_.numberOfSimulcastStreams == 0) {
+    // No simulcast, just set the target as this has been capped already.
+    if (codec_.active) {
+      allocated_bitrates->SetBitrate(
+          0, 0,
+          std::max(DataRate::KilobitsPerSec(codec_.minBitrate),
+                   left_in_total_allocation)
+              .bps());
+    }
+    return;
+  }
+
+  // Sort the layers by maxFramerate, they might not always be from smallest
+  // to biggest
+  std::vector<size_t> layer_index(codec_.numberOfSimulcastStreams);
+  std::iota(layer_index.begin(), layer_index.end(), 0);
+  std::stable_sort(layer_index.begin(), layer_index.end(),
+                   [this](size_t a, size_t b) {
+                     return std::tie(codec_.simulcastStream[a].maxBitrate) <
+                            std::tie(codec_.simulcastStream[b].maxBitrate);
+                   });
+
+  // Find the first active layer. We don't allocate to inactive layers.
+  size_t active_layer = 0;
+  for (; active_layer < codec_.numberOfSimulcastStreams; ++active_layer) {
+    if (codec_.simulcastStream[layer_index[active_layer]].active) {
+      // Found the first active layer.
+      break;
+    }
+  }
+  // All streams could be inactive, and nothing more to do.
+  if (active_layer == codec_.numberOfSimulcastStreams) {
+    return;
+  }
+
+  // Always allocate enough bitrate for the minimum bitrate of the first
+  // active layer. Suspending below min bitrate is controlled outside the
+  // codec implementation and is not overridden by this.
+  DataRate min_rate = DataRate::KilobitsPerSec(
+      codec_.simulcastStream[layer_index[active_layer]].minBitrate);
+  left_in_total_allocation = std::max(left_in_total_allocation, min_rate);
+  left_in_stable_allocation = std::max(left_in_stable_allocation, min_rate);
+
+  // Begin by allocating bitrate to simulcast streams, putting all bitrate in
+  // temporal layer 0. We'll then distribute this bitrate, across potential
+  // temporal layers, when stream allocation is done.
+
+  bool first_allocation = false;
+  if (stream_enabled_.empty()) {
+    // First time allocating, this means we should not include hysteresis in
+    // case this is a reconfiguration of an existing enabled stream.
+    first_allocation = true;
+    stream_enabled_.resize(codec_.numberOfSimulcastStreams, false);
+  }
+
+  size_t top_active_layer = active_layer;
+  // Allocate up to the target bitrate for each active simulcast layer.
+  for (; active_layer < codec_.numberOfSimulcastStreams; ++active_layer) {
+    const SimulcastStream& stream =
+        codec_.simulcastStream[layer_index[active_layer]];
+    if (!stream.active) {
+      stream_enabled_[layer_index[active_layer]] = false;
+      continue;
+    }
+    // If we can't allocate to the current layer we can't allocate to higher
+    // layers because they require a higher minimum bitrate.
+    DataRate min_bitrate = DataRate::KilobitsPerSec(stream.minBitrate);
+    DataRate target_bitrate = DataRate::KilobitsPerSec(stream.targetBitrate);
+    double hysteresis_factor =
+        codec_.mode == VideoCodecMode::kRealtimeVideo
+            ? stable_rate_settings_.GetVideoHysteresisFactor()
+            : stable_rate_settings_.GetScreenshareHysteresisFactor();
+    if (!first_allocation && !stream_enabled_[layer_index[active_layer]]) {
+      min_bitrate = std::min(hysteresis_factor * min_bitrate, target_bitrate);
+    }
+    if (left_in_stable_allocation < min_bitrate) {
+      allocated_bitrates->set_bw_limited(true);
+      break;
+    }
+
+    // We are allocating to this layer so it is the current active allocation.
+    top_active_layer = layer_index[active_layer];
+    stream_enabled_[layer_index[active_layer]] = true;
+    DataRate layer_rate = std::min(left_in_total_allocation, target_bitrate);
+    allocated_bitrates->SetBitrate(layer_index[active_layer], 0,
+                                   layer_rate.bps());
+    left_in_total_allocation -= layer_rate;
+    left_in_stable_allocation -=
+        std::min(left_in_stable_allocation, target_bitrate);
+  }
+
+  // All layers above this one are not active.
+  for (; active_layer < codec_.numberOfSimulcastStreams; ++active_layer) {
+    stream_enabled_[layer_index[active_layer]] = false;
+  }
+
+  // Next, try allocate remaining bitrate, up to max bitrate, in top active
+  // stream.
+  // TODO(sprang): Allocate up to max bitrate for all layers once we have a
+  //               better idea of possible performance implications.
+  if (left_in_total_allocation > DataRate::Zero()) {
+    const SimulcastStream& stream = codec_.simulcastStream[top_active_layer];
+    DataRate initial_layer_rate = DataRate::BitsPerSec(
+        allocated_bitrates->GetSpatialLayerSum(top_active_layer));
+    DataRate additional_allocation = std::min(
+        left_in_total_allocation,
+        DataRate::KilobitsPerSec(stream.maxBitrate) - initial_layer_rate);
+    allocated_bitrates->SetBitrate(
+        top_active_layer, 0,
+        (initial_layer_rate + additional_allocation).bps());
+  }
+}
+
+void SimulcastRateAllocator::DistributeAllocationToTemporalLayers(
+    VideoBitrateAllocation* allocated_bitrates_bps) const {
+  const int num_spatial_streams =
+      std::max(1, static_cast<int>(codec_.numberOfSimulcastStreams));
+
+  // Finally, distribute the bitrate for the simulcast streams across the
+  // available temporal layers.
+  for (int simulcast_id = 0; simulcast_id < num_spatial_streams;
+       ++simulcast_id) {
+    uint32_t target_bitrate_kbps =
+        allocated_bitrates_bps->GetBitrate(simulcast_id, 0) / 1000;
+    if (target_bitrate_kbps == 0) {
+      continue;
+    }
+
+    const uint32_t expected_allocated_bitrate_kbps = target_bitrate_kbps;
+    RTC_DCHECK_EQ(
+        target_bitrate_kbps,
+        allocated_bitrates_bps->GetSpatialLayerSum(simulcast_id) / 1000);
+    const int num_temporal_streams = NumTemporalStreams(simulcast_id);
+    uint32_t max_bitrate_kbps;
+    // Legacy temporal-layered only screenshare, or simulcast screenshare
+    // with legacy mode for simulcast stream 0.
+    if (codec_.mode == VideoCodecMode::kScreensharing &&
+        legacy_conference_mode_ && simulcast_id == 0) {
+      // TODO(holmer): This is a "temporary" hack for screensharing, where we
+      // interpret the startBitrate as the encoder target bitrate. This is
+      // to allow for a different max bitrate, so if the codec can't meet
+      // the target we still allow it to overshoot up to the max before dropping
+      // frames. This hack should be improved.
+      max_bitrate_kbps =
+          std::min(kLegacyScreenshareTl1BitrateKbps, target_bitrate_kbps);
+      target_bitrate_kbps =
+          std::min(kLegacyScreenshareTl0BitrateKbps, target_bitrate_kbps);
+    } else if (num_spatial_streams == 1) {
+      max_bitrate_kbps = codec_.maxBitrate;
+    } else {
+      max_bitrate_kbps = codec_.simulcastStream[simulcast_id].maxBitrate;
+    }
+
+    std::vector<uint32_t> tl_allocation;
+    if (num_temporal_streams == 1) {
+      tl_allocation.push_back(target_bitrate_kbps);
+    } else {
+      if (codec_.mode == VideoCodecMode::kScreensharing &&
+          legacy_conference_mode_ && simulcast_id == 0) {
+        tl_allocation = ScreenshareTemporalLayerAllocation(
+            target_bitrate_kbps, max_bitrate_kbps, simulcast_id);
+      } else {
+        tl_allocation = DefaultTemporalLayerAllocation(
+            target_bitrate_kbps, max_bitrate_kbps, simulcast_id);
+      }
+    }
+    RTC_DCHECK_GT(tl_allocation.size(), 0);
+    RTC_DCHECK_LE(tl_allocation.size(), num_temporal_streams);
+
+    uint64_t tl_allocation_sum_kbps = 0;
+    for (size_t tl_index = 0; tl_index < tl_allocation.size(); ++tl_index) {
+      uint32_t layer_rate_kbps = tl_allocation[tl_index];
+      if (layer_rate_kbps > 0) {
+        allocated_bitrates_bps->SetBitrate(simulcast_id, tl_index,
+                                           layer_rate_kbps * 1000);
+      }
+      tl_allocation_sum_kbps += layer_rate_kbps;
+    }
+    RTC_DCHECK_LE(tl_allocation_sum_kbps, expected_allocated_bitrate_kbps);
+  }
+}
+
+std::vector<uint32_t> SimulcastRateAllocator::DefaultTemporalLayerAllocation(
+    int bitrate_kbps,
+    int max_bitrate_kbps,
+    int simulcast_id) const {
+  const size_t num_temporal_layers = NumTemporalStreams(simulcast_id);
+  std::vector<uint32_t> bitrates;
+  for (size_t i = 0; i < num_temporal_layers; ++i) {
+    float layer_bitrate =
+        bitrate_kbps *
+        GetTemporalRateAllocation(
+            num_temporal_layers, i,
+            rate_control_settings_.Vp8BaseHeavyTl3RateAllocation());
+    bitrates.push_back(static_cast<uint32_t>(layer_bitrate + 0.5));
+  }
+
+  // Allocation table is of aggregates, transform to individual rates.
+  uint32_t sum = 0;
+  for (size_t i = 0; i < num_temporal_layers; ++i) {
+    uint32_t layer_bitrate = bitrates[i];
+    RTC_DCHECK_LE(sum, bitrates[i]);
+    bitrates[i] -= sum;
+    sum = layer_bitrate;
+
+    if (sum >= static_cast<uint32_t>(bitrate_kbps)) {
+      // Sum adds up; any subsequent layers will be 0.
+      bitrates.resize(i + 1);
+      break;
+    }
+  }
+
+  return bitrates;
+}
+
+std::vector<uint32_t>
+SimulcastRateAllocator::ScreenshareTemporalLayerAllocation(
+    int bitrate_kbps,
+    int max_bitrate_kbps,
+    int simulcast_id) const {
+  if (simulcast_id > 0) {
+    return DefaultTemporalLayerAllocation(bitrate_kbps, max_bitrate_kbps,
+                                          simulcast_id);
+  }
+  std::vector<uint32_t> allocation;
+  allocation.push_back(bitrate_kbps);
+  if (max_bitrate_kbps > bitrate_kbps)
+    allocation.push_back(max_bitrate_kbps - bitrate_kbps);
+  return allocation;
+}
+
+const VideoCodec& webrtc::SimulcastRateAllocator::GetCodec() const {
+  return codec_;
+}
+
+int SimulcastRateAllocator::NumTemporalStreams(size_t simulcast_id) const {
+  return std::max<uint8_t>(
+      1,
+      codec_.codecType == kVideoCodecVP8 && codec_.numberOfSimulcastStreams == 0
+          ? codec_.VP8().numberOfTemporalLayers
+          : codec_.simulcastStream[simulcast_id].numberOfTemporalLayers);
+}
+
+void SimulcastRateAllocator::SetLegacyConferenceMode(bool enabled) {
+  legacy_conference_mode_ = enabled;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator.h b/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator.h
new file mode 100644
index 0000000000..6f93dbde74
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator.h
@@ -0,0 +1,70 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_SIMULCAST_RATE_ALLOCATOR_H_
+#define MODULES_VIDEO_CODING_UTILITY_SIMULCAST_RATE_ALLOCATOR_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <vector>
+
+#include "api/video/video_bitrate_allocation.h"
+#include "api/video/video_bitrate_allocator.h"
+#include "api/video_codecs/video_codec.h"
+#include "rtc_base/experiments/rate_control_settings.h"
+#include "rtc_base/experiments/stable_target_rate_experiment.h"
+
+namespace webrtc {
+
+class SimulcastRateAllocator : public VideoBitrateAllocator {
+ public:
+  explicit SimulcastRateAllocator(const VideoCodec& codec);
+  ~SimulcastRateAllocator() override;
+
+  SimulcastRateAllocator(const SimulcastRateAllocator&) = delete;
+  SimulcastRateAllocator& operator=(const SimulcastRateAllocator&) = delete;
+
+  VideoBitrateAllocation Allocate(
+      VideoBitrateAllocationParameters parameters) override;
+  const VideoCodec& GetCodec() const;
+
+  static float GetTemporalRateAllocation(int num_layers,
+                                         int temporal_id,
+                                         bool base_heavy_tl3_alloc);
+
+  void SetLegacyConferenceMode(bool mode) override;
+
+ private:
+  void DistributeAllocationToSimulcastLayers(
+      DataRate total_bitrate,
+      DataRate stable_bitrate,
+      VideoBitrateAllocation* allocated_bitrates);
+  void DistributeAllocationToTemporalLayers(
+      VideoBitrateAllocation* allocated_bitrates) const;
+  std::vector<uint32_t> DefaultTemporalLayerAllocation(int bitrate_kbps,
+                                                       int max_bitrate_kbps,
+                                                       int simulcast_id) const;
+  std::vector<uint32_t> ScreenshareTemporalLayerAllocation(
+      int bitrate_kbps,
+      int max_bitrate_kbps,
+      int simulcast_id) const;
+  int NumTemporalStreams(size_t simulcast_id) const;
+
+  const VideoCodec codec_;
+  const StableTargetRateExperiment stable_rate_settings_;
+  const RateControlSettings rate_control_settings_;
+  std::vector<bool> stream_enabled_;
+  bool legacy_conference_mode_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_SIMULCAST_RATE_ALLOCATOR_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator_unittest.cc
new file mode 100644
index 0000000000..24d7c58bcd
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/simulcast_rate_allocator_unittest.cc
@@ -0,0 +1,824 @@
+/*
+ *  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/video_coding/utility/simulcast_rate_allocator.h"
+
+#include <limits>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "api/video_codecs/vp8_frame_buffer_controller.h"
+#include "api/video_codecs/vp8_frame_config.h"
+#include "api/video_codecs/vp8_temporal_layers.h"
+#include "rtc_base/checks.h"
+#include "test/field_trial.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+using ::testing::_;
+
+constexpr uint32_t kFramerateFps = 5;
+constexpr uint32_t kMinBitrateKbps = 50;
+// These correspond to kLegacyScreenshareTl(0|1)BitrateKbps in cc.
+constexpr uint32_t kLegacyScreenshareTargetBitrateKbps = 200;
+constexpr uint32_t kLegacyScreenshareMaxBitrateKbps = 1000;
+// Bitrates for upper simulcast screenshare layer.
+constexpr uint32_t kSimulcastScreenshareMinBitrateKbps = 600;
+constexpr uint32_t kSimulcastScreenshareMaxBitrateKbps = 1250;
+// Default video hysteresis factor: allocatable bitrate for next layer must
+// exceed 20% of min setting in order to be initially turned on.
