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b1e031a156
The frame time deltas are now capped based on the current noise. This has been tested in various conditions using both screen content and typical mobile video settings, to produce delays that are not overly high screen content, and simultaneously not negatively affect mobile calls on really bad network that may have high natural jitter. Bug: webrtc:9898 Change-Id: I51ad279af156aba1b5cc75ae203334a34bce9d48 Reviewed-on: https://webrtc-review.googlesource.com/c/107349 Reviewed-by: Stefan Holmer <stefan@webrtc.org> Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Commit-Queue: Erik Språng <sprang@webrtc.org> Cr-Commit-Position: refs/heads/master@{#25469}
111 lines
3.6 KiB
C++
111 lines
3.6 KiB
C++
/* Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "modules/video_coding/jitter_estimator.h"
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#include "rtc_base/experiments/jitter_upper_bound_experiment.h"
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#include "rtc_base/logging.h"
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#include "rtc_base/numerics/histogram_percentile_counter.h"
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#include "rtc_base/timeutils.h"
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#include "system_wrappers/include/clock.h"
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#include "test/field_trial.h"
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#include "test/gtest.h"
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namespace webrtc {
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class TestVCMJitterEstimator : public ::testing::Test {
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protected:
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TestVCMJitterEstimator() : fake_clock_(0) {}
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virtual void SetUp() {
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estimator_ = absl::make_unique<VCMJitterEstimator>(&fake_clock_, 0, 0);
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}
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void AdvanceClock(int64_t microseconds) {
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fake_clock_.AdvanceTimeMicroseconds(microseconds);
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}
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SimulatedClock fake_clock_;
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std::unique_ptr<VCMJitterEstimator> estimator_;
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};
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// Generates some simple test data in the form of a sawtooth wave.
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class ValueGenerator {
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public:
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explicit ValueGenerator(int32_t amplitude)
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: amplitude_(amplitude), counter_(0) {}
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virtual ~ValueGenerator() {}
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int64_t Delay() { return ((counter_ % 11) - 5) * amplitude_; }
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uint32_t FrameSize() { return 1000 + Delay(); }
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void Advance() { ++counter_; }
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private:
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const int32_t amplitude_;
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int64_t counter_;
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};
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// 5 fps, disable jitter delay altogether.
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TEST_F(TestVCMJitterEstimator, TestLowRate) {
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ValueGenerator gen(10);
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uint64_t time_delta_us = rtc::kNumMicrosecsPerSec / 5;
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for (int i = 0; i < 60; ++i) {
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estimator_->UpdateEstimate(gen.Delay(), gen.FrameSize());
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AdvanceClock(time_delta_us);
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if (i > 2)
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EXPECT_EQ(estimator_->GetJitterEstimate(0), 0);
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gen.Advance();
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}
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}
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TEST_F(TestVCMJitterEstimator, TestUpperBound) {
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struct TestContext {
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TestContext() : upper_bound(0.0), percentiles(1000) {}
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double upper_bound;
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rtc::HistogramPercentileCounter percentiles;
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};
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std::vector<TestContext> test_cases(2);
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test_cases[0].upper_bound = 100.0; // First use essentially no cap.
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test_cases[1].upper_bound = 3.5; // Second, reasonably small cap.
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for (TestContext& context : test_cases) {
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// Set up field trial and reset jitter estimator.
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char string_buf[64];
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rtc::SimpleStringBuilder ssb(string_buf);
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ssb << JitterUpperBoundExperiment::kJitterUpperBoundExperimentName
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<< "/Enabled-" << context.upper_bound << "/";
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test::ScopedFieldTrials field_trials(ssb.str());
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SetUp();
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ValueGenerator gen(50);
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uint64_t time_delta_us = rtc::kNumMicrosecsPerSec / 30;
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for (int i = 0; i < 100; ++i) {
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estimator_->UpdateEstimate(gen.Delay(), gen.FrameSize());
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AdvanceClock(time_delta_us);
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context.percentiles.Add(
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static_cast<uint32_t>(estimator_->GetJitterEstimate(0)));
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gen.Advance();
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}
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}
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// Median should be similar after three seconds. Allow 5% error margin.
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uint32_t median_unbound = *test_cases[0].percentiles.GetPercentile(0.5);
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uint32_t median_bounded = *test_cases[1].percentiles.GetPercentile(0.5);
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EXPECT_NEAR(median_unbound, median_bounded, (median_unbound * 5) / 100);
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// Max should be lower for the bounded case.
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uint32_t max_unbound = *test_cases[0].percentiles.GetPercentile(1.0);
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uint32_t max_bounded = *test_cases[1].percentiles.GetPercentile(1.0);
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EXPECT_GT(max_unbound, static_cast<uint32_t>(max_bounded * 1.25));
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}
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} // namespace webrtc
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