| /* |
| * Copyright (c) 2019 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #include "video/encoder_overshoot_detector.h" |
| |
| #include <string> |
| |
| #include "api/units/data_rate.h" |
| #include "rtc_base/fake_clock.h" |
| #include "rtc_base/time_utils.h" |
| #include "system_wrappers/include/metrics.h" |
| #include "test/gtest.h" |
| |
| namespace webrtc { |
| |
| namespace { |
| |
| using ::testing::TestWithParam; |
| using ::testing::ValuesIn; |
| |
| static std::string CodecTypeToHistogramSuffix(VideoCodecType codec) { |
| switch (codec) { |
| case kVideoCodecVP8: |
| return "Vp8"; |
| case kVideoCodecVP9: |
| return "Vp9"; |
| case kVideoCodecAV1: |
| return "Av1"; |
| case kVideoCodecH264: |
| return "H264"; |
| case kVideoCodecH265: |
| return "H265"; |
| case kVideoCodecGeneric: |
| return "Generic"; |
| } |
| } |
| |
| struct TestParams { |
| VideoCodecType codec_type; |
| bool is_screenshare; |
| }; |
| |
| } // namespace |
| |
| class EncoderOvershootDetectorTest : public TestWithParam<TestParams> { |
| public: |
| static constexpr int kDefaultBitrateBps = 300000; |
| static constexpr double kDefaultFrameRateFps = 15; |
| EncoderOvershootDetectorTest() |
| : detector_(kWindowSizeMs, |
| GetParam().codec_type, |
| GetParam().is_screenshare), |
| target_bitrate_(DataRate::BitsPerSec(kDefaultBitrateBps)), |
| target_framerate_fps_(kDefaultFrameRateFps) {} |
| |
| protected: |
| void SetUp() override { metrics::Reset(); } |
| void RunConstantUtilizationTest(double actual_utilization_factor, |
| double expected_utilization_factor, |
| double allowed_error, |
| int64_t test_duration_ms) { |
| const int frame_size_bytes = |
| static_cast<int>(actual_utilization_factor * |
| (target_bitrate_.bps() / target_framerate_fps_) / 8); |
| detector_.SetTargetRate(target_bitrate_, target_framerate_fps_, |
| rtc::TimeMillis()); |
| |
| if (rtc::TimeMillis() == 0) { |
| // Encode a first frame which by definition has no overuse factor. |
| detector_.OnEncodedFrame(frame_size_bytes, rtc::TimeMillis()); |
| clock_.AdvanceTime(TimeDelta::Seconds(1) / target_framerate_fps_); |
| } |
| |
| int64_t runtime_us = 0; |
| while (runtime_us < test_duration_ms * 1000) { |
| detector_.OnEncodedFrame(frame_size_bytes, rtc::TimeMillis()); |
| runtime_us += rtc::kNumMicrosecsPerSec / target_framerate_fps_; |
| clock_.AdvanceTime(TimeDelta::Seconds(1) / target_framerate_fps_); |
| } |
| |
| // At constant utilization, both network and media utilization should be |
| // close to expected. |
| const std::optional<double> network_utilization_factor = |
| detector_.GetNetworkRateUtilizationFactor(rtc::TimeMillis()); |
| EXPECT_NEAR(network_utilization_factor.value_or(-1), |
| expected_utilization_factor, allowed_error); |
| |
| const std::optional<double> media_utilization_factor = |
| detector_.GetMediaRateUtilizationFactor(rtc::TimeMillis()); |
| EXPECT_NEAR(media_utilization_factor.value_or(-1), |
| expected_utilization_factor, allowed_error); |
| } |
| |
| static constexpr int64_t kWindowSizeMs = 3000; |
| EncoderOvershootDetector detector_; |
| rtc::ScopedFakeClock clock_; |
| DataRate target_bitrate_; |
| double target_framerate_fps_; |
| }; |
| |
| TEST_P(EncoderOvershootDetectorTest, NoUtilizationIfNoRate) { |
| const int frame_size_bytes = 1000; |
| const int64_t time_interval_ms = 33; |
| detector_.SetTargetRate(target_bitrate_, target_framerate_fps_, |
| rtc::TimeMillis()); |
| |
| // No data points, can't determine overshoot rate. |
| EXPECT_FALSE( |
| detector_.GetNetworkRateUtilizationFactor(rtc::TimeMillis()).has_value()); |
| |
| detector_.OnEncodedFrame(frame_size_bytes, rtc::TimeMillis()); |
| clock_.AdvanceTime(TimeDelta::Millis(time_interval_ms)); |