+const double kDefaultHysteresis = 1.2;
+
+class MockTemporalLayers : public Vp8FrameBufferController {
+ public:
+  MOCK_METHOD(Vp8FrameConfig, NextFrameConfig, (size_t, uint32_t), (override));
+  MOCK_METHOD(void,
+              OnRatesUpdated,
+              (size_t, const std::vector<uint32_t>&, int),
+              (override));
+  MOCK_METHOD(Vp8EncoderConfig, UpdateConfiguration, (size_t), (override));
+  MOCK_METHOD(void,
+              OnEncodeDone,
+              (size_t, uint32_t, size_t, bool, int, CodecSpecificInfo*),
+              (override));
+};
+}  // namespace
+
+class SimulcastRateAllocatorTest : public ::testing::TestWithParam<bool> {
+ public:
+  SimulcastRateAllocatorTest() {
+    codec_.codecType = kVideoCodecVP8;
+    codec_.minBitrate = kMinBitrateKbps;
+    codec_.maxBitrate = kLegacyScreenshareMaxBitrateKbps;
+    codec_.active = true;
+    CreateAllocator();
+  }
+  virtual ~SimulcastRateAllocatorTest() {}
+
+  template <size_t S>
+  void ExpectEqual(uint32_t (&expected)[S],
+                   const std::vector<uint32_t>& actual) {
+    EXPECT_EQ(S, actual.size());
+    for (size_t i = 0; i < S; ++i)
+      EXPECT_EQ(expected[i], actual[i]) << "Mismatch at index " << i;
+  }
+
+  template <size_t S>
+  void ExpectEqual(uint32_t (&expected)[S],
+                   const VideoBitrateAllocation& actual) {
+    // EXPECT_EQ(S, actual.size());
+    uint32_t sum = 0;
+    for (size_t i = 0; i < S; ++i) {
+      uint32_t layer_bitrate = actual.GetSpatialLayerSum(i);
+      if (layer_bitrate == 0) {
+        EXPECT_FALSE(actual.IsSpatialLayerUsed(i));
+      }
+      EXPECT_EQ(expected[i] * 1000U, layer_bitrate)
+          << "Mismatch at index " << i;
+      sum += layer_bitrate;
+    }
+    EXPECT_EQ(sum, actual.get_sum_bps());
+  }
+
+  void CreateAllocator(bool legacy_conference_mode = false) {
+    allocator_.reset(new SimulcastRateAllocator(codec_));
+    allocator_->SetLegacyConferenceMode(legacy_conference_mode);
+  }
+
+  void SetupCodec3SL3TL(const std::vector<bool>& active_streams) {
+    const size_t num_simulcast_layers = 3;
+    RTC_DCHECK_GE(active_streams.size(), num_simulcast_layers);
+    SetupCodec2SL3TL(active_streams);
+    codec_.numberOfSimulcastStreams = num_simulcast_layers;
+    codec_.simulcastStream[2].numberOfTemporalLayers = 3;
+    codec_.simulcastStream[2].maxBitrate = 4000;
+    codec_.simulcastStream[2].targetBitrate = 3000;
+    codec_.simulcastStream[2].minBitrate = 2000;
+    codec_.simulcastStream[2].active = active_streams[2];
+  }
+
+  void SetupCodec2SL3TL(const std::vector<bool>& active_streams) {
+    const size_t num_simulcast_layers = 2;
+    RTC_DCHECK_GE(active_streams.size(), num_simulcast_layers);
+    SetupCodec1SL3TL(active_streams);
+    codec_.numberOfSimulcastStreams = num_simulcast_layers;
+    codec_.simulcastStream[1].numberOfTemporalLayers = 3;
+    codec_.simulcastStream[1].maxBitrate = 1000;
+    codec_.simulcastStream[1].targetBitrate = 500;
+    codec_.simulcastStream[1].minBitrate = 50;
+    codec_.simulcastStream[1].active = active_streams[1];
+  }
+
+  void SetupCodec1SL3TL(const std::vector<bool>& active_streams) {
+    const size_t num_simulcast_layers = 2;
+    RTC_DCHECK_GE(active_streams.size(), num_simulcast_layers);
+    SetupCodec3TL();
+    codec_.numberOfSimulcastStreams = num_simulcast_layers;
+    codec_.simulcastStream[0].numberOfTemporalLayers = 3;
+    codec_.simulcastStream[0].maxBitrate = 500;
+    codec_.simulcastStream[0].targetBitrate = 100;
+    codec_.simulcastStream[0].minBitrate = 10;
+    codec_.simulcastStream[0].active = active_streams[0];
+  }
+
+  void SetupCodec3TL() {
+    codec_.maxBitrate = 0;
+    codec_.VP8()->numberOfTemporalLayers = 3;
+  }
+
+  VideoBitrateAllocation GetAllocation(uint32_t target_bitrate) {
+    return allocator_->Allocate(VideoBitrateAllocationParameters(
+        DataRate::KilobitsPerSec(target_bitrate), kDefaultFrameRate));
+  }
+
+  VideoBitrateAllocation GetAllocation(DataRate target_rate,
+                                       DataRate stable_rate) {
+    return allocator_->Allocate(VideoBitrateAllocationParameters(
+        target_rate, stable_rate, kDefaultFrameRate));
+  }
+
+  DataRate MinRate(size_t layer_index) const {
+    return DataRate::KilobitsPerSec(
+        codec_.simulcastStream[layer_index].minBitrate);
+  }
+
+  DataRate TargetRate(size_t layer_index) const {
+    return DataRate::KilobitsPerSec(
+        codec_.simulcastStream[layer_index].targetBitrate);
+  }
+
+  DataRate MaxRate(size_t layer_index) const {
+    return DataRate::KilobitsPerSec(
+        codec_.simulcastStream[layer_index].maxBitrate);
+  }
+
+ protected:
+  static const int kDefaultFrameRate = 30;
+  VideoCodec codec_;
+  std::unique_ptr<SimulcastRateAllocator> allocator_;
+};
+
+TEST_F(SimulcastRateAllocatorTest, NoSimulcastBelowMin) {
+  uint32_t expected[] = {codec_.minBitrate};
+  codec_.active = true;
+  ExpectEqual(expected, GetAllocation(codec_.minBitrate - 1));
+  ExpectEqual(expected, GetAllocation(1));
+  ExpectEqual(expected, GetAllocation(0));
+}
+
+TEST_F(SimulcastRateAllocatorTest, NoSimulcastAboveMax) {
+  uint32_t expected[] = {codec_.maxBitrate};
+  codec_.active = true;
+  ExpectEqual(expected, GetAllocation(codec_.maxBitrate + 1));
+  ExpectEqual(expected, GetAllocation(std::numeric_limits<uint32_t>::max()));
+}
+
+TEST_F(SimulcastRateAllocatorTest, NoSimulcastNoMax) {
+  const uint32_t kMax = VideoBitrateAllocation::kMaxBitrateBps / 1000;
+  codec_.active = true;
+  codec_.maxBitrate = 0;
+  CreateAllocator();
+
+  uint32_t expected[] = {kMax};
+  ExpectEqual(expected, GetAllocation(kMax));
+}
+
+TEST_F(SimulcastRateAllocatorTest, NoSimulcastWithinLimits) {
+  codec_.active = true;
+  for (uint32_t bitrate = codec_.minBitrate; bitrate <= codec_.maxBitrate;
+       ++bitrate) {
+    uint32_t expected[] = {bitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+}
+
+// Tests that when we aren't using simulcast and the codec is marked inactive no
+// bitrate will be allocated.
+TEST_F(SimulcastRateAllocatorTest, NoSimulcastInactive) {
+  codec_.active = false;
+  uint32_t expected[] = {0};
+  CreateAllocator();
+
+  ExpectEqual(expected, GetAllocation(kMinBitrateKbps - 10));
+  ExpectEqual(expected, GetAllocation(kLegacyScreenshareTargetBitrateKbps));
+  ExpectEqual(expected, GetAllocation(kLegacyScreenshareMaxBitrateKbps + 10));
+}
+
+TEST_F(SimulcastRateAllocatorTest, SingleSimulcastBelowMin) {
+  // With simulcast, use the min bitrate from the ss spec instead of the global.
+  codec_.numberOfSimulcastStreams = 1;
+  const uint32_t kMin = codec_.minBitrate - 10;
+  codec_.simulcastStream[0].minBitrate = kMin;
+  codec_.simulcastStream[0].targetBitrate = kLegacyScreenshareTargetBitrateKbps;
+  codec_.simulcastStream[0].active = true;
+  CreateAllocator();
+
+  uint32_t expected[] = {kMin};
+  ExpectEqual(expected, GetAllocation(kMin - 1));
+  ExpectEqual(expected, GetAllocation(1));
+  ExpectEqual(expected, GetAllocation(0));
+}
+
+TEST_F(SimulcastRateAllocatorTest, SignalsBwLimited) {
+  // Enough to enable all layers.
+  const int kVeryBigBitrate = 100000;
+
+  // With simulcast, use the min bitrate from the ss spec instead of the global.
+  SetupCodec3SL3TL({true, true, true});
+  CreateAllocator();
+
+  EXPECT_TRUE(
+      GetAllocation(codec_.simulcastStream[0].minBitrate - 10).is_bw_limited());
+  EXPECT_TRUE(
+      GetAllocation(codec_.simulcastStream[0].targetBitrate).is_bw_limited());
+  EXPECT_TRUE(GetAllocation(codec_.simulcastStream[0].targetBitrate +
+                            codec_.simulcastStream[1].minBitrate)
+                  .is_bw_limited());
+  EXPECT_FALSE(
+      GetAllocation(
+          codec_.simulcastStream[0].targetBitrate +
+          codec_.simulcastStream[1].targetBitrate +
+          static_cast<uint32_t>(
+              codec_.simulcastStream[2].minBitrate * kDefaultHysteresis + 0.5))
+          .is_bw_limited());
+  EXPECT_FALSE(GetAllocation(kVeryBigBitrate).is_bw_limited());
+}
+
+TEST_F(SimulcastRateAllocatorTest, SingleSimulcastAboveMax) {
+  codec_.numberOfSimulcastStreams = 1;
+  codec_.simulcastStream[0].minBitrate = kMinBitrateKbps;
+  const uint32_t kMax = codec_.simulcastStream[0].maxBitrate + 1000;
+  codec_.simulcastStream[0].maxBitrate = kMax;
+  codec_.simulcastStream[0].active = true;
+  CreateAllocator();
+
+  uint32_t expected[] = {kMax};
+  ExpectEqual(expected, GetAllocation(kMax));
+  ExpectEqual(expected, GetAllocation(kMax + 1));
+  ExpectEqual(expected, GetAllocation(std::numeric_limits<uint32_t>::max()));
+}
+
+TEST_F(SimulcastRateAllocatorTest, SingleSimulcastWithinLimits) {
+  codec_.numberOfSimulcastStreams = 1;
+  codec_.simulcastStream[0].minBitrate = kMinBitrateKbps;
+  codec_.simulcastStream[0].targetBitrate = kLegacyScreenshareTargetBitrateKbps;
+  codec_.simulcastStream[0].maxBitrate = kLegacyScreenshareMaxBitrateKbps;
+  codec_.simulcastStream[0].active = true;
+  CreateAllocator();
+
+  for (uint32_t bitrate = kMinBitrateKbps;
+       bitrate <= kLegacyScreenshareMaxBitrateKbps; ++bitrate) {
+    uint32_t expected[] = {bitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+}
+
+TEST_F(SimulcastRateAllocatorTest, Regular3TLTemporalRateAllocation) {
+  SetupCodec3SL3TL({true, true, true});
+  CreateAllocator();
+
+  const VideoBitrateAllocation alloc = GetAllocation(kMinBitrateKbps);
+  // 40/20/40.
+  EXPECT_EQ(static_cast<uint32_t>(0.4 * kMinBitrateKbps),
+            alloc.GetBitrate(0, 0) / 1000);
+  EXPECT_EQ(static_cast<uint32_t>(0.2 * kMinBitrateKbps),
+            alloc.GetBitrate(0, 1) / 1000);
+  EXPECT_EQ(static_cast<uint32_t>(0.4 * kMinBitrateKbps),
+            alloc.GetBitrate(0, 2) / 1000);
+}
+
+TEST_F(SimulcastRateAllocatorTest, BaseHeavy3TLTemporalRateAllocation) {
+  test::ScopedFieldTrials field_trials(
+      "WebRTC-UseBaseHeavyVP8TL3RateAllocation/Enabled/");
+
+  SetupCodec3SL3TL({true, true, true});
+  CreateAllocator();
+
+  const VideoBitrateAllocation alloc = GetAllocation(kMinBitrateKbps);
+  // 60/20/20.
+  EXPECT_EQ(static_cast<uint32_t>(0.6 * kMinBitrateKbps),
+            alloc.GetBitrate(0, 0) / 1000);
+  EXPECT_EQ(static_cast<uint32_t>(0.2 * kMinBitrateKbps),
+            alloc.GetBitrate(0, 1) / 1000);
+  EXPECT_EQ(static_cast<uint32_t>(0.2 * kMinBitrateKbps),
+            alloc.GetBitrate(0, 2) / 1000);
+}
+
+TEST_F(SimulcastRateAllocatorTest, SingleSimulcastInactive) {
+  codec_.numberOfSimulcastStreams = 1;
+  codec_.simulcastStream[0].minBitrate = kMinBitrateKbps;
+  codec_.simulcastStream[0].targetBitrate = kLegacyScreenshareTargetBitrateKbps;
+  codec_.simulcastStream[0].maxBitrate = kLegacyScreenshareMaxBitrateKbps;
+  codec_.simulcastStream[0].active = false;
+  CreateAllocator();
+
+  uint32_t expected[] = {0};
+  ExpectEqual(expected, GetAllocation(kMinBitrateKbps - 10));
+  ExpectEqual(expected, GetAllocation(kLegacyScreenshareTargetBitrateKbps));
+  ExpectEqual(expected, GetAllocation(kLegacyScreenshareMaxBitrateKbps + 10));
+}
+
+TEST_F(SimulcastRateAllocatorTest, OneToThreeStreams) {
+  SetupCodec3SL3TL({true, true, true});
+  CreateAllocator();
+
+  {
+    // Single stream, min bitrate.
+    const uint32_t bitrate = codec_.simulcastStream[0].minBitrate;
+    uint32_t expected[] = {bitrate, 0, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Single stream at target bitrate.
+    const uint32_t bitrate = codec_.simulcastStream[0].targetBitrate;
+    uint32_t expected[] = {bitrate, 0, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  uint32_t kMinInitialRateTwoLayers =
+      codec_.simulcastStream[0].targetBitrate +
+      static_cast<uint32_t>(codec_.simulcastStream[1].minBitrate *
+                            kDefaultHysteresis);
+  {
+    // Bitrate above target for first stream, but below min for the next one.
+    const uint32_t bitrate = kMinInitialRateTwoLayers - 1;
+    uint32_t expected[] = {bitrate, 0, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Just enough for two streams.
+    const uint32_t bitrate = kMinInitialRateTwoLayers;
+    uint32_t expected[] = {
+        codec_.simulcastStream[0].targetBitrate,
+        kMinInitialRateTwoLayers - codec_.simulcastStream[0].targetBitrate, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Second stream maxed out, but not enough for third.
+    const uint32_t bitrate = codec_.simulcastStream[0].targetBitrate +
+                             codec_.simulcastStream[1].maxBitrate;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate,
+                           codec_.simulcastStream[1].maxBitrate, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  uint32_t kMinInitialRateThreeLayers =
+      codec_.simulcastStream[0].targetBitrate +
+      codec_.simulcastStream[1].targetBitrate +
+      static_cast<uint32_t>(codec_.simulcastStream[2].minBitrate *
+                            kDefaultHysteresis);
+  {
+    // First two streams maxed out, but not enough for third. Nowhere to put
+    // remaining bits.
+    const uint32_t bitrate = kMinInitialRateThreeLayers - 1;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate,
+                           codec_.simulcastStream[1].maxBitrate, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Just enough for all three streams.
+    const uint32_t bitrate = kMinInitialRateThreeLayers;
+    uint32_t expected[] = {
+        codec_.simulcastStream[0].targetBitrate,
+        codec_.simulcastStream[1].targetBitrate,
+        static_cast<uint32_t>(codec_.simulcastStream[2].minBitrate *
+                              kDefaultHysteresis)};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Third maxed out.
+    const uint32_t bitrate = codec_.simulcastStream[0].targetBitrate +
+                             codec_.simulcastStream[1].targetBitrate +
+                             codec_.simulcastStream[2].maxBitrate;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate,
+                           codec_.simulcastStream[1].targetBitrate,
+                           codec_.simulcastStream[2].maxBitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Enough to max out all streams which will allocate the target amount to
+    // the lower streams.
+    const uint32_t bitrate = codec_.simulcastStream[0].maxBitrate +
+                             codec_.simulcastStream[1].maxBitrate +
+                             codec_.simulcastStream[2].maxBitrate;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate,
+                           codec_.simulcastStream[1].targetBitrate,
+                           codec_.simulcastStream[2].maxBitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+}
+
+// If three simulcast streams that are all inactive, none of them should be
+// allocated bitrate.
+TEST_F(SimulcastRateAllocatorTest, ThreeStreamsInactive) {
+  SetupCodec3SL3TL({false, false, false});
+  CreateAllocator();
+
+  // Just enough to allocate the min.
+  const uint32_t min_bitrate = codec_.simulcastStream[0].minBitrate +
+                               codec_.simulcastStream[1].minBitrate +
+                               codec_.simulcastStream[2].minBitrate;
+  // Enough bitrate to allocate target to all streams.
+  const uint32_t target_bitrate = codec_.simulcastStream[0].targetBitrate +
+                                  codec_.simulcastStream[1].targetBitrate +
+                                  codec_.simulcastStream[2].targetBitrate;
+  // Enough bitrate to allocate max to all streams.
+  const uint32_t max_bitrate = codec_.simulcastStream[0].maxBitrate +
+                               codec_.simulcastStream[1].maxBitrate +
+                               codec_.simulcastStream[2].maxBitrate;
+  uint32_t expected[] = {0, 0, 0};
+  ExpectEqual(expected, GetAllocation(0));
+  ExpectEqual(expected, GetAllocation(min_bitrate));
+  ExpectEqual(expected, GetAllocation(target_bitrate));
+  ExpectEqual(expected, GetAllocation(max_bitrate));
+}
+
+// If there are two simulcast streams, we expect the high active stream to be
+// allocated as if it is a single active stream.
+TEST_F(SimulcastRateAllocatorTest, TwoStreamsLowInactive) {
+  SetupCodec2SL3TL({false, true});
+  CreateAllocator();
+
+  const uint32_t kActiveStreamMinBitrate = codec_.simulcastStream[1].minBitrate;
+  const uint32_t kActiveStreamTargetBitrate =
+      codec_.simulcastStream[1].targetBitrate;
+  const uint32_t kActiveStreamMaxBitrate = codec_.simulcastStream[1].maxBitrate;
+  {
+    // Expect that the stream is always allocated its min bitrate.
+    uint32_t expected[] = {0, kActiveStreamMinBitrate};
+    ExpectEqual(expected, GetAllocation(0));
+    ExpectEqual(expected, GetAllocation(kActiveStreamMinBitrate - 10));
+    ExpectEqual(expected, GetAllocation(kActiveStreamMinBitrate));
+  }
+
+  {
+    // The stream should be allocated its target bitrate.
+    uint32_t expected[] = {0, kActiveStreamTargetBitrate};
+    ExpectEqual(expected, GetAllocation(kActiveStreamTargetBitrate));
+  }
+
+  {
+    // The stream should be allocated its max if the target input is sufficient.
+    uint32_t expected[] = {0, kActiveStreamMaxBitrate};
+    ExpectEqual(expected, GetAllocation(kActiveStreamMaxBitrate));
+    ExpectEqual(expected, GetAllocation(std::numeric_limits<uint32_t>::max()));
+  }
+}
+
+// If there are two simulcast streams, we expect the low active stream to be
+// allocated as if it is a single active stream.
+TEST_F(SimulcastRateAllocatorTest, TwoStreamsHighInactive) {
+  SetupCodec2SL3TL({true, false});
+  CreateAllocator();
+
+  const uint32_t kActiveStreamMinBitrate = codec_.simulcastStream[0].minBitrate;
+  const uint32_t kActiveStreamTargetBitrate =
+      codec_.simulcastStream[0].targetBitrate;
+  const uint32_t kActiveStreamMaxBitrate = codec_.simulcastStream[0].maxBitrate;
+  {
+    // Expect that the stream is always allocated its min bitrate.
+    uint32_t expected[] = {kActiveStreamMinBitrate, 0};
+    ExpectEqual(expected, GetAllocation(0));
+    ExpectEqual(expected, GetAllocation(kActiveStreamMinBitrate - 10));
+    ExpectEqual(expected, GetAllocation(kActiveStreamMinBitrate));
+  }
+
+  {
+    // The stream should be allocated its target bitrate.
