text: /*
   *  Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #include "video/adaptation/overuse_frame_detector.h"
  
  #include <memory>
  
  #include "api/video/encoded_image.h"
  #include "api/video/i420_buffer.h"
  #include "api/video/video_adaptation_reason.h"
  #include "modules/video_coding/utility/quality_scaler.h"
  #include "rtc_base/event.h"
  #include "rtc_base/fake_clock.h"
  #include "rtc_base/random.h"
  #include "rtc_base/task_queue_for_test.h"
  #include "test/gmock.h"
  #include "test/gtest.h"
  
  namespace webrtc {
  
  using ::testing::_;
  using ::testing::InvokeWithoutArgs;
  
  namespace {
  const int kWidth = 640;
  const int kHeight = 480;
  // Corresponds to load of 15%
  const int kFrameIntervalUs = 33 * rtc::kNumMicrosecsPerMillisec;
  const int kProcessTimeUs = 5 * rtc::kNumMicrosecsPerMillisec;
  }  // namespace
  
  class MockCpuOveruseObserver : public OveruseFrameDetectorObserverInterface {
   public:
    MockCpuOveruseObserver() {}
    virtual ~MockCpuOveruseObserver() {}
  
    MOCK_METHOD(void, AdaptUp, (), (override));
    MOCK_METHOD(void, AdaptDown, (), (override));
  };
  
  class CpuOveruseObserverImpl : public OveruseFrameDetectorObserverInterface {
   public:
    CpuOveruseObserverImpl() : overuse_(0), normaluse_(0) {}
    virtual ~CpuOveruseObserverImpl() {}
  
    void AdaptDown() override { ++overuse_; }
    void AdaptUp() override { ++normaluse_; }
  
    int overuse_;
    int normaluse_;
  };
  
  class OveruseFrameDetectorUnderTest : public OveruseFrameDetector {
   public:
    explicit OveruseFrameDetectorUnderTest(
        CpuOveruseMetricsObserver* metrics_observer)
        : OveruseFrameDetector(metrics_observer) {}
    ~OveruseFrameDetectorUnderTest() {}
  
    using OveruseFrameDetector::CheckForOveruse;
    using OveruseFrameDetector::SetOptions;
  };
  
  class OveruseFrameDetectorTest : public ::testing::Test,
                                   public CpuOveruseMetricsObserver {
   protected:
    void SetUp() override {
      observer_ = &mock_observer_;
      options_.min_process_count = 0;
      overuse_detector_ = std::make_unique<OveruseFrameDetectorUnderTest>(this);
      // Unfortunately, we can't call SetOptions here, since that would break
      // single-threading requirements in the RunOnTqNormalUsage test.
    }
  
    void OnEncodedFrameTimeMeasured(int encode_time_ms,
                                    int encode_usage_percent) override {
      encode_usage_percent_ = encode_usage_percent;
    }
  
    int InitialUsage() {
      return ((options_.low_encode_usage_threshold_percent +
               options_.high_encode_usage_threshold_percent) /
              2.0f) +
             0.5;
    }
  
    virtual void InsertAndSendFramesWithInterval(int num_frames,
                                                 int interval_us,
                                                 int width,
                                                 int height,
                                                 int delay_us) {
      VideoFrame frame =
          VideoFrame::Builder()
              .set_video_frame_buffer(I420Buffer::Create(width, height))
              .set_rotation(webrtc::kVideoRotation_0)
              .set_timestamp_us(0)
              .build();
      uint32_t timestamp = 0;
      while (num_frames-- > 0) {
        frame.set_timestamp(timestamp);
        int64_t capture_time_us = rtc::TimeMicros();
        overuse_detector_->FrameCaptured(frame, capture_time_us);
        clock_.AdvanceTime(TimeDelta::Micros(delay_us));
        overuse_detector_->FrameSent(timestamp, rtc::TimeMicros(),
                                     capture_time_us, delay_us);
        clock_.AdvanceTime(TimeDelta::Micros(interval_us - delay_us));
        timestamp += interval_us * 90 / 1000;
      }
    }
  
    virtual void InsertAndSendSimulcastFramesWithInterval(
        int num_frames,
        int interval_us,
        int width,
        int height,
        // One element per layer
        rtc::ArrayView<const int> delays_us) {
      VideoFrame frame =
          VideoFrame::Builder()
              .set_video_frame_buffer(I420Buffer::Create(width, height))
              .set_rotation(webrtc::kVideoRotation_0)
              .set_timestamp_us(0)
              .build();
      uint32_t timestamp = 0;
      while (num_frames-- > 0) {
        frame.set_timestamp(timestamp);
        int64_t capture_time_us = rtc::TimeMicros();
        overuse_detector_->FrameCaptured(frame, capture_time_us);
        int max_delay_us = 0;
        for (int delay_us : delays_us) {
          if (delay_us > max_delay_us) {
            clock_.AdvanceTime(TimeDelta::Micros(delay_us - max_delay_us));
            max_delay_us = delay_us;
          }
  
          overuse_detector_->FrameSent(timestamp, rtc::TimeMicros(),
                                       capture_time_us, delay_us);
        }
        overuse_detector_->CheckForOveruse(observer_);
        clock_.AdvanceTime(TimeDelta::Micros(interval_us - max_delay_us));
        timestamp += interval_us * 90 / 1000;
      }
    }
  
    virtual void InsertAndSendFramesWithRandomInterval(int num_frames,
                                                       int min_interval_us,
                                                       int max_interval_us,
                                                       int width,
                                                       int height,
                                                       int delay_us) {
      webrtc::Random random(17);
  