| EXPECT_TRUE( |
| detector_.GetNetworkRateUtilizationFactor(rtc::TimeMillis()).has_value()); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, OptimalSize) { |
| // Optimally behaved encoder. |
| // Allow some error margin due to rounding errors, eg due to frame |
| // interval not being an integer. |
| RunConstantUtilizationTest(1.0, 1.0, 0.01, kWindowSizeMs); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, Undershoot) { |
| // Undershoot, reported utilization factor should be capped to 1.0 so |
| // that we don't incorrectly boost encoder bitrate during movement. |
| RunConstantUtilizationTest(0.5, 1.0, 0.00, kWindowSizeMs); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, Overshoot) { |
| // Overshoot by 20%. |
| // Allow some error margin due to rounding errors. |
| RunConstantUtilizationTest(1.2, 1.2, 0.01, kWindowSizeMs); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, ConstantOvershootVaryingRates) { |
| // Overshoot by 20%, but vary framerate and bitrate. |
| // Allow some error margin due to rounding errors. |
| RunConstantUtilizationTest(1.2, 1.2, 0.01, kWindowSizeMs); |
| target_framerate_fps_ /= 2; |
| RunConstantUtilizationTest(1.2, 1.2, 0.01, kWindowSizeMs / 2); |
| target_bitrate_ = DataRate::BitsPerSec(target_bitrate_.bps() / 2); |
| RunConstantUtilizationTest(1.2, 1.2, 0.01, kWindowSizeMs / 2); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, ConstantRateVaryingOvershoot) { |
| // Overshoot by 10%, keep framerate and bitrate constant. |
| // Allow some error margin due to rounding errors. |
| RunConstantUtilizationTest(1.1, 1.1, 0.01, kWindowSizeMs); |
| // Change overshoot to 20%, run for half window and expect overshoot |
| // to be 15%. |
| RunConstantUtilizationTest(1.2, 1.15, 0.01, kWindowSizeMs / 2); |
| // Keep running at 20% overshoot, after window is full that should now |
| // be the reported overshoot. |
| RunConstantUtilizationTest(1.2, 1.2, 0.01, kWindowSizeMs / 2); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, PartialOvershoot) { |
| const int ideal_frame_size_bytes = |
| (target_bitrate_.bps() / target_framerate_fps_) / 8; |
| detector_.SetTargetRate(target_bitrate_, target_framerate_fps_, |
| rtc::TimeMillis()); |
| |
| // Test scenario with average bitrate matching the target bitrate, but |
| // with some utilization factor penalty as the frames can't be paced out |
| // on the network at the target rate. |
| // Insert a series of four frames: |
| // 1) 20% overshoot, not penalized as buffer if empty. |
| // 2) 20% overshoot, the 20% overshoot from the first frame is penalized. |
| // 3) 20% undershoot, negating the overshoot from the last frame. |
| // 4) 20% undershoot, no penalty. |
| // On average then utilization penalty is thus 5%. |
| |
| int64_t runtime_us = 0; |
| int i = 0; |
| while (runtime_us < kWindowSizeMs * rtc::kNumMicrosecsPerMillisec) { |
| runtime_us += rtc::kNumMicrosecsPerSec / target_framerate_fps_; |
| clock_.AdvanceTime(TimeDelta::Seconds(1) / target_framerate_fps_); |
| int frame_size_bytes = (i++ % 4 < 2) ? (ideal_frame_size_bytes * 120) / 100 |
| : (ideal_frame_size_bytes * 80) / 100; |
| detector_.OnEncodedFrame(frame_size_bytes, rtc::TimeMillis()); |
| } |
| |
| // Expect 5% overshoot for network rate, see above. |
| const std::optional<double> network_utilization_factor = |
| detector_.GetNetworkRateUtilizationFactor(rtc::TimeMillis()); |
| EXPECT_NEAR(network_utilization_factor.value_or(-1), 1.05, 0.01); |
| |
| // Expect media rate to be on average correct. |
| const std::optional<double> media_utilization_factor = |
| detector_.GetMediaRateUtilizationFactor(rtc::TimeMillis()); |
