| /* |
| * Copyright (c) 2016 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #include "modules/video_coding/nack_module.h" |
| |
| #include <algorithm> |
| #include <cstdint> |
| #include <cstring> |
| #include <memory> |
| |
| #include "system_wrappers/include/clock.h" |
| #include "test/field_trial.h" |
| #include "test/gtest.h" |
| |
| namespace webrtc { |
| class TestNackModule : public ::testing::TestWithParam<bool>, |
| public NackSender, |
| public KeyFrameRequestSender { |
| protected: |
| TestNackModule() |
| : clock_(new SimulatedClock(0)), |
| field_trial_(GetParam() |
| ? "WebRTC-ExponentialNackBackoff/enabled:true/" |
| : "WebRTC-ExponentialNackBackoff/enabled:false/"), |
| nack_module_(clock_.get(), this, this), |
| keyframes_requested_(0) {} |
| |
| void SetUp() override { nack_module_.UpdateRtt(kDefaultRttMs); } |
| |
| void SendNack(const std::vector<uint16_t>& sequence_numbers, |
| bool buffering_allowed) override { |
| sent_nacks_.insert(sent_nacks_.end(), sequence_numbers.begin(), |
| sequence_numbers.end()); |
| } |
| |
| void RequestKeyFrame() override { ++keyframes_requested_; } |
| |
| static constexpr int64_t kDefaultRttMs = 20; |
| std::unique_ptr<SimulatedClock> clock_; |
| test::ScopedFieldTrials field_trial_; |
| NackModule nack_module_; |
| std::vector<uint16_t> sent_nacks_; |
| int keyframes_requested_; |
| }; |
| |
| TEST_P(TestNackModule, NackOnePacket) { |
| nack_module_.OnReceivedPacket(1, false, false); |
| nack_module_.OnReceivedPacket(3, false, false); |
| EXPECT_EQ(1u, sent_nacks_.size()); |
| EXPECT_EQ(2, sent_nacks_[0]); |
| } |
| |
| TEST_P(TestNackModule, WrappingSeqNum) { |
| nack_module_.OnReceivedPacket(0xfffe, false, false); |
| nack_module_.OnReceivedPacket(1, false, false); |
| EXPECT_EQ(2u, sent_nacks_.size()); |
| EXPECT_EQ(0xffff, sent_nacks_[0]); |
| EXPECT_EQ(0, sent_nacks_[1]); |
| } |
| |
| TEST_P(TestNackModule, WrappingSeqNumClearToKeyframe) { |
| nack_module_.OnReceivedPacket(0xfffe, false, false); |
| nack_module_.OnReceivedPacket(1, false, false); |
| EXPECT_EQ(2u, sent_nacks_.size()); |
| EXPECT_EQ(0xffff, sent_nacks_[0]); |
| EXPECT_EQ(0, sent_nacks_[1]); |
| |
| sent_nacks_.clear(); |
| nack_module_.OnReceivedPacket(2, true, false); |
| EXPECT_EQ(0u, sent_nacks_.size()); |
| |
| nack_module_.OnReceivedPacket(501, true, false); |
| EXPECT_EQ(498u, sent_nacks_.size()); |
| for (int seq_num = 3; seq_num < 501; ++seq_num) |
| EXPECT_EQ(seq_num, sent_nacks_[seq_num - 3]); |
| |
| sent_nacks_.clear(); |
| nack_module_.OnReceivedPacket(1001, false, false); |
| EXPECT_EQ(499u, sent_nacks_.size()); |
| for (int seq_num = 502; seq_num < 1001; ++seq_num) |
| EXPECT_EQ(seq_num, sent_nacks_[seq_num - 502]); |
| |
| sent_nacks_.clear(); |
| clock_->AdvanceTimeMilliseconds(100); |
| nack_module_.Process(); |
| EXPECT_EQ(999u, sent_nacks_.size()); |
| EXPECT_EQ(0xffff, sent_nacks_[0]); |
| EXPECT_EQ(0, sent_nacks_[1]); |
| for (int seq_num = 3; seq_num < 501; ++seq_num) |
| EXPECT_EQ(seq_num, sent_nacks_[seq_num - 1]); |
| for (int seq_num = 502; seq_num < 1001; ++seq_num) |
| EXPECT_EQ(seq_num, sent_nacks_[seq_num - 2]); |
| |
| // Adding packet 1004 will cause the nack list to reach it's max limit. |
| // It will then clear all nacks up to the next keyframe (seq num 2), |
