/*
 *  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 "media/engine/simulcast_encoder_adapter.h"

#include <stddef.h>
#include <stdint.h>

#include <array>
#include <atomic>
#include <memory>
#include <optional>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include "absl/container/inlined_vector.h"
#include "absl/functional/any_invocable.h"
#include "api/environment/environment.h"
#include "api/environment/environment_factory.h"
#include "api/fec_controller_override.h"
#include "api/field_trials.h"
#include "api/make_ref_counted.h"
#include "api/rtp_parameters.h"
#include "api/scoped_refptr.h"
#include "api/task_queue/task_queue_base.h"
#include "api/task_queue/task_queue_factory.h"
#include "api/test/create_simulcast_test_fixture.h"
#include "api/test/mock_video_bitrate_allocator.h"
#include "api/test/mock_video_decoder.h"
#include "api/test/mock_video_encoder.h"
#include "api/test/simulcast_test_fixture.h"
#include "api/test/video/function_video_decoder_factory.h"
#include "api/test/video/function_video_encoder_factory.h"
#include "api/units/data_rate.h"
#include "api/units/timestamp.h"
#include "api/video/encoded_image.h"
#include "api/video/i420_buffer.h"
#include "api/video/video_bitrate_allocation.h"
#include "api/video/video_bitrate_allocator.h"
#include "api/video/video_codec_constants.h"
#include "api/video/video_codec_type.h"
#include "api/video/video_frame.h"
#include "api/video/video_frame_buffer.h"
#include "api/video/video_frame_type.h"
#include "api/video/video_rotation.h"
#include "api/video_codecs/scalability_mode.h"
#include "api/video_codecs/sdp_video_format.h"
#include "api/video_codecs/video_codec.h"
#include "api/video_codecs/video_decoder_factory.h"
#include "api/video_codecs/video_encoder.h"
#include "api/video_codecs/video_encoder_factory.h"
#include "media/engine/internal_encoder_factory.h"
#include "modules/video_coding/codecs/vp8/include/vp8.h"
#include "modules/video_coding/include/video_codec_interface.h"
#include "modules/video_coding/include/video_error_codes.h"
#include "modules/video_coding/utility/simulcast_rate_allocator.h"
#include "modules/video_coding/utility/simulcast_test_fixture_impl.h"
#include "rtc_base/checks.h"
#include "rtc_base/cpu_info.h"
#include "rtc_base/event.h"
#include "rtc_base/synchronization/mutex.h"
#include "rtc_base/thread_annotations.h"
#include "test/create_test_field_trials.h"
#include "test/gmock.h"
#include "test/gtest.h"
#include "test/run_loop.h"

using ::testing::_;
using ::testing::Return;
using EncoderInfo = webrtc::VideoEncoder::EncoderInfo;
using FramerateFractions =
    absl::InlinedVector<uint8_t, webrtc::kMaxTemporalStreams>;

namespace webrtc {

namespace test {

namespace {

constexpr int kDefaultWidth = 1280;
constexpr int kDefaultHeight = 720;

const VideoEncoder::Capabilities kCapabilities(false);
const VideoEncoder::Settings kSettings(kCapabilities, 1, 1200);

std::unique_ptr<SimulcastTestFixture> CreateSpecificSimulcastTestFixture(
    VideoEncoderFactory* internal_encoder_factory) {
  std::unique_ptr<VideoEncoderFactory> encoder_factory =
      std::make_unique<FunctionVideoEncoderFactory>(
          [internal_encoder_factory](const Environment& env,
                                     const SdpVideoFormat& /* format */) {
            return std::make_unique<SimulcastEncoderAdapter>(
                env, internal_encoder_factory, nullptr, SdpVideoFormat::VP8());
          });
  std::unique_ptr<VideoDecoderFactory> decoder_factory =
      std::make_unique<FunctionVideoDecoderFactory>(
          [](const Environment& env, const SdpVideoFormat& /* format */) {
            return CreateVp8Decoder(env);
          });
  return CreateSimulcastTestFixture(std::move(encoder_factory),
                                    std::move(decoder_factory),
                                    SdpVideoFormat::VP8());
}

}  // namespace

TEST(SimulcastEncoderAdapterSimulcastTest, TestKeyFrameRequestsOnAllStreams) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestKeyFrameRequestsOnAllStreams();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestPaddingAllStreams) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestPaddingAllStreams();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestPaddingTwoStreams) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestPaddingTwoStreams();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestPaddingTwoStreamsOneMaxedOut) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestPaddingTwoStreamsOneMaxedOut();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestPaddingOneStream) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestPaddingOneStream();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestPaddingOneStreamTwoMaxedOut) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestPaddingOneStreamTwoMaxedOut();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestSendAllStreams) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestSendAllStreams();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestDisablingStreams) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestDisablingStreams();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestActiveStreams) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestActiveStreams();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestSwitchingToOneStream) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestSwitchingToOneStream();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestSwitchingToOneOddStream) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestSwitchingToOneOddStream();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestStrideEncodeDecode) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestStrideEncodeDecode();
}

TEST(SimulcastEncoderAdapterSimulcastTest,
     TestSpatioTemporalLayers333PatternEncoder) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestSpatioTemporalLayers333PatternEncoder();
}

TEST(SimulcastEncoderAdapterSimulcastTest,
     TestSpatioTemporalLayers321PatternEncoder) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestSpatioTemporalLayers321PatternEncoder();
}

TEST(SimulcastEncoderAdapterSimulcastTest, TestDecodeWidthHeightSet) {
  InternalEncoderFactory internal_encoder_factory;
  auto fixture = CreateSpecificSimulcastTestFixture(&internal_encoder_factory);
  fixture->TestDecodeWidthHeightSet();
}

class MockVideoEncoder;

class MockVideoEncoderFactory : public VideoEncoderFactory {
 public:
  explicit MockVideoEncoderFactory(const Environment& env) : env_(env) {}
  std::vector<SdpVideoFormat> GetSupportedFormats() const override;

  std::unique_ptr<VideoEncoder> Create(const Environment& env,
                                       const SdpVideoFormat& format) override;

  const std::vector<MockVideoEncoder*>& encoders() const;
  void SetEncoderNames(const std::vector<const char*>& encoder_names);
  void set_create_video_encode_return_nullptr(bool return_nullptr) {
    create_video_encoder_return_nullptr_ = return_nullptr;
  }
  void set_init_encode_return_value(int32_t value);
  void set_requested_resolution_alignments(
      std::vector<uint32_t> requested_resolution_alignments) {
    requested_resolution_alignments_ = requested_resolution_alignments;
  }
  void set_supports_simulcast(bool supports_simulcast) {
    supports_simulcast_ = supports_simulcast;
  }
  void set_resolution_bitrate_limits(
      std::vector<VideoEncoder::ResolutionBitrateLimits> limits) {
    resolution_bitrate_limits_ = limits;
  }
  void set_fallback_from_simulcast(std::optional<int32_t> return_value) {
    fallback_from_simulcast_ = return_value;
  }
  TaskQueueBase* GetAsyncEncoderQueue() {
    if (!async_encoder_queue_) {
      async_encoder_queue_ = env_.task_queue_factory().CreateTaskQueue(
          "AsyncEncoderQueue", TaskQueueFactory::Priority::NORMAL);
    }
    return async_encoder_queue_.get();
  }

  void DestroyVideoEncoder(VideoEncoder* encoder);

 private:
  const Environment& env_;
  bool create_video_encoder_return_nullptr_ = false;
  int32_t init_encode_return_value_ = 0;
  std::optional<int32_t> fallback_from_simulcast_;
  std::vector<MockVideoEncoder*> encoders_;
  std::vector<const char*> encoder_names_;
  // Keep number of entries in sync with `kMaxSimulcastStreams`.
  std::vector<uint32_t> requested_resolution_alignments_ = {1, 1, 1};
  bool supports_simulcast_ = false;
  std::vector<VideoEncoder::ResolutionBitrateLimits> resolution_bitrate_limits_;
  std::unique_ptr<TaskQueueBase, TaskQueueDeleter> async_encoder_queue_;
};

class MockVideoEncoder : public VideoEncoder {
 public:
  explicit MockVideoEncoder(MockVideoEncoderFactory* factory)
      : factory_(factory),
        scaling_settings_(VideoEncoder::ScalingSettings::kOff),
        video_format_("unknown"),
        callback_(nullptr) {}

  MOCK_METHOD(void,
              SetFecControllerOverride,
              (FecControllerOverride * fec_controller_override),
              (override));

  int32_t InitEncode(const VideoCodec* codecSettings,
                     const VideoEncoder::Settings& /* settings */) override {
    codec_ = *codecSettings;
    if (codec_.numberOfSimulcastStreams > 1 && fallback_from_simulcast_) {
      return *fallback_from_simulcast_;
    }
    return init_encode_return_value_;
  }

  MOCK_METHOD(int32_t,
              Encode,
              (const VideoFrame& inputImage,
               const std::vector<VideoFrameType>* frame_types),
              (override));

  int32_t RegisterEncodeCompleteCallback(
      EncodedImageCallback* callback) override {
    callback_ = callback;
    return 0;
  }

  MOCK_METHOD(int32_t, ReleaseMock, ());
  int32_t Release() override {
    RunUntilIdle();
    return ReleaseMock();
  }

  void SetRates(const RateControlParameters& parameters) override {
    last_set_rates_ = parameters;
  }

  EncoderInfo GetEncoderInfo() const override {
    EncoderInfo info;
    info.supports_native_handle = supports_native_handle_;
    info.implementation_name = implementation_name_;
    info.scaling_settings = scaling_settings_;
    info.requested_resolution_alignment = requested_resolution_alignment_;
    info.apply_alignment_to_all_simulcast_layers =
        apply_alignment_to_all_simulcast_layers_;
    info.has_trusted_rate_controller = has_trusted_rate_controller_;
    info.is_hardware_accelerated = is_hardware_accelerated_;
    info.enable_cpu_overuse_detection = enable_cpu_overuse_detection_;
    info.fps_allocation[0] = fps_allocation_;
    info.supports_simulcast = supports_simulcast_;
    info.is_qp_trusted = is_qp_trusted_;
    info.resolution_bitrate_limits = resolution_bitrate_limits;
    return info;
  }

  ~MockVideoEncoder() override { factory_->DestroyVideoEncoder(this); }

  const VideoCodec& codec() const { return codec_; }

  EncodedImageCallback* callback() const { return callback_; }

  void SendEncodedImage(int width,
                        int height,
                        uint32_t rtp_timestamp = 0,
                        std::optional<int> simulcast_index = std::nullopt) {
    // Sends a fake image of the given width/height.
    EncodedImage image;
    image._encodedWidth = width;
    image._encodedHeight = height;
    image.SetRtpTimestamp(rtp_timestamp);
    if (simulcast_index.has_value()) {
      image.SetSimulcastIndex(*simulcast_index);
    }
    CodecSpecificInfo codec_specific_info;
    codec_specific_info.codecType = kVideoCodecVP8;
    callback_->OnEncodedImage(image, &codec_specific_info);
  }

  void PostTask(absl::AnyInvocable<void() &&> task) {
    if (is_async_) {
      factory_->GetAsyncEncoderQueue()->PostTask(std::move(task));
    } else {
      std::move(task)();
    }
  }

  void set_is_async(bool is_async) {
    if (is_async_ && !is_async) {
      // Turning from asynchronous to synchronous. Wait for any pending tasks to
      // complete.
      RunUntilIdle();
    }
    is_async_ = is_async;
  }

  void set_supports_native_handle(bool enabled) {
    supports_native_handle_ = enabled;
  }

  void set_implementation_name(const std::string& name) {
    implementation_name_ = name;
  }

  void set_init_encode_return_value(int32_t value) {
    init_encode_return_value_ = value;
  }

  void set_fallback_from_simulcast(std::optional<int32_t> value) {
    fallback_from_simulcast_ = value;
  }

  void set_scaling_settings(const VideoEncoder::ScalingSettings& settings) {
    scaling_settings_ = settings;
  }

  void set_requested_resolution_alignment(
      uint32_t requested_resolution_alignment) {
    requested_resolution_alignment_ = requested_resolution_alignment;
  }

  void set_apply_alignment_to_all_simulcast_layers(bool apply) {
    apply_alignment_to_all_simulcast_layers_ = apply;
  }

  void set_has_trusted_rate_controller(bool trusted) {
    has_trusted_rate_controller_ = trusted;
  }

  void set_is_hardware_accelerated(bool is_hardware_accelerated) {
    is_hardware_accelerated_ = is_hardware_accelerated;
  }

  void set_enable_cpu_overuse_detection(bool enable) {
    enable_cpu_overuse_detection_ = enable;
  }

  void set_fps_allocation(const FramerateFractions& fps_allocation) {
    fps_allocation_ = fps_allocation;
  }