      VideoFrame frame =
          VideoFrame::Builder()
              .set_video_frame_buffer(I420Buffer::Create(width, height))
              .set_rotation(webrtc::kVideoRotation_0)
              .set_timestamp_us(0)
              .build();
      uint32_t timestamp = 0;
      while (num_frames-- > 0) {
        frame.set_timestamp(timestamp);
        int interval_us = random.Rand(min_interval_us, max_interval_us);
        int64_t capture_time_us = rtc::TimeMicros();
        overuse_detector_->FrameCaptured(frame, capture_time_us);
        clock_.AdvanceTime(TimeDelta::Micros(delay_us));
        overuse_detector_->FrameSent(timestamp, rtc::TimeMicros(),
                                     capture_time_us,
                                     absl::optional<int>(delay_us));
  
        overuse_detector_->CheckForOveruse(observer_);
        // Avoid turning clock backwards.
        if (interval_us > delay_us)
          clock_.AdvanceTime(TimeDelta::Micros(interval_us - delay_us));
  
        timestamp += interval_us * 90 / 1000;
      }
    }
  
    virtual void ForceUpdate(int width, int height) {
      // Insert one frame, wait a second and then put in another to force update
      // the usage. From the tests where these are used, adding another sample
      // doesn't affect the expected outcome (this is mainly to check initial
      // values and whether the overuse detector has been reset or not).
      InsertAndSendFramesWithInterval(2, rtc::kNumMicrosecsPerSec, width, height,
                                      kFrameIntervalUs);
    }
    void TriggerOveruse(int num_times) {
      const int kDelayUs = 32 * rtc::kNumMicrosecsPerMillisec;
      for (int i = 0; i < num_times; ++i) {
        InsertAndSendFramesWithInterval(1000, kFrameIntervalUs, kWidth, kHeight,
                                        kDelayUs);
        overuse_detector_->CheckForOveruse(observer_);
      }
    }
  
    void TriggerUnderuse() {
      const int kDelayUs1 = 5000;
      const int kDelayUs2 = 6000;
      InsertAndSendFramesWithInterval(1300, kFrameIntervalUs, kWidth, kHeight,
                                      kDelayUs1);
      InsertAndSendFramesWithInterval(1, kFrameIntervalUs, kWidth, kHeight,
                                      kDelayUs2);
      overuse_detector_->CheckForOveruse(observer_);
    }
  
    int UsagePercent() { return encode_usage_percent_; }
  
    int64_t OveruseProcessingTimeLimitForFramerate(int fps) const {
      int64_t frame_interval = rtc::kNumMicrosecsPerSec / fps;
      int64_t max_processing_time_us =
          (frame_interval * options_.high_encode_usage_threshold_percent) / 100;
      return max_processing_time_us;
    }
  
    int64_t UnderuseProcessingTimeLimitForFramerate(int fps) const {
      int64_t frame_interval = rtc::kNumMicrosecsPerSec / fps;
      int64_t max_processing_time_us =
          (frame_interval * options_.low_encode_usage_threshold_percent) / 100;
      return max_processing_time_us;
    }
  
    CpuOveruseOptions options_;
    rtc::ScopedFakeClock clock_;
    MockCpuOveruseObserver mock_observer_;
    OveruseFrameDetectorObserverInterface* observer_;
    std::unique_ptr<OveruseFrameDetectorUnderTest> overuse_detector_;
    int encode_usage_percent_ = -1;
  };
  
  // UsagePercent() > high_encode_usage_threshold_percent => overuse.
  // UsagePercent() < low_encode_usage_threshold_percent => underuse.
  TEST_F(OveruseFrameDetectorTest, TriggerOveruse) {
    // usage > high => overuse
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    TriggerOveruse(options_.high_threshold_consecutive_count);
  }
  
  TEST_F(OveruseFrameDetectorTest, OveruseAndRecover) {
    // usage > high => overuse
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    TriggerOveruse(options_.high_threshold_consecutive_count);
    // usage < low => underuse
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(::testing::AtLeast(1));
    TriggerUnderuse();
  }
  
  TEST_F(OveruseFrameDetectorTest, DoubleOveruseAndRecover) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(2);
    TriggerOveruse(options_.high_threshold_consecutive_count);
    TriggerOveruse(options_.high_threshold_consecutive_count);
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(::testing::AtLeast(1));
    TriggerUnderuse();
  }
  
  TEST_F(OveruseFrameDetectorTest, TriggerUnderuseWithMinProcessCount) {
    const int kProcessIntervalUs = 5 * rtc::kNumMicrosecsPerSec;
    options_.min_process_count = 1;
    CpuOveruseObserverImpl overuse_observer;
    observer_ = nullptr;
    overuse_detector_->SetOptions(options_);
    InsertAndSendFramesWithInterval(1200, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    overuse_detector_->CheckForOveruse(&overuse_observer);
    EXPECT_EQ(0, overuse_observer.normaluse_);
    clock_.AdvanceTime(TimeDelta::Micros(kProcessIntervalUs));
    overuse_detector_->CheckForOveruse(&overuse_observer);
    EXPECT_EQ(1, overuse_observer.normaluse_);
  }
  