| EXPECT_NEAR(media_utilization_factor.value_or(-1), 1.00, 0.01); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, RecordsZeroErrorMetricWithNoOvershoot) { |
| DataSize ideal_frame_size = |
| target_bitrate_ / Frequency::Hertz(target_framerate_fps_); |
| detector_.SetTargetRate(target_bitrate_, target_framerate_fps_, |
| rtc::TimeMillis()); |
| detector_.OnEncodedFrame(ideal_frame_size.bytes(), rtc::TimeMillis()); |
| detector_.Reset(); |
| |
| const VideoCodecType codec = GetParam().codec_type; |
| const bool is_screenshare = GetParam().is_screenshare; |
| const std::string rmse_histogram_prefix = |
| is_screenshare ? "WebRTC.Video.Screenshare.RMSEOfEncodingBitrateInKbps." |
| : "WebRTC.Video.RMSEOfEncodingBitrateInKbps."; |
| const std::string overshoot_histogram_prefix = |
| is_screenshare ? "WebRTC.Video.Screenshare.EncodingBitrateOvershoot." |
| : "WebRTC.Video.EncodingBitrateOvershoot."; |
| // RMSE and overshoot percent = 0, since we used ideal frame size. |
| EXPECT_METRIC_EQ(1, metrics::NumSamples(rmse_histogram_prefix + |
| CodecTypeToHistogramSuffix(codec))); |
| EXPECT_METRIC_EQ( |
| 1, metrics::NumEvents( |
| rmse_histogram_prefix + CodecTypeToHistogramSuffix(codec), 0)); |
| |
| EXPECT_METRIC_EQ(1, metrics::NumSamples(overshoot_histogram_prefix + |
| CodecTypeToHistogramSuffix(codec))); |
| EXPECT_METRIC_EQ(1, metrics::NumEvents(overshoot_histogram_prefix + |
| CodecTypeToHistogramSuffix(codec), |
| 0)); |
| } |
| |
| TEST_P(EncoderOvershootDetectorTest, |
| RecordScreenshareZeroMetricWithNoOvershoot) { |
| DataSize ideal_frame_size = |
| target_bitrate_ / Frequency::Hertz(target_framerate_fps_); |
| // Use target frame size with 50% overshoot. |
| DataSize target_frame_size = ideal_frame_size * 3 / 2; |
| detector_.SetTargetRate(target_bitrate_, target_framerate_fps_, |
| rtc::TimeMillis()); |
| detector_.OnEncodedFrame(target_frame_size.bytes(), rtc::TimeMillis()); |
| detector_.Reset(); |
| |
| const VideoCodecType codec = GetParam().codec_type; |
| const bool is_screenshare = GetParam().is_screenshare; |
| const std::string rmse_histogram_prefix = |
| is_screenshare ? "WebRTC.Video.Screenshare.RMSEOfEncodingBitrateInKbps." |
| : "WebRTC.Video.RMSEOfEncodingBitrateInKbps."; |
| const std::string overshoot_histogram_prefix = |
| is_screenshare ? "WebRTC.Video.Screenshare.EncodingBitrateOvershoot." |
| : "WebRTC.Video.EncodingBitrateOvershoot."; |
| // Use ideal_frame_size_kbits to represnt ideal_frame_size.bytes()*8/1000, |
| // then rmse_in_kbps = ideal_frame_size_kbits/2 |
| // since we use target frame size with 50% overshoot. |
| int64_t rmse_in_kbps = ideal_frame_size.bytes() * 8 / 1000 / 2; |
| EXPECT_METRIC_EQ(1, metrics::NumSamples(rmse_histogram_prefix + |
| CodecTypeToHistogramSuffix(codec))); |
| EXPECT_METRIC_EQ(1, metrics::NumEvents(rmse_histogram_prefix + |
| CodecTypeToHistogramSuffix(codec), |
| rmse_in_kbps)); |
| // overshoot percent = 50, since we used ideal_frame_size * 3 / 2; |
| EXPECT_METRIC_EQ(1, metrics::NumSamples(overshoot_histogram_prefix + |
| CodecTypeToHistogramSuffix(codec))); |
| EXPECT_METRIC_EQ(1, metrics::NumEvents(overshoot_histogram_prefix + |
| CodecTypeToHistogramSuffix(codec), |
| 50)); |
| } |
| |
| INSTANTIATE_TEST_SUITE_P( |
| PerCodecType, |
| EncoderOvershootDetectorTest, |
| ValuesIn<TestParams>({{VideoCodecType::kVideoCodecVP8, false}, |
| {VideoCodecType::kVideoCodecVP8, true}, |
| {VideoCodecType::kVideoCodecVP9, false}, |
| {VideoCodecType::kVideoCodecVP9, true}, |
| {VideoCodecType::kVideoCodecAV1, false}, |
| {VideoCodecType::kVideoCodecAV1, true}, |
| {VideoCodecType::kVideoCodecH264, false}, |
| {VideoCodecType::kVideoCodecH264, true}, |
| {VideoCodecType::kVideoCodecH265, false}, |
| {VideoCodecType::kVideoCodecH265, true}})); |
| |
| } // namespace webrtc |