  RateControlParameters last_set_rates() const { return last_set_rates_; }

  void set_supports_simulcast(bool supports_simulcast) {
    supports_simulcast_ = supports_simulcast;
  }

  void set_video_format(const SdpVideoFormat& video_format) {
    video_format_ = video_format;
  }

  void set_is_qp_trusted(std::optional<bool> is_qp_trusted) {
    is_qp_trusted_ = is_qp_trusted;
  }

  void set_resolution_bitrate_limits(
      std::vector<VideoEncoder::ResolutionBitrateLimits> limits) {
    resolution_bitrate_limits = limits;
  }

  bool supports_simulcast() const { return supports_simulcast_; }

  SdpVideoFormat video_format() const { return video_format_; }

 private:
  void RunUntilIdle() {
    // This is dangerous, only do it here for testing.
    Event event;
    factory_->GetAsyncEncoderQueue()->PostTask([&event] { event.Set(); });
    event.Wait(Event::kForever);
  }

  MockVideoEncoderFactory* const factory_;
  bool supports_native_handle_ = false;
  std::string implementation_name_ = "unknown";
  VideoEncoder::ScalingSettings scaling_settings_;
  uint32_t requested_resolution_alignment_ = 1;
  bool apply_alignment_to_all_simulcast_layers_ = false;
  bool has_trusted_rate_controller_ = false;
  bool is_hardware_accelerated_ = false;
  bool enable_cpu_overuse_detection_ = true;
  int32_t init_encode_return_value_ = 0;
  std::optional<int32_t> fallback_from_simulcast_;
  VideoEncoder::RateControlParameters last_set_rates_;
  FramerateFractions fps_allocation_;
  bool supports_simulcast_ = false;
  std::optional<bool> is_qp_trusted_;
  SdpVideoFormat video_format_;
  std::vector<VideoEncoder::ResolutionBitrateLimits> resolution_bitrate_limits;
  bool is_async_ = false;

  VideoCodec codec_;
  EncodedImageCallback* callback_;
};

std::vector<SdpVideoFormat> MockVideoEncoderFactory::GetSupportedFormats()
    const {
  return {SdpVideoFormat::VP8()};
}

std::unique_ptr<VideoEncoder> MockVideoEncoderFactory::Create(
    const Environment& /* env */,
    const SdpVideoFormat& format) {
  if (create_video_encoder_return_nullptr_) {
    return nullptr;
  }

  auto encoder = std::make_unique<::testing::NiceMock<MockVideoEncoder>>(this);
  encoder->set_init_encode_return_value(init_encode_return_value_);
  encoder->set_fallback_from_simulcast(fallback_from_simulcast_);
  const char* encoder_name = encoder_names_.empty()
                                 ? "codec_implementation_name"
                                 : encoder_names_[encoders_.size()];
  encoder->set_implementation_name(encoder_name);
  RTC_CHECK_LT(encoders_.size(), requested_resolution_alignments_.size());
  encoder->set_requested_resolution_alignment(
      requested_resolution_alignments_[encoders_.size()]);
  encoder->set_supports_simulcast(supports_simulcast_);
  encoder->set_video_format(format);
  encoder->set_resolution_bitrate_limits(resolution_bitrate_limits_);
  encoders_.push_back(encoder.get());
  return encoder;
}

void MockVideoEncoderFactory::DestroyVideoEncoder(VideoEncoder* encoder) {
  for (size_t i = 0; i < encoders_.size(); ++i) {
    if (encoders_[i] == encoder) {
      encoders_.erase(encoders_.begin() + i);
      break;
    }
  }
}

const std::vector<MockVideoEncoder*>& MockVideoEncoderFactory::encoders()
    const {
  return encoders_;
}
void MockVideoEncoderFactory::SetEncoderNames(
    const std::vector<const char*>& encoder_names) {
  encoder_names_ = encoder_names;
}
void MockVideoEncoderFactory::set_init_encode_return_value(int32_t value) {
  init_encode_return_value_ = value;
}

class TestSimulcastEncoderAdapterFakeHelper {
 public:
  explicit TestSimulcastEncoderAdapterFakeHelper(
      const Environment& env,
      bool use_fallback_factory,
      const SdpVideoFormat& video_format)
      : env_(env),
        primary_factory_(env_),
        fallback_factory_(use_fallback_factory
                              ? std::make_unique<MockVideoEncoderFactory>(env_)
                              : nullptr),
        video_format_(video_format) {}

  std::unique_ptr<VideoEncoder> CreateMockEncoderAdapter() {
    return std::make_unique<SimulcastEncoderAdapter>(
        env_, &primary_factory_, fallback_factory_.get(), video_format_);
  }

  MockVideoEncoderFactory* factory() { return &primary_factory_; }
  MockVideoEncoderFactory* fallback_factory() {
    return fallback_factory_.get();
  }

 private:
  const Environment env_;
  MockVideoEncoderFactory primary_factory_;
  std::unique_ptr<MockVideoEncoderFactory> fallback_factory_;
  SdpVideoFormat video_format_;
};

static const int kTestTemporalLayerProfile[3] = {3, 2, 1};

class TestSimulcastEncoderAdapterFake : public ::testing::Test,
                                        public EncodedImageCallback {
 public:
  TestSimulcastEncoderAdapterFake() : use_fallback_factory_(false) {}

  ~TestSimulcastEncoderAdapterFake() override {
    if (adapter_) {
      adapter_->Release();
    }
  }

  void SetUp() override {
    env_ = CreateEnvironment(field_trials_.CreateCopy());
    helper_ = std::make_unique<TestSimulcastEncoderAdapterFakeHelper>(
        env_, use_fallback_factory_,
        SdpVideoFormat("VP8", sdp_video_parameters_));
    adapter_ = helper_->CreateMockEncoderAdapter();
    MutexLock lock(&mutex_);
    last_encoded_image_width_ = std::nullopt;
    last_encoded_image_height_ = std::nullopt;
    last_encoded_image_simulcast_index_ = std::nullopt;
  }

  void ReSetUp() {
    if (adapter_) {
      adapter_->Release();
      // `helper_` owns factories which `adapter_` needs to destroy encoders.
      // Release `adapter_` before `helper_` (released in SetUp()).
      adapter_.reset();
    }
    SetUp();
  }

  Result OnEncodedImage(
      const EncodedImage& encoded_image,
      const CodecSpecificInfo* /* codec_specific_info */) override {
    MutexLock lock(&mutex_);
    last_encoded_image_width_ = encoded_image._encodedWidth;
    last_encoded_image_height_ = encoded_image._encodedHeight;
    last_encoded_image_simulcast_index_ = encoded_image.SimulcastIndex();

    return Result(Result::OK, encoded_image.RtpTimestamp());
  }

  void OnFrameDropped(uint32_t rtp_timestamp,
                      int spatial_id,
                      bool is_end_of_temporal_unit) override {
    dropped_frames_.emplace_back(rtp_timestamp, spatial_id,
                                 is_end_of_temporal_unit);
  }

  const std::vector<std::tuple<uint32_t, int, bool>>& GetDroppedFrames() const {
    return dropped_frames_;
  }

  bool GetLastEncodedImageInfo(std::optional<int>* out_width,
                               std::optional<int>* out_height,
                               std::optional<int>* out_simulcast_index) {
    MutexLock lock(&mutex_);
    if (!last_encoded_image_width_.has_value()) {
      return false;
    }
    *out_width = last_encoded_image_width_;
    *out_height = last_encoded_image_height_;
    *out_simulcast_index = last_encoded_image_simulcast_index_;
    return true;
  }

  void SetupCodec() { SetupCodec(/*active_streams=*/{true, true, true}); }

  void SetupCodec(std::vector<bool> active_streams) {
    SimulcastTestFixtureImpl::DefaultSettings(
        &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
        kVideoCodecVP8);
    ASSERT_LE(active_streams.size(), codec_.numberOfSimulcastStreams);
    codec_.numberOfSimulcastStreams = active_streams.size();
    for (size_t stream_idx = 0; stream_idx < kMaxSimulcastStreams;
         ++stream_idx) {
      if (stream_idx >= codec_.numberOfSimulcastStreams) {
        // Reset parameters of unspecified stream.
        codec_.simulcastStream[stream_idx] = {};
      } else {
        codec_.simulcastStream[stream_idx].active = active_streams[stream_idx];
      }
    }
    rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
    EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
    adapter_->RegisterEncodeCompleteCallback(this);
  }

  struct StreamDescription {
    bool active;
    SdpVideoFormat format;
  };

  void SetupMixedCodec(std::vector<StreamDescription> stream_descriptions) {
    SimulcastTestFixtureImpl::DefaultSettings(
        &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
        kVideoCodecVP8);
    ASSERT_LE(stream_descriptions.size(), codec_.numberOfSimulcastStreams);
    codec_.numberOfSimulcastStreams = stream_descriptions.size();
    for (size_t stream_idx = 0; stream_idx < kMaxSimulcastStreams;
         ++stream_idx) {
      if (stream_idx >= codec_.numberOfSimulcastStreams) {
        // Reset parameters of unspecified stream.
        codec_.simulcastStream[stream_idx] = {.width = 0};
      } else {
        codec_.simulcastStream[stream_idx].active =
            stream_descriptions[stream_idx].active;
        codec_.simulcastStream[stream_idx].format =
            stream_descriptions[stream_idx].format;
      }
    }
    rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
    EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
    adapter_->RegisterEncodeCompleteCallback(this);
  }

  void SetupCodecWithEarlyEncodeCompleteCallback(
      std::vector<bool> active_streams) {
    SimulcastTestFixtureImpl::DefaultSettings(
        &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
        kVideoCodecVP8);
    ASSERT_LE(active_streams.size(), codec_.numberOfSimulcastStreams);
    codec_.numberOfSimulcastStreams = active_streams.size();
    for (size_t stream_idx = 0; stream_idx < kMaxSimulcastStreams;
         ++stream_idx) {
      if (stream_idx >= codec_.numberOfSimulcastStreams) {
        // Reset parameters of unspecified stream.
        codec_.simulcastStream[stream_idx] = {};
      } else {
        codec_.simulcastStream[stream_idx].active = active_streams[stream_idx];
      }
    }
    rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
    // Register the callback before the InitEncode().
    adapter_->RegisterEncodeCompleteCallback(this);
    EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  }

  void VerifyCodec(const VideoCodec& ref, int stream_index) {
    const VideoCodec& target =
        helper_->factory()->encoders()[stream_index]->codec();
    EXPECT_EQ(ref.codecType, target.codecType);
    EXPECT_EQ(ref.width, target.width);
    EXPECT_EQ(ref.height, target.height);
    EXPECT_EQ(ref.startBitrate, target.startBitrate);
    EXPECT_EQ(ref.maxBitrate, target.maxBitrate);
    EXPECT_EQ(ref.minBitrate, target.minBitrate);
    EXPECT_EQ(ref.maxFramerate, target.maxFramerate);
    EXPECT_EQ(ref.GetVideoEncoderComplexity(),
              target.GetVideoEncoderComplexity());
    EXPECT_EQ(ref.VP8().numberOfTemporalLayers,
              target.VP8().numberOfTemporalLayers);
    EXPECT_EQ(ref.VP8().denoisingOn, target.VP8().denoisingOn);
    EXPECT_EQ(ref.VP8().automaticResizeOn, target.VP8().automaticResizeOn);
    EXPECT_EQ(ref.GetFrameDropEnabled(), target.GetFrameDropEnabled());
    EXPECT_EQ(ref.VP8().keyFrameInterval, target.VP8().keyFrameInterval);
    EXPECT_EQ(ref.qpMax, target.qpMax);
    EXPECT_EQ(0, target.numberOfSimulcastStreams);
    EXPECT_EQ(ref.mode, target.mode);

    // No need to compare simulcastStream as numberOfSimulcastStreams should
    // always be 0.
  }

  void InitRefCodec(int stream_index,
                    VideoCodec* ref_codec,
                    bool reverse_layer_order = false) {
    *ref_codec = codec_;
    ref_codec->VP8()->numberOfTemporalLayers =
        kTestTemporalLayerProfile[reverse_layer_order ? 2 - stream_index
                                                      : stream_index];
    ref_codec->width = codec_.simulcastStream[stream_index].width;
    ref_codec->height = codec_.simulcastStream[stream_index].height;
    ref_codec->maxBitrate = codec_.simulcastStream[stream_index].maxBitrate;
    ref_codec->minBitrate = codec_.simulcastStream[stream_index].minBitrate;
    ref_codec->qpMax = codec_.simulcastStream[stream_index].qpMax;
  }

  void VerifyCodecSettings() {
    EXPECT_EQ(3u, helper_->factory()->encoders().size());
    VideoCodec ref_codec;