+    uint32_t expected[] = {kActiveStreamTargetBitrate, 0};
+    ExpectEqual(expected, GetAllocation(kActiveStreamTargetBitrate));
+  }
+
+  {
+    // The stream should be allocated its max if the target input is sufficent.
+    uint32_t expected[] = {kActiveStreamMaxBitrate, 0};
+    ExpectEqual(expected, GetAllocation(kActiveStreamMaxBitrate));
+    ExpectEqual(expected, GetAllocation(std::numeric_limits<uint32_t>::max()));
+  }
+}
+
+// If there are three simulcast streams and the middle stream is inactive, the
+// other two streams should be allocated bitrate the same as if they are two
+// active simulcast streams.
+TEST_F(SimulcastRateAllocatorTest, ThreeStreamsMiddleInactive) {
+  SetupCodec3SL3TL({true, false, true});
+  CreateAllocator();
+
+  {
+    const uint32_t kLowStreamMinBitrate = codec_.simulcastStream[0].minBitrate;
+    // The lowest stream should always be allocated its minimum bitrate.
+    uint32_t expected[] = {kLowStreamMinBitrate, 0, 0};
+    ExpectEqual(expected, GetAllocation(0));
+    ExpectEqual(expected, GetAllocation(kLowStreamMinBitrate - 10));
+    ExpectEqual(expected, GetAllocation(kLowStreamMinBitrate));
+  }
+
+  {
+    // The lowest stream gets its target bitrate.
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate, 0, 0};
+    ExpectEqual(expected,
+                GetAllocation(codec_.simulcastStream[0].targetBitrate));
+  }
+
+  {
+    // The lowest stream gets its max bitrate, but not enough for the high
+    // stream.
+    const uint32_t bitrate = codec_.simulcastStream[0].targetBitrate +
+                             codec_.simulcastStream[2].minBitrate - 1;
+    uint32_t expected[] = {codec_.simulcastStream[0].maxBitrate, 0, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Both active streams get allocated target bitrate.
+    const uint32_t bitrate = codec_.simulcastStream[0].targetBitrate +
+                             codec_.simulcastStream[2].targetBitrate;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate, 0,
+                           codec_.simulcastStream[2].targetBitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Lowest stream gets its target bitrate, high stream gets its max bitrate.
+    uint32_t bitrate = codec_.simulcastStream[0].targetBitrate +
+                       codec_.simulcastStream[2].maxBitrate;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate, 0,
+                           codec_.simulcastStream[2].maxBitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+    ExpectEqual(expected, GetAllocation(bitrate + 10));
+    ExpectEqual(expected, GetAllocation(std::numeric_limits<uint32_t>::max()));
+  }
+}
+
+TEST_F(SimulcastRateAllocatorTest, NonConferenceModeScreenshare) {
+  codec_.mode = VideoCodecMode::kScreensharing;
+  SetupCodec3SL3TL({true, true, true});
+  CreateAllocator();
+
+  // Make sure we have enough bitrate for all 3 simulcast layers
+  const uint32_t bitrate = codec_.simulcastStream[0].maxBitrate +
+                           codec_.simulcastStream[1].maxBitrate +
+                           codec_.simulcastStream[2].maxBitrate;
+  const VideoBitrateAllocation alloc = GetAllocation(bitrate);
+
+  EXPECT_EQ(alloc.GetTemporalLayerAllocation(0).size(), 3u);
+  EXPECT_EQ(alloc.GetTemporalLayerAllocation(1).size(), 3u);
+  EXPECT_EQ(alloc.GetTemporalLayerAllocation(2).size(), 3u);
+}
+
+TEST_F(SimulcastRateAllocatorTest, StableRate) {
+  webrtc::test::ScopedFieldTrials field_trials(
+      "WebRTC-StableTargetRate/"
+      "enabled:true,"
+      "video_hysteresis_factor:1.1/");
+
+  SetupCodec3SL3TL({true, true, true});
+  CreateAllocator();
+
+  // Let the volatile rate always be be enough for all streams, in this test we
+  // are only interested in how the stable rate affects enablement.
+  const DataRate volatile_rate =
+      (TargetRate(0) + TargetRate(1) + MinRate(2)) * 1.1;
+
+  {
+    // On the first call to a new SimulcastRateAllocator instance, hysteresis
+    // is disabled, but stable rate still caps layers.
+    uint32_t expected[] = {TargetRate(0).kbps<uint32_t>(),
+                           MaxRate(1).kbps<uint32_t>()};
+    ExpectEqual(expected,
+                GetAllocation(volatile_rate, TargetRate(0) + MinRate(1)));
+  }
+
+  {
+    // Let stable rate go to a bitrate below what is needed for two streams.
+    uint32_t expected[] = {MaxRate(0).kbps<uint32_t>(), 0};
+    ExpectEqual(expected,
+                GetAllocation(volatile_rate, TargetRate(0) + MinRate(1) -
+                                                 DataRate::BitsPerSec(1)));
+  }
+
+  {
+    // Don't enable stream as we need to get up above hysteresis threshold.
+    uint32_t expected[] = {MaxRate(0).kbps<uint32_t>(), 0};
+    ExpectEqual(expected,
+                GetAllocation(volatile_rate, TargetRate(0) + MinRate(1)));
+  }
+
+  {
+    // Above threshold with hysteresis, enable second stream.
+    uint32_t expected[] = {TargetRate(0).kbps<uint32_t>(),
+                           MaxRate(1).kbps<uint32_t>()};
+    ExpectEqual(expected, GetAllocation(volatile_rate,
+                                        (TargetRate(0) + MinRate(1)) * 1.1));
+  }
+
+  {
+    // Enough to enable all thee layers.
+    uint32_t expected[] = {
+        TargetRate(0).kbps<uint32_t>(), TargetRate(1).kbps<uint32_t>(),
+        (volatile_rate - TargetRate(0) - TargetRate(1)).kbps<uint32_t>()};
+    ExpectEqual(expected, GetAllocation(volatile_rate, volatile_rate));
+  }
+
+  {
+    // Drop hysteresis, all three still on.
+    uint32_t expected[] = {
+        TargetRate(0).kbps<uint32_t>(), TargetRate(1).kbps<uint32_t>(),
+        (volatile_rate - TargetRate(0) - TargetRate(1)).kbps<uint32_t>()};
+    ExpectEqual(expected,
+                GetAllocation(volatile_rate,
+                              TargetRate(0) + TargetRate(1) + MinRate(2)));
+  }
+}
+
+class ScreenshareRateAllocationTest : public SimulcastRateAllocatorTest {
+ public:
+  void SetupConferenceScreenshare(bool use_simulcast, bool active = true) {
+    codec_.mode = VideoCodecMode::kScreensharing;
+    codec_.minBitrate = kMinBitrateKbps;
+    codec_.maxBitrate =
+        kLegacyScreenshareMaxBitrateKbps + kSimulcastScreenshareMaxBitrateKbps;
+    if (use_simulcast) {
+      codec_.numberOfSimulcastStreams = 2;
+      codec_.simulcastStream[0].minBitrate = kMinBitrateKbps;
+      codec_.simulcastStream[0].targetBitrate =
+          kLegacyScreenshareTargetBitrateKbps;
+      codec_.simulcastStream[0].maxBitrate = kLegacyScreenshareMaxBitrateKbps;
+      codec_.simulcastStream[0].numberOfTemporalLayers = 2;
+      codec_.simulcastStream[0].active = active;
+
+      codec_.simulcastStream[1].minBitrate =
+          kSimulcastScreenshareMinBitrateKbps;
+      codec_.simulcastStream[1].targetBitrate =
+          kSimulcastScreenshareMaxBitrateKbps;
+      codec_.simulcastStream[1].maxBitrate =
+          kSimulcastScreenshareMaxBitrateKbps;
+      codec_.simulcastStream[1].numberOfTemporalLayers = 2;
+      codec_.simulcastStream[1].active = active;
+    } else {
+      codec_.numberOfSimulcastStreams = 0;
+      codec_.VP8()->numberOfTemporalLayers = 2;
+      codec_.active = active;
+    }
+  }
+};
+
+INSTANTIATE_TEST_SUITE_P(ScreenshareTest,
+                         ScreenshareRateAllocationTest,
+                         ::testing::Bool());
+
+TEST_P(ScreenshareRateAllocationTest, ConferenceBitrateBelowTl0) {
+  SetupConferenceScreenshare(GetParam());
+  CreateAllocator(true);
+
+  VideoBitrateAllocation allocation =
+      allocator_->Allocate(VideoBitrateAllocationParameters(
+          kLegacyScreenshareTargetBitrateKbps * 1000, kFramerateFps));
+
+  // All allocation should go in TL0.
+  EXPECT_EQ(kLegacyScreenshareTargetBitrateKbps, allocation.get_sum_kbps());
+  EXPECT_EQ(kLegacyScreenshareTargetBitrateKbps,
+            allocation.GetBitrate(0, 0) / 1000);
+  EXPECT_EQ(allocation.is_bw_limited(), GetParam());
+}
+
+TEST_P(ScreenshareRateAllocationTest, ConferenceBitrateAboveTl0) {
+  SetupConferenceScreenshare(GetParam());
+  CreateAllocator(true);
+
+  uint32_t target_bitrate_kbps =
+      (kLegacyScreenshareTargetBitrateKbps + kLegacyScreenshareMaxBitrateKbps) /
+      2;
+  VideoBitrateAllocation allocation =
+      allocator_->Allocate(VideoBitrateAllocationParameters(
+          target_bitrate_kbps * 1000, kFramerateFps));
+
+  // Fill TL0, then put the rest in TL1.
+  EXPECT_EQ(target_bitrate_kbps, allocation.get_sum_kbps());
+  EXPECT_EQ(kLegacyScreenshareTargetBitrateKbps,
+            allocation.GetBitrate(0, 0) / 1000);
+  EXPECT_EQ(target_bitrate_kbps - kLegacyScreenshareTargetBitrateKbps,
+            allocation.GetBitrate(0, 1) / 1000);
+  EXPECT_EQ(allocation.is_bw_limited(), GetParam());
+}
+
+TEST_F(ScreenshareRateAllocationTest, ConferenceBitrateAboveTl1) {
+  // This test is only for the non-simulcast case.
+  SetupConferenceScreenshare(false);
+  CreateAllocator(true);
+
+  VideoBitrateAllocation allocation =
+      allocator_->Allocate(VideoBitrateAllocationParameters(
+          kLegacyScreenshareMaxBitrateKbps * 2000, kFramerateFps));
+
+  // Fill both TL0 and TL1, but no more.
+  EXPECT_EQ(kLegacyScreenshareMaxBitrateKbps, allocation.get_sum_kbps());
+  EXPECT_EQ(kLegacyScreenshareTargetBitrateKbps,
+            allocation.GetBitrate(0, 0) / 1000);
+  EXPECT_EQ(
+      kLegacyScreenshareMaxBitrateKbps - kLegacyScreenshareTargetBitrateKbps,
+      allocation.GetBitrate(0, 1) / 1000);
+  EXPECT_FALSE(allocation.is_bw_limited());
+}
+
+// This tests when the screenshare is inactive it should be allocated 0 bitrate
+// for all layers.
+TEST_P(ScreenshareRateAllocationTest, InactiveScreenshare) {
+  SetupConferenceScreenshare(GetParam(), false);
+  CreateAllocator();
+
+  // Enough bitrate for TL0 and TL1.
+  uint32_t target_bitrate_kbps =
+      (kLegacyScreenshareTargetBitrateKbps + kLegacyScreenshareMaxBitrateKbps) /
+      2;
+  VideoBitrateAllocation allocation =
+      allocator_->Allocate(VideoBitrateAllocationParameters(
+          target_bitrate_kbps * 1000, kFramerateFps));
+
+  EXPECT_EQ(0U, allocation.get_sum_kbps());
+}
+
+TEST_F(ScreenshareRateAllocationTest, Hysteresis) {
+  // This test is only for the simulcast case.
+  SetupConferenceScreenshare(true);
+  CreateAllocator();
+
+  // The bitrate at which we would normally enable the upper simulcast stream.
+  const uint32_t default_enable_rate_bps =
+      codec_.simulcastStream[0].targetBitrate +
+      codec_.simulcastStream[1].minBitrate;
+  const uint32_t enable_rate_with_hysteresis_bps =
+      (default_enable_rate_bps * 135) / 100;
+
+  {
+    // On the first call to a new SimulcastRateAllocator instance, hysteresis
+    // is disabled.
+    const uint32_t bitrate = default_enable_rate_bps;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate,
+                           codec_.simulcastStream[1].minBitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Go down to a bitrate below what is needed for two streams.
+    const uint32_t bitrate = default_enable_rate_bps - 1;
+    uint32_t expected[] = {bitrate, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Don't enable stream as we need to get up above hysteresis threshold.
+    const uint32_t bitrate = default_enable_rate_bps;
+    uint32_t expected[] = {bitrate, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Above threshold, enable second stream.
+    const uint32_t bitrate = enable_rate_with_hysteresis_bps;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate,
+                           enable_rate_with_hysteresis_bps -
+                               codec_.simulcastStream[0].targetBitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Go down again, still keep the second stream alive.
+    const uint32_t bitrate = default_enable_rate_bps;
+    uint32_t expected[] = {codec_.simulcastStream[0].targetBitrate,
+                           codec_.simulcastStream[1].minBitrate};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Go down below default enable, second stream is shut down again.
+    const uint32_t bitrate = default_enable_rate_bps - 1;
+    uint32_t expected[] = {bitrate, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+
+  {
+    // Go up, hysteresis is blocking us again.
+    const uint32_t bitrate = default_enable_rate_bps;
+    uint32_t expected[] = {bitrate, 0};
+    ExpectEqual(expected, GetAllocation(bitrate));
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/simulcast_test_fixture_impl.cc b/third_party/libwebrtc/modules/video_coding/utility/simulcast_test_fixture_impl.cc
new file mode 100644
index 0000000000..c6e51e8068
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/simulcast_test_fixture_impl.cc
@@ -0,0 +1,967 @@
+/*
+ *  Copyright (c) 2014 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/video_coding/utility/simulcast_test_fixture_impl.h"
+
+#include <algorithm>
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "api/video/encoded_image.h"
+#include "api/video_codecs/sdp_video_format.h"
+#include "api/video_codecs/video_encoder.h"
+#include "common_video/libyuv/include/webrtc_libyuv.h"
+#include "modules/video_coding/include/video_codec_interface.h"
+#include "modules/video_coding/include/video_coding_defines.h"
+#include "rtc_base/checks.h"
+#include "test/gtest.h"
+
+using ::testing::_;
+using ::testing::AllOf;
+using ::testing::Field;
+using ::testing::Return;
+
+namespace webrtc {
+namespace test {
+
+namespace {
+
+const int kDefaultWidth = 1280;
+const int kDefaultHeight = 720;
+const int kNumberOfSimulcastStreams = 3;
+const int kColorY = 66;
+const int kColorU = 22;
+const int kColorV = 33;
+const int kMaxBitrates[kNumberOfSimulcastStreams] = {150, 600, 1200};
+const int kMinBitrates[kNumberOfSimulcastStreams] = {50, 150, 600};
+const int kTargetBitrates[kNumberOfSimulcastStreams] = {100, 450, 1000};
+const float kMaxFramerates[kNumberOfSimulcastStreams] = {30, 30, 30};
+const int kScaleResolutionDownBy[kNumberOfSimulcastStreams] = {4, 2, 1};
+const int kDefaultTemporalLayerProfile[3] = {3, 3, 3};
+const int kNoTemporalLayerProfile[3] = {0, 0, 0};
+
+const VideoEncoder::Capabilities kCapabilities(false);
+const VideoEncoder::Settings kSettings(kCapabilities, 1, 1200);
+
+template <typename T>
+void SetExpectedValues3(T value0, T value1, T value2, T* expected_values) {
+  expected_values[0] = value0;
+  expected_values[1] = value1;
+  expected_values[2] = value2;
+}
+
+enum PlaneType {
+  kYPlane = 0,
+  kUPlane = 1,
+  kVPlane = 2,
+  kNumOfPlanes = 3,
+};
+
+}  // namespace
+
+class SimulcastTestFixtureImpl::TestEncodedImageCallback
+    : public EncodedImageCallback {
+ public:
+  TestEncodedImageCallback() {
+    memset(temporal_layer_, -1, sizeof(temporal_layer_));
+    memset(layer_sync_, false, sizeof(layer_sync_));
+  }
+
+  Result OnEncodedImage(const EncodedImage& encoded_image,
+                        const CodecSpecificInfo* codec_specific_info) override {
+    bool is_vp8 = (codec_specific_info->codecType == kVideoCodecVP8);
+    bool is_h264 = (codec_specific_info->codecType == kVideoCodecH264);
+    // Only store the base layer.
+    if (encoded_image.SimulcastIndex().value_or(0) == 0) {
+      if (encoded_image._frameType == VideoFrameType::kVideoFrameKey) {
+        encoded_key_frame_.SetEncodedData(EncodedImageBuffer::Create(
+            encoded_image.data(), encoded_image.size()));
+        encoded_key_frame_._frameType = VideoFrameType::kVideoFrameKey;
+      } else {
+        encoded_frame_.SetEncodedData(EncodedImageBuffer::Create(
+            encoded_image.data(), encoded_image.size()));
+      }
+    }
+    if (is_vp8) {
+      layer_sync_[encoded_image.SimulcastIndex().value_or(0)] =
+          codec_specific_info->codecSpecific.VP8.layerSync;
+      temporal_layer_[encoded_image.SimulcastIndex().value_or(0)] =
+          codec_specific_info->codecSpecific.VP8.temporalIdx;
+    } else if (is_h264) {
+      layer_sync_[encoded_image.SimulcastIndex().value_or(0)] =
+          codec_specific_info->codecSpecific.H264.base_layer_sync;
+      temporal_layer_[encoded_image.SimulcastIndex().value_or(0)] =
+          codec_specific_info->codecSpecific.H264.temporal_idx;
+    }
+    return Result(Result::OK, encoded_image.RtpTimestamp());
+  }
+  // This method only makes sense for VP8.