| // thus removing 0xffff and 0 from the nack list. |
| sent_nacks_.clear(); |
| nack_module_.OnReceivedPacket(1004, false, false); |
| EXPECT_EQ(2u, sent_nacks_.size()); |
| EXPECT_EQ(1002, sent_nacks_[0]); |
| EXPECT_EQ(1003, sent_nacks_[1]); |
| |
| sent_nacks_.clear(); |
| clock_->AdvanceTimeMilliseconds(100); |
| nack_module_.Process(); |
| EXPECT_EQ(999u, sent_nacks_.size()); |
| for (int seq_num = 3; seq_num < 501; ++seq_num) |
| EXPECT_EQ(seq_num, sent_nacks_[seq_num - 3]); |
| for (int seq_num = 502; seq_num < 1001; ++seq_num) |
| EXPECT_EQ(seq_num, sent_nacks_[seq_num - 4]); |
| |
| // Adding packet 1007 will cause the nack module to overflow again, thus |
| // clearing everything up to 501 which is the next keyframe. |
| nack_module_.OnReceivedPacket(1007, false, false); |
| sent_nacks_.clear(); |
| clock_->AdvanceTimeMilliseconds(100); |
| nack_module_.Process(); |
| EXPECT_EQ(503u, sent_nacks_.size()); |
| for (int seq_num = 502; seq_num < 1001; ++seq_num) |
| EXPECT_EQ(seq_num, sent_nacks_[seq_num - 502]); |
| EXPECT_EQ(1005, sent_nacks_[501]); |
| EXPECT_EQ(1006, sent_nacks_[502]); |
| } |
| |
| TEST_P(TestNackModule, DontBurstOnTimeSkip) { |
| nack_module_.Process(); |
| clock_->AdvanceTimeMilliseconds(20); |
| EXPECT_EQ(0, nack_module_.TimeUntilNextProcess()); |
| nack_module_.Process(); |
| |
| clock_->AdvanceTimeMilliseconds(100); |
| EXPECT_EQ(0, nack_module_.TimeUntilNextProcess()); |
| nack_module_.Process(); |
| EXPECT_EQ(20, nack_module_.TimeUntilNextProcess()); |
| |
| clock_->AdvanceTimeMilliseconds(19); |
| EXPECT_EQ(1, nack_module_.TimeUntilNextProcess()); |
| clock_->AdvanceTimeMilliseconds(2); |
| nack_module_.Process(); |
| EXPECT_EQ(19, nack_module_.TimeUntilNextProcess()); |
| |
| clock_->AdvanceTimeMilliseconds(19); |
| EXPECT_EQ(0, nack_module_.TimeUntilNextProcess()); |
| nack_module_.Process(); |
| |
| clock_->AdvanceTimeMilliseconds(21); |
| EXPECT_EQ(0, nack_module_.TimeUntilNextProcess()); |
| nack_module_.Process(); |
| EXPECT_EQ(19, nack_module_.TimeUntilNextProcess()); |
| } |
| |
| TEST_P(TestNackModule, ResendNack) { |
| nack_module_.OnReceivedPacket(1, false, false); |
| nack_module_.OnReceivedPacket(3, false, false); |
| size_t expected_nacks_sent = 1; |
| EXPECT_EQ(expected_nacks_sent, sent_nacks_.size()); |
| EXPECT_EQ(2, sent_nacks_[0]); |
| |
| if (GetParam()) { |
| // Retry has to wait at least 5ms by default. |
| nack_module_.UpdateRtt(1); |
| clock_->AdvanceTimeMilliseconds(4); |
| nack_module_.Process(); // Too early. |
| EXPECT_EQ(expected_nacks_sent, sent_nacks_.size()); |
| |
| clock_->AdvanceTimeMilliseconds(1); |
| nack_module_.Process(); // Now allowed. |
| EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size()); |
| } else { |
| nack_module_.UpdateRtt(1); |
| clock_->AdvanceTimeMilliseconds(1); |
| nack_module_.Process(); // Fast retransmit allowed. |
| EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size()); |
| } |
| |
| // N:th try has to wait b^(N-1) * rtt by default. |
| const double b = GetParam() ? 1.25 : 1.0; |
| for (int i = 2; i < 10; ++i) { |
| // Change RTT, above the 40ms max for exponential backoff. |
| TimeDelta rtt = TimeDelta::Millis(160); // + (i * 10 - 40) |
| nack_module_.UpdateRtt(rtt.ms()); |
| |
| // RTT gets capped at 160ms in backoff calculations. |
| TimeDelta expected_backoff_delay = |