    // stream 0, the lowest resolution stream.
    InitRefCodec(0, &ref_codec);
    ref_codec.qpMax = 45;
    ref_codec.SetVideoEncoderComplexity(
        VideoCodecComplexity::kComplexityHigher);
    ref_codec.VP8()->denoisingOn = false;
    ref_codec.startBitrate = 100;  // Should equal to the target bitrate.
    VerifyCodec(ref_codec, 0);

    // stream 1
    InitRefCodec(1, &ref_codec);
    ref_codec.VP8()->denoisingOn = false;
    // The start bitrate (300kbit) minus what we have for the lower layers
    // (100kbit).
    ref_codec.startBitrate = 200;
    VerifyCodec(ref_codec, 1);

    // stream 2, the biggest resolution stream.
    InitRefCodec(2, &ref_codec);
    // We don't have enough bits to send this, so the adapter should have
    // configured it to use the min bitrate for this layer (600kbit) but turn
    // off sending.
    ref_codec.startBitrate = 600;
    VerifyCodec(ref_codec, 2);
  }

 protected:
  FieldTrials field_trials_ = CreateTestFieldTrials();
  Environment env_ = EnvironmentFactory().Create();
  std::unique_ptr<TestSimulcastEncoderAdapterFakeHelper> helper_;
  std::unique_ptr<VideoEncoder> adapter_;
  VideoCodec codec_;
  std::optional<int> last_encoded_image_width_ RTC_GUARDED_BY(mutex_);
  std::optional<int> last_encoded_image_height_ RTC_GUARDED_BY(mutex_);
  std::optional<int> last_encoded_image_simulcast_index_ RTC_GUARDED_BY(mutex_);
  Mutex mutex_;
  std::unique_ptr<VideoBitrateAllocator> rate_allocator_;
  bool use_fallback_factory_;
  CodecParameterMap sdp_video_parameters_;
  test::RunLoop run_loop_;
  std::vector<std::tuple<uint32_t, int, bool>> dropped_frames_;
};

TEST_F(TestSimulcastEncoderAdapterFake, InitEncode) {
  SetupCodec();
  VerifyCodecSettings();
}

TEST_F(TestSimulcastEncoderAdapterFake, EarlyCallbackSetupNotLost) {
  helper_->factory()->set_supports_simulcast(true);
  helper_->factory()->set_fallback_from_simulcast(
      WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE);
  SetupCodecWithEarlyEncodeCompleteCallback(
      /*active_streams=*/{true, true, true});
  for (size_t idx = 0; idx < 3; ++idx) {
    auto callback = helper_->factory()->encoders()[idx]->callback();
    EXPECT_NE(callback, nullptr);
  }
}

TEST_F(TestSimulcastEncoderAdapterFake, ReleaseWithoutInitEncode) {
  EXPECT_EQ(0, adapter_->Release());
}

TEST_F(TestSimulcastEncoderAdapterFake, DestructorCallsReleaseIfInitialized) {
  SetupCodec();
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  for (auto* encoder : encoders) {
    EXPECT_CALL(*encoder, ReleaseMock()).WillOnce(testing::Return(0));
  }

  adapter_.reset();
}

TEST_F(TestSimulcastEncoderAdapterFake, Reinit) {
  SetupCodec();
  EXPECT_EQ(0, adapter_->Release());

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
}

TEST_F(TestSimulcastEncoderAdapterFake, EncodedCallbackForDifferentEncoders) {
  SetupCodec();

  // Set bitrates so that we send all layers.
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  // At this point, the simulcast encoder adapter should have 3 streams: HD,
  // quarter HD, and quarter quarter HD. We're going to mostly ignore the exact
  // resolutions, to test that the adapter forwards on the correct resolution
  // and simulcast index values, going only off the encoder that generates the
  // image.
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(0)
                               .set_timestamp_ms(0)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  encoders[0]->SendEncodedImage(1152, 704);
  std::optional<int> width;
  std::optional<int> height;
  std::optional<int> simulcast_index;
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(width.has_value());
  EXPECT_EQ(1152, width.value());
  ASSERT_TRUE(height.has_value());
  EXPECT_EQ(704, height.value());
  // SEA should intercept frame encode complete callback for all streams.
  EXPECT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(0, simulcast_index.value());

  encoders[1]->SendEncodedImage(300, 620);
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(width.has_value());
  EXPECT_EQ(300, width.value());
  ASSERT_TRUE(height.has_value());
  EXPECT_EQ(620, height.value());
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(1, simulcast_index.value());

  encoders[2]->SendEncodedImage(120, 240);
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(width.has_value());
  EXPECT_EQ(120, width.value());
  ASSERT_TRUE(height.has_value());
  EXPECT_EQ(240, height.value());
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(2, simulcast_index.value());
}

TEST_F(TestSimulcastEncoderAdapterFake,
       EncodedCallbackForDifferentEncodersOverwritesIndex) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  std::vector<const char*> names;
  names.push_back("codec1");
  names.push_back("codec2");
  names.push_back("codec3");
  helper_->factory()->SetEncoderNames(names);
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));

  // Initialize rate allocator.
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);

  // Set bitrates so that we send all layers.
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  // Trigger an Encode call to populate pending_frames for non-bypass mode.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Have the 2nd encoder (stream 1) send a frame with simulcast_index = 0.
  // This simulates an encoder that doesn't know its own index.
  // We expect SEA to overwrite it to 1.
  encoders[1]->SendEncodedImage(640, 360, 100, /*simulcast_index=*/0);

  std::optional<int> last_simulcast_index;
  std::optional<int> width;
  std::optional<int> height;
  ASSERT_TRUE(GetLastEncodedImageInfo(&width, &height, &last_simulcast_index));
  EXPECT_EQ(1, last_simulcast_index);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       EncodedCallbackInBypassModeDoesNotOverwriteIndex) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  std::vector<const char*> names;
  names.push_back("codec1");
  // Supports simulcast, so SEA enters bypass mode for single stream.
  helper_->factory()->set_supports_simulcast(true);
  helper_->factory()->SetEncoderNames(names);
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));

  // Trigger an Encode call to populate pending_frames.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Get the single encoder.
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(1u, encoders.size());

  // 1. Send frame with missing simulcast index.
  // SEA should NOT add an index (bypass mode).
  encoders[0]->SendEncodedImage(1280, 720, 100,
                                /*simulcast_index=*/std::nullopt);
  std::optional<int> last_simulcast_index;
  std::optional<int> width;
  std::optional<int> height;
  ASSERT_TRUE(GetLastEncodedImageInfo(&width, &height, &last_simulcast_index));
  EXPECT_FALSE(last_simulcast_index.has_value());

  // 2. Send frame with existing simulcast index.
  // SEA should preserve it.
  encoders[0]->SendEncodedImage(1280, 720, 100, /*simulcast_index=*/0);
  ASSERT_TRUE(GetLastEncodedImageInfo(&width, &height, &last_simulcast_index));
  EXPECT_EQ(0, last_simulcast_index);
}

// This test verifies that the underlying encoders are reused, when the
// adapter is reinited with different number of simulcast streams. It further
// checks that the allocated encoders are reused in the same order as before,
// starting with the lowest stream.
TEST_F(TestSimulcastEncoderAdapterFake, ReusesEncodersInOrder) {
  // Set up common settings for three streams.
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  adapter_->RegisterEncodeCompleteCallback(this);
  const uint32_t target_bitrate =
      1000 * (codec_.simulcastStream[0].targetBitrate +
              codec_.simulcastStream[1].targetBitrate +
              codec_.simulcastStream[2].minBitrate);

  // Input data.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();
  std::vector<VideoFrameType> frame_types;

  // Encode with three streams.
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  VerifyCodecSettings();
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate, 30)),
      30.0));

  std::vector<MockVideoEncoder*> original_encoders =
      helper_->factory()->encoders();
  ASSERT_EQ(3u, original_encoders.size());
  EXPECT_CALL(*original_encoders[0], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[1], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[2], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  frame_types.resize(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
  EXPECT_CALL(*original_encoders[0], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[1], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[2], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Release());

  // Encode with two streams.
  codec_.width /= 2;
  codec_.height /= 2;
  codec_.numberOfSimulcastStreams = 2;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate, 30)),
      30.0));
  std::vector<MockVideoEncoder*> new_encoders = helper_->factory()->encoders();
  ASSERT_EQ(2u, new_encoders.size());
  ASSERT_EQ(original_encoders[0], new_encoders[0]);
  EXPECT_CALL(*original_encoders[0], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  ASSERT_EQ(original_encoders[1], new_encoders[1]);
  EXPECT_CALL(*original_encoders[1], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  frame_types.resize(2, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
  EXPECT_CALL(*original_encoders[0], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[1], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Release());

  // Encode with single stream.
  codec_.width /= 2;
  codec_.height /= 2;
  codec_.numberOfSimulcastStreams = 1;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate, 30)),
      30.0));
  new_encoders = helper_->factory()->encoders();
  ASSERT_EQ(1u, new_encoders.size());
  ASSERT_EQ(original_encoders[0], new_encoders[0]);
  EXPECT_CALL(*original_encoders[0], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  frame_types.resize(1, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
  EXPECT_CALL(*original_encoders[0], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Release());

  // Encode with three streams, again.
  codec_.width *= 4;
  codec_.height *= 4;
  codec_.numberOfSimulcastStreams = 3;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate, 30)),
      30.0));
  new_encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, new_encoders.size());
  // The first encoder is reused.
  ASSERT_EQ(original_encoders[0], new_encoders[0]);
  EXPECT_CALL(*original_encoders[0], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  // The second and third encoders are new.
  EXPECT_CALL(*new_encoders[1], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*new_encoders[2], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  frame_types.resize(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
  EXPECT_CALL(*original_encoders[0], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*new_encoders[1], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*new_encoders[2], ReleaseMock())
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Release());
}

TEST_F(TestSimulcastEncoderAdapterFake, DoesNotLeakEncoders) {
  SetupCodec();
  VerifyCodecSettings();

  EXPECT_EQ(3u, helper_->factory()->encoders().size());

  // The adapter should destroy all encoders it has allocated. Since
  // `helper_->factory()` is owned by `adapter_`, however, we need to rely on
  // lsan to find leaks here.
  EXPECT_EQ(0, adapter_->Release());
  adapter_.reset();
}

// This test verifies that an adapter reinit with the same codec settings as
// before does not change the underlying encoder codec settings.
TEST_F(TestSimulcastEncoderAdapterFake, ReinitDoesNotReorderEncoderSettings) {
  SetupCodec();
  VerifyCodecSettings();

  // Capture current codec settings.
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());
  std::array<VideoCodec, 3> codecs_before;
  for (int i = 0; i < 3; ++i) {
    codecs_before[i] = encoders[i]->codec();
  }

  // Reinitialize and verify that the new codec settings are the same.
  EXPECT_EQ(0, adapter_->Release());
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  for (int i = 0; i < 3; ++i) {
    const VideoCodec& codec_before = codecs_before[i];
    const VideoCodec& codec_after = encoders[i]->codec();

    // webrtc::VideoCodec does not implement operator==.
    EXPECT_EQ(codec_before.codecType, codec_after.codecType);
    EXPECT_EQ(codec_before.width, codec_after.width);
    EXPECT_EQ(codec_before.height, codec_after.height);
    EXPECT_EQ(codec_before.startBitrate, codec_after.startBitrate);
    EXPECT_EQ(codec_before.maxBitrate, codec_after.maxBitrate);
    EXPECT_EQ(codec_before.minBitrate, codec_after.minBitrate);
    EXPECT_EQ(codec_before.maxFramerate, codec_after.maxFramerate);
    EXPECT_EQ(codec_before.qpMax, codec_after.qpMax);
    EXPECT_EQ(codec_before.numberOfSimulcastStreams,
              codec_after.numberOfSimulcastStreams);
    EXPECT_EQ(codec_before.mode, codec_after.mode);
    EXPECT_EQ(codec_before.expect_encode_from_texture,
              codec_after.expect_encode_from_texture);
  }
}