+  void GetLastEncodedFrameInfo(int* temporal_layer,
+                               bool* layer_sync,
+                               int stream) {
+    *temporal_layer = temporal_layer_[stream];
+    *layer_sync = layer_sync_[stream];
+  }
+  void GetLastEncodedKeyFrame(EncodedImage* encoded_key_frame) {
+    *encoded_key_frame = encoded_key_frame_;
+  }
+  void GetLastEncodedFrame(EncodedImage* encoded_frame) {
+    *encoded_frame = encoded_frame_;
+  }
+
+ private:
+  EncodedImage encoded_key_frame_;
+  EncodedImage encoded_frame_;
+  int temporal_layer_[kNumberOfSimulcastStreams];
+  bool layer_sync_[kNumberOfSimulcastStreams];
+};
+
+class SimulcastTestFixtureImpl::TestDecodedImageCallback
+    : public DecodedImageCallback {
+ public:
+  TestDecodedImageCallback() : decoded_frames_(0) {}
+  int32_t Decoded(VideoFrame& decoded_image) override {
+    rtc::scoped_refptr<I420BufferInterface> i420_buffer =
+        decoded_image.video_frame_buffer()->ToI420();
+    for (int i = 0; i < decoded_image.width(); ++i) {
+      EXPECT_NEAR(kColorY, i420_buffer->DataY()[i], 1);
+    }
+
+    // TODO(mikhal): Verify the difference between U,V and the original.
+    for (int i = 0; i < i420_buffer->ChromaWidth(); ++i) {
+      EXPECT_NEAR(kColorU, i420_buffer->DataU()[i], 4);
+      EXPECT_NEAR(kColorV, i420_buffer->DataV()[i], 4);
+    }
+    decoded_frames_++;
+    return 0;
+  }
+  int32_t Decoded(VideoFrame& decoded_image, int64_t decode_time_ms) override {
+    RTC_DCHECK_NOTREACHED();
+    return -1;
+  }
+  void Decoded(VideoFrame& decoded_image,
+               absl::optional<int32_t> decode_time_ms,
+               absl::optional<uint8_t> qp) override {
+    Decoded(decoded_image);
+  }
+  int DecodedFrames() { return decoded_frames_; }
+
+ private:
+  int decoded_frames_;
+};
+
+namespace {
+
+void SetPlane(uint8_t* data, uint8_t value, int width, int height, int stride) {
+  for (int i = 0; i < height; i++, data += stride) {
+    // Setting allocated area to zero - setting only image size to
+    // requested values - will make it easier to distinguish between image
+    // size and frame size (accounting for stride).
+    memset(data, value, width);
+    memset(data + width, 0, stride - width);
+  }
+}
+
+// Fills in an I420Buffer from `plane_colors`.
+void CreateImage(const rtc::scoped_refptr<I420Buffer>& buffer,
+                 int plane_colors[kNumOfPlanes]) {
+  SetPlane(buffer->MutableDataY(), plane_colors[0], buffer->width(),
+           buffer->height(), buffer->StrideY());
+
+  SetPlane(buffer->MutableDataU(), plane_colors[1], buffer->ChromaWidth(),
+           buffer->ChromaHeight(), buffer->StrideU());
+
+  SetPlane(buffer->MutableDataV(), plane_colors[2], buffer->ChromaWidth(),
+           buffer->ChromaHeight(), buffer->StrideV());
+}
+
+void ConfigureStream(int width,
+                     int height,
+                     int max_bitrate,
+                     int min_bitrate,
+                     int target_bitrate,
+                     float max_framerate,
+                     SimulcastStream* stream,
+                     int num_temporal_layers) {
+  RTC_DCHECK(stream);
+  stream->width = width;
+  stream->height = height;
+  stream->maxBitrate = max_bitrate;
+  stream->minBitrate = min_bitrate;
+  stream->targetBitrate = target_bitrate;
+  stream->maxFramerate = max_framerate;
+  if (num_temporal_layers >= 0) {
+    stream->numberOfTemporalLayers = num_temporal_layers;
+  }
+  stream->qpMax = 45;
+  stream->active = true;
+}
+
+}  // namespace
+
+void SimulcastTestFixtureImpl::DefaultSettings(
+    VideoCodec* settings,
+    const int* temporal_layer_profile,
+    VideoCodecType codec_type,
+    bool reverse_layer_order) {
+  RTC_CHECK(settings);
+  *settings = {};
+  settings->codecType = codec_type;
+  settings->startBitrate = 300;
+  settings->minBitrate = 30;
+  settings->maxBitrate = 0;
+  settings->maxFramerate = 30;
+  settings->width = kDefaultWidth;
+  settings->height = kDefaultHeight;
+  settings->numberOfSimulcastStreams = kNumberOfSimulcastStreams;
+  settings->active = true;
+  ASSERT_EQ(3, kNumberOfSimulcastStreams);
+  int layer_order[3] = {0, 1, 2};
+  if (reverse_layer_order) {
+    layer_order[0] = 2;
+    layer_order[2] = 0;
+  }
+  settings->timing_frame_thresholds = {kDefaultTimingFramesDelayMs,
+                                       kDefaultOutlierFrameSizePercent};
+  ConfigureStream(kDefaultWidth / 4, kDefaultHeight / 4, kMaxBitrates[0],
+                  kMinBitrates[0], kTargetBitrates[0], kMaxFramerates[0],
+                  &settings->simulcastStream[layer_order[0]],
+                  temporal_layer_profile[0]);
+  ConfigureStream(kDefaultWidth / 2, kDefaultHeight / 2, kMaxBitrates[1],
+                  kMinBitrates[1], kTargetBitrates[1], kMaxFramerates[1],
+                  &settings->simulcastStream[layer_order[1]],
+                  temporal_layer_profile[1]);
+  ConfigureStream(kDefaultWidth, kDefaultHeight, kMaxBitrates[2],
+                  kMinBitrates[2], kTargetBitrates[2], kMaxFramerates[2],
+                  &settings->simulcastStream[layer_order[2]],
+                  temporal_layer_profile[2]);
+  settings->SetFrameDropEnabled(true);
+  if (codec_type == kVideoCodecVP8) {
+    settings->VP8()->denoisingOn = true;
+    settings->VP8()->automaticResizeOn = false;
+    settings->VP8()->keyFrameInterval = 3000;
+  } else {
+    settings->H264()->keyFrameInterval = 3000;
+  }
+}
+
+SimulcastTestFixtureImpl::SimulcastTestFixtureImpl(
+    std::unique_ptr<VideoEncoderFactory> encoder_factory,
+    std::unique_ptr<VideoDecoderFactory> decoder_factory,
+    SdpVideoFormat video_format)
+    : codec_type_(PayloadStringToCodecType(video_format.name)) {
+  encoder_ = encoder_factory->CreateVideoEncoder(video_format);
+  decoder_ = decoder_factory->CreateVideoDecoder(video_format);
+  SetUpCodec((codec_type_ == kVideoCodecVP8 || codec_type_ == kVideoCodecH264)
+                 ? kDefaultTemporalLayerProfile
+                 : kNoTemporalLayerProfile);
+}
+
+SimulcastTestFixtureImpl::~SimulcastTestFixtureImpl() {
+  encoder_->Release();
+  decoder_->Release();
+}
+
+void SimulcastTestFixtureImpl::SetUpCodec(const int* temporal_layer_profile) {
+  encoder_->RegisterEncodeCompleteCallback(&encoder_callback_);
+  decoder_->RegisterDecodeCompleteCallback(&decoder_callback_);
+  DefaultSettings(&settings_, temporal_layer_profile, codec_type_);
+  SetUpRateAllocator();
+  EXPECT_EQ(0, encoder_->InitEncode(&settings_, kSettings));
+  VideoDecoder::Settings decoder_settings;
+  decoder_settings.set_max_render_resolution({kDefaultWidth, kDefaultHeight});
+  decoder_settings.set_codec_type(codec_type_);
+  EXPECT_TRUE(decoder_->Configure(decoder_settings));
+  input_buffer_ = I420Buffer::Create(kDefaultWidth, kDefaultHeight);
+  input_buffer_->InitializeData();
+  input_frame_ = std::make_unique<webrtc::VideoFrame>(
+      webrtc::VideoFrame::Builder()
+          .set_video_frame_buffer(input_buffer_)
+          .set_rotation(webrtc::kVideoRotation_0)
+          .set_timestamp_us(0)
+          .build());
+}
+
+void SimulcastTestFixtureImpl::SetUpRateAllocator() {
+  rate_allocator_.reset(new SimulcastRateAllocator(settings_));
+}
+
+void SimulcastTestFixtureImpl::SetRates(uint32_t bitrate_kbps, uint32_t fps) {
+  encoder_->SetRates(VideoEncoder::RateControlParameters(
+      rate_allocator_->Allocate(
+          VideoBitrateAllocationParameters(bitrate_kbps * 1000, fps)),
+      static_cast<double>(fps)));
+}
+
+void SimulcastTestFixtureImpl::RunActiveStreamsTest(
+    const std::vector<bool> active_streams) {
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  UpdateActiveStreams(active_streams);
+  // Set sufficient bitrate for all streams so we can test active without
+  // bitrate being an issue.
+  SetRates(kMaxBitrates[0] + kMaxBitrates[1] + kMaxBitrates[2], 30);
+
+  ExpectStreams(VideoFrameType::kVideoFrameKey, active_streams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, active_streams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::UpdateActiveStreams(
+    const std::vector<bool> active_streams) {
+  ASSERT_EQ(static_cast<int>(active_streams.size()), kNumberOfSimulcastStreams);
+  for (size_t i = 0; i < active_streams.size(); ++i) {
+    settings_.simulcastStream[i].active = active_streams[i];
+  }
+  // Re initialize the allocator and encoder with the new settings.
+  // TODO(bugs.webrtc.org/8807): Currently, we do a full "hard"
+  // reconfiguration of the allocator and encoder. When the video bitrate
+  // allocator has support for updating active streams without a
+  // reinitialization, we can just call that here instead.
+  SetUpRateAllocator();
+  EXPECT_EQ(0, encoder_->InitEncode(&settings_, kSettings));
+}
+
+void SimulcastTestFixtureImpl::ExpectStream(VideoFrameType frame_type,
+                                            int scaleResolutionDownBy) {
+  EXPECT_CALL(
+      encoder_callback_,
+      OnEncodedImage(AllOf(Field(&EncodedImage::_frameType, frame_type),
+                           Field(&EncodedImage::_encodedWidth,
+                                 kDefaultWidth / scaleResolutionDownBy),
+                           Field(&EncodedImage::_encodedHeight,
+                                 kDefaultHeight / scaleResolutionDownBy)),
+                     _))
+      .Times(1)
+      .WillRepeatedly(Return(
+          EncodedImageCallback::Result(EncodedImageCallback::Result::OK, 0)));
+}
+
+void SimulcastTestFixtureImpl::ExpectStreams(
+    VideoFrameType frame_type,
+    const std::vector<bool> expected_streams_active) {
+  ASSERT_EQ(static_cast<int>(expected_streams_active.size()),
+            kNumberOfSimulcastStreams);
+  for (size_t i = 0; i < kNumberOfSimulcastStreams; i++) {
+    if (expected_streams_active[i]) {
+      ExpectStream(frame_type, kScaleResolutionDownBy[i]);
+    }
+  }
+}
+
+void SimulcastTestFixtureImpl::ExpectStreams(VideoFrameType frame_type,
+                                             int expected_video_streams) {
+  ASSERT_GE(expected_video_streams, 0);
+  ASSERT_LE(expected_video_streams, kNumberOfSimulcastStreams);
+  std::vector<bool> expected_streams_active(kNumberOfSimulcastStreams, false);
+  for (int i = 0; i < expected_video_streams; ++i) {
+    expected_streams_active[i] = true;
+  }
+  ExpectStreams(frame_type, expected_streams_active);
+}
+
+void SimulcastTestFixtureImpl::VerifyTemporalIdxAndSyncForAllSpatialLayers(
+    TestEncodedImageCallback* encoder_callback,
+    const int* expected_temporal_idx,
+    const bool* expected_layer_sync,
+    int num_spatial_layers) {
+  int temporal_layer = -1;
+  bool layer_sync = false;
+  for (int i = 0; i < num_spatial_layers; i++) {
+    encoder_callback->GetLastEncodedFrameInfo(&temporal_layer, &layer_sync, i);
+    EXPECT_EQ(expected_temporal_idx[i], temporal_layer);
+    EXPECT_EQ(expected_layer_sync[i], layer_sync);
+  }
+}
+
+// For some codecs (VP8) expect all active streams to generate a key frame even
+// though a key frame was only requested for some of them.
+void SimulcastTestFixtureImpl::TestKeyFrameRequestsOnAllStreams() {
+  SetRates(kMaxBitrates[2], 30);  // To get all three streams.
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, kNumberOfSimulcastStreams);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, kNumberOfSimulcastStreams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  frame_types[0] = VideoFrameType::kVideoFrameKey;
+  ExpectStreams(VideoFrameType::kVideoFrameKey, kNumberOfSimulcastStreams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameDelta);
+  frame_types[1] = VideoFrameType::kVideoFrameKey;
+  ExpectStreams(VideoFrameType::kVideoFrameKey, kNumberOfSimulcastStreams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameDelta);
+  frame_types[2] = VideoFrameType::kVideoFrameKey;
+  ExpectStreams(VideoFrameType::kVideoFrameKey, kNumberOfSimulcastStreams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, kNumberOfSimulcastStreams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+// For some codecs (H264) expect only particular active streams to generate a
+// key frame when a key frame was only requested for some of them.
+void SimulcastTestFixtureImpl::TestKeyFrameRequestsOnSpecificStreams() {
+  SetRates(kMaxBitrates[2], 30);  // To get all three streams.
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, kNumberOfSimulcastStreams);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, kNumberOfSimulcastStreams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  frame_types[0] = VideoFrameType::kVideoFrameKey;
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[0]);
+  ExpectStream(VideoFrameType::kVideoFrameDelta, kScaleResolutionDownBy[1]);
+  ExpectStream(VideoFrameType::kVideoFrameDelta, kScaleResolutionDownBy[2]);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameDelta);
+  frame_types[1] = VideoFrameType::kVideoFrameKey;
+  ExpectStream(VideoFrameType::kVideoFrameDelta, kScaleResolutionDownBy[0]);
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[1]);
+  ExpectStream(VideoFrameType::kVideoFrameDelta, kScaleResolutionDownBy[2]);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameDelta);
+  frame_types[2] = VideoFrameType::kVideoFrameKey;
+  ExpectStream(VideoFrameType::kVideoFrameDelta, kScaleResolutionDownBy[0]);
+  ExpectStream(VideoFrameType::kVideoFrameDelta, kScaleResolutionDownBy[1]);
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[2]);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameDelta);
+  frame_types[0] = VideoFrameType::kVideoFrameKey;
+  frame_types[2] = VideoFrameType::kVideoFrameKey;
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[0]);
+  ExpectStream(VideoFrameType::kVideoFrameDelta, kScaleResolutionDownBy[1]);
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[2]);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameKey);
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[0]);
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[1]);
+  ExpectStream(VideoFrameType::kVideoFrameKey, kScaleResolutionDownBy[2]);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  std::fill(frame_types.begin(), frame_types.end(),
+            VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, kNumberOfSimulcastStreams);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestPaddingAllStreams() {
+  // We should always encode the base layer.
+  SetRates(kMinBitrates[0] - 1, 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 1);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 1);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestPaddingTwoStreams() {
+  // We have just enough to get only the first stream and padding for two.
+  SetRates(kMinBitrates[0], 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 1);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 1);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestPaddingTwoStreamsOneMaxedOut() {
+  // We are just below limit of sending second stream, so we should get
+  // the first stream maxed out (at `maxBitrate`), and padding for two.
+  SetRates(kTargetBitrates[0] + kMinBitrates[1] - 1, 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 1);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 1);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestPaddingOneStream() {
+  // We have just enough to send two streams, so padding for one stream.
+  SetRates(kTargetBitrates[0] + kMinBitrates[1], 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 2);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 2);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestPaddingOneStreamTwoMaxedOut() {
+  // We are just below limit of sending third stream, so we should get
+  // first stream's rate maxed out at `targetBitrate`, second at `maxBitrate`.
+  SetRates(kTargetBitrates[0] + kTargetBitrates[1] + kMinBitrates[2] - 1, 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 2);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 2);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestSendAllStreams() {
+  // We have just enough to send all streams.
+  SetRates(kTargetBitrates[0] + kTargetBitrates[1] + kMinBitrates[2], 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 3);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 3);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestDisablingStreams() {
+  // We should get three media streams.
+  SetRates(kMaxBitrates[0] + kMaxBitrates[1] + kMaxBitrates[2], 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 3);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 3);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  // We should only get two streams and padding for one.
+  SetRates(kTargetBitrates[0] + kTargetBitrates[1] + kMinBitrates[2] / 2, 30);
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 2);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  // We should only get the first stream and padding for two.
+  SetRates(kTargetBitrates[0] + kMinBitrates[1] / 2, 30);
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 1);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  // We don't have enough bitrate for the thumbnail stream, but we should get
+  // it anyway with current configuration.
+  SetRates(kTargetBitrates[0] - 1, 30);
+  ExpectStreams(VideoFrameType::kVideoFrameDelta, 1);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  // We should only get two streams and padding for one.
+  SetRates(kTargetBitrates[0] + kTargetBitrates[1] + kMinBitrates[2] / 2, 30);
+  // We get a key frame because a new stream is being enabled.
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 2);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  // We should get all three streams.
+  SetRates(kTargetBitrates[0] + kTargetBitrates[1] + kTargetBitrates[2], 30);
+  // We get a key frame because a new stream is being enabled.
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 3);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestActiveStreams() {
+  // All streams on.