  TEST_F(OveruseFrameDetectorTest, ConstantOveruseGivesNoNormalUsage) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(0);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(64);
    for (size_t i = 0; i < 64; ++i) {
      TriggerOveruse(options_.high_threshold_consecutive_count);
    }
  }
  
  TEST_F(OveruseFrameDetectorTest, ConsecutiveCountTriggersOveruse) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    options_.high_threshold_consecutive_count = 2;
    overuse_detector_->SetOptions(options_);
    TriggerOveruse(2);
  }
  
  TEST_F(OveruseFrameDetectorTest, IncorrectConsecutiveCountTriggersNoOveruse) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    options_.high_threshold_consecutive_count = 2;
    overuse_detector_->SetOptions(options_);
    TriggerOveruse(1);
  }
  
  TEST_F(OveruseFrameDetectorTest, ProcessingUsage) {
    overuse_detector_->SetOptions(options_);
    InsertAndSendFramesWithInterval(1000, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_EQ(kProcessTimeUs * 100 / kFrameIntervalUs, UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest, ResetAfterResolutionChange) {
    overuse_detector_->SetOptions(options_);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
    InsertAndSendFramesWithInterval(1000, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_NE(InitialUsage(), UsagePercent());
    // Verify reset (with new width/height).
    ForceUpdate(kWidth, kHeight + 1);
    EXPECT_EQ(InitialUsage(), UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest, ResetAfterFrameTimeout) {
    overuse_detector_->SetOptions(options_);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
    InsertAndSendFramesWithInterval(1000, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_NE(InitialUsage(), UsagePercent());
    InsertAndSendFramesWithInterval(
        2, options_.frame_timeout_interval_ms * rtc::kNumMicrosecsPerMillisec,
        kWidth, kHeight, kProcessTimeUs);
    EXPECT_NE(InitialUsage(), UsagePercent());
    // Verify reset.
    InsertAndSendFramesWithInterval(
        2,
        (options_.frame_timeout_interval_ms + 1) * rtc::kNumMicrosecsPerMillisec,
        kWidth, kHeight, kProcessTimeUs);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest, MinFrameSamplesBeforeUpdating) {
    options_.min_frame_samples = 40;
    overuse_detector_->SetOptions(options_);
    InsertAndSendFramesWithInterval(40, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_EQ(InitialUsage(), UsagePercent());
    // Pass time far enough to digest all previous samples.
    clock_.AdvanceTime(TimeDelta::Seconds(1));
    InsertAndSendFramesWithInterval(1, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    // The last sample has not been processed here.
    EXPECT_EQ(InitialUsage(), UsagePercent());
  
    // Pass time far enough to digest all previous samples, 41 in total.
    clock_.AdvanceTime(TimeDelta::Seconds(1));
    InsertAndSendFramesWithInterval(1, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_NE(InitialUsage(), UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest, InitialProcessingUsage) {
    overuse_detector_->SetOptions(options_);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest, MeasuresMultipleConcurrentSamples) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(::testing::AtLeast(1));
    static const int kIntervalUs = 33 * rtc::kNumMicrosecsPerMillisec;
    static const size_t kNumFramesEncodingDelay = 3;
    VideoFrame frame =
        VideoFrame::Builder()
            .set_video_frame_buffer(I420Buffer::Create(kWidth, kHeight))
            .set_rotation(webrtc::kVideoRotation_0)
            .set_timestamp_us(0)
            .build();
    for (size_t i = 0; i < 1000; ++i) {
      // Unique timestamps.
      frame.set_timestamp(static_cast<uint32_t>(i));
      int64_t capture_time_us = rtc::TimeMicros();
      overuse_detector_->FrameCaptured(frame, capture_time_us);
      clock_.AdvanceTime(TimeDelta::Micros(kIntervalUs));
      if (i > kNumFramesEncodingDelay) {
        overuse_detector_->FrameSent(
            static_cast<uint32_t>(i - kNumFramesEncodingDelay), rtc::TimeMicros(),
            capture_time_us, kIntervalUs);
      }
      overuse_detector_->CheckForOveruse(observer_);
    }
  }
  