TEST_F(TestSimulcastEncoderAdapterFake, FrameDroppingAllLayers) {
  SetupCodec();
  VideoBitrateAllocation allocation;
  allocation.SetBitrate(0, 0, 100000);
  allocation.SetBitrate(1, 0, 500000);
  allocation.SetBitrate(2, 0, 1500000);
  auto mock_allocator = std::make_unique<MockVideoBitrateAllocator>();
  EXPECT_CALL(*mock_allocator, Allocate(_)).WillRepeatedly(Return(allocation));
  rate_allocator_ = std::move(mock_allocator);
  adapter_->SetRates(VideoEncoder::RateControlParameters(allocation, 30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_CALL(*encoders[0], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[1], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[2], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Simulate all 3 internal encoders dropping the frame.
  encoders[0]->callback()->OnFrameDropped(100, 0, true);
  encoders[1]->callback()->OnFrameDropped(100, 0, true);
  encoders[2]->callback()->OnFrameDropped(100, 0, true);

  // We should receive 3 drops.
  // The first two should NOT match the end of temporal unit logic,
  // but the LAST one (which empties the pending list for this timestamp)
  // SHOULD. Note: OnFrameDropped in adapter calls callback with (timestamp,
  // stream_idx). The spatial indices are 0, 1, 2.
  auto dropped = GetDroppedFrames();
  ASSERT_EQ(3u, dropped.size());
  EXPECT_EQ(dropped[0], std::make_tuple(100u, 0, false));
  EXPECT_EQ(dropped[1], std::make_tuple(100u, 1, false));
  EXPECT_EQ(dropped[2], std::make_tuple(100u, 2, true));
}

TEST_F(TestSimulcastEncoderAdapterFake, FrameDroppingMixed) {
  SetupCodec();
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_CALL(*encoders[0], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[1], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[2], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Layer 0 sends encoded image.
  encoders[0]->SendEncodedImage(1152, 704, 100);
  // Layer 1 drops frame.
  encoders[1]->callback()->OnFrameDropped(100, 0, true);
  // Layer 2 sends encoded image.
  encoders[2]->SendEncodedImage(120, 240, 100);

  // Verify encoded images.
  std::optional<int> width;
  std::optional<int> height;
  std::optional<int> simulcast_index;
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  // The last encoded image was from layer 2.
  ASSERT_TRUE(width.has_value());
  EXPECT_EQ(120, width.value());

  // Verify dropped frame.
  auto dropped = GetDroppedFrames();
  ASSERT_EQ(1u, dropped.size());
  // Stream index 1.
  EXPECT_EQ(dropped[0], std::make_tuple(100u, 1, false));
}

TEST_F(TestSimulcastEncoderAdapterFake, FrameDroppingOutOfOrder) {
  SetupCodec();
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_CALL(*encoders[0], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[1], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[2], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Simulate out of order completion.
  // Layer 2 finishes FIRST (dropped).
  encoders[2]->callback()->OnFrameDropped(100, 0, true);
  auto dropped = GetDroppedFrames();
  ASSERT_EQ(1u, dropped.size());
  EXPECT_EQ(dropped[0], std::make_tuple(100u, 2, false));

  // Layer 0 finishes SECOND (encoded).
  encoders[0]->SendEncodedImage(1152, 704, 100);
  // No new dropped frame.
  EXPECT_EQ(1u, GetDroppedFrames().size());

  // Layer 1 finishes LAST (dropped).
  encoders[1]->callback()->OnFrameDropped(100, 0, true);
  dropped = GetDroppedFrames();
  ASSERT_EQ(2u, dropped.size());
  // This last drop should have is_end_of_temporal_unit = true.
  EXPECT_EQ(dropped[1], std::make_tuple(100u, 1, true));
}

TEST_F(TestSimulcastEncoderAdapterFake, InterleavedFrames) {
  SetupCodec();
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  // Frame 1 (ts=100)
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame1 = VideoFrame::Builder()
                                .set_video_frame_buffer(buffer)
                                .set_rtp_timestamp(100)
                                .set_timestamp_ms(1000)
                                .set_rotation(kVideoRotation_0)
                                .build();
  // Frame 2 (ts=200)
  VideoFrame input_frame2 = VideoFrame::Builder()
                                .set_video_frame_buffer(buffer)
                                .set_rtp_timestamp(200)
                                .set_timestamp_ms(2000)
                                .set_rotation(kVideoRotation_0)
                                .build();

  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);

  // Expect Encode calls.
  EXPECT_CALL(*encoders[0], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[1], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[2], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));

  EXPECT_EQ(0, adapter_->Encode(input_frame1, &frame_types));
  EXPECT_EQ(0, adapter_->Encode(input_frame2, &frame_types));

  // Interleaved results.
  // Frame 1 Layer 0 (Dropped)
  encoders[0]->callback()->OnFrameDropped(100, 0, true);
  auto dropped = GetDroppedFrames();
  ASSERT_EQ(1u, dropped.size());
  EXPECT_EQ(dropped[0], std::make_tuple(100u, 0, false));

  // Frame 2 Layer 0 (Dropped)
  encoders[0]->callback()->OnFrameDropped(200, 0, true);
  dropped = GetDroppedFrames();
  ASSERT_EQ(2u, dropped.size());
  EXPECT_EQ(dropped[1], std::make_tuple(200u, 0, false));

  // Frame 2 Layer 1 (Dropped)
  encoders[1]->callback()->OnFrameDropped(200, 0, true);
  dropped = GetDroppedFrames();
  ASSERT_EQ(4u, dropped.size());
  EXPECT_EQ(dropped[2], std::make_tuple(100u, 1, false));
  EXPECT_EQ(dropped[3], std::make_tuple(200u, 1, false));

  // We still have Frame 1 Layer 2 and Frame 2 Layer 2 pending.
  // Finish Frame 1 Layer 2 (Dropped) -> This completes Frame 1!
  encoders[2]->callback()->OnFrameDropped(100, 0, true);
  dropped = GetDroppedFrames();
  ASSERT_EQ(5u, dropped.size());
  EXPECT_EQ(dropped[4],
            std::make_tuple(100u, 2, true));  // End of TU for Frame 1

  // Finish Frame 2 Layer 2 (Dropped) -> This completes Frame 2!
  encoders[2]->callback()->OnFrameDropped(200, 0, true);
  dropped = GetDroppedFrames();
  ASSERT_EQ(6u, dropped.size());
  EXPECT_EQ(dropped[5],
            std::make_tuple(200u, 2, true));  // End of TU for Frame 2
}

TEST_F(TestSimulcastEncoderAdapterFake, OldFramesAreCulled) {
  SetupCodec();
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame1 = VideoFrame::Builder()
                                .set_video_frame_buffer(buffer)
                                .set_rtp_timestamp(100)
                                .set_timestamp_ms(1000)
                                .set_rotation(kVideoRotation_0)
                                .build();
  VideoFrame input_frame2 = VideoFrame::Builder()
                                .set_video_frame_buffer(buffer)
                                .set_rtp_timestamp(200)
                                .set_timestamp_ms(2000)
                                .set_rotation(kVideoRotation_0)
                                .build();

  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);

  EXPECT_CALL(*encoders[0], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[1], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[2], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));

  EXPECT_EQ(0, adapter_->Encode(input_frame1, &frame_types));
  EXPECT_EQ(0, adapter_->Encode(input_frame2, &frame_types));

  encoders[0]->callback()->OnFrameDropped(200, 0, true);

  auto dropped = GetDroppedFrames();
  ASSERT_GE(dropped.size(), 2u);
  EXPECT_EQ(dropped[0], std::make_tuple(100u, 0, false));
  EXPECT_EQ(dropped[1], std::make_tuple(200u, 0, false));

  // What about Stream 1? It hasn't received anything yet.
  // Send Frame 2 for Stream 1.
  encoders[1]->callback()->OnFrameDropped(200, 0, true);
  dropped = GetDroppedFrames();
  ASSERT_GE(dropped.size(), 4u);
  EXPECT_EQ(
      dropped[2],
      std::make_tuple(100u, 1, false));  // Implicit drop of 100 on Stream 1
  EXPECT_EQ(
      dropped[3],
      std::make_tuple(200u, 1, false));  // Explicit drop of 200 on Stream 1
}

// This test is similar to the one above, except that it tests the
// simulcastIdx from the CodecSpecificInfo that is connected to an encoded
// frame. The PayloadRouter demuxes the incoming encoded frames on different
// RTP modules using the simulcastIdx, so it's important that there is no
// corresponding encoder reordering in between adapter reinits as this would
// lead to PictureID discontinuities.
TEST_F(TestSimulcastEncoderAdapterFake, ReinitDoesNotReorderFrameSimulcastIdx) {
  SetupCodec();
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));
  VerifyCodecSettings();

  // Send frames on all streams.
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(0)
                               .set_timestamp_ms(0)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  encoders[0]->SendEncodedImage(1152, 704);
  std::optional<int> width;
  std::optional<int> height;
  std::optional<int> simulcast_index;
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  // SEA should intercept frame encode complete callback for all streams.
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(0, simulcast_index.value());

  encoders[1]->SendEncodedImage(300, 620);
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(1, simulcast_index.value());

  encoders[2]->SendEncodedImage(120, 240);
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(2, simulcast_index.value());

  // Reinitialize.
  EXPECT_EQ(0, adapter_->Release());
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  // Verify that the same encoder sends out frames on the same simulcast
  // index.
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
  encoders[0]->SendEncodedImage(1152, 704);
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(0, simulcast_index.value());

  encoders[1]->SendEncodedImage(300, 620);
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(1, simulcast_index.value());

  encoders[2]->SendEncodedImage(120, 240);
  EXPECT_TRUE(GetLastEncodedImageInfo(&width, &height, &simulcast_index));
  ASSERT_TRUE(simulcast_index.has_value());
  EXPECT_EQ(2, simulcast_index.value());
}

TEST_F(TestSimulcastEncoderAdapterFake, SupportsNativeHandleForSingleStreams) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 1;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);
  ASSERT_EQ(1u, helper_->factory()->encoders().size());
  helper_->factory()->encoders()[0]->set_supports_native_handle(true);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(adapter_->GetEncoderInfo().supports_native_handle);
  helper_->factory()->encoders()[0]->set_supports_native_handle(false);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().supports_native_handle);
}

TEST_F(TestSimulcastEncoderAdapterFake, SetRatesUnderMinBitrate) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.minBitrate = 50;
  codec_.numberOfSimulcastStreams = 1;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);

  // Above min should be respected.
  VideoBitrateAllocation target_bitrate = rate_allocator_->Allocate(
      VideoBitrateAllocationParameters(codec_.minBitrate * 1000, 30));
  adapter_->SetRates(VideoEncoder::RateControlParameters(target_bitrate, 30.0));
  EXPECT_EQ(target_bitrate,
            helper_->factory()->encoders()[0]->last_set_rates().bitrate);

  // Below min but non-zero should be replaced with the min bitrate.
  VideoBitrateAllocation too_low_bitrate = rate_allocator_->Allocate(
      VideoBitrateAllocationParameters((codec_.minBitrate - 1) * 1000, 30));
  adapter_->SetRates(
      VideoEncoder::RateControlParameters(too_low_bitrate, 30.0));
  EXPECT_EQ(target_bitrate,
            helper_->factory()->encoders()[0]->last_set_rates().bitrate);

  // Zero should be passed on as is, since it means "pause".
  adapter_->SetRates(
      VideoEncoder::RateControlParameters(VideoBitrateAllocation(), 30.0));
  EXPECT_EQ(VideoBitrateAllocation(),
            helper_->factory()->encoders()[0]->last_set_rates().bitrate);
}

TEST_F(TestSimulcastEncoderAdapterFake, SupportsImplementationName) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 2;
  std::vector<const char*> encoder_names;
  encoder_names.push_back("codec1");
  encoder_names.push_back("codec2");
  helper_->factory()->SetEncoderNames(encoder_names);
  EXPECT_EQ("SimulcastEncoderAdapter",
            adapter_->GetEncoderInfo().implementation_name);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_EQ("SimulcastEncoderAdapter (codec1, codec2)",
            adapter_->GetEncoderInfo().implementation_name);

  // Single streams should not expose "SimulcastEncoderAdapter" in name.
  EXPECT_EQ(0, adapter_->Release());
  codec_.numberOfSimulcastStreams = 1;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);
  ASSERT_EQ(1u, helper_->factory()->encoders().size());
  EXPECT_EQ("codec1", adapter_->GetEncoderInfo().implementation_name);
}

TEST_F(TestSimulcastEncoderAdapterFake, RuntimeEncoderInfoUpdate) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  std::vector<const char*> encoder_names;
  encoder_names.push_back("codec1");
  encoder_names.push_back("codec2");
  encoder_names.push_back("codec3");
  helper_->factory()->SetEncoderNames(encoder_names);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_EQ("SimulcastEncoderAdapter (codec1, codec2)",
            adapter_->GetEncoderInfo().implementation_name);