| std::pow(b, i - 1) * std::min(rtt, TimeDelta::Millis(160)); |
| |
| // Move to one millisecond before next allowed NACK. |
| clock_->AdvanceTimeMilliseconds(expected_backoff_delay.ms() - 1); |
| nack_module_.Process(); |
| EXPECT_EQ(expected_nacks_sent, sent_nacks_.size()); |
| |
| // Move to one millisecond after next allowed NACK. |
| // After rather than on to avoid rounding errors. |
| clock_->AdvanceTimeMilliseconds(2); |
| nack_module_.Process(); // Now allowed. |
| EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size()); |
| } |
| |
| // Giving up after 10 tries. |
| clock_->AdvanceTimeMilliseconds(3000); |
| nack_module_.Process(); |
| EXPECT_EQ(expected_nacks_sent, sent_nacks_.size()); |
| } |
| |
| TEST_P(TestNackModule, ResendPacketMaxRetries) { |
| nack_module_.OnReceivedPacket(1, false, false); |
| nack_module_.OnReceivedPacket(3, false, false); |
| EXPECT_EQ(1u, sent_nacks_.size()); |
| EXPECT_EQ(2, sent_nacks_[0]); |
| |
| int backoff_factor = 1; |
| for (size_t retries = 1; retries < 10; ++retries) { |
| // Exponential backoff, so that we don't reject NACK because of time. |
| clock_->AdvanceTimeMilliseconds(backoff_factor * kDefaultRttMs); |
| backoff_factor *= 2; |
| nack_module_.Process(); |
| EXPECT_EQ(retries + 1, sent_nacks_.size()); |
| } |
| |
| clock_->AdvanceTimeMilliseconds(backoff_factor * kDefaultRttMs); |
| nack_module_.Process(); |
| EXPECT_EQ(10u, sent_nacks_.size()); |
| } |
| |
| TEST_P(TestNackModule, TooLargeNackList) { |
| nack_module_.OnReceivedPacket(0, false, false); |
| nack_module_.OnReceivedPacket(1001, false, false); |
| EXPECT_EQ(1000u, sent_nacks_.size()); |
| EXPECT_EQ(0, keyframes_requested_); |
| nack_module_.OnReceivedPacket(1003, false, false); |
| EXPECT_EQ(1000u, sent_nacks_.size()); |
| EXPECT_EQ(1, keyframes_requested_); |
| nack_module_.OnReceivedPacket(1004, false, false); |
| EXPECT_EQ(1000u, sent_nacks_.size()); |
| EXPECT_EQ(1, keyframes_requested_); |
| } |
| |
| TEST_P(TestNackModule, TooLargeNackListWithKeyFrame) { |
| nack_module_.OnReceivedPacket(0, false, false); |
| nack_module_.OnReceivedPacket(1, true, false); |
| nack_module_.OnReceivedPacket(1001, false, false); |
| EXPECT_EQ(999u, sent_nacks_.size()); |
| EXPECT_EQ(0, keyframes_requested_); |
| nack_module_.OnReceivedPacket(1003, false, false); |
| EXPECT_EQ(1000u, sent_nacks_.size()); |
| EXPECT_EQ(0, keyframes_requested_); |
| nack_module_.OnReceivedPacket(1005, false, false); |
| EXPECT_EQ(1000u, sent_nacks_.size()); |
| EXPECT_EQ(1, keyframes_requested_); |
| } |
| |
| TEST_P(TestNackModule, ClearUpTo) { |
| nack_module_.OnReceivedPacket(0, false, false); |
| nack_module_.OnReceivedPacket(100, false, false); |
| EXPECT_EQ(99u, sent_nacks_.size()); |
| |
| sent_nacks_.clear(); |
| clock_->AdvanceTimeMilliseconds(100); |
| nack_module_.ClearUpTo(50); |
| nack_module_.Process(); |
| EXPECT_EQ(50u, sent_nacks_.size()); |
| EXPECT_EQ(50, sent_nacks_[0]); |
| } |
| |
| TEST_P(TestNackModule, ClearUpToWrap) { |
| nack_module_.OnReceivedPacket(0xfff0, false, false); |
| nack_module_.OnReceivedPacket(0xf, false, false); |
| EXPECT_EQ(30u, sent_nacks_.size()); |
| |
| sent_nacks_.clear(); |
| clock_->AdvanceTimeMilliseconds(100); |
| nack_module_.ClearUpTo(0); |
| nack_module_.Process(); |
| EXPECT_EQ(15u, sent_nacks_.size()); |