  TEST_F(OveruseFrameDetectorTest, UpdatesExistingSamples) {
    // >85% encoding time should trigger overuse.
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(::testing::AtLeast(1));
    static const int kIntervalUs = 33 * rtc::kNumMicrosecsPerMillisec;
    static const int kDelayUs = 30 * rtc::kNumMicrosecsPerMillisec;
    VideoFrame frame =
        VideoFrame::Builder()
            .set_video_frame_buffer(I420Buffer::Create(kWidth, kHeight))
            .set_rotation(webrtc::kVideoRotation_0)
            .set_timestamp_us(0)
            .build();
    uint32_t timestamp = 0;
    for (size_t i = 0; i < 1000; ++i) {
      frame.set_timestamp(timestamp);
      int64_t capture_time_us = rtc::TimeMicros();
      overuse_detector_->FrameCaptured(frame, capture_time_us);
      // Encode and send first parts almost instantly.
      clock_.AdvanceTime(TimeDelta::Millis(1));
      overuse_detector_->FrameSent(timestamp, rtc::TimeMicros(), capture_time_us,
                                   rtc::kNumMicrosecsPerMillisec);
      // Encode heavier part, resulting in >85% usage total.
      clock_.AdvanceTime(TimeDelta::Micros(kDelayUs) - TimeDelta::Millis(1));
      overuse_detector_->FrameSent(timestamp, rtc::TimeMicros(), capture_time_us,
                                   kDelayUs);
      clock_.AdvanceTime(TimeDelta::Micros(kIntervalUs - kDelayUs));
      timestamp += kIntervalUs * 90 / 1000;
      overuse_detector_->CheckForOveruse(observer_);
    }
  }
  
  TEST_F(OveruseFrameDetectorTest, RunOnTqNormalUsage) {
    TaskQueueForTest queue("OveruseFrameDetectorTestQueue");
  
    queue.SendTask(
        [&] {
          overuse_detector_->StartCheckForOveruse(queue.Get(), options_,
                                                  observer_);
        },
        RTC_FROM_HERE);
  
    rtc::Event event;
    // Expect NormalUsage(). When called, stop the |overuse_detector_| and then
    // set |event| to end the test.
    EXPECT_CALL(mock_observer_, AdaptUp())
        .WillOnce(InvokeWithoutArgs([this, &event] {
          overuse_detector_->StopCheckForOveruse();
          event.Set();
        }));
  
    queue.PostTask([this] {
      const int kDelayUs1 = 5 * rtc::kNumMicrosecsPerMillisec;
      const int kDelayUs2 = 6 * rtc::kNumMicrosecsPerMillisec;
      InsertAndSendFramesWithInterval(1300, kFrameIntervalUs, kWidth, kHeight,
                                      kDelayUs1);
      InsertAndSendFramesWithInterval(1, kFrameIntervalUs, kWidth, kHeight,
                                      kDelayUs2);
    });
  
    EXPECT_TRUE(event.Wait(10000));
  }
  
  TEST_F(OveruseFrameDetectorTest, MaxIntervalScalesWithFramerate) {
    const int kCapturerMaxFrameRate = 30;
    const int kEncodeMaxFrameRate = 20;  // Maximum fps the encoder can sustain.
  
    overuse_detector_->SetOptions(options_);
    // Trigger overuse.
    int64_t frame_interval_us = rtc::kNumMicrosecsPerSec / kCapturerMaxFrameRate;
    // Processing time just below over use limit given kEncodeMaxFrameRate.
    int64_t processing_time_us =
        (98 * OveruseProcessingTimeLimitForFramerate(kEncodeMaxFrameRate)) / 100;
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, frame_interval_us, kWidth, kHeight,
                                      processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  
    // Simulate frame rate reduction and normal usage.
    frame_interval_us = rtc::kNumMicrosecsPerSec / kEncodeMaxFrameRate;
    overuse_detector_->OnTargetFramerateUpdated(kEncodeMaxFrameRate);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, frame_interval_us, kWidth, kHeight,
                                      processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  
    // Reduce processing time to trigger underuse.
    processing_time_us =
        (98 * UnderuseProcessingTimeLimitForFramerate(kEncodeMaxFrameRate)) / 100;
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(1);
    InsertAndSendFramesWithInterval(1200, frame_interval_us, kWidth, kHeight,
                                    processing_time_us);
    overuse_detector_->CheckForOveruse(observer_);
  }
  
  TEST_F(OveruseFrameDetectorTest, RespectsMinFramerate) {
    const int kMinFrameRate = 7;  // Minimum fps allowed by current detector impl.
    overuse_detector_->SetOptions(options_);
    overuse_detector_->OnTargetFramerateUpdated(kMinFrameRate);
  
    // Normal usage just at the limit.
    int64_t frame_interval_us = rtc::kNumMicrosecsPerSec / kMinFrameRate;
    // Processing time just below over use limit given kEncodeMaxFrameRate.
    int64_t processing_time_us =
        (98 * OveruseProcessingTimeLimitForFramerate(kMinFrameRate)) / 100;
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, frame_interval_us, kWidth, kHeight,
                                      processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  
    // Over the limit to overuse.
    processing_time_us =
        (102 * OveruseProcessingTimeLimitForFramerate(kMinFrameRate)) / 100;
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, frame_interval_us, kWidth, kHeight,
                                      processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  
    // Reduce input frame rate. Should still trigger overuse.
    overuse_detector_->OnTargetFramerateUpdated(kMinFrameRate - 1);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, frame_interval_us, kWidth, kHeight,
                                      processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  }
  