  // Change name of first encoder to indicate it has done a fallback to another
  // implementation.
  helper_->factory()->encoders().front()->set_implementation_name("fallback1");
  EXPECT_EQ("SimulcastEncoderAdapter (fallback1, codec2)",
            adapter_->GetEncoderInfo().implementation_name);
}

TEST_F(TestSimulcastEncoderAdapterFake, EncoderInfoDeactiveLayersUpdatesName) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  const DataRate target_bitrate =
      DataRate::KilobitsPerSec(codec_.simulcastStream[0].targetBitrate +
                               codec_.simulcastStream[1].targetBitrate +
                               codec_.simulcastStream[2].targetBitrate);
  const DataRate bandwidth_allocation =
      target_bitrate + DataRate::KilobitsPerSec(600);
  const DataRate target_bitrate_without_layer3 =
      target_bitrate -
      DataRate::KilobitsPerSec(codec_.simulcastStream[2].targetBitrate);
  const DataRate bandwidth_allocation_without_layer3 =
      target_bitrate + DataRate::KilobitsPerSec(300);

  std::vector<const char*> encoder_names = {"codec1", "codec2", "codec3"};
  helper_->factory()->SetEncoderNames(encoder_names);
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate, 30)),
      30.0, bandwidth_allocation));
  EXPECT_EQ("SimulcastEncoderAdapter (codec1, codec2, codec3)",
            adapter_->GetEncoderInfo().implementation_name);

  // Disable the third encoder using bitrate allocation.
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate_without_layer3, 30)),
      30.0, bandwidth_allocation_without_layer3));
  EXPECT_EQ("SimulcastEncoderAdapter (codec1, codec2)",
            adapter_->GetEncoderInfo().implementation_name);

  // Enable the third encoder again using bitrate allocation.
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate, 30)),
      30.0, bandwidth_allocation));
  EXPECT_EQ("SimulcastEncoderAdapter (codec1, codec2, codec3)",
            adapter_->GetEncoderInfo().implementation_name);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       SupportsNativeHandleForMultipleStreams) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  for (MockVideoEncoder* encoder : helper_->factory()->encoders())
    encoder->set_supports_native_handle(true);
  // As long as one encoder supports native handle, it's enabled.
  helper_->factory()->encoders()[0]->set_supports_native_handle(false);
  EXPECT_TRUE(adapter_->GetEncoderInfo().supports_native_handle);
  // Once none do, then the adapter claims no support.
  helper_->factory()->encoders()[1]->set_supports_native_handle(false);
  helper_->factory()->encoders()[2]->set_supports_native_handle(false);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().supports_native_handle);
}

class FakeNativeBufferI420 : public VideoFrameBuffer {
 public:
  FakeNativeBufferI420(int width, int height, bool allow_to_i420)
      : width_(width), height_(height), allow_to_i420_(allow_to_i420) {}

  Type type() const override { return Type::kNative; }
  int width() const override { return width_; }
  int height() const override { return height_; }

  scoped_refptr<I420BufferInterface> ToI420() override {
    if (allow_to_i420_) {
      return I420Buffer::Create(width_, height_);
    } else {
      RTC_DCHECK_NOTREACHED();
    }
    return nullptr;
  }

 private:
  const int width_;
  const int height_;
  const bool allow_to_i420_;
};

TEST_F(TestSimulcastEncoderAdapterFake,
       NativeHandleForwardingForMultipleStreams) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  // High start bitrate, so all streams are enabled.
  codec_.startBitrate = 3000;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  for (MockVideoEncoder* encoder : helper_->factory()->encoders())
    encoder->set_supports_native_handle(true);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(adapter_->GetEncoderInfo().supports_native_handle);

  scoped_refptr<VideoFrameBuffer> buffer(
      make_ref_counted<FakeNativeBufferI420>(1280, 720,
                                             /*allow_to_i420=*/false));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();
  // Expect calls with the given video frame verbatim, since it's a texture
  // frame and can't otherwise be modified/resized.
  for (MockVideoEncoder* encoder : helper_->factory()->encoders())
    EXPECT_CALL(*encoder, Encode(::testing::Ref(input_frame), _)).Times(1);
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, NativeHandleForwardingOnlyIfSupported) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  // High start bitrate, so all streams are enabled.
  codec_.startBitrate = 3000;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);
  ASSERT_EQ(3u, helper_->factory()->encoders().size());

  // QVGA encoders has fallen back to software.
  auto& encoders = helper_->factory()->encoders();
  encoders[0]->set_supports_native_handle(false);
  encoders[1]->set_supports_native_handle(true);
  encoders[2]->set_supports_native_handle(true);

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(adapter_->GetEncoderInfo().supports_native_handle);

  scoped_refptr<VideoFrameBuffer> buffer(
      make_ref_counted<FakeNativeBufferI420>(1280, 720,
                                             /*allow_to_i420=*/true));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();
  // Expect calls with the given video frame verbatim, since it's a texture
  // frame and can't otherwise be modified/resized, but only on the two
  // streams supporting it...
  EXPECT_CALL(*encoders[1], Encode(::testing::Ref(input_frame), _)).Times(1);
  EXPECT_CALL(*encoders[2], Encode(::testing::Ref(input_frame), _)).Times(1);
  // ...the lowest one gets a software buffer.
  EXPECT_CALL(*encoders[0], Encode)
      .WillOnce([&](const VideoFrame& frame,
                    const std::vector<VideoFrameType>* /* frame_types */) {
        EXPECT_EQ(frame.video_frame_buffer()->type(),
                  VideoFrameBuffer::Type::kI420);
        return 0;
      });
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, GeneratesKeyFramesOnRequestedLayers) {
  // Set up common settings for three streams.
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  adapter_->RegisterEncodeCompleteCallback(this);

  // Input data.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));

  // Encode with three streams.
  codec_.startBitrate = 3000;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));

  std::vector<VideoFrameType> frame_types;
  frame_types.resize(3, VideoFrameType::kVideoFrameKey);

  std::vector<VideoFrameType> expected_keyframe(1,
                                                VideoFrameType::kVideoFrameKey);
  std::vector<VideoFrameType> expected_deltaframe(
      1, VideoFrameType::kVideoFrameDelta);

  std::vector<MockVideoEncoder*> original_encoders =
      helper_->factory()->encoders();
  ASSERT_EQ(3u, original_encoders.size());
  EXPECT_CALL(*original_encoders[0],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_keyframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[1],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_keyframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[2],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_keyframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  VideoFrame first_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(0)
                               .set_timestamp_ms(0)
                               .build();
  EXPECT_EQ(0, adapter_->Encode(first_frame, &frame_types));

  // Request [key, delta, delta].
  EXPECT_CALL(*original_encoders[0],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_keyframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[1],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_deltaframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[2],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_deltaframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  frame_types[1] = VideoFrameType::kVideoFrameKey;
  frame_types[1] = VideoFrameType::kVideoFrameDelta;
  frame_types[2] = VideoFrameType::kVideoFrameDelta;
  VideoFrame second_frame = VideoFrame::Builder()
                                .set_video_frame_buffer(buffer)
                                .set_rtp_timestamp(10000)
                                .set_timestamp_ms(100000)
                                .build();
  EXPECT_EQ(0, adapter_->Encode(second_frame, &frame_types));

  // Request [delta, key, delta].
  EXPECT_CALL(*original_encoders[0],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_deltaframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[1],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_keyframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[2],
              Encode(_, ::testing::Pointee(::testing::Eq(expected_deltaframe))))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  frame_types[0] = VideoFrameType::kVideoFrameDelta;
  frame_types[1] = VideoFrameType::kVideoFrameKey;
  frame_types[2] = VideoFrameType::kVideoFrameDelta;
  VideoFrame third_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(20000)
                               .set_timestamp_ms(200000)
                               .build();
  EXPECT_EQ(0, adapter_->Encode(third_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, TestFailureReturnCodesFromEncodeCalls) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  // Tell the 2nd encoder to request software fallback.
  EXPECT_CALL(*helper_->factory()->encoders()[1], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE));

  // Send a fake frame and assert the return is software fallback.
  scoped_refptr<I420Buffer> input_buffer =
      I420Buffer::Create(kDefaultWidth, kDefaultHeight);
  input_buffer->InitializeData();
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(input_buffer)
                               .set_rtp_timestamp(0)
                               .set_timestamp_us(0)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE,
            adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, TestPendingFramesQueueLimit) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  std::vector<const char*> names;
  names.push_back("codec1");
  names.push_back("codec2");
  names.push_back("codec3");
  helper_->factory()->SetEncoderNames(names);
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(VideoBitrateAllocationParameters(5000000, 30)),
      30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, encoders.size());

  // Encoders will accept the frame but NOT call OnEncodedImage, duplicating a
  // stuck encoder scenario.
  EXPECT_CALL(*encoders[0], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[1], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*encoders[2], Encode(_, _))
      .WillRepeatedly(Return(WEBRTC_VIDEO_CODEC_OK));

  // Fill the queue up to the limit (15).
  for (int i = 0; i < 15; ++i) {
    scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
    VideoFrame input_frame = VideoFrame::Builder()
                                 .set_video_frame_buffer(buffer)
                                 .set_rtp_timestamp(100 + i * 10)
                                 .set_timestamp_ms(1000 + i * 100)
                                 .set_rotation(kVideoRotation_0)
                                 .build();
    std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
    EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
  }

  // The 16th frame should cause the 1st frame (timestamp 100) to be dropped.
  // Expect OnFrameDropped for timestamp 100, spatial_idx 0, 1, 2.
  // 3 streams active.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(9000)
                               .set_timestamp_ms(9000)
                               .set_rotation(kVideoRotation_0)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  const std::vector<std::tuple<uint32_t, int, bool>>& dropped_frames =
      GetDroppedFrames();
  ASSERT_EQ(3u, dropped_frames.size());
  EXPECT_EQ(std::make_tuple(100u, 0, false), dropped_frames[0]);
  EXPECT_EQ(std::make_tuple(100u, 1, false), dropped_frames[1]);
  EXPECT_EQ(std::make_tuple(100u, 2, true), dropped_frames[2]);
}

TEST_F(TestSimulcastEncoderAdapterFake, TestInitFailureCleansUpEncoders) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  helper_->factory()->set_init_encode_return_value(
      WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE);
  EXPECT_EQ(WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE,
            adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(helper_->factory()->encoders().empty());
}

TEST_F(TestSimulcastEncoderAdapterFake,
       SingleStreamInitEncodeReturnsEncoderError) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 1;

  EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(1u, helper_->factory()->encoders().size());

  helper_->factory()->encoders()[0]->set_init_encode_return_value(
      WEBRTC_VIDEO_CODEC_ENCODER_FAILURE);

  EXPECT_EQ(WEBRTC_VIDEO_CODEC_ENCODER_FAILURE,
            adapter_->InitEncode(&codec_, kSettings));
}

TEST_F(TestSimulcastEncoderAdapterFake, DoesNotAlterMaxQpForScreenshare) {
  const int kHighMaxQp = 56;
  const int kLowMaxQp = 46;

  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  codec_.simulcastStream[0].qpMax = kHighMaxQp;
  codec_.mode = VideoCodecMode::kScreensharing;

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_EQ(3u, helper_->factory()->encoders().size());

  // Just check the lowest stream, which is the one that where the adapter
  // might alter the max qp setting.
  VideoCodec ref_codec;
  InitRefCodec(0, &ref_codec);
  ref_codec.qpMax = kHighMaxQp;
  ref_codec.SetVideoEncoderComplexity(VideoCodecComplexity::kComplexityHigher);
  ref_codec.VP8()->denoisingOn = false;
  ref_codec.startBitrate = 100;  // Should equal to the target bitrate.
  VerifyCodec(ref_codec, 0);

  // Change the max qp and try again.
  codec_.simulcastStream[0].qpMax = kLowMaxQp;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_EQ(3u, helper_->factory()->encoders().size());
  ref_codec.qpMax = kLowMaxQp;
  VerifyCodec(ref_codec, 0);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       DoesNotAlterMaxQpForScreenshareReversedLayer) {
  const int kHighMaxQp = 56;
  const int kLowMaxQp = 46;

  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8, true /* reverse_layer_order */);
  codec_.numberOfSimulcastStreams = 3;
  codec_.simulcastStream[2].qpMax = kHighMaxQp;
  codec_.mode = VideoCodecMode::kScreensharing;