+  RunActiveStreamsTest({true, true, true});
+  // All streams off.
+  RunActiveStreamsTest({false, false, false});
+  // Low stream off.
+  RunActiveStreamsTest({false, true, true});
+  // Middle stream off.
+  RunActiveStreamsTest({true, false, true});
+  // High stream off.
+  RunActiveStreamsTest({true, true, false});
+  // Only low stream turned on.
+  RunActiveStreamsTest({true, false, false});
+  // Only middle stream turned on.
+  RunActiveStreamsTest({false, true, false});
+  // Only high stream turned on.
+  RunActiveStreamsTest({false, false, true});
+}
+
+void SimulcastTestFixtureImpl::SwitchingToOneStream(int width, int height) {
+  const int* temporal_layer_profile = nullptr;
+  // Disable all streams except the last and set the bitrate of the last to
+  // 100 kbps. This verifies the way GTP switches to screenshare mode.
+  if (codec_type_ == kVideoCodecVP8) {
+    settings_.VP8()->numberOfTemporalLayers = 1;
+    temporal_layer_profile = kDefaultTemporalLayerProfile;
+  } else {
+    settings_.H264()->numberOfTemporalLayers = 1;
+    temporal_layer_profile = kNoTemporalLayerProfile;
+  }
+  settings_.maxBitrate = 100;
+  settings_.startBitrate = 100;
+  settings_.width = width;
+  settings_.height = height;
+  for (int i = 0; i < settings_.numberOfSimulcastStreams - 1; ++i) {
+    settings_.simulcastStream[i].maxBitrate = 0;
+    settings_.simulcastStream[i].width = settings_.width;
+    settings_.simulcastStream[i].height = settings_.height;
+    settings_.simulcastStream[i].numberOfTemporalLayers = 1;
+  }
+  // Setting input image to new resolution.
+  input_buffer_ = I420Buffer::Create(settings_.width, settings_.height);
+  input_buffer_->InitializeData();
+
+  input_frame_ = std::make_unique<webrtc::VideoFrame>(
+      webrtc::VideoFrame::Builder()
+          .set_video_frame_buffer(input_buffer_)
+          .set_rotation(webrtc::kVideoRotation_0)
+          .set_timestamp_us(0)
+          .build());
+
+  // The for loop above did not set the bitrate of the highest layer.
+  settings_.simulcastStream[settings_.numberOfSimulcastStreams - 1].maxBitrate =
+      0;
+  // The highest layer has to correspond to the non-simulcast resolution.
+  settings_.simulcastStream[settings_.numberOfSimulcastStreams - 1].width =
+      settings_.width;
+  settings_.simulcastStream[settings_.numberOfSimulcastStreams - 1].height =
+      settings_.height;
+  SetUpRateAllocator();
+  EXPECT_EQ(0, encoder_->InitEncode(&settings_, kSettings));
+
+  // Encode one frame and verify.
+  SetRates(kMaxBitrates[0] + kMaxBitrates[1], 30);
+  std::vector<VideoFrameType> frame_types(kNumberOfSimulcastStreams,
+                                          VideoFrameType::kVideoFrameDelta);
+  EXPECT_CALL(
+      encoder_callback_,
+      OnEncodedImage(AllOf(Field(&EncodedImage::_frameType,
+                                 VideoFrameType::kVideoFrameKey),
+                           Field(&EncodedImage::_encodedWidth, width),
+                           Field(&EncodedImage::_encodedHeight, height)),
+                     _))
+      .Times(1)
+      .WillRepeatedly(Return(
+          EncodedImageCallback::Result(EncodedImageCallback::Result::OK, 0)));
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+
+  // Switch back.
+  DefaultSettings(&settings_, temporal_layer_profile, codec_type_);
+  // Start at the lowest bitrate for enabling base stream.
+  settings_.startBitrate = kMinBitrates[0];
+  SetUpRateAllocator();
+  EXPECT_EQ(0, encoder_->InitEncode(&settings_, kSettings));
+  SetRates(settings_.startBitrate, 30);
+  ExpectStreams(VideoFrameType::kVideoFrameKey, 1);
+  // Resize `input_frame_` to the new resolution.
+  input_buffer_ = I420Buffer::Create(settings_.width, settings_.height);
+  input_buffer_->InitializeData();
+  input_frame_ = std::make_unique<webrtc::VideoFrame>(
+      webrtc::VideoFrame::Builder()
+          .set_video_frame_buffer(input_buffer_)
+          .set_rotation(webrtc::kVideoRotation_0)
+          .set_timestamp_us(0)
+          .build());
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, &frame_types));
+}
+
+void SimulcastTestFixtureImpl::TestSwitchingToOneStream() {
+  SwitchingToOneStream(1024, 768);
+}
+
+void SimulcastTestFixtureImpl::TestSwitchingToOneOddStream() {
+  SwitchingToOneStream(1023, 769);
+}
+
+void SimulcastTestFixtureImpl::TestSwitchingToOneSmallStream() {
+  SwitchingToOneStream(4, 4);
+}
+
+// Test the layer pattern and sync flag for various spatial-temporal patterns.
+// 3-3-3 pattern: 3 temporal layers for all spatial streams, so same
+// temporal_layer id and layer_sync is expected for all streams.
+void SimulcastTestFixtureImpl::TestSpatioTemporalLayers333PatternEncoder() {
+  bool is_h264 = codec_type_ == kVideoCodecH264;
+  TestEncodedImageCallback encoder_callback;
+  encoder_->RegisterEncodeCompleteCallback(&encoder_callback);
+  SetRates(kMaxBitrates[2], 30);  // To get all three streams.
+
+  int expected_temporal_idx[3] = {-1, -1, -1};
+  bool expected_layer_sync[3] = {false, false, false};
+
+  // First frame: #0.
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(0, 0, 0, expected_temporal_idx);
+  SetExpectedValues3<bool>(!is_h264, !is_h264, !is_h264, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #1.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(2, 2, 2, expected_temporal_idx);
+  SetExpectedValues3<bool>(true, true, true, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #2.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(1, 1, 1, expected_temporal_idx);
+  SetExpectedValues3<bool>(true, true, true, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #3.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(2, 2, 2, expected_temporal_idx);
+  SetExpectedValues3<bool>(false, false, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #4.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(0, 0, 0, expected_temporal_idx);
+  SetExpectedValues3<bool>(false, false, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #5.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(2, 2, 2, expected_temporal_idx);
+  SetExpectedValues3<bool>(is_h264, is_h264, is_h264, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+}
+
+// Test the layer pattern and sync flag for various spatial-temporal patterns.
+// 3-2-1 pattern: 3 temporal layers for lowest resolution, 2 for middle, and
+// 1 temporal layer for highest resolution.
+// For this profile, we expect the temporal index pattern to be:
+// 1st stream: 0, 2, 1, 2, ....
+// 2nd stream: 0, 1, 0, 1, ...
+// 3rd stream: -1, -1, -1, -1, ....
+// Regarding the 3rd stream, note that a stream/encoder with 1 temporal layer
+// should always have temporal layer idx set to kNoTemporalIdx = -1.
+// Since CodecSpecificInfoVP8.temporalIdx is uint8_t, this will wrap to 255.
+// TODO(marpan): Although this seems safe for now, we should fix this.
+void SimulcastTestFixtureImpl::TestSpatioTemporalLayers321PatternEncoder() {
+  EXPECT_EQ(codec_type_, kVideoCodecVP8);
+  int temporal_layer_profile[3] = {3, 2, 1};
+  SetUpCodec(temporal_layer_profile);
+  TestEncodedImageCallback encoder_callback;
+  encoder_->RegisterEncodeCompleteCallback(&encoder_callback);
+  SetRates(kMaxBitrates[2], 30);  // To get all three streams.
+
+  int expected_temporal_idx[3] = {-1, -1, -1};
+  bool expected_layer_sync[3] = {false, false, false};
+
+  // First frame: #0.
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(0, 0, 255, expected_temporal_idx);
+  SetExpectedValues3<bool>(true, true, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #1.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(2, 1, 255, expected_temporal_idx);
+  SetExpectedValues3<bool>(true, true, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #2.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(1, 0, 255, expected_temporal_idx);
+  SetExpectedValues3<bool>(true, false, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #3.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(2, 1, 255, expected_temporal_idx);
+  SetExpectedValues3<bool>(false, false, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #4.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(0, 0, 255, expected_temporal_idx);
+  SetExpectedValues3<bool>(false, false, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+
+  // Next frame: #5.
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+  SetExpectedValues3<int>(2, 1, 255, expected_temporal_idx);
+  SetExpectedValues3<bool>(false, true, false, expected_layer_sync);
+  VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      &encoder_callback, expected_temporal_idx, expected_layer_sync, 3);
+}
+
+void SimulcastTestFixtureImpl::TestStrideEncodeDecode() {
+  TestEncodedImageCallback encoder_callback;
+  TestDecodedImageCallback decoder_callback;
+  encoder_->RegisterEncodeCompleteCallback(&encoder_callback);
+  decoder_->RegisterDecodeCompleteCallback(&decoder_callback);
+
+  SetRates(kMaxBitrates[2], 30);  // To get all three streams.
+  // Setting two (possibly) problematic use cases for stride:
+  // 1. stride > width 2. stride_y != stride_uv/2
+  int stride_y = kDefaultWidth + 20;
+  int stride_uv = ((kDefaultWidth + 1) / 2) + 5;
+  input_buffer_ = I420Buffer::Create(kDefaultWidth, kDefaultHeight, stride_y,
+                                     stride_uv, stride_uv);
+  input_frame_ = std::make_unique<webrtc::VideoFrame>(
+      webrtc::VideoFrame::Builder()
+          .set_video_frame_buffer(input_buffer_)
+          .set_rotation(webrtc::kVideoRotation_0)
+          .set_timestamp_us(0)
+          .build());
+
+  // Set color.
+  int plane_offset[kNumOfPlanes];
+  plane_offset[kYPlane] = kColorY;
+  plane_offset[kUPlane] = kColorU;
+  plane_offset[kVPlane] = kColorV;
+  CreateImage(input_buffer_, plane_offset);
+
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+
+  // Change color.
+  plane_offset[kYPlane] += 1;
+  plane_offset[kUPlane] += 1;
+  plane_offset[kVPlane] += 1;
+  CreateImage(input_buffer_, plane_offset);
+  input_frame_->set_timestamp(input_frame_->timestamp() + 3000);
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+
+  EncodedImage encoded_frame;
+  // Only encoding one frame - so will be a key frame.
+  encoder_callback.GetLastEncodedKeyFrame(&encoded_frame);
+  EXPECT_EQ(0, decoder_->Decode(encoded_frame, 0));
+  encoder_callback.GetLastEncodedFrame(&encoded_frame);
+  decoder_->Decode(encoded_frame, 0);
+  EXPECT_EQ(2, decoder_callback.DecodedFrames());
+}
+
+void SimulcastTestFixtureImpl::TestDecodeWidthHeightSet() {
+  MockEncodedImageCallback encoder_callback;
+  MockDecodedImageCallback decoder_callback;
+
+  EncodedImage encoded_frame[3];
+  SetRates(kMaxBitrates[2], 30);  // To get all three streams.
+  encoder_->RegisterEncodeCompleteCallback(&encoder_callback);
+  decoder_->RegisterDecodeCompleteCallback(&decoder_callback);
+
+  EXPECT_CALL(encoder_callback, OnEncodedImage(_, _))
+      .Times(3)
+      .WillRepeatedly(
+          ::testing::Invoke([&](const EncodedImage& encoded_image,
+                                const CodecSpecificInfo* codec_specific_info) {
+            EXPECT_EQ(encoded_image._frameType, VideoFrameType::kVideoFrameKey);
+
+            size_t index = encoded_image.SimulcastIndex().value_or(0);
+            encoded_frame[index].SetEncodedData(EncodedImageBuffer::Create(
+                encoded_image.data(), encoded_image.size()));
+            encoded_frame[index]._frameType = encoded_image._frameType;
+            return EncodedImageCallback::Result(
+                EncodedImageCallback::Result::OK, 0);
+          }));
+  EXPECT_EQ(0, encoder_->Encode(*input_frame_, NULL));
+
+  EXPECT_CALL(decoder_callback, Decoded(_, _, _))
+      .WillOnce(::testing::Invoke([](VideoFrame& decodedImage,
+                                     absl::optional<int32_t> decode_time_ms,
+                                     absl::optional<uint8_t> qp) {
+        EXPECT_EQ(decodedImage.width(), kDefaultWidth / 4);
+        EXPECT_EQ(decodedImage.height(), kDefaultHeight / 4);
+      }));
+  EXPECT_EQ(0, decoder_->Decode(encoded_frame[0], 0));
+
+  EXPECT_CALL(decoder_callback, Decoded(_, _, _))
+      .WillOnce(::testing::Invoke([](VideoFrame& decodedImage,
+                                     absl::optional<int32_t> decode_time_ms,
+                                     absl::optional<uint8_t> qp) {
+        EXPECT_EQ(decodedImage.width(), kDefaultWidth / 2);
+        EXPECT_EQ(decodedImage.height(), kDefaultHeight / 2);
+      }));
+  EXPECT_EQ(0, decoder_->Decode(encoded_frame[1], 0));
+
+  EXPECT_CALL(decoder_callback, Decoded(_, _, _))
+      .WillOnce(::testing::Invoke([](VideoFrame& decodedImage,
+                                     absl::optional<int32_t> decode_time_ms,
+                                     absl::optional<uint8_t> qp) {
+        EXPECT_EQ(decodedImage.width(), kDefaultWidth);
+        EXPECT_EQ(decodedImage.height(), kDefaultHeight);
+      }));
+  EXPECT_EQ(0, decoder_->Decode(encoded_frame[2], 0));
+}
+
+void SimulcastTestFixtureImpl::
+    TestEncoderInfoForDefaultTemporalLayerProfileHasFpsAllocation() {
+  VideoEncoder::EncoderInfo encoder_info = encoder_->GetEncoderInfo();
+  EXPECT_EQ(encoder_info.fps_allocation[0].size(),
+            static_cast<size_t>(kDefaultTemporalLayerProfile[0]));
+  EXPECT_EQ(encoder_info.fps_allocation[1].size(),
+            static_cast<size_t>(kDefaultTemporalLayerProfile[1]));
+  EXPECT_EQ(encoder_info.fps_allocation[2].size(),
+            static_cast<size_t>(kDefaultTemporalLayerProfile[2]));
+}
+}  // namespace test
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/simulcast_test_fixture_impl.h b/third_party/libwebrtc/modules/video_coding/utility/simulcast_test_fixture_impl.h
new file mode 100644
index 0000000000..f142ab4813
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/simulcast_test_fixture_impl.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_VIDEO_CODING_UTILITY_SIMULCAST_TEST_FIXTURE_IMPL_H_
+#define MODULES_VIDEO_CODING_UTILITY_SIMULCAST_TEST_FIXTURE_IMPL_H_
+
+#include <memory>
+#include <vector>
+
+#include "api/test/mock_video_decoder.h"
+#include "api/test/mock_video_encoder.h"
+#include "api/test/simulcast_test_fixture.h"
+#include "api/video/i420_buffer.h"
+#include "api/video/video_frame.h"
+#include "api/video_codecs/video_decoder_factory.h"
+#include "api/video_codecs/video_encoder_factory.h"
+#include "modules/video_coding/utility/simulcast_rate_allocator.h"
+
+namespace webrtc {
+namespace test {
+
+class SimulcastTestFixtureImpl final : public SimulcastTestFixture {
+ public:
+  SimulcastTestFixtureImpl(std::unique_ptr<VideoEncoderFactory> encoder_factory,
+                           std::unique_ptr<VideoDecoderFactory> decoder_factory,
+                           SdpVideoFormat video_format);
+  ~SimulcastTestFixtureImpl() final;
+
+  // Implements SimulcastTestFixture.
+  void TestKeyFrameRequestsOnAllStreams() override;
+  void TestKeyFrameRequestsOnSpecificStreams() override;
+  void TestPaddingAllStreams() override;
+  void TestPaddingTwoStreams() override;
+  void TestPaddingTwoStreamsOneMaxedOut() override;
+  void TestPaddingOneStream() override;
+  void TestPaddingOneStreamTwoMaxedOut() override;
+  void TestSendAllStreams() override;
+  void TestDisablingStreams() override;
+  void TestActiveStreams() override;
+  void TestSwitchingToOneStream() override;
+  void TestSwitchingToOneOddStream() override;
+  void TestSwitchingToOneSmallStream() override;
+  void TestSpatioTemporalLayers333PatternEncoder() override;
+  void TestSpatioTemporalLayers321PatternEncoder() override;
+  void TestStrideEncodeDecode() override;
+  void TestDecodeWidthHeightSet() override;
+  void TestEncoderInfoForDefaultTemporalLayerProfileHasFpsAllocation() override;
+
+  static void DefaultSettings(VideoCodec* settings,
+                              const int* temporal_layer_profile,
+                              VideoCodecType codec_type,
+                              bool reverse_layer_order = false);
+
+ private:
+  class TestEncodedImageCallback;
+  class TestDecodedImageCallback;
+
+  void SetUpCodec(const int* temporal_layer_profile);
+  void SetUpRateAllocator();
+  void SetRates(uint32_t bitrate_kbps, uint32_t fps);
+  void RunActiveStreamsTest(std::vector<bool> active_streams);
+  void UpdateActiveStreams(std::vector<bool> active_streams);
+  void ExpectStream(VideoFrameType frame_type, int scaleResolutionDownBy);
+  void ExpectStreams(VideoFrameType frame_type,
+                     std::vector<bool> expected_streams_active);
+  void ExpectStreams(VideoFrameType frame_type, int expected_video_streams);
+  void VerifyTemporalIdxAndSyncForAllSpatialLayers(
+      TestEncodedImageCallback* encoder_callback,
+      const int* expected_temporal_idx,
+      const bool* expected_layer_sync,
+      int num_spatial_layers);
+  void SwitchingToOneStream(int width, int height);
+
+  std::unique_ptr<VideoEncoder> encoder_;
+  MockEncodedImageCallback encoder_callback_;
+  std::unique_ptr<VideoDecoder> decoder_;
+  MockDecodedImageCallback decoder_callback_;
+  VideoCodec settings_;
+  rtc::scoped_refptr<I420Buffer> input_buffer_;
+  std::unique_ptr<VideoFrame> input_frame_;
+  std::unique_ptr<SimulcastRateAllocator> rate_allocator_;
+  VideoCodecType codec_type_;
+};
+
+}  // namespace test
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_SIMULCAST_TEST_FIXTURE_IMPL_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/simulcast_utility.cc b/third_party/libwebrtc/modules/video_coding/utility/simulcast_utility.cc
new file mode 100644
index 0000000000..824f4b0eac
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/simulcast_utility.cc
@@ -0,0 +1,115 @@
+/*
+ *  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/video_coding/utility/simulcast_utility.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include "modules/video_coding/svc/scalability_mode_util.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+uint32_t SimulcastUtility::SumStreamMaxBitrate(int streams,
+                                               const VideoCodec& codec) {
+  uint32_t bitrate_sum = 0;
+  for (int i = 0; i < streams; ++i) {
+    bitrate_sum += codec.simulcastStream[i].maxBitrate;
+  }
+  return bitrate_sum;
+}
+
+int SimulcastUtility::NumberOfSimulcastStreams(const VideoCodec& codec) {
+  int streams =
+      codec.numberOfSimulcastStreams < 1 ? 1 : codec.numberOfSimulcastStreams;
+  uint32_t simulcast_max_bitrate = SumStreamMaxBitrate(streams, codec);
+  if (simulcast_max_bitrate == 0) {
+    streams = 1;
+  }
+  return streams;
+}
+
+bool SimulcastUtility::ValidSimulcastParameters(const VideoCodec& codec,
+                                                int num_streams) {
+  // Check resolution.
