blob: ab1c76f1b5c66293725866a6a90d63a33782fb5b [file] [log] [blame]
/*
* 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