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_EQ(3u, helper_->factory()->encoders().size());

  // Just check the lowest stream, which is the one that where the adapter
  // might alter the max qp setting.
  VideoCodec ref_codec;
  InitRefCodec(2, &ref_codec, true /* reverse_layer_order */);
  ref_codec.qpMax = kHighMaxQp;
  ref_codec.SetVideoEncoderComplexity(VideoCodecComplexity::kComplexityHigher);
  ref_codec.VP8()->denoisingOn = false;
  ref_codec.startBitrate = 100;  // Should equal to the target bitrate.
  VerifyCodec(ref_codec, 2);

  // Change the max qp and try again.
  codec_.simulcastStream[2].qpMax = kLowMaxQp;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_EQ(3u, helper_->factory()->encoders().size());
  ref_codec.qpMax = kLowMaxQp;
  VerifyCodec(ref_codec, 2);
}

TEST_F(TestSimulcastEncoderAdapterFake, ActivatesCorrectStreamsInInitEncode) {
  // Set up common settings for three streams.
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  adapter_->RegisterEncodeCompleteCallback(this);

  // Only enough start bitrate for the lowest stream.
  ASSERT_EQ(3u, codec_.numberOfSimulcastStreams);
  codec_.startBitrate = codec_.simulcastStream[0].targetBitrate +
                        codec_.simulcastStream[1].minBitrate - 1;

  // Input data.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();

  // Encode with three streams.
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  std::vector<MockVideoEncoder*> original_encoders =
      helper_->factory()->encoders();
  ASSERT_EQ(3u, original_encoders.size());
  // Only first encoder will be active and called.
  EXPECT_CALL(*original_encoders[0], Encode(_, _))
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*original_encoders[1], Encode(_, _)).Times(0);
  EXPECT_CALL(*original_encoders[2], Encode(_, _)).Times(0);

  std::vector<VideoFrameType> frame_types;
  frame_types.resize(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, TrustedRateControl) {
  // Set up common settings for three streams.
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  adapter_->RegisterEncodeCompleteCallback(this);

  // Only enough start bitrate for the lowest stream.
  ASSERT_EQ(3u, codec_.numberOfSimulcastStreams);
  codec_.startBitrate = codec_.simulcastStream[0].targetBitrate +
                        codec_.simulcastStream[1].minBitrate - 1;

  // Input data.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();

  // No encoder trusted, so simulcast adapter should not be either.
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().has_trusted_rate_controller);

  // Encode with three streams.
  std::vector<MockVideoEncoder*> original_encoders =
      helper_->factory()->encoders();

  // All encoders are trusted, so simulcast adapter should be too.
  original_encoders[0]->set_has_trusted_rate_controller(true);
  original_encoders[1]->set_has_trusted_rate_controller(true);
  original_encoders[2]->set_has_trusted_rate_controller(true);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(adapter_->GetEncoderInfo().has_trusted_rate_controller);

  // One encoder not trusted, so simulcast adapter should not be either.
  original_encoders[2]->set_has_trusted_rate_controller(false);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().has_trusted_rate_controller);

  // No encoder trusted, so simulcast adapter should not be either.
  original_encoders[0]->set_has_trusted_rate_controller(false);
  original_encoders[1]->set_has_trusted_rate_controller(false);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().has_trusted_rate_controller);
}

TEST_F(TestSimulcastEncoderAdapterFake, ReportsHardwareAccelerated) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());

  // None of the encoders uses HW support, so simulcast adapter reports false.
  for (MockVideoEncoder* encoder : helper_->factory()->encoders()) {
    encoder->set_is_hardware_accelerated(false);
  }
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().is_hardware_accelerated);

  // One encoder uses HW support, so simulcast adapter reports true.
  helper_->factory()->encoders()[2]->set_is_hardware_accelerated(true);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(adapter_->GetEncoderInfo().is_hardware_accelerated);
}

TEST_F(TestSimulcastEncoderAdapterFake, ReportsEnableCpuOveruseDetection) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());

  // All encoders opt out, so simulcast adapter should report false.
  for (MockVideoEncoder* encoder : helper_->factory()->encoders()) {
    encoder->set_enable_cpu_overuse_detection(false);
  }
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().enable_cpu_overuse_detection);

  // One encoder opts in, so simulcast adapter should report true.
  helper_->factory()->encoders()[1]->set_enable_cpu_overuse_detection(true);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(adapter_->GetEncoderInfo().enable_cpu_overuse_detection);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       ReportsLeastCommonMultipleOfRequestedResolutionAlignments) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  helper_->factory()->set_requested_resolution_alignments({2, 4, 7});
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));

  EXPECT_EQ(adapter_->GetEncoderInfo().requested_resolution_alignment, 28u);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       ReportsApplyAlignmentToSimulcastLayers) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;

  // No encoder has apply_alignment_to_all_simulcast_layers, report false.
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  for (MockVideoEncoder* encoder : helper_->factory()->encoders()) {
    encoder->set_apply_alignment_to_all_simulcast_layers(false);
  }
  EXPECT_FALSE(
      adapter_->GetEncoderInfo().apply_alignment_to_all_simulcast_layers);

  // One encoder has apply_alignment_to_all_simulcast_layers, report true.
  helper_->factory()
      ->encoders()[1]
      ->set_apply_alignment_to_all_simulcast_layers(true);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(
      adapter_->GetEncoderInfo().apply_alignment_to_all_simulcast_layers);
}

TEST_F(
    TestSimulcastEncoderAdapterFake,
    EncoderInfoFromFieldTrialDoesNotOverrideExistingBitrateLimitsInSinglecast) {
  field_trials_.Set("WebRTC-SimulcastEncoderAdapter-GetEncoderInfoOverride",
                    "frame_size_pixels:123|456|789,"
                    "min_start_bitrate_bps:11000|22000|33000,"
                    "min_bitrate_bps:44000|55000|66000,"
                    "max_bitrate_bps:77000|88000|99000");
  SetUp();

  std::vector<VideoEncoder::ResolutionBitrateLimits> bitrate_limits;
  bitrate_limits.push_back(
      VideoEncoder::ResolutionBitrateLimits(111, 11100, 44400, 77700));
  bitrate_limits.push_back(
      VideoEncoder::ResolutionBitrateLimits(444, 22200, 55500, 88700));
  bitrate_limits.push_back(
      VideoEncoder::ResolutionBitrateLimits(777, 33300, 66600, 99900));
  SetUp();
  helper_->factory()->set_resolution_bitrate_limits(bitrate_limits);

  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 1;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(1u, helper_->factory()->encoders().size());
  EXPECT_EQ(adapter_->GetEncoderInfo().resolution_bitrate_limits,
            bitrate_limits);
}

TEST_F(TestSimulcastEncoderAdapterFake, EncoderInfoFromFieldTrial) {
  field_trials_.Set("WebRTC-SimulcastEncoderAdapter-GetEncoderInfoOverride",
                    "requested_resolution_alignment:8,"
                    "apply_alignment_to_all_simulcast_layers");
  SetUp();
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());

  EXPECT_EQ(8u, adapter_->GetEncoderInfo().requested_resolution_alignment);
  EXPECT_TRUE(
      adapter_->GetEncoderInfo().apply_alignment_to_all_simulcast_layers);
  EXPECT_TRUE(adapter_->GetEncoderInfo().resolution_bitrate_limits.empty());
}

TEST_F(TestSimulcastEncoderAdapterFake,
       EncoderInfoFromFieldTrialForSingleStream) {
  field_trials_.Set("WebRTC-SimulcastEncoderAdapter-GetEncoderInfoOverride",
                    "requested_resolution_alignment:9,"
                    "frame_size_pixels:123|456|789,"
                    "min_start_bitrate_bps:11000|22000|33000,"
                    "min_bitrate_bps:44000|55000|66000,"
                    "max_bitrate_bps:77000|88000|99000");
  SetUp();
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 1;
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(1u, helper_->factory()->encoders().size());

  EXPECT_EQ(9u, adapter_->GetEncoderInfo().requested_resolution_alignment);
  EXPECT_FALSE(
      adapter_->GetEncoderInfo().apply_alignment_to_all_simulcast_layers);
  EXPECT_THAT(
      adapter_->GetEncoderInfo().resolution_bitrate_limits,
      ::testing::ElementsAre(
          VideoEncoder::ResolutionBitrateLimits{123, 11000, 44000, 77000},
          VideoEncoder::ResolutionBitrateLimits{456, 22000, 55000, 88000},
          VideoEncoder::ResolutionBitrateLimits{789, 33000, 66000, 99000}));
}

TEST_F(TestSimulcastEncoderAdapterFake, ReportsIsQpTrusted) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());

  // All encoders have internal source, simulcast adapter reports true.
  for (MockVideoEncoder* encoder : helper_->factory()->encoders()) {
    encoder->set_is_qp_trusted(true);
  }
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_TRUE(adapter_->GetEncoderInfo().is_qp_trusted.value_or(false));

  // One encoder reports QP not trusted, simulcast adapter reports false.
  helper_->factory()->encoders()[2]->set_is_qp_trusted(false);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_FALSE(adapter_->GetEncoderInfo().is_qp_trusted.value_or(true));
}

TEST_F(TestSimulcastEncoderAdapterFake, ReportsFpsAllocation) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());

  // Combination of three different supported mode:
  // Simulcast stream 0 has undefined fps behavior.
  // Simulcast stream 1 has three temporal layers.
  // Simulcast stream 2 has 1 temporal layer.
  FramerateFractions expected_fps_allocation[kMaxSpatialLayers];
  expected_fps_allocation[1].push_back(EncoderInfo::kMaxFramerateFraction / 4);
  expected_fps_allocation[1].push_back(EncoderInfo::kMaxFramerateFraction / 2);
  expected_fps_allocation[1].push_back(EncoderInfo::kMaxFramerateFraction);
  expected_fps_allocation[2].push_back(EncoderInfo::kMaxFramerateFraction);

  // All encoders have internal source, simulcast adapter reports true.
  for (size_t i = 0; i < codec_.numberOfSimulcastStreams; ++i) {
    MockVideoEncoder* encoder = helper_->factory()->encoders()[i];
    encoder->set_fps_allocation(expected_fps_allocation[i]);
  }
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  EXPECT_THAT(adapter_->GetEncoderInfo().fps_allocation,
              ::testing::ElementsAreArray(expected_fps_allocation));
}

TEST_F(TestSimulcastEncoderAdapterFake, SetRateDistributesBandwithAllocation) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  const DataRate target_bitrate =
      DataRate::KilobitsPerSec(codec_.simulcastStream[0].targetBitrate +
                               codec_.simulcastStream[1].targetBitrate +
                               codec_.simulcastStream[2].minBitrate);
  const DataRate bandwidth_allocation =
      target_bitrate + DataRate::KilobitsPerSec(600);

  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);

  // Set bitrates so that we send all layers.
  adapter_->SetRates(VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(target_bitrate.bps(), 30)),
      30.0, bandwidth_allocation));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();

  ASSERT_EQ(3u, encoders.size());

  for (size_t i = 0; i < 3; ++i) {
    const uint32_t layer_bitrate_bps =
        (i < static_cast<size_t>(codec_.numberOfSimulcastStreams) - 1
             ? codec_.simulcastStream[i].targetBitrate
             : codec_.simulcastStream[i].minBitrate) *
        1000;
    EXPECT_EQ(layer_bitrate_bps,
              encoders[i]->last_set_rates().bitrate.get_sum_bps())
        << i;
    EXPECT_EQ(
        (layer_bitrate_bps * bandwidth_allocation.bps()) / target_bitrate.bps(),
        encoders[i]->last_set_rates().bandwidth_allocation.bps())
        << i;
  }
}

TEST_F(TestSimulcastEncoderAdapterFake, CanSetZeroBitrateWithHeadroom) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;

  rate_allocator_ = std::make_unique<SimulcastRateAllocator>(env_, codec_);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->RegisterEncodeCompleteCallback(this);

  // Set allocated bitrate to 0, but keep (network) bandwidth allocation.
  VideoEncoder::RateControlParameters rate_params;
  rate_params.framerate_fps = 30;
  rate_params.bandwidth_allocation = DataRate::KilobitsPerSec(600);

  adapter_->SetRates(rate_params);

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();

  ASSERT_EQ(3u, encoders.size());
  for (size_t i = 0; i < 3; ++i) {
    EXPECT_EQ(0u, encoders[i]->last_set_rates().bitrate.get_sum_bps());
  }
}

TEST_F(TestSimulcastEncoderAdapterFake, SupportsSimulcast) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;