+  if (codec.width != codec.simulcastStream[num_streams - 1].width ||
+      codec.height != codec.simulcastStream[num_streams - 1].height) {
+    return false;
+  }
+  for (int i = 0; i < num_streams; ++i) {
+    if (codec.width * codec.simulcastStream[i].height !=
+        codec.height * codec.simulcastStream[i].width) {
+      return false;
+    }
+  }
+  for (int i = 1; i < num_streams; ++i) {
+    if (codec.simulcastStream[i].width < codec.simulcastStream[i - 1].width) {
+      return false;
+    }
+  }
+
+  // Check frame-rate.
+  for (int i = 1; i < num_streams; ++i) {
+    if (fabs(codec.simulcastStream[i].maxFramerate -
+             codec.simulcastStream[i - 1].maxFramerate) > 1e-9) {
+      return false;
+    }
+  }
+
+  // Check temporal layers.
+  for (int i = 0; i < num_streams - 1; ++i) {
+    if (codec.simulcastStream[i].numberOfTemporalLayers !=
+        codec.simulcastStream[i + 1].numberOfTemporalLayers)
+      return false;
+  }
+  return true;
+}
+
+bool SimulcastUtility::IsConferenceModeScreenshare(const VideoCodec& codec) {
+  return codec.mode == VideoCodecMode::kScreensharing &&
+         codec.legacy_conference_mode;
+}
+
+int SimulcastUtility::NumberOfTemporalLayers(const VideoCodec& codec,
+                                             int spatial_id) {
+  int num_temporal_layers = 0;
+  if (auto scalability_mode = codec.GetScalabilityMode(); scalability_mode) {
+    num_temporal_layers = ScalabilityModeToNumTemporalLayers(*scalability_mode);
+  } else {
+    switch (codec.codecType) {
+      case kVideoCodecVP8:
+        num_temporal_layers = codec.VP8().numberOfTemporalLayers;
+        break;
+      case kVideoCodecVP9:
+        num_temporal_layers = codec.VP9().numberOfTemporalLayers;
+        break;
+      case kVideoCodecH264:
+        num_temporal_layers = codec.H264().numberOfTemporalLayers;
+        break;
+      case kVideoCodecH265:
+        // TODO(bugs.webrtc.org/13485)
+        break;
+      default:
+        break;
+    }
+  }
+
+  if (codec.numberOfSimulcastStreams > 0) {
+    RTC_DCHECK_LT(spatial_id, codec.numberOfSimulcastStreams);
+    num_temporal_layers =
+        std::max(num_temporal_layers,
+                 static_cast<int>(
+                     codec.simulcastStream[spatial_id].numberOfTemporalLayers));
+  }
+  return std::max(1, num_temporal_layers);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/simulcast_utility.h b/third_party/libwebrtc/modules/video_coding/utility/simulcast_utility.h
new file mode 100644
index 0000000000..e25a594360
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/simulcast_utility.h
@@ -0,0 +1,33 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_SIMULCAST_UTILITY_H_
+#define MODULES_VIDEO_CODING_UTILITY_SIMULCAST_UTILITY_H_
+
+#include <stdint.h>
+
+#include "api/video_codecs/video_codec.h"
+
+namespace webrtc {
+
+class SimulcastUtility {
+ public:
+  static uint32_t SumStreamMaxBitrate(int streams, const VideoCodec& codec);
+  static int NumberOfSimulcastStreams(const VideoCodec& codec);
+  static bool ValidSimulcastParameters(const VideoCodec& codec,
+                                       int num_streams);
+  static int NumberOfTemporalLayers(const VideoCodec& codec, int spatial_id);
+  // TODO(sprang): Remove this hack when ScreenshareLayers is gone.
+  static bool IsConferenceModeScreenshare(const VideoCodec& codec);
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_SIMULCAST_UTILITY_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/vp8_constants.h b/third_party/libwebrtc/modules/video_coding/utility/vp8_constants.h
new file mode 100644
index 0000000000..9321864dbc
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/vp8_constants.h
@@ -0,0 +1,27 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_VP8_CONSTANTS_H_
+#define MODULES_VIDEO_CODING_UTILITY_VP8_CONSTANTS_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <string>
+
+namespace webrtc {
+
+// QP level below which VP8 variable framerate and zero hertz screencast reduces
+// framerate due to diminishing quality enhancement returns.
+constexpr int kVp8SteadyStateQpThreshold = 15;
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_VP8_CONSTANTS_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/vp8_header_parser.cc b/third_party/libwebrtc/modules/video_coding/utility/vp8_header_parser.cc
new file mode 100644
index 0000000000..80026f9a0f
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/vp8_header_parser.cc
@@ -0,0 +1,200 @@
+/*
+ *  Copyright (c) 2015 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/video_coding/utility/vp8_header_parser.h"
+
+#include "rtc_base/logging.h"
+#include "rtc_base/system/arch.h"
+
+namespace webrtc {
+
+namespace vp8 {
+namespace {
+const size_t kCommonPayloadHeaderLength = 3;
+const size_t kKeyPayloadHeaderLength = 10;
+const int kMbFeatureTreeProbs = 3;
+const int kNumMbSegments = 4;
+const int kNumRefLfDeltas = 4;
+const int kNumModeLfDeltas = 4;
+
+}  // namespace
+
+// Bitstream parser according to
+// https://tools.ietf.org/html/rfc6386#section-7.3
+void VP8InitBitReader(VP8BitReader* const br,
+                      const uint8_t* start,
+                      const uint8_t* end) {
+  br->range_ = 255;
+  br->buf_ = start;
+  br->buf_end_ = end;
+  br->value_ = 0;
+  br->bits_ = 0;
+
+  // Read 2 bytes.
+  int i = 0;
+  while (++i <= 2) {
+    if (br->buf_ != br->buf_end_) {
+      br->value_ = br->value_ << 8 | *br->buf_++;
+    } else {
+      br->value_ = br->value_ << 8;
+    }
+  }
+}
+
+// Bit decoder according to https://tools.ietf.org/html/rfc6386#section-7.3
+// Reads one bit from the bitstream, given that it has probability prob/256 to
+// be 1.
+int Vp8BitReaderGetBool(VP8BitReader* br, int prob) {
+  uint32_t split = 1 + (((br->range_ - 1) * prob) >> 8);
+  uint32_t split_hi = split << 8;
+  int retval = 0;
+  if (br->value_ >= split_hi) {
+    retval = 1;
+    br->range_ -= split;
+    br->value_ -= split_hi;
+  } else {
+    retval = 0;
+    br->range_ = split;
+  }
+
+  while (br->range_ < 128) {
+    br->value_ <<= 1;
+    br->range_ <<= 1;
+    if (++br->bits_ == 8) {
+      br->bits_ = 0;
+      if (br->buf_ != br->buf_end_) {
+        br->value_ |= *br->buf_++;
+      }
+    }
+  }
+  return retval;
+}
+
+uint32_t VP8GetValue(VP8BitReader* br, int num_bits) {
+  uint32_t v = 0;
+  while (num_bits--) {
+    // According to https://tools.ietf.org/html/rfc6386
+    // Probability 128/256 is used to encode header fields.
+    v = (v << 1) | Vp8BitReaderGetBool(br, 128);
+  }
+  return v;
+}
+
+// Not a read_signed_literal() from RFC 6386!
+// This one is used to read e.g. quantizer_update, which is written as:
+// L(num_bits), sign-bit.
+int32_t VP8GetSignedValue(VP8BitReader* br, int num_bits) {
+  int v = VP8GetValue(br, num_bits);
+  int sign = VP8GetValue(br, 1);
+  return sign ? -v : v;
+}
+
+static void ParseSegmentHeader(VP8BitReader* br) {
+  int use_segment = VP8GetValue(br, 1);
+  if (use_segment) {
+    int update_map = VP8GetValue(br, 1);
+    if (VP8GetValue(br, 1)) {  // update_segment_feature_data.
+      VP8GetValue(br, 1);      // segment_feature_mode.
+      int s;
+      for (s = 0; s < kNumMbSegments; ++s) {
+        bool quantizer_update = VP8GetValue(br, 1);
+        if (quantizer_update) {
+          VP8GetSignedValue(br, 7);
+        }
+      }
+      for (s = 0; s < kNumMbSegments; ++s) {
+        bool loop_filter_update = VP8GetValue(br, 1);
+        if (loop_filter_update) {
+          VP8GetSignedValue(br, 6);
+        }
+      }
+    }
+    if (update_map) {
+      int s;
+      for (s = 0; s < kMbFeatureTreeProbs; ++s) {
+        bool segment_prob_update = VP8GetValue(br, 1);
+        if (segment_prob_update) {
+          VP8GetValue(br, 8);
+        }
+      }
+    }
+  }
+}
+
+static void ParseFilterHeader(VP8BitReader* br) {
+  VP8GetValue(br, 1);  // filter_type.
+  VP8GetValue(br, 6);  // loop_filter_level.
+  VP8GetValue(br, 3);  // sharpness_level.
+
+  // mb_lf_adjustments.
+  int loop_filter_adj_enable = VP8GetValue(br, 1);
+  if (loop_filter_adj_enable) {
+    int mode_ref_lf_delta_update = VP8GetValue(br, 1);
+    if (mode_ref_lf_delta_update) {
+      int i;
+      for (i = 0; i < kNumRefLfDeltas; ++i) {
+        int ref_frame_delta_update_flag = VP8GetValue(br, 1);
+        if (ref_frame_delta_update_flag) {
+          VP8GetSignedValue(br, 6);  // delta_magnitude.
+        }
+      }
+      for (i = 0; i < kNumModeLfDeltas; ++i) {
+        int mb_mode_delta_update_flag = VP8GetValue(br, 1);
+        if (mb_mode_delta_update_flag) {
+          VP8GetSignedValue(br, 6);  // delta_magnitude.
+        }
+      }
+    }
+  }
+}
+
+bool GetQp(const uint8_t* buf, size_t length, int* qp) {
+  if (length < kCommonPayloadHeaderLength) {
+    RTC_LOG(LS_WARNING) << "Failed to get QP, invalid length.";
+    return false;
+  }
+  VP8BitReader br;
+  const uint32_t bits = buf[0] | (buf[1] << 8) | (buf[2] << 16);
+  int key_frame = !(bits & 1);
+  // Size of first partition in bytes.
+  uint32_t partition_length = (bits >> 5);
+  size_t header_length = kCommonPayloadHeaderLength;
+  if (key_frame) {
+    header_length = kKeyPayloadHeaderLength;
+  }
+  if (header_length + partition_length > length) {
+    RTC_LOG(LS_WARNING) << "Failed to get QP, invalid length: " << length;
+    return false;
+  }
+  buf += header_length;
+
+  VP8InitBitReader(&br, buf, buf + partition_length);
+  if (key_frame) {
+    // Color space and pixel type.
+    VP8GetValue(&br, 1);
+    VP8GetValue(&br, 1);
+  }
+  ParseSegmentHeader(&br);
+  ParseFilterHeader(&br);
+  // Parse log2_nbr_of_dct_partitions value.
+  VP8GetValue(&br, 2);
+  // Base QP.
+  const int base_q0 = VP8GetValue(&br, 7);
+  if (br.buf_ == br.buf_end_) {
+    RTC_LOG(LS_WARNING) << "Failed to get QP, bitstream is truncated or"
+                           " corrupted.";
+    return false;
+  }
+  *qp = base_q0;
+  return true;
+}
+
+}  // namespace vp8
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/vp8_header_parser.h b/third_party/libwebrtc/modules/video_coding/utility/vp8_header_parser.h
new file mode 100644
index 0000000000..dbad999dc8
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/vp8_header_parser.h
@@ -0,0 +1,40 @@
+/*
+ *  Copyright (c) 2015 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_VIDEO_CODING_UTILITY_VP8_HEADER_PARSER_H_
+#define MODULES_VIDEO_CODING_UTILITY_VP8_HEADER_PARSER_H_
+
+#include <stdint.h>
+#include <stdio.h>
+
+namespace webrtc {
+
+namespace vp8 {
+
+typedef struct VP8BitReader VP8BitReader;
+struct VP8BitReader {
+  // Boolean decoder.
+  uint32_t value_;  // Current value (2 bytes).
+  uint32_t range_;  // Current range (always in [128..255] interval).
+  int bits_;        // Number of bits shifted out of value, at most 7.
+  // Read buffer.
+  const uint8_t* buf_;      // Next byte to be read.
+  const uint8_t* buf_end_;  // End of read buffer.
+};
+
+// Gets the QP, QP range: [0, 127].
+// Returns true on success, false otherwise.
+bool GetQp(const uint8_t* buf, size_t length, int* qp);
+
+}  // namespace vp8
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_VP8_HEADER_PARSER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/vp9_constants.h b/third_party/libwebrtc/modules/video_coding/utility/vp9_constants.h
new file mode 100644
index 0000000000..af2c701b82
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/vp9_constants.h
@@ -0,0 +1,198 @@
+/*
+ *  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_VIDEO_CODING_UTILITY_VP9_CONSTANTS_H_
+#define MODULES_VIDEO_CODING_UTILITY_VP9_CONSTANTS_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <string>
+
+namespace webrtc {
+
+// Number of frames that can be stored for future reference.
+constexpr size_t kVp9NumRefFrames = 8;
+// Number of frame contexts that can be store for future reference.
+constexpr size_t kVp9NumFrameContexts = 4;
+// Each inter frame can use up to 3 frames for reference.
+constexpr size_t kVp9RefsPerFrame = 3;
+// Number of values that can be decoded for mv_fr.
+constexpr size_t kVp9MvFrSize = 4;
+// Number of positions to search in motion vector prediction.
+constexpr size_t kVp9MvrefNeighbours = 8;
+// Number of contexts when decoding intra_mode .
+constexpr size_t kVp9BlockSizeGroups = 4;
+// Number of different block sizes used.
+constexpr size_t kVp9BlockSizes = 13;
+// Sentinel value to mark partition choices that are illegal.
+constexpr size_t kVp9BlockInvalid = 14;
+// Number of contexts when decoding partition.
+constexpr size_t kVp9PartitionContexts = 16;
+// Smallest size of a mode info block.
+constexpr size_t kVp9MiSize = 8;
+// Minimum  width  of a  tile  in  units  of  superblocks  (although tiles on
+// the right hand edge can be narrower).
+constexpr size_t kVp9MinTileWidth_B64 = 4;
+// Maximum width of a tile in units of superblocks.
+constexpr size_t kVp9MaxTileWidth_B64 = 64;
+// Number of motion vectors returned by find_mv_refs process.
+constexpr size_t kVp9MaxMvRefCandidates = 2;
+// Number of values that can be derived for ref_frame.
+constexpr size_t kVp9MaxRefFrames = 4;
+// Number of contexts for is_inter.
+constexpr size_t kVp9IsInterContexts = 4;
+// Number of contexts for comp_mode.
+constexpr size_t kVp9CompModeContexts = 5;
+// Number of contexts for single_ref and comp_ref.
+constexpr size_t kVp9RefContexts = 5;
+// Number of segments allowed in segmentation map.
+constexpr size_t kVp9MaxSegments = 8;
+// Index for quantizer segment feature.
+constexpr size_t kVp9SegLvlAlt_Q = 0;
+// Index for loop filter segment feature.
+constexpr size_t kVp9SegLvlAlt_L = 1;
+// Index for reference frame segment feature.
+constexpr size_t kVp9SegLvlRefFrame = 2;
+// Index for skip segment feature.
+constexpr size_t kVp9SegLvlSkip = 3;
+// Number of segment features.
+constexpr size_t kVp9SegLvlMax = 4;
+// Number of different plane types (Y or UV).
+constexpr size_t kVp9BlockTypes = 2;
+// Number of different prediction types (intra or inter).
+constexpr size_t kVp9RefTypes = 2;
+// Number of coefficient bands.
+constexpr size_t kVp9CoefBands = 6;
+// Number of contexts for decoding coefficients.
+constexpr size_t kVp9PrevCoefContexts = 6;
+// Number  of  coefficient  probabilities  that  are  directly transmitted.
+constexpr size_t kVp9UnconstrainedNodes = 3;
+// Number of contexts for transform size.