  TEST_F(OveruseFrameDetectorTest, LimitsMaxFrameInterval) {
    const int kMaxFrameRate = 20;
    overuse_detector_->SetOptions(options_);
    overuse_detector_->OnTargetFramerateUpdated(kMaxFrameRate);
    int64_t frame_interval_us = rtc::kNumMicrosecsPerSec / kMaxFrameRate;
    // Maximum frame interval allowed is 35% above ideal.
    int64_t max_frame_interval_us = (135 * frame_interval_us) / 100;
    // Maximum processing time, without triggering overuse, allowed with the above
    // frame interval.
    int64_t max_processing_time_us =
        (max_frame_interval_us * options_.high_encode_usage_threshold_percent) /
        100;
  
    // Processing time just below overuse limit given kMaxFrameRate.
    int64_t processing_time_us = (98 * max_processing_time_us) / 100;
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, max_frame_interval_us, kWidth,
                                      kHeight, processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  
    // Go above limit, trigger overuse.
    processing_time_us = (102 * max_processing_time_us) / 100;
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, max_frame_interval_us, kWidth,
                                      kHeight, processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  
    // Increase frame interval, should still trigger overuse.
    max_frame_interval_us *= 2;
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    for (int i = 0; i < options_.high_threshold_consecutive_count; ++i) {
      InsertAndSendFramesWithInterval(1200, max_frame_interval_us, kWidth,
                                      kHeight, processing_time_us);
      overuse_detector_->CheckForOveruse(observer_);
    }
  }
  
  // Models screencast, with irregular arrival of frames which are heavy
  // to encode.
  TEST_F(OveruseFrameDetectorTest, NoOveruseForLargeRandomFrameInterval) {
    // TODO(bugs.webrtc.org/8504): When new estimator is relanded,
    // behavior is improved in this scenario, with only AdaptUp events,
    // and estimated load closer to the true average.
  
    // EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    // EXPECT_CALL(mock_observer_, AdaptUp())
    //     .Times(::testing::AtLeast(1));
    overuse_detector_->SetOptions(options_);
  
    const int kNumFrames = 500;
    const int kEncodeTimeUs = 100 * rtc::kNumMicrosecsPerMillisec;
  
    const int kMinIntervalUs = 30 * rtc::kNumMicrosecsPerMillisec;
    const int kMaxIntervalUs = 1000 * rtc::kNumMicrosecsPerMillisec;
  
    const int kTargetFramerate = 5;
  
    overuse_detector_->OnTargetFramerateUpdated(kTargetFramerate);
  
    InsertAndSendFramesWithRandomInterval(kNumFrames, kMinIntervalUs,
                                          kMaxIntervalUs, kWidth, kHeight,
                                          kEncodeTimeUs);
    // Average usage 19%. Check that estimate is in the right ball park.
    // EXPECT_NEAR(UsagePercent(), 20, 10);
    EXPECT_NEAR(UsagePercent(), 20, 35);
  }
  
  // Models screencast, with irregular arrival of frames, often
  // exceeding the timeout interval.
  TEST_F(OveruseFrameDetectorTest, NoOveruseForRandomFrameIntervalWithReset) {
    // TODO(bugs.webrtc.org/8504): When new estimator is relanded,
    // behavior is improved in this scenario, and we get AdaptUp events.
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    // EXPECT_CALL(mock_observer_, AdaptUp())
    //     .Times(::testing::AtLeast(1));
  
    const int kNumFrames = 500;
    const int kEncodeTimeUs = 100 * rtc::kNumMicrosecsPerMillisec;
  
    const int kMinIntervalUs = 30 * rtc::kNumMicrosecsPerMillisec;
    const int kMaxIntervalUs = 3000 * rtc::kNumMicrosecsPerMillisec;
  
    const int kTargetFramerate = 5;
  
    overuse_detector_->OnTargetFramerateUpdated(kTargetFramerate);
  
    InsertAndSendFramesWithRandomInterval(kNumFrames, kMinIntervalUs,
                                          kMaxIntervalUs, kWidth, kHeight,
                                          kEncodeTimeUs);
  
    // Average usage 6.6%, but since the frame_timeout_interval_ms is
    // only 1500 ms, we often reset the estimate to the initial value.
    // Check that estimate is in the right ball park.
    EXPECT_GE(UsagePercent(), 1);
    EXPECT_LE(UsagePercent(), InitialUsage() + 5);
  }
  
  // Models simulcast, with multiple encoded frames for each input frame.
  // Load estimate should be based on the maximum encode time per input frame.
  TEST_F(OveruseFrameDetectorTest, NoOveruseForSimulcast) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
  
    constexpr int kNumFrames = 500;
    constexpr int kEncodeTimesUs[] = {
        10 * rtc::kNumMicrosecsPerMillisec,
        8 * rtc::kNumMicrosecsPerMillisec,
        12 * rtc::kNumMicrosecsPerMillisec,
    };
    constexpr int kIntervalUs = 30 * rtc::kNumMicrosecsPerMillisec;
  
    InsertAndSendSimulcastFramesWithInterval(kNumFrames, kIntervalUs, kWidth,
                                             kHeight, kEncodeTimesUs);
  
    // Average usage 40%. 12 ms / 30 ms.
    EXPECT_GE(UsagePercent(), 35);
    EXPECT_LE(UsagePercent(), 45);
  }
  