| EXPECT_EQ(0, sent_nacks_[0]); |
| } |
| |
| TEST_P(TestNackModule, PacketNackCount) { |
| EXPECT_EQ(0, nack_module_.OnReceivedPacket(0, false, false)); |
| EXPECT_EQ(0, nack_module_.OnReceivedPacket(2, false, false)); |
| EXPECT_EQ(1, nack_module_.OnReceivedPacket(1, false, false)); |
| |
| sent_nacks_.clear(); |
| nack_module_.UpdateRtt(100); |
| EXPECT_EQ(0, nack_module_.OnReceivedPacket(5, false, false)); |
| clock_->AdvanceTimeMilliseconds(100); |
| nack_module_.Process(); |
| clock_->AdvanceTimeMilliseconds(125); |
| nack_module_.Process(); |
| EXPECT_EQ(3, nack_module_.OnReceivedPacket(3, false, false)); |
| EXPECT_EQ(3, nack_module_.OnReceivedPacket(4, false, false)); |
| EXPECT_EQ(0, nack_module_.OnReceivedPacket(4, false, false)); |
| } |
| |
| TEST_P(TestNackModule, NackListFullAndNoOverlapWithKeyframes) { |
| const int kMaxNackPackets = 1000; |
| const unsigned int kFirstGap = kMaxNackPackets - 20; |
| const unsigned int kSecondGap = 200; |
| uint16_t seq_num = 0; |
| nack_module_.OnReceivedPacket(seq_num++, true, false); |
| seq_num += kFirstGap; |
| nack_module_.OnReceivedPacket(seq_num++, true, false); |
| EXPECT_EQ(kFirstGap, sent_nacks_.size()); |
| sent_nacks_.clear(); |
| seq_num += kSecondGap; |
| nack_module_.OnReceivedPacket(seq_num, true, false); |
| EXPECT_EQ(kSecondGap, sent_nacks_.size()); |
| } |
| |
| TEST_P(TestNackModule, HandleFecRecoveredPacket) { |
| nack_module_.OnReceivedPacket(1, false, false); |
| nack_module_.OnReceivedPacket(4, false, true); |
| EXPECT_EQ(0u, sent_nacks_.size()); |
| nack_module_.OnReceivedPacket(5, false, false); |
| EXPECT_EQ(2u, sent_nacks_.size()); |
| } |
| |
| TEST_P(TestNackModule, SendNackWithoutDelay) { |
| nack_module_.OnReceivedPacket(0, false, false); |
| nack_module_.OnReceivedPacket(100, false, false); |
| EXPECT_EQ(99u, sent_nacks_.size()); |
| } |
| |
| INSTANTIATE_TEST_SUITE_P(WithAndWithoutBackoff, |
| TestNackModule, |
| ::testing::Values(true, false)); |
| |
| class TestNackModuleWithFieldTrial : public ::testing::Test, |
| public NackSender, |
| public KeyFrameRequestSender { |
| protected: |
| TestNackModuleWithFieldTrial() |
| : nack_delay_field_trial_("WebRTC-SendNackDelayMs/10/"), |
| clock_(new SimulatedClock(0)), |
| nack_module_(clock_.get(), this, this), |
| keyframes_requested_(0) {} |
| |
| void SendNack(const std::vector<uint16_t>& sequence_numbers, |
| bool buffering_allowed) override { |
| sent_nacks_.insert(sent_nacks_.end(), sequence_numbers.begin(), |
| sequence_numbers.end()); |
| } |
| |
| void RequestKeyFrame() override { ++keyframes_requested_; } |
| |
| test::ScopedFieldTrials nack_delay_field_trial_; |
| std::unique_ptr<SimulatedClock> clock_; |
| NackModule nack_module_; |
| std::vector<uint16_t> sent_nacks_; |
| int keyframes_requested_; |
| }; |
| |
| TEST_F(TestNackModuleWithFieldTrial, SendNackWithDelay) { |
| nack_module_.OnReceivedPacket(0, false, false); |
| nack_module_.OnReceivedPacket(100, false, false); |
| EXPECT_EQ(0u, sent_nacks_.size()); |
| clock_->AdvanceTimeMilliseconds(10); |
| nack_module_.OnReceivedPacket(106, false, false); |
| EXPECT_EQ(99u, sent_nacks_.size()); |
| clock_->AdvanceTimeMilliseconds(10); |
| nack_module_.OnReceivedPacket(109, false, false); |
| EXPECT_EQ(104u, sent_nacks_.size()); |
| } |
| } // namespace webrtc |