+constexpr size_t kVp9TxSizeContexts = 2;
+// Number of values for interp_filter.
+constexpr size_t kVp9SwitchableFilters = 3;
+// Number of contexts for interp_filter.
+constexpr size_t kVp9InterpFilterContexts = 4;
+// Number of contexts for decoding skip.
+constexpr size_t kVp9SkipContexts = 3;
+// Number of values for partition.
+constexpr size_t kVp9PartitionTypes = 4;
+// Number of values for tx_size.
+constexpr size_t kVp9TxSizes = 4;
+// Number of values for tx_mode.
+constexpr size_t kVp9TxModes = 5;
+// Inverse transform rows with DCT and columns with DCT.
+constexpr size_t kVp9DctDct = 0;
+// Inverse transform rows with DCT and columns with ADST.
+constexpr size_t kVp9AdstDct = 1;
+// Inverse transform rows with ADST and columns with DCT.
+constexpr size_t kVp9DctAdst = 2;
+// Inverse transform rows with ADST and columns with ADST.
+constexpr size_t kVp9AdstAdst = 3;
+// Number of values for y_mode.
+constexpr size_t kVp9MbModeCount = 14;
+// Number of values for intra_mode.
+constexpr size_t kVp9IntraModes = 10;
+// Number of values for inter_mode.
+constexpr size_t kVp9InterModes = 4;
+// Number of contexts for inter_mode.
+constexpr size_t kVp9InterModeContexts = 7;
+// Number of values for mv_joint.
+constexpr size_t kVp9MvJoints = 4;
+// Number of values for mv_class.
+constexpr size_t kVp9MvClasses = 11;
+// Number of values for mv_class0_bit.
+constexpr size_t kVp9Class0Size = 2;
+// Maximum number of bits for decoding motion vectors.
+constexpr size_t kVp9MvOffsetBits = 10;
+// Number of values allowed for a probability adjustment.
+constexpr size_t kVp9MaxProb = 255;
+// Number of different mode types for loop filtering.
+constexpr size_t kVp9MaxModeLfDeltas = 2;
+// Threshold at which motion vectors are considered large.
+constexpr size_t kVp9CompandedMvrefThresh = 8;
+// Maximum value used for loop filtering.
+constexpr size_t kVp9MaxLoopFilter = 63;
+// Number of bits of precision when scaling reference frames.
+constexpr size_t kVp9RefScaleShift = 14;
+// Number of bits of precision when performing inter prediction.
+constexpr size_t kVp9SubpelBits = 4;
+// 1 << kVp9SubpelBits.
+constexpr size_t kVp9SubpelShifts = 16;
+// kVp9SubpelShifts - 1.
+constexpr size_t kVp9SubpelMask = 15;
+// Value used when clipping motion vectors.
+constexpr size_t kVp9MvBorder = 128;
+// Value used when clipping motion vectors.
+constexpr size_t kVp9InterpExtend = 4;
+// Value used when clipping motion vectors.
+constexpr size_t kVp9Borderinpixels = 160;
+// Value used in adapting probabilities.
+constexpr size_t kVp9MaxUpdateFactor = 128;
+// Value used in adapting probabilities.
+constexpr size_t kVp9CountSat = 20;
+// Both candidates use ZEROMV.
+constexpr size_t kVp9BothZero = 0;
+// One  candidate uses ZEROMV, one uses NEARMV or NEARESTMV.
+constexpr size_t kVp9ZeroPlusPredicted = 1;
+// Both candidates use NEARMV or NEARESTMV.
+constexpr size_t kVp9BothPredicted = 2;
+// One candidate uses NEWMV, one uses ZEROMV.
+constexpr size_t kVp9NewPlusNonIntra = 3;
+// Both candidates use NEWMV.
+constexpr size_t kVp9BothNew = 4;
+// One candidate uses intra prediction, one uses inter prediction.
+constexpr size_t kVp9IntraPlusNonIntra = 5;
+// Both candidates use intra prediction.
+constexpr size_t kVp9BothIntra = 6;
+// Sentinel value marking a case that can never occur.
+constexpr size_t kVp9InvalidCase = 9;
+
+enum class Vp9TxMode : uint8_t {
+  kOnly4X4 = 0,
+  kAllow8X8 = 1,
+  kAllow16x16 = 2,
+  kAllow32x32 = 3,
+  kTxModeSelect = 4
+};
+
+enum Vp9BlockSize : uint8_t {
+  kBlock4X4 = 0,
+  kBlock4X8 = 1,
+  kBlock8X4 = 2,
+  kBlock8X8 = 3,
+  kBlock8X16 = 4,
+  kBlock16X8 = 5,
+  kBlock16X16 = 6,
+  kBlock16X32 = 7,
+  kBlock32X16 = 8,
+  kBlock32X32 = 9,
+  kBlock32X64 = 10,
+  kBlock64X32 = 11,
+  kBlock64X64 = 12
+};
+
+enum Vp9Partition : uint8_t {
+  kPartitionNone = 0,
+  kPartitionHorizontal = 1,
+  kPartitionVertical = 2,
+  kPartitionSplit = 3
+};
+
+enum class Vp9ReferenceMode : uint8_t {
+  kSingleReference = 0,
+  kCompoundReference = 1,
+  kReferenceModeSelect = 2,
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_VP9_CONSTANTS_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser.cc b/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser.cc
new file mode 100644
index 0000000000..bf9d51f692
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser.cc
@@ -0,0 +1,533 @@
+/*
+ *  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.
+ */
+#include "modules/video_coding/utility/vp9_uncompressed_header_parser.h"
+
+#include "absl/numeric/bits.h"
+#include "absl/strings/string_view.h"
+#include "rtc_base/bitstream_reader.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/strings/string_builder.h"
+
+namespace webrtc {
+namespace {
+const size_t kVp9NumRefsPerFrame = 3;
+const size_t kVp9MaxRefLFDeltas = 4;
+const size_t kVp9MaxModeLFDeltas = 2;
+const size_t kVp9MinTileWidthB64 = 4;
+const size_t kVp9MaxTileWidthB64 = 64;
+
+void Vp9ReadColorConfig(BitstreamReader& br,
+                        Vp9UncompressedHeader* frame_info) {
+  if (frame_info->profile == 2 || frame_info->profile == 3) {
+    frame_info->bit_detph =
+        br.Read<bool>() ? Vp9BitDept::k12Bit : Vp9BitDept::k10Bit;
+  } else {
+    frame_info->bit_detph = Vp9BitDept::k8Bit;
+  }
+
+  frame_info->color_space = static_cast<Vp9ColorSpace>(br.ReadBits(3));
+
+  if (frame_info->color_space != Vp9ColorSpace::CS_RGB) {
+    frame_info->color_range =
+        br.Read<bool>() ? Vp9ColorRange::kFull : Vp9ColorRange::kStudio;
+
+    if (frame_info->profile == 1 || frame_info->profile == 3) {
+      static constexpr Vp9YuvSubsampling kSubSamplings[] = {
+          Vp9YuvSubsampling::k444, Vp9YuvSubsampling::k440,
+          Vp9YuvSubsampling::k422, Vp9YuvSubsampling::k420};
+      frame_info->sub_sampling = kSubSamplings[br.ReadBits(2)];
+
+      if (br.Read<bool>()) {
+        RTC_LOG(LS_WARNING) << "Failed to parse header. Reserved bit set.";
+        br.Invalidate();
+        return;
+      }
+    } else {
+      // Profile 0 or 2.
+      frame_info->sub_sampling = Vp9YuvSubsampling::k420;
+    }
+  } else {
+    // SRGB
+    frame_info->color_range = Vp9ColorRange::kFull;
+    if (frame_info->profile == 1 || frame_info->profile == 3) {
+      frame_info->sub_sampling = Vp9YuvSubsampling::k444;
+      if (br.Read<bool>()) {
+        RTC_LOG(LS_WARNING) << "Failed to parse header. Reserved bit set.";
+        br.Invalidate();
+      }
+    } else {
+      RTC_LOG(LS_WARNING) << "Failed to parse header. 4:4:4 color not supported"
+                             " in profile 0 or 2.";
+      br.Invalidate();
+    }
+  }
+}
+
+void ReadRefreshFrameFlags(BitstreamReader& br,
+                           Vp9UncompressedHeader* frame_info) {
+  // Refresh frame flags.
+  uint8_t flags = br.Read<uint8_t>();
+  for (int i = 0; i < 8; ++i) {
+    frame_info->updated_buffers.set(i, (flags & (0x01 << (7 - i))) != 0);
+  }
+}
+
+void Vp9ReadFrameSize(BitstreamReader& br, Vp9UncompressedHeader* frame_info) {
+  // 16 bits: frame (width|height) - 1.
+  frame_info->frame_width = br.Read<uint16_t>() + 1;
+  frame_info->frame_height = br.Read<uint16_t>() + 1;
+}
+
+void Vp9ReadRenderSize(size_t total_buffer_size_bits,
+                       BitstreamReader& br,
+                       Vp9UncompressedHeader* frame_info) {
+  // render_and_frame_size_different
+  if (br.Read<bool>()) {
+    frame_info->render_size_offset_bits =
+        total_buffer_size_bits - br.RemainingBitCount();
+    // 16 bits: render (width|height) - 1.
+    frame_info->render_width = br.Read<uint16_t>() + 1;
+    frame_info->render_height = br.Read<uint16_t>() + 1;
+  } else {
+    frame_info->render_height = frame_info->frame_height;
+    frame_info->render_width = frame_info->frame_width;
+  }
+}
+
+void Vp9ReadFrameSizeFromRefs(BitstreamReader& br,
+                              Vp9UncompressedHeader* frame_info) {
+  for (size_t i = 0; i < kVp9NumRefsPerFrame; i++) {
+    // Size in refs.
+    if (br.Read<bool>()) {
+      frame_info->infer_size_from_reference = frame_info->reference_buffers[i];
+      return;
+    }
+  }
+
+  Vp9ReadFrameSize(br, frame_info);
+}
+
+void Vp9ReadLoopfilter(BitstreamReader& br) {
+  // 6 bits: filter level.
+  // 3 bits: sharpness level.
+  br.ConsumeBits(9);
+
+  if (!br.Read<bool>()) {  // mode_ref_delta_enabled
+    return;
+  }
+  if (!br.Read<bool>()) {  // mode_ref_delta_update
+    return;
+  }
+
+  for (size_t i = 0; i < kVp9MaxRefLFDeltas; i++) {
+    if (br.Read<bool>()) {  // update_ref_delta
+      br.ConsumeBits(7);
+    }
+  }
+  for (size_t i = 0; i < kVp9MaxModeLFDeltas; i++) {
+    if (br.Read<bool>()) {  // update_mode_delta
+      br.ConsumeBits(7);
+    }
+  }
+}
+
+void Vp9ReadQp(BitstreamReader& br, Vp9UncompressedHeader* frame_info) {
+  frame_info->base_qp = br.Read<uint8_t>();
+
+  // yuv offsets
+  frame_info->is_lossless = frame_info->base_qp == 0;
+  for (int i = 0; i < 3; ++i) {
+    if (br.Read<bool>()) {  // if delta_coded
+      // delta_q is a signed integer with leading 4 bits containing absolute
+      // value and last bit containing sign. There are are two ways to represent
+      // zero with such encoding.
+      if ((br.ReadBits(5) & 0b1111'0) != 0) {  // delta_q
+        frame_info->is_lossless = false;
+      }
+    }
+  }
+}
+
+void Vp9ReadSegmentationParams(BitstreamReader& br,
+                               Vp9UncompressedHeader* frame_info) {
+  constexpr int kSegmentationFeatureBits[kVp9SegLvlMax] = {8, 6, 2, 0};
+  constexpr bool kSegmentationFeatureSigned[kVp9SegLvlMax] = {true, true, false,
+                                                              false};
+
+  frame_info->segmentation_enabled = br.Read<bool>();
+  if (!frame_info->segmentation_enabled) {
+    return;
+  }
+
+  if (br.Read<bool>()) {  // update_map
+    frame_info->segmentation_tree_probs.emplace();
+    for (int i = 0; i < 7; ++i) {
+      if (br.Read<bool>()) {
+        (*frame_info->segmentation_tree_probs)[i] = br.Read<uint8_t>();
+      } else {
+        (*frame_info->segmentation_tree_probs)[i] = 255;
+      }
+    }
+
+    // temporal_update
+    frame_info->segmentation_pred_prob.emplace();
+    if (br.Read<bool>()) {
+      for (int i = 0; i < 3; ++i) {
+        if (br.Read<bool>()) {
+          (*frame_info->segmentation_pred_prob)[i] = br.Read<uint8_t>();
+        } else {
+          (*frame_info->segmentation_pred_prob)[i] = 255;
+        }
+      }
+    } else {
+      frame_info->segmentation_pred_prob->fill(255);
+    }
+  }
+
+  if (br.Read<bool>()) {  // segmentation_update_data
+    frame_info->segmentation_is_delta = br.Read<bool>();
+    for (size_t i = 0; i < kVp9MaxSegments; ++i) {
+      for (size_t j = 0; j < kVp9SegLvlMax; ++j) {
+        if (!br.Read<bool>()) {  // feature_enabled
+          continue;
+        }
+        if (kSegmentationFeatureBits[j] == 0) {
+          // No feature bits used and no sign, just mark it and return.
+          frame_info->segmentation_features[i][j] = 1;
+          continue;
+        }
+        frame_info->segmentation_features[i][j] =
+            br.ReadBits(kSegmentationFeatureBits[j]);
+        if (kSegmentationFeatureSigned[j] && br.Read<bool>()) {
+          (*frame_info->segmentation_features[i][j]) *= -1;
+        }
+      }
+    }
+  }
+}
+
+void Vp9ReadTileInfo(BitstreamReader& br, Vp9UncompressedHeader* frame_info) {
+  size_t mi_cols = (frame_info->frame_width + 7) >> 3;
+  size_t sb64_cols = (mi_cols + 7) >> 3;
+
+  size_t min_log2 = 0;
+  while ((kVp9MaxTileWidthB64 << min_log2) < sb64_cols) {
+    ++min_log2;
+  }
+
+  size_t max_log2 = 1;
+  while ((sb64_cols >> max_log2) >= kVp9MinTileWidthB64) {
+    ++max_log2;
+  }
+  --max_log2;
+
+  frame_info->tile_cols_log2 = min_log2;
+  while (frame_info->tile_cols_log2 < max_log2) {
+    if (br.Read<bool>()) {
+      ++frame_info->tile_cols_log2;
+    } else {
+      break;
+    }
+  }
+  frame_info->tile_rows_log2 = 0;
+  if (br.Read<bool>()) {
+    ++frame_info->tile_rows_log2;
+    if (br.Read<bool>()) {
+      ++frame_info->tile_rows_log2;
+    }
+  }
+}
+
+const Vp9InterpolationFilter kLiteralToType[4] = {
+    Vp9InterpolationFilter::kEightTapSmooth, Vp9InterpolationFilter::kEightTap,
+    Vp9InterpolationFilter::kEightTapSharp, Vp9InterpolationFilter::kBilinear};
+}  // namespace
+
+std::string Vp9UncompressedHeader::ToString() const {
+  char buf[1024];
+  rtc::SimpleStringBuilder oss(buf);
+
+  oss << "Vp9UncompressedHeader { "
+      << "profile = " << profile;
+
+  if (show_existing_frame) {
+    oss << ", show_existing_frame = " << *show_existing_frame << " }";
+    return oss.str();
+  }
+
+  oss << ", frame type = " << (is_keyframe ? "key" : "delta")
+      << ", show_frame = " << (show_frame ? "true" : "false")
+      << ", error_resilient = " << (error_resilient ? "true" : "false");
+
+  oss << ", bit_depth = ";
+  switch (bit_detph) {
+    case Vp9BitDept::k8Bit:
+      oss << "8bit";
+      break;
+    case Vp9BitDept::k10Bit:
+      oss << "10bit";
+      break;
+    case Vp9BitDept::k12Bit:
+      oss << "12bit";
+      break;
+  }
+
+  if (color_space) {
+    oss << ", color_space = ";
+    switch (*color_space) {
+      case Vp9ColorSpace::CS_UNKNOWN:
+        oss << "unknown";
+        break;
+      case Vp9ColorSpace::CS_BT_601:
+        oss << "CS_BT_601 Rec. ITU-R BT.601-7";
+        break;
+      case Vp9ColorSpace::CS_BT_709:
+        oss << "Rec. ITU-R BT.709-6";
+        break;
+      case Vp9ColorSpace::CS_SMPTE_170:
+        oss << "SMPTE-170";
+        break;
+      case Vp9ColorSpace::CS_SMPTE_240:
+        oss << "SMPTE-240";
+        break;
+      case Vp9ColorSpace::CS_BT_2020:
+        oss << "Rec. ITU-R BT.2020-2";
+        break;
+      case Vp9ColorSpace::CS_RESERVED:
+        oss << "Reserved";
+        break;
+      case Vp9ColorSpace::CS_RGB:
+        oss << "sRGB (IEC 61966-2-1)";
+        break;
+    }
+  }
+
+  if (color_range) {
+    oss << ", color_range = ";
+    switch (*color_range) {
+      case Vp9ColorRange::kFull:
+        oss << "full";
+        break;
+      case Vp9ColorRange::kStudio:
+        oss << "studio";
+        break;
+    }
+  }
+
+  if (sub_sampling) {
+    oss << ", sub_sampling = ";
+    switch (*sub_sampling) {
+      case Vp9YuvSubsampling::k444:
+        oss << "444";
+        break;
+      case Vp9YuvSubsampling::k440:
+        oss << "440";
+        break;
+      case Vp9YuvSubsampling::k422:
+        oss << "422";
+        break;
+      case Vp9YuvSubsampling::k420:
+        oss << "420";
+        break;
+    }
+  }
+
+  if (infer_size_from_reference) {
+    oss << ", infer_frame_resolution_from = " << *infer_size_from_reference;
+  } else {
+    oss << ", frame_width = " << frame_width
+        << ", frame_height = " << frame_height;
+  }
+  if (render_width != 0 && render_height != 0) {
+    oss << ", render_width = " << render_width
+        << ", render_height = " << render_height;
+  }
+
+  oss << ", base qp = " << base_qp;
+  if (reference_buffers[0] != -1) {
+    oss << ", last_buffer = " << reference_buffers[0];
+  }
+  if (reference_buffers[1] != -1) {
+    oss << ", golden_buffer = " << reference_buffers[1];
+  }
+  if (reference_buffers[2] != -1) {
+    oss << ", altref_buffer = " << reference_buffers[2];
+  }
+
+  oss << ", updated buffers = { ";
+  bool first = true;
+  for (int i = 0; i < 8; ++i) {
+    if (updated_buffers.test(i)) {
+      if (first) {
+        first = false;
+      } else {
+        oss << ", ";
+      }
+      oss << i;
+    }
+  }
+  oss << " }";
+
+  oss << ", compressed_header_size_bytes = " << compressed_header_size;
+
+  oss << " }";
+  return oss.str();
+}
+
+void Parse(BitstreamReader& br,
+           Vp9UncompressedHeader* frame_info,
+           bool qp_only) {
+  const size_t total_buffer_size_bits = br.RemainingBitCount();
+
+  // Frame marker.