  // Tests using new cpu load estimator
  class OveruseFrameDetectorTest2 : public OveruseFrameDetectorTest {
   protected:
    void SetUp() override {
      options_.filter_time_ms = 5 * rtc::kNumMillisecsPerSec;
      OveruseFrameDetectorTest::SetUp();
    }
  
    void InsertAndSendFramesWithInterval(int num_frames,
                                         int interval_us,
                                         int width,
                                         int height,
                                         int delay_us) override {
      VideoFrame frame =
          VideoFrame::Builder()
              .set_video_frame_buffer(I420Buffer::Create(width, height))
              .set_rotation(webrtc::kVideoRotation_0)
              .set_timestamp_us(0)
              .build();
      while (num_frames-- > 0) {
        int64_t capture_time_us = rtc::TimeMicros();
        overuse_detector_->FrameCaptured(frame, capture_time_us /* ignored */);
        overuse_detector_->FrameSent(0 /* ignored timestamp */,
                                     0 /* ignored send_time_us */,
                                     capture_time_us, delay_us);
        clock_.AdvanceTime(TimeDelta::Micros(interval_us));
      }
    }
  
    void InsertAndSendFramesWithRandomInterval(int num_frames,
                                               int min_interval_us,
                                               int max_interval_us,
                                               int width,
                                               int height,
                                               int delay_us) override {
      webrtc::Random random(17);
  
      VideoFrame frame =
          VideoFrame::Builder()
              .set_video_frame_buffer(I420Buffer::Create(width, height))
              .set_rotation(webrtc::kVideoRotation_0)
              .set_timestamp_us(0)
              .build();
      for (int i = 0; i < num_frames; i++) {
        int interval_us = random.Rand(min_interval_us, max_interval_us);
        int64_t capture_time_us = rtc::TimeMicros();
        overuse_detector_->FrameCaptured(frame, capture_time_us);
        overuse_detector_->FrameSent(0 /* ignored timestamp */,
                                     0 /* ignored send_time_us */,
                                     capture_time_us, delay_us);
  
        overuse_detector_->CheckForOveruse(observer_);
        clock_.AdvanceTime(TimeDelta::Micros(interval_us));
      }
    }
  
    void ForceUpdate(int width, int height) override {
      // This is mainly to check initial values and whether the overuse
      // detector has been reset or not.
      InsertAndSendFramesWithInterval(1, rtc::kNumMicrosecsPerSec, width, height,
                                      kFrameIntervalUs);
    }
  };
  
  // UsagePercent() > high_encode_usage_threshold_percent => overuse.
  // UsagePercent() < low_encode_usage_threshold_percent => underuse.
  TEST_F(OveruseFrameDetectorTest2, TriggerOveruse) {
    // usage > high => overuse
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    TriggerOveruse(options_.high_threshold_consecutive_count);
  }
  
  TEST_F(OveruseFrameDetectorTest2, OveruseAndRecover) {
    // usage > high => overuse
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    TriggerOveruse(options_.high_threshold_consecutive_count);
    // usage < low => underuse
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(::testing::AtLeast(1));
    TriggerUnderuse();
  }
  
  TEST_F(OveruseFrameDetectorTest2, DoubleOveruseAndRecover) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(2);
    TriggerOveruse(options_.high_threshold_consecutive_count);
    TriggerOveruse(options_.high_threshold_consecutive_count);
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(::testing::AtLeast(1));
    TriggerUnderuse();
  }
  
  TEST_F(OveruseFrameDetectorTest2, TriggerUnderuseWithMinProcessCount) {
    const int kProcessIntervalUs = 5 * rtc::kNumMicrosecsPerSec;
    options_.min_process_count = 1;
    CpuOveruseObserverImpl overuse_observer;
    observer_ = nullptr;
    overuse_detector_->SetOptions(options_);
    InsertAndSendFramesWithInterval(1200, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    overuse_detector_->CheckForOveruse(&overuse_observer);
    EXPECT_EQ(0, overuse_observer.normaluse_);
    clock_.AdvanceTime(TimeDelta::Micros(kProcessIntervalUs));
    overuse_detector_->CheckForOveruse(&overuse_observer);
    EXPECT_EQ(1, overuse_observer.normaluse_);
  }
  
  TEST_F(OveruseFrameDetectorTest2, ConstantOveruseGivesNoNormalUsage) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(0);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(64);
    for (size_t i = 0; i < 64; ++i) {
      TriggerOveruse(options_.high_threshold_consecutive_count);
    }
  }
  
  TEST_F(OveruseFrameDetectorTest2, ConsecutiveCountTriggersOveruse) {
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(1);
    options_.high_threshold_consecutive_count = 2;
    overuse_detector_->SetOptions(options_);
    TriggerOveruse(2);
  }
  
  TEST_F(OveruseFrameDetectorTest2, IncorrectConsecutiveCountTriggersNoOveruse) {
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    options_.high_threshold_consecutive_count = 2;
    overuse_detector_->SetOptions(options_);
    TriggerOveruse(1);
  }
  