  // Indicate that mock encoders internally support simulcast.
  helper_->factory()->set_supports_simulcast(true);
  adapter_->RegisterEncodeCompleteCallback(this);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));

  // Only one encoder should have been produced.
  ASSERT_EQ(1u, helper_->factory()->encoders().size());

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();
  EXPECT_CALL(*helper_->factory()->encoders()[0], Encode)
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, PassesSdpVideoFormatToEncoder) {
  sdp_video_parameters_ = {{"test_param", "test_value"}};
  SetUp();
  SetupCodec();
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_GT(encoders.size(), 0u);
  EXPECT_EQ(encoders[0]->video_format(),
            SdpVideoFormat("VP8", sdp_video_parameters_));
}

TEST_F(TestSimulcastEncoderAdapterFake, SupportsFallback) {
  // Enable support for fallback encoder factory and re-setup.
  use_fallback_factory_ = true;
  SetUp();

  SetupCodec();

  // Make sure we have bitrate for all layers.
  DataRate max_bitrate = DataRate::Zero();
  for (int i = 0; i < 3; ++i) {
    max_bitrate +=
        DataRate::KilobitsPerSec(codec_.simulcastStream[i].maxBitrate);
  }
  const auto rate_settings = VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(max_bitrate.bps(), 30)),
      30.0, max_bitrate);
  adapter_->SetRates(rate_settings);

  std::vector<MockVideoEncoder*> primary_encoders =
      helper_->factory()->encoders();
  std::vector<MockVideoEncoder*> fallback_encoders =
      helper_->fallback_factory()->encoders();

  ASSERT_EQ(3u, primary_encoders.size());
  ASSERT_EQ(3u, fallback_encoders.size());

  // Create frame to test with.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);

  // All primary encoders used.
  for (auto codec : primary_encoders) {
    EXPECT_CALL(*codec, Encode).WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  }
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Trigger fallback on first encoder.
  primary_encoders[0]->set_init_encode_return_value(
      WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(rate_settings);
  EXPECT_CALL(*fallback_encoders[0], Encode)
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*primary_encoders[1], Encode)
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*primary_encoders[2], Encode)
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Trigger fallback on all encoder.
  primary_encoders[1]->set_init_encode_return_value(
      WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE);
  primary_encoders[2]->set_init_encode_return_value(
      WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(rate_settings);
  EXPECT_CALL(*fallback_encoders[0], Encode)
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*fallback_encoders[1], Encode)
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_CALL(*fallback_encoders[2], Encode)
      .WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));

  // Return to primary encoders on all streams.
  for (int i = 0; i < 3; ++i) {
    primary_encoders[i]->set_init_encode_return_value(WEBRTC_VIDEO_CODEC_OK);
  }
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  adapter_->SetRates(rate_settings);
  for (auto codec : primary_encoders) {
    EXPECT_CALL(*codec, Encode).WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  }
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake,
       SupportsHardwareSimulcastWithBadParametrs) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);

  // Enable support for fallback encoder factory and re-setup.
  use_fallback_factory_ = true;
  SetUp();

  helper_->factory()->set_supports_simulcast(true);
  // Make encoders reject the simulcast configuration despite supporting it
  // because parameters are not good for simulcast (e.g. different temporal
  // layers setting).
  helper_->factory()->set_fallback_from_simulcast(
      WEBRTC_VIDEO_CODEC_ERR_SIMULCAST_PARAMETERS_NOT_SUPPORTED);

  SetupCodec();

  // Make sure we have bitrate for all layers.
  DataRate max_bitrate = DataRate::Zero();
  for (int i = 0; i < 3; ++i) {
    max_bitrate +=
        DataRate::KilobitsPerSec(codec_.simulcastStream[i].maxBitrate);
  }
  const auto rate_settings = VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(max_bitrate.bps(), 30)),
      30.0, max_bitrate);
  adapter_->SetRates(rate_settings);

  std::vector<MockVideoEncoder*> primary_encoders =
      helper_->factory()->encoders();
  std::vector<MockVideoEncoder*> fallback_encoders =
      helper_->fallback_factory()->encoders();

  ASSERT_EQ(3u, primary_encoders.size());
  ASSERT_EQ(3u, fallback_encoders.size());

  // Create frame to test with.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);

  // All primary encoders must be used.
  for (auto codec : primary_encoders) {
    EXPECT_CALL(*codec, Encode).WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  }
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, SupportsHardwareSimulcast) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);

  // Enable support for fallback encoder factory and re-setup.
  use_fallback_factory_ = true;
  SetUp();

  helper_->factory()->set_supports_simulcast(true);
  helper_->factory()->set_fallback_from_simulcast(std::nullopt);

  SetupCodec();

  // Make sure we have bitrate for all layers.
  DataRate max_bitrate = DataRate::Zero();
  for (int i = 0; i < 3; ++i) {
    max_bitrate +=
        DataRate::KilobitsPerSec(codec_.simulcastStream[i].maxBitrate);
  }
  const auto rate_settings = VideoEncoder::RateControlParameters(
      rate_allocator_->Allocate(
          VideoBitrateAllocationParameters(max_bitrate.bps(), 30)),
      30.0, max_bitrate);
  adapter_->SetRates(rate_settings);

  std::vector<MockVideoEncoder*> primary_encoders =
      helper_->factory()->encoders();
  std::vector<MockVideoEncoder*> fallback_encoders =
      helper_->fallback_factory()->encoders();

  ASSERT_EQ(1u, primary_encoders.size());
  ASSERT_EQ(1u, fallback_encoders.size());

  // Create frame to test with.
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(100)
                               .set_timestamp_ms(1000)
                               .set_rotation(kVideoRotation_180)
                               .build();
  std::vector<VideoFrameType> frame_types(3, VideoFrameType::kVideoFrameKey);

  // A primary encoders must be used.
  for (auto codec : primary_encoders) {
    EXPECT_CALL(*codec, Encode).WillOnce(Return(WEBRTC_VIDEO_CODEC_OK));
  }
  EXPECT_EQ(0, adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake, SupportsPerSimulcastLayerMaxFramerate) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  codec_.simulcastStream[0].maxFramerate = 60;
  codec_.simulcastStream[1].maxFramerate = 30;
  codec_.simulcastStream[2].maxFramerate = 10;

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  EXPECT_EQ(60u, helper_->factory()->encoders()[0]->codec().maxFramerate);
  EXPECT_EQ(30u, helper_->factory()->encoders()[1]->codec().maxFramerate);
  EXPECT_EQ(10u, helper_->factory()->encoders()[2]->codec().maxFramerate);
}

TEST_F(TestSimulcastEncoderAdapterFake, CreatesEncoderOnlyIfStreamIsActive) {
  // Legacy singlecast
  SetupCodec(/*active_streams=*/{});
  EXPECT_EQ(1u, helper_->factory()->encoders().size());

  // Simulcast-capable underlaying encoder
  ReSetUp();
  helper_->factory()->set_supports_simulcast(true);
  SetupCodec(/*active_streams=*/{true, true});
  EXPECT_EQ(1u, helper_->factory()->encoders().size());

  // Muti-encoder simulcast
  ReSetUp();
  helper_->factory()->set_supports_simulcast(false);
  SetupCodec(/*active_streams=*/{true, true});
  EXPECT_EQ(2u, helper_->factory()->encoders().size());

  // Singlecast via layers deactivation. Lowest layer is active.
  ReSetUp();
  helper_->factory()->set_supports_simulcast(false);
  SetupCodec(/*active_streams=*/{true, false});
  EXPECT_EQ(1u, helper_->factory()->encoders().size());

  // Singlecast via layers deactivation. Highest layer is active.
  ReSetUp();
  helper_->factory()->set_supports_simulcast(false);
  SetupCodec(/*active_streams=*/{false, true});
  EXPECT_EQ(1u, helper_->factory()->encoders().size());
}

TEST_F(TestSimulcastEncoderAdapterFake,
       RecreateEncoderIfPreferTemporalSupportIsEnabled) {
  // Normally SEA reuses encoders. But, when TL-based SW fallback is enabled,
  // the encoder which served the lowest stream should be recreated before it
  // can be used to process an upper layer and vice-versa.
  field_trials_.Set("WebRTC-Video-PreferTemporalSupportOnBaseLayer", "Enabled");
  use_fallback_factory_ = true;
  ReSetUp();

  // Legacy singlecast
  SetupCodec(/*active_streams=*/{});
  ASSERT_EQ(1u, helper_->factory()->encoders().size());

  // Singlecast, the lowest stream is active. Encoder should be reused.
  MockVideoEncoder* prev_encoder = helper_->factory()->encoders()[0];
  SetupCodec(/*active_streams=*/{true, false});
  ASSERT_EQ(1u, helper_->factory()->encoders().size());
  EXPECT_EQ(helper_->factory()->encoders()[0], prev_encoder);

  // Singlecast, an upper stream is active. Encoder should be recreated.
  EXPECT_CALL(*prev_encoder, ReleaseMock()).Times(1);
  SetupCodec(/*active_streams=*/{false, true});
  ASSERT_EQ(1u, helper_->factory()->encoders().size());
  EXPECT_NE(helper_->factory()->encoders()[0], prev_encoder);

  // Singlecast, the lowest stream is active. Encoder should be recreated.
  prev_encoder = helper_->factory()->encoders()[0];
  EXPECT_CALL(*prev_encoder, ReleaseMock()).Times(1);
  SetupCodec(/*active_streams=*/{true, false});
  ASSERT_EQ(1u, helper_->factory()->encoders().size());
  EXPECT_NE(helper_->factory()->encoders()[0], prev_encoder);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       UseFallbackEncoderIfCreatePrimaryEncoderFailed) {
  // Enable support for fallback encoder factory and re-setup.
  use_fallback_factory_ = true;
  SetUp();
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 1;
  helper_->factory()->SetEncoderNames({"primary"});
  helper_->fallback_factory()->SetEncoderNames({"fallback"});

  // Emulate failure at creating of primary encoder and verify that SEA switches
  // to fallback encoder.
  helper_->factory()->set_create_video_encode_return_nullptr(true);
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(0u, helper_->factory()->encoders().size());
  ASSERT_EQ(1u, helper_->fallback_factory()->encoders().size());
  EXPECT_EQ("fallback", adapter_->GetEncoderInfo().implementation_name);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       InitEncodeReturnsErrorIfEncoderCannotBeCreated) {
  // Enable support for fallback encoder factory and re-setup.
  use_fallback_factory_ = true;
  SetUp();
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 1;
  helper_->factory()->SetEncoderNames({"primary"});
  helper_->fallback_factory()->SetEncoderNames({"fallback"});

  // Emulate failure at creating of primary and fallback encoders and verify
  // that `InitEncode` returns an error.
  helper_->factory()->set_create_video_encode_return_nullptr(true);
  helper_->fallback_factory()->set_create_video_encode_return_nullptr(true);
  EXPECT_EQ(WEBRTC_VIDEO_CODEC_MEMORY,
            adapter_->InitEncode(&codec_, kSettings));
}

TEST_F(TestSimulcastEncoderAdapterFake, PopulatesScalabilityModeOfSubcodecs) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 3;
  codec_.simulcastStream[0].numberOfTemporalLayers = 1;
  codec_.simulcastStream[1].numberOfTemporalLayers = 2;
  codec_.simulcastStream[2].numberOfTemporalLayers = 3;

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  EXPECT_EQ(helper_->factory()->encoders()[0]->codec().GetScalabilityMode(),
            ScalabilityMode::kL1T1);
  EXPECT_EQ(helper_->factory()->encoders()[1]->codec().GetScalabilityMode(),
            ScalabilityMode::kL1T2);
  EXPECT_EQ(helper_->factory()->encoders()[2]->codec().GetScalabilityMode(),
            ScalabilityMode::kL1T3);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       ScalabilityModeWithInactiveFirstStream) {
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  codec_.numberOfSimulcastStreams = 2;
  codec_.SetScalabilityMode(ScalabilityMode::kL1T3);

  codec_.simulcastStream[0].numberOfTemporalLayers = 3;
  codec_.simulcastStream[0].active = false;
  codec_.simulcastStream[1].numberOfTemporalLayers = 2;
  codec_.simulcastStream[1].active = true;

  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));

  // Only one encoder should be created for the active stream.
  ASSERT_EQ(1u, helper_->factory()->encoders().size());

  // The encoder should be configured with L1T2, matching the active stream.
  EXPECT_EQ(helper_->factory()->encoders()[0]->codec().GetScalabilityMode(),
            ScalabilityMode::kL1T2);