+  if (br.ReadBits(2) != 0b10) {
+    RTC_LOG(LS_WARNING) << "Failed to parse header. Frame marker should be 2.";
+    br.Invalidate();
+    return;
+  }
+
+  // Profile has low bit first.
+  frame_info->profile = br.ReadBit();
+  frame_info->profile |= br.ReadBit() << 1;
+  if (frame_info->profile > 2 && br.Read<bool>()) {
+    RTC_LOG(LS_WARNING)
+        << "Failed to parse header. Unsupported bitstream profile.";
+    br.Invalidate();
+    return;
+  }
+
+  // Show existing frame.
+  if (br.Read<bool>()) {
+    frame_info->show_existing_frame = br.ReadBits(3);
+    return;
+  }
+
+  // Frame type: KEY_FRAME(0), INTER_FRAME(1).
+  frame_info->is_keyframe = !br.Read<bool>();
+  frame_info->show_frame = br.Read<bool>();
+  frame_info->error_resilient = br.Read<bool>();
+
+  if (frame_info->is_keyframe) {
+    if (br.ReadBits(24) != 0x498342) {
+      RTC_LOG(LS_WARNING) << "Failed to parse header. Invalid sync code.";
+      br.Invalidate();
+      return;
+    }
+
+    Vp9ReadColorConfig(br, frame_info);
+    Vp9ReadFrameSize(br, frame_info);
+    Vp9ReadRenderSize(total_buffer_size_bits, br, frame_info);
+
+    // Key-frames implicitly update all buffers.
+    frame_info->updated_buffers.set();
+  } else {
+    // Non-keyframe.
+    bool is_intra_only = false;
+    if (!frame_info->show_frame) {
+      is_intra_only = br.Read<bool>();
+    }
+    if (!frame_info->error_resilient) {
+      br.ConsumeBits(2);  // Reset frame context.
+    }
+
+    if (is_intra_only) {
+      if (br.ReadBits(24) != 0x498342) {
+        RTC_LOG(LS_WARNING) << "Failed to parse header. Invalid sync code.";
+        br.Invalidate();
+        return;
+      }
+
+      if (frame_info->profile > 0) {
+        Vp9ReadColorConfig(br, frame_info);
+      } else {
+        frame_info->color_space = Vp9ColorSpace::CS_BT_601;
+        frame_info->sub_sampling = Vp9YuvSubsampling::k420;
+        frame_info->bit_detph = Vp9BitDept::k8Bit;
+      }
+      frame_info->reference_buffers.fill(-1);
+      ReadRefreshFrameFlags(br, frame_info);
+      Vp9ReadFrameSize(br, frame_info);
+      Vp9ReadRenderSize(total_buffer_size_bits, br, frame_info);
+    } else {
+      ReadRefreshFrameFlags(br, frame_info);
+
+      frame_info->reference_buffers_sign_bias[0] = false;
+      for (size_t i = 0; i < kVp9NumRefsPerFrame; i++) {
+        frame_info->reference_buffers[i] = br.ReadBits(3);
+        frame_info->reference_buffers_sign_bias[Vp9ReferenceFrame::kLast + i] =
+            br.Read<bool>();
+      }
+
+      Vp9ReadFrameSizeFromRefs(br, frame_info);
+      Vp9ReadRenderSize(total_buffer_size_bits, br, frame_info);
+
+      frame_info->allow_high_precision_mv = br.Read<bool>();
+
+      // Interpolation filter.
+      if (br.Read<bool>()) {
+        frame_info->interpolation_filter = Vp9InterpolationFilter::kSwitchable;
+      } else {
+        frame_info->interpolation_filter = kLiteralToType[br.ReadBits(2)];
+      }
+    }
+  }
+
+  if (!frame_info->error_resilient) {
+    // 1 bit: Refresh frame context.
+    // 1 bit: Frame parallel decoding mode.
+    br.ConsumeBits(2);
+  }
+
+  // Frame context index.
+  frame_info->frame_context_idx = br.ReadBits(2);
+
+  Vp9ReadLoopfilter(br);
+
+  // Read base QP.
+  Vp9ReadQp(br, frame_info);
+
+  if (qp_only) {
+    // Not interested in the rest of the header, return early.
+    return;
+  }
+
+  Vp9ReadSegmentationParams(br, frame_info);
+  Vp9ReadTileInfo(br, frame_info);
+  frame_info->compressed_header_size = br.Read<uint16_t>();
+  frame_info->uncompressed_header_size =
+      (total_buffer_size_bits / 8) - (br.RemainingBitCount() / 8);
+}
+
+absl::optional<Vp9UncompressedHeader> ParseUncompressedVp9Header(
+    rtc::ArrayView<const uint8_t> buf) {
+  BitstreamReader reader(buf);
+  Vp9UncompressedHeader frame_info;
+  Parse(reader, &frame_info, /*qp_only=*/false);
+  if (reader.Ok() && frame_info.frame_width > 0) {
+    return frame_info;
+  }
+  return absl::nullopt;
+}
+
+namespace vp9 {
+
+bool GetQp(const uint8_t* buf, size_t length, int* qp) {
+  BitstreamReader reader(rtc::MakeArrayView(buf, length));
+  Vp9UncompressedHeader frame_info;
+  Parse(reader, &frame_info, /*qp_only=*/true);
+  if (!reader.Ok()) {
+    return false;
+  }
+  *qp = frame_info.base_qp;
+  return true;
+}
+
+}  // namespace vp9
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser.h b/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser.h
new file mode 100644
index 0000000000..8d1b88c3d3
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser.h
@@ -0,0 +1,155 @@
+/*
+ *  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.
+ */
+
+#ifndef MODULES_VIDEO_CODING_UTILITY_VP9_UNCOMPRESSED_HEADER_PARSER_H_
+#define MODULES_VIDEO_CODING_UTILITY_VP9_UNCOMPRESSED_HEADER_PARSER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <array>
+#include <bitset>
+#include <string>
+
+#include "absl/types/optional.h"
+#include "api/array_view.h"
+#include "modules/video_coding/utility/vp9_constants.h"
+
+namespace webrtc {
+
+namespace vp9 {
+
+// Gets the QP, QP range: [0, 255].
+// Returns true on success, false otherwise.
+bool GetQp(const uint8_t* buf, size_t length, int* qp);
+
+}  // namespace vp9
+
+// Bit depth per channel. Support varies by profile.
+enum class Vp9BitDept : uint8_t {
+  k8Bit = 8,
+  k10Bit = 10,
+  k12Bit = 12,
+};
+
+enum class Vp9ColorSpace : uint8_t {
+  CS_UNKNOWN = 0,    // Unknown (in this case the color space must be signaled
+                     // outside the VP9 bitstream).
+  CS_BT_601 = 1,     // CS_BT_601 Rec. ITU-R BT.601-7
+  CS_BT_709 = 2,     // Rec. ITU-R BT.709-6
+  CS_SMPTE_170 = 3,  // SMPTE-170
+  CS_SMPTE_240 = 4,  // SMPTE-240
+  CS_BT_2020 = 5,    // Rec. ITU-R BT.2020-2
+  CS_RESERVED = 6,   // Reserved
+  CS_RGB = 7,        // sRGB (IEC 61966-2-1)
+};
+
+enum class Vp9ColorRange {
+  kStudio,  // Studio swing:
+            // For BitDepth equals 8:
+            //     Y is between 16 and 235 inclusive.
+            //     U and V are between 16 and 240 inclusive.
+            // For BitDepth equals 10:
+            //     Y is between 64 and 940 inclusive.
+            //     U and V are between 64 and 960 inclusive.
+            // For BitDepth equals 12:
+            //     Y is between 256 and 3760.
+            //     U and V are between 256 and 3840 inclusive.
+  kFull     // Full swing; no restriction on Y, U, V values.
+};
+
+enum class Vp9YuvSubsampling {
+  k444,
+  k440,
+  k422,
+  k420,
+};
+
+enum Vp9ReferenceFrame : int {
+  kNone = -1,
+  kIntra = 0,
+  kLast = 1,
+  kGolden = 2,
+  kAltref = 3,
+};
+
+enum class Vp9InterpolationFilter : uint8_t {
+  kEightTap = 0,
+  kEightTapSmooth = 1,
+  kEightTapSharp = 2,
+  kBilinear = 3,
+  kSwitchable = 4
+};
+
+struct Vp9UncompressedHeader {
+  int profile = 0;  // Profiles 0-3 are valid.
+  absl::optional<uint8_t> show_existing_frame;
+  bool is_keyframe = false;
+  bool show_frame = false;
+  bool error_resilient = false;
+  Vp9BitDept bit_detph = Vp9BitDept::k8Bit;
+  absl::optional<Vp9ColorSpace> color_space;
+  absl::optional<Vp9ColorRange> color_range;
+  absl::optional<Vp9YuvSubsampling> sub_sampling;
+  int frame_width = 0;
+  int frame_height = 0;
+  int render_width = 0;
+  int render_height = 0;
+  // Width/height of the tiles used (in units of 8x8 blocks).
+  size_t tile_cols_log2 = 0;  // tile_cols = 1 << tile_cols_log2
+  size_t tile_rows_log2 = 0;  // tile_rows = 1 << tile_rows_log2
+  absl::optional<size_t> render_size_offset_bits;
+  Vp9InterpolationFilter interpolation_filter =
+      Vp9InterpolationFilter::kEightTap;
+  bool allow_high_precision_mv = false;
+  int base_qp = 0;
+  bool is_lossless = false;
+  uint8_t frame_context_idx = 0;
+
+  bool segmentation_enabled = false;
+  absl::optional<std::array<uint8_t, 7>> segmentation_tree_probs;
+  absl::optional<std::array<uint8_t, 3>> segmentation_pred_prob;
+  bool segmentation_is_delta = false;
+  std::array<std::array<absl::optional<int>, kVp9SegLvlMax>, kVp9MaxSegments>
+      segmentation_features;
+
+  // Which of the 8 reference buffers may be used as references for this frame.
+  // -1 indicates not used (e.g. {-1, -1, -1} for intra-only frames).
+  std::array<int, kVp9RefsPerFrame> reference_buffers = {-1, -1, -1};
+  // Sign bias corresponding to reference buffers, where the index is a
+  // ReferenceFrame.
+  // false/0 indidate backwards reference, true/1 indicate forwards reference).
+  std::bitset<kVp9MaxRefFrames> reference_buffers_sign_bias = 0;
+
+  // Indicates which reference buffer [0,7] to infer the frame size from.
+  absl::optional<int> infer_size_from_reference;
+  // Which of the 8 reference buffers are updated by this frame.
+  std::bitset<kVp9NumRefFrames> updated_buffers = 0;
+
+  // Header sizes, in bytes.
+  uint32_t uncompressed_header_size = 0;
+  uint32_t compressed_header_size = 0;
+
+  bool is_intra_only() const {
+    return reference_buffers[0] == -1 && reference_buffers[1] == -1 &&
+           reference_buffers[2] == -1;
+  }
+
+  std::string ToString() const;
+};
+
+// Parses the uncompressed header and populates (most) values in a
+// UncompressedHeader struct. Returns nullopt on failure.
+absl::optional<Vp9UncompressedHeader> ParseUncompressedVp9Header(
+    rtc::ArrayView<const uint8_t> buf);
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_VP9_UNCOMPRESSED_HEADER_PARSER_H_
diff --git a/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser_unittest.cc b/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser_unittest.cc
new file mode 100644
index 0000000000..d8cc738e07
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/utility/vp9_uncompressed_header_parser_unittest.cc
@@ -0,0 +1,94 @@
+/*
+ *  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/video_coding/utility/vp9_uncompressed_header_parser.h"
+
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace vp9 {
+using ::testing::AllOf;
+using ::testing::ElementsAre;
+using ::testing::Eq;
+using ::testing::Field;
+using ::testing::Optional;
+
+TEST(Vp9UncompressedHeaderParserTest, FrameWithSegmentation) {
+  // Uncompressed header from a frame generated with libvpx.
+  // Encoded QVGA frame (SL0 of a VGA frame) that includes a segmentation.
+  const uint8_t kHeader[] = {
+      0x87, 0x01, 0x00, 0x00, 0x02, 0x7e, 0x01, 0xdf, 0x02, 0x7f, 0x01, 0xdf,
+      0xc6, 0x87, 0x04, 0x83, 0x83, 0x2e, 0x46, 0x60, 0x20, 0x38, 0x0c, 0x06,
+      0x03, 0xcd, 0x80, 0xc0, 0x60, 0x9f, 0xc5, 0x46, 0x00, 0x00, 0x00, 0x00,
+      0x2e, 0x73, 0xb7, 0xee, 0x22, 0x06, 0x81, 0x82, 0xd4, 0xef, 0xc3, 0x58,
+      0x1f, 0x12, 0xd2, 0x7b, 0x28, 0x1f, 0x80, 0xfc, 0x07, 0xe0, 0x00, 0x00};
+
+  absl::optional<Vp9UncompressedHeader> frame_info =
+      ParseUncompressedVp9Header(kHeader);
+  ASSERT_TRUE(frame_info.has_value());
+
+  EXPECT_FALSE(frame_info->is_keyframe);
+  EXPECT_TRUE(frame_info->error_resilient);
+  EXPECT_TRUE(frame_info->show_frame);
+  EXPECT_FALSE(frame_info->show_existing_frame);
+  EXPECT_EQ(frame_info->base_qp, 185);
+  EXPECT_EQ(frame_info->frame_width, 320);
+  EXPECT_EQ(frame_info->frame_height, 240);
+  EXPECT_EQ(frame_info->render_width, 640);
+  EXPECT_EQ(frame_info->render_height, 480);
+  EXPECT_TRUE(frame_info->allow_high_precision_mv);
+  EXPECT_EQ(frame_info->frame_context_idx, 0u);
+  EXPECT_EQ(frame_info->interpolation_filter,
+            Vp9InterpolationFilter::kSwitchable);
+  EXPECT_EQ(frame_info->is_lossless, false);
+  EXPECT_EQ(frame_info->profile, 0);
+  EXPECT_THAT(frame_info->reference_buffers, ElementsAre(0, 0, 0));
+  EXPECT_THAT(frame_info->reference_buffers_sign_bias, 0b0000);
+  EXPECT_EQ(frame_info->updated_buffers, 0b10000000);
+  EXPECT_EQ(frame_info->tile_cols_log2, 0u);
+  EXPECT_EQ(frame_info->tile_rows_log2, 0u);
+  EXPECT_EQ(frame_info->render_size_offset_bits, 64u);
+  EXPECT_EQ(frame_info->compressed_header_size, 23u);
+  EXPECT_EQ(frame_info->uncompressed_header_size, 37u);
+
+  EXPECT_TRUE(frame_info->segmentation_enabled);
+  EXPECT_FALSE(frame_info->segmentation_is_delta);
+  EXPECT_THAT(frame_info->segmentation_pred_prob,
+              Optional(ElementsAre(205, 1, 1)));
+  EXPECT_THAT(frame_info->segmentation_tree_probs,
+              Optional(ElementsAre(255, 255, 128, 1, 128, 128, 128)));
+  EXPECT_THAT(frame_info->segmentation_features[1][kVp9SegLvlAlt_Q], Eq(-63));
+  EXPECT_THAT(frame_info->segmentation_features[2][kVp9SegLvlAlt_Q], Eq(-81));
+}
+
+TEST(Vp9UncompressedHeaderParserTest, SegmentationWithDefaultPredProbs) {
+  const uint8_t kHeader[] = {0x90, 0x49, 0x83, 0x42, 0x80, 0x2e,
+                             0x30, 0x0,  0xb0, 0x0,  0x37, 0xff,
+                             0x06, 0x80, 0x0,  0x0,  0x0,  0x0};
+  absl::optional<Vp9UncompressedHeader> frame_info =
+      ParseUncompressedVp9Header(kHeader);
+  ASSERT_TRUE(frame_info.has_value());
+  EXPECT_THAT(frame_info->segmentation_pred_prob,
+              Optional(ElementsAre(255, 255, 255)));
+}
+
+TEST(Vp9UncompressedHeaderParserTest, SegmentationWithSkipLevel) {
+  const uint8_t kHeader[] = {0x90, 0x49, 0x83, 0x42, 0x80, 0x2e, 0x30, 0x00,
+                             0xb0, 0x00, 0x37, 0xff, 0x06, 0x80, 0x01, 0x08,
+                             0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  absl::optional<Vp9UncompressedHeader> frame_info =
+      ParseUncompressedVp9Header(kHeader);
+  ASSERT_TRUE(frame_info.has_value());
+  EXPECT_THAT(frame_info->segmentation_features[0][kVp9SegLvlSkip], Eq(1));
+}
+
+}  // namespace vp9
+}  // namespace webrtc