  TEST_F(OveruseFrameDetectorTest2, ProcessingUsage) {
    overuse_detector_->SetOptions(options_);
    InsertAndSendFramesWithInterval(1000, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_EQ(kProcessTimeUs * 100 / kFrameIntervalUs, UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest2, ResetAfterResolutionChange) {
    overuse_detector_->SetOptions(options_);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
    InsertAndSendFramesWithInterval(1000, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_NE(InitialUsage(), UsagePercent());
    // Verify reset (with new width/height).
    ForceUpdate(kWidth, kHeight + 1);
    EXPECT_EQ(InitialUsage(), UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest2, ResetAfterFrameTimeout) {
    overuse_detector_->SetOptions(options_);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
    InsertAndSendFramesWithInterval(1000, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_NE(InitialUsage(), UsagePercent());
    InsertAndSendFramesWithInterval(
        2, options_.frame_timeout_interval_ms * rtc::kNumMicrosecsPerMillisec,
        kWidth, kHeight, kProcessTimeUs);
    EXPECT_NE(InitialUsage(), UsagePercent());
    // Verify reset.
    InsertAndSendFramesWithInterval(
        2,
        (options_.frame_timeout_interval_ms + 1) * rtc::kNumMicrosecsPerMillisec,
        kWidth, kHeight, kProcessTimeUs);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest2, ConvergesSlowly) {
    overuse_detector_->SetOptions(options_);
    InsertAndSendFramesWithInterval(1, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    // No update for the first sample.
    EXPECT_EQ(InitialUsage(), UsagePercent());
  
    // Total time approximately 40 * 33ms = 1.3s, significantly less
    // than the 5s time constant.
    InsertAndSendFramesWithInterval(40, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
  
    // Should have started to approach correct load of 15%, but not very far.
    EXPECT_LT(UsagePercent(), InitialUsage());
    EXPECT_GT(UsagePercent(), (InitialUsage() * 3 + 15) / 4);
  
    // Run for roughly 10s more, should now be closer.
    InsertAndSendFramesWithInterval(300, kFrameIntervalUs, kWidth, kHeight,
                                    kProcessTimeUs);
    EXPECT_NEAR(UsagePercent(), 20, 5);
  }
  
  TEST_F(OveruseFrameDetectorTest2, InitialProcessingUsage) {
    overuse_detector_->SetOptions(options_);
    ForceUpdate(kWidth, kHeight);
    EXPECT_EQ(InitialUsage(), UsagePercent());
  }
  
  TEST_F(OveruseFrameDetectorTest2, MeasuresMultipleConcurrentSamples) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(::testing::AtLeast(1));
    static const int kIntervalUs = 33 * rtc::kNumMicrosecsPerMillisec;
    static const size_t kNumFramesEncodingDelay = 3;
    VideoFrame frame =
        VideoFrame::Builder()
            .set_video_frame_buffer(I420Buffer::Create(kWidth, kHeight))
            .set_rotation(webrtc::kVideoRotation_0)
            .set_timestamp_us(0)
            .build();
    for (size_t i = 0; i < 1000; ++i) {
      // Unique timestamps.
      frame.set_timestamp(static_cast<uint32_t>(i));
      int64_t capture_time_us = rtc::TimeMicros();
      overuse_detector_->FrameCaptured(frame, capture_time_us);
      clock_.AdvanceTime(TimeDelta::Micros(kIntervalUs));
      if (i > kNumFramesEncodingDelay) {
        overuse_detector_->FrameSent(
            static_cast<uint32_t>(i - kNumFramesEncodingDelay), rtc::TimeMicros(),
            capture_time_us, kIntervalUs);
      }
      overuse_detector_->CheckForOveruse(observer_);
    }
  }
  
  TEST_F(OveruseFrameDetectorTest2, UpdatesExistingSamples) {
    // >85% encoding time should trigger overuse.
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(::testing::AtLeast(1));
    static const int kIntervalUs = 33 * rtc::kNumMicrosecsPerMillisec;
    static const int kDelayUs = 30 * rtc::kNumMicrosecsPerMillisec;
    VideoFrame frame =
        VideoFrame::Builder()
            .set_video_frame_buffer(I420Buffer::Create(kWidth, kHeight))
            .set_rotation(webrtc::kVideoRotation_0)
            .set_timestamp_us(0)
            .build();
    uint32_t timestamp = 0;
    for (size_t i = 0; i < 1000; ++i) {
      frame.set_timestamp(timestamp);
      int64_t capture_time_us = rtc::TimeMicros();
      overuse_detector_->FrameCaptured(frame, capture_time_us);
      // Encode and send first parts almost instantly.
      clock_.AdvanceTime(TimeDelta::Millis(1));
      overuse_detector_->FrameSent(timestamp, rtc::TimeMicros(), capture_time_us,
                                   rtc::kNumMicrosecsPerMillisec);
      // Encode heavier part, resulting in >85% usage total.
      clock_.AdvanceTime(TimeDelta::Micros(kDelayUs) - TimeDelta::Millis(1));
      overuse_detector_->FrameSent(timestamp, rtc::TimeMicros(), capture_time_us,
                                   kDelayUs);
      clock_.AdvanceTime(TimeDelta::Micros(kIntervalUs - kDelayUs));
      timestamp += kIntervalUs * 90 / 1000;
      overuse_detector_->CheckForOveruse(observer_);
    }
  }
  