  // Verify rate allocation.
  VideoBitrateAllocation allocation;
  allocation.SetBitrate(0, 0, 0);       // Stream 0 inactive
  allocation.SetBitrate(1, 0, 100000);  // Stream 1, temporal 0
  allocation.SetBitrate(1, 1, 200000);  // Stream 1, temporal 1

  adapter_->SetRates(VideoEncoder::RateControlParameters(allocation, 30.0));

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(1u, encoders.size());

  // The active encoder should get the allocation for stream 1 mapped to its own
  // spatial layer 0.
  EXPECT_EQ(100000u, encoders[0]->last_set_rates().bitrate.GetBitrate(0, 0));
  EXPECT_EQ(200000u, encoders[0]->last_set_rates().bitrate.GetBitrate(0, 1));
}

// In the case of mixed-codec simulcast, verify whether each encoder is created
// with the specified video format.
TEST_F(TestSimulcastEncoderAdapterFake, InitEncodeForMixedCodec) {
  std::vector<SdpVideoFormat> codecs = {SdpVideoFormat::VP8(),
                                        SdpVideoFormat::VP9Profile0(),
                                        SdpVideoFormat::VP9Profile1()};
  SetupMixedCodec({{.active = true, .format = SdpVideoFormat::VP8()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile0()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile1()}});
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  EXPECT_EQ(encoders[0]->video_format(), SdpVideoFormat::VP8());
  EXPECT_EQ(encoders[1]->video_format(), SdpVideoFormat::VP9Profile0());
  EXPECT_EQ(encoders[2]->video_format(), SdpVideoFormat::VP9Profile1());
  EXPECT_EQ(encoders[0]->codec().codecType, webrtc::kVideoCodecVP8);
  EXPECT_EQ(encoders[1]->codec().codecType, webrtc::kVideoCodecVP9);
  EXPECT_EQ(encoders[2]->codec().codecType, webrtc::kVideoCodecVP9);

  SetupMixedCodec({{.active = false, .format = SdpVideoFormat::VP8()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile0()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile1()}});
  encoders = helper_->factory()->encoders();
  ASSERT_EQ(2u, helper_->factory()->encoders().size());
  EXPECT_EQ(encoders[0]->video_format(), SdpVideoFormat::VP9Profile0());
  EXPECT_EQ(encoders[1]->video_format(), SdpVideoFormat::VP9Profile1());
  EXPECT_EQ(encoders[0]->codec().codecType, webrtc::kVideoCodecVP9);
  EXPECT_EQ(encoders[1]->codec().codecType, webrtc::kVideoCodecVP9);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       CodecSpecificSettingsIsInitializedDefaultValueForMixedCodec) {
  std::vector<SdpVideoFormat> codecs = {SdpVideoFormat::VP8(),
                                        SdpVideoFormat::VP9Profile0(),
                                        SdpVideoFormat::VP9Profile1()};
  SetupMixedCodec({{.active = true, .format = SdpVideoFormat::VP8()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile0()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile1()}});
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  EXPECT_EQ(encoders[0]->codec().codecType, webrtc::kVideoCodecVP8);
  EXPECT_EQ(encoders[1]->codec().codecType, webrtc::kVideoCodecVP9);
  EXPECT_EQ(encoders[2]->codec().codecType, webrtc::kVideoCodecVP9);

  // Fields in the codec specific settings that are not set in
  // SimulcastEncoderAdapter should be initialized with default values.
  auto vp8_defaults = VideoEncoder::GetDefaultVp8Settings();
  auto vp9_defaults = VideoEncoder::GetDefaultVp9Settings();
  EXPECT_EQ(encoders[0]->codec().VP8().automaticResizeOn,
            vp8_defaults.automaticResizeOn);
  EXPECT_EQ(encoders[0]->codec().VP8().keyFrameInterval,
            vp8_defaults.keyFrameInterval);
  for (int i = 1; i <= 2; i++) {
    EXPECT_EQ(encoders[i]->codec().VP9().denoisingOn, vp9_defaults.denoisingOn);
    EXPECT_EQ(encoders[i]->codec().VP9().keyFrameInterval,
              vp9_defaults.keyFrameInterval);
    EXPECT_EQ(encoders[i]->codec().VP9().adaptiveQpMode,
              vp9_defaults.adaptiveQpMode);
    EXPECT_EQ(encoders[i]->codec().VP9().automaticResizeOn,
              vp9_defaults.automaticResizeOn);
    EXPECT_EQ(encoders[i]->codec().VP9().flexibleMode,
              vp9_defaults.flexibleMode);
  }
}

// In the case of mixed-codec simulcast, multiple encoders are used even if
// supports_simulcast() == true.
TEST_F(TestSimulcastEncoderAdapterFake,
       CreateMultipleEncodersEvenIfSimulcastIsSupportedForMixedCodec) {
  std::vector<SdpVideoFormat> codecs = {SdpVideoFormat::VP8(),
                                        SdpVideoFormat::VP9Profile0(),
                                        SdpVideoFormat::VP9Profile1()};
  helper_->factory()->set_supports_simulcast(true);
  SetupMixedCodec({{.active = true, .format = SdpVideoFormat::VP8()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile0()},
                   {.active = true, .format = SdpVideoFormat::VP9Profile1()}});
  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(3u, helper_->factory()->encoders().size());
  EXPECT_EQ(encoders[0]->video_format(), SdpVideoFormat::VP8());
  EXPECT_EQ(encoders[1]->video_format(), SdpVideoFormat::VP9Profile0());
  EXPECT_EQ(encoders[2]->video_format(), SdpVideoFormat::VP9Profile1());
  EXPECT_EQ(encoders[0]->codec().codecType, webrtc::kVideoCodecVP8);
  EXPECT_EQ(encoders[1]->codec().codecType, webrtc::kVideoCodecVP9);
  EXPECT_EQ(encoders[2]->codec().codecType, webrtc::kVideoCodecVP9);
}

TEST_F(TestSimulcastEncoderAdapterFake,
       EncodeDropsFrameIfResolutionIsNotAlignedByDefault) {
  field_trials_.Set("WebRTC-SimulcastEncoderAdapter-GetEncoderInfoOverride",
                    "requested_resolution_alignment:8,"
                    "apply_alignment_to_all_simulcast_layers");
  SetUp();
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  SetupCodec();
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(0)
                               .set_timestamp_ms(0)
                               .build();
  std::vector<VideoFrameType> frame_types;
  frame_types.resize(codec_.numberOfSimulcastStreams,
                     VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(WEBRTC_VIDEO_CODEC_NO_OUTPUT,
            adapter_->Encode(input_frame, &frame_types));
}

TEST_F(TestSimulcastEncoderAdapterFake,
       EncodeReturnsErrorIfResolutionIsNotAlignedAndDroppingIsDisabled) {
  field_trials_.Set("WebRTC-SimulcastEncoderAdapter-DropUnalignedResolution",
                    "Disabled");
  field_trials_.Set("WebRTC-SimulcastEncoderAdapter-GetEncoderInfoOverride",
                    "requested_resolution_alignment:8,"
                    "apply_alignment_to_all_simulcast_layers");
  SetUp();
  SimulcastTestFixtureImpl::DefaultSettings(
      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
      kVideoCodecVP8);
  SetupCodec();
  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));
  VideoFrame input_frame = VideoFrame::Builder()
                               .set_video_frame_buffer(buffer)
                               .set_rtp_timestamp(0)
                               .set_timestamp_ms(0)
                               .build();
  std::vector<VideoFrameType> frame_types;
  frame_types.resize(codec_.numberOfSimulcastStreams,
                     VideoFrameType::kVideoFrameKey);
  EXPECT_EQ(WEBRTC_VIDEO_CODEC_ERROR,
            adapter_->Encode(input_frame, &frame_types));
}

// Only run this test under TSAN, otherwise it doesn't make much sense and
// mostly wastes CPU resources.
#if defined(THREAD_SANITIZER)
#define MAYBE_ConcurrentEncodeAndOnEncodedImage \
  ConcurrentEncodeAndOnEncodedImage
#else
#define MAYBE_ConcurrentEncodeAndOnEncodedImage \
  DISABLED_ConcurrentEncodeAndOnEncodedImage
#endif

TEST_F(TestSimulcastEncoderAdapterFake,
       MAYBE_ConcurrentEncodeAndOnEncodedImage) {
  // The test setup here is quite complex, but that is needed in order to make
  // sure tools like TSAN is able to reliable detect issue in the wrapper
  // encoder instances used for each stream. The code below makes sure that
  // there is concurrent usage of both an `Encode()` to request encoding of
  // a new frame at the same time that an encoder is calling `OnEncodedImage()`
  // on a separate thread.

  if (cpu_info::DetectNumberOfCores() <= 2) {
    GTEST_SKIP()
        << "Skipping test on low core count machine due to risk of flakiness.";
  }

  SetUp();
  helper_->factory()->set_supports_simulcast(false);
  SetupCodec({true, true});

  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
  ASSERT_EQ(2u, encoders.size());
  encoders[0]->set_is_async(true);
  encoders[1]->set_is_async(true);

  std::atomic<bool> wait_for_second_frame{false};

  EXPECT_CALL(*encoders[0], ReleaseMock()).WillRepeatedly(testing::Return(0));
  EXPECT_CALL(*encoders[1], ReleaseMock()).WillRepeatedly(testing::Return(0));

  MockEncodedImageCallback mock_encoded_image_callback;
  EXPECT_CALL(mock_encoded_image_callback, OnEncodedImage)
      .WillRepeatedly(Return(
          EncodedImageCallback::Result(EncodedImageCallback::Result::OK)));
  adapter_->RegisterEncodeCompleteCallback(&mock_encoded_image_callback);
  EXPECT_CALL(*encoders[0], Encode)
      .WillRepeatedly([&wait_for_second_frame, encoders](
                          const VideoFrame& frame,
                          const std::vector<VideoFrameType>* types) {
        if (frame.rtp_timestamp() == 100) {
          encoders[0]->PostTask([width = frame.width(), height = frame.height(),
                                 rtp_timestamp = frame.rtp_timestamp(),
                                 &wait_for_second_frame,
                                 encoder = encoders[0]]() {
            // Spin until the main thread is just about to encode the second
            // frame. Using relaxed memory order prevents TSAN from seeing a
            // happens-before edge but abort after 1000000 iterations.
            constexpr int kMaxLoops = 1000000;
            int loops = 0;
            while (!wait_for_second_frame.load(std::memory_order_relaxed) &&
                   ++loops <= kMaxLoops) {
            }
            EXPECT_LT(loops, kMaxLoops);
            encoder->SendEncodedImage(width, height, rtp_timestamp,
                                      /*simulcast_index=*/1);
          });
        }
        return WEBRTC_VIDEO_CODEC_OK;
      });

  EXPECT_CALL(*encoders[1], Encode)
      .WillRepeatedly([&](const VideoFrame& frame,
                          const std::vector<VideoFrameType>* types) {
        encoders[1]->SendEncodedImage(frame.width() / 2, frame.height() / 2,
                                      frame.rtp_timestamp(),
                                      /*simulcast_index=*/0);
        return WEBRTC_VIDEO_CODEC_OK;
      });

  scoped_refptr<VideoFrameBuffer> buffer(I420Buffer::Create(1280, 720));

  std::vector<VideoFrameType> frame_types0{VideoFrameType::kVideoFrameKey,
                                           VideoFrameType::kVideoFrameKey};
  EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK,
            adapter_->Encode(VideoFrame::Builder()
                                 .set_video_frame_buffer(buffer)
                                 .set_rtp_timestamp(100)
                                 .set_timestamp_ms(0)
                                 .build(),
                             &frame_types0));

  std::vector<VideoFrameType> frame_types1{VideoFrameType::kVideoFrameDelta,
                                           VideoFrameType::kVideoFrameDelta};

  // Signal the async thread to proceed. To maximize the chance of a collision,
  // we use a relaxed atomic flag which TSAN won't treat as a happens-before
  // edge.
  wait_for_second_frame.store(true, std::memory_order_relaxed);

  EXPECT_EQ(WEBRTC_VIDEO_CODEC_OK,
            adapter_->Encode(VideoFrame::Builder()
                                 .set_video_frame_buffer(buffer)
                                 .set_rtp_timestamp(90100)
                                 .set_timestamp_ms(1000)
                                 .build(),
                             &frame_types1));

  // The callbacks should have executed via the task queue, but we don't have
  // strict ordering guarantees on the main thread until we call adapter
  // Release, which will indirectly call Release on the encoders, flushing
  // their queues.
  EXPECT_EQ(0, adapter_->Release());
}

}  // namespace test
}  // namespace webrtc