  TEST_F(OveruseFrameDetectorTest2, RunOnTqNormalUsage) {
    TaskQueueForTest queue("OveruseFrameDetectorTestQueue");
  
    queue.SendTask(
        [&] {
          overuse_detector_->StartCheckForOveruse(queue.Get(), options_,
                                                  observer_);
        },
        RTC_FROM_HERE);
  
    rtc::Event event;
    // Expect NormalUsage(). When called, stop the |overuse_detector_| and then
    // set |event| to end the test.
    EXPECT_CALL(mock_observer_, AdaptUp())
        .WillOnce(InvokeWithoutArgs([this, &event] {
          overuse_detector_->StopCheckForOveruse();
          event.Set();
        }));
  
    queue.PostTask([this] {
      const int kDelayUs1 = 5 * rtc::kNumMicrosecsPerMillisec;
      const int kDelayUs2 = 6 * rtc::kNumMicrosecsPerMillisec;
      InsertAndSendFramesWithInterval(1300, kFrameIntervalUs, kWidth, kHeight,
                                      kDelayUs1);
      InsertAndSendFramesWithInterval(1, kFrameIntervalUs, kWidth, kHeight,
                                      kDelayUs2);
    });
  
    EXPECT_TRUE(event.Wait(10000));
  }
  
  // Models screencast, with irregular arrival of frames which are heavy
  // to encode.
  TEST_F(OveruseFrameDetectorTest2, NoOveruseForLargeRandomFrameInterval) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(::testing::AtLeast(1));
  
    const int kNumFrames = 500;
    const int kEncodeTimeUs = 100 * rtc::kNumMicrosecsPerMillisec;
  
    const int kMinIntervalUs = 30 * rtc::kNumMicrosecsPerMillisec;
    const int kMaxIntervalUs = 1000 * rtc::kNumMicrosecsPerMillisec;
  
    InsertAndSendFramesWithRandomInterval(kNumFrames, kMinIntervalUs,
                                          kMaxIntervalUs, kWidth, kHeight,
                                          kEncodeTimeUs);
    // Average usage 19%. Check that estimate is in the right ball park.
    EXPECT_NEAR(UsagePercent(), 20, 10);
  }
  
  // Models screencast, with irregular arrival of frames, often
  // exceeding the timeout interval.
  TEST_F(OveruseFrameDetectorTest2, NoOveruseForRandomFrameIntervalWithReset) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
    EXPECT_CALL(mock_observer_, AdaptUp()).Times(::testing::AtLeast(1));
  
    const int kNumFrames = 500;
    const int kEncodeTimeUs = 100 * rtc::kNumMicrosecsPerMillisec;
  
    const int kMinIntervalUs = 30 * rtc::kNumMicrosecsPerMillisec;
    const int kMaxIntervalUs = 3000 * rtc::kNumMicrosecsPerMillisec;
  
    InsertAndSendFramesWithRandomInterval(kNumFrames, kMinIntervalUs,
                                          kMaxIntervalUs, kWidth, kHeight,
                                          kEncodeTimeUs);
  
    // Average usage 6.6%, but since the frame_timeout_interval_ms is
    // only 1500 ms, we often reset the estimate to the initial value.
    // Check that estimate is in the right ball park.
    EXPECT_GE(UsagePercent(), 1);
    EXPECT_LE(UsagePercent(), InitialUsage() + 5);
  }
  
  TEST_F(OveruseFrameDetectorTest2, ToleratesOutOfOrderFrames) {
    overuse_detector_->SetOptions(options_);
    // Represents a cpu utilization close to 100%. First input frame results in
    // three encoded frames, and the last of those isn't finished until after the
    // first encoded frame corresponding to the next input frame.
    const int kEncodeTimeUs = 30 * rtc::kNumMicrosecsPerMillisec;
    const int kCaptureTimesMs[] = {33, 33, 66, 33};
  
    for (int capture_time_ms : kCaptureTimesMs) {
      overuse_detector_->FrameSent(
          0, 0, capture_time_ms * rtc::kNumMicrosecsPerMillisec, kEncodeTimeUs);
    }
    EXPECT_GE(UsagePercent(), InitialUsage());
  }
  
  // Models simulcast, with multiple encoded frames for each input frame.
  // Load estimate should be based on the maximum encode time per input frame.
  TEST_F(OveruseFrameDetectorTest2, NoOveruseForSimulcast) {
    overuse_detector_->SetOptions(options_);
    EXPECT_CALL(mock_observer_, AdaptDown()).Times(0);
  
    constexpr int kNumFrames = 500;
    constexpr int kEncodeTimesUs[] = {
        10 * rtc::kNumMicrosecsPerMillisec,
        8 * rtc::kNumMicrosecsPerMillisec,
        12 * rtc::kNumMicrosecsPerMillisec,
    };
    constexpr int kIntervalUs = 30 * rtc::kNumMicrosecsPerMillisec;
  
    InsertAndSendSimulcastFramesWithInterval(kNumFrames, kIntervalUs, kWidth,
                                             kHeight, kEncodeTimesUs);
  
    // Average usage 40%. 12 ms / 30 ms.
    EXPECT_GE(UsagePercent(), 35);
    EXPECT_LE(UsagePercent(), 45);
  }
  
  }  // namespace webrtc
  