/*
* 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 "modules/pacing/pacing_controller.h"
#include <algorithm>
#include <list>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "api/units/data_rate.h"
#include "modules/pacing/packet_router.h"
#include "system_wrappers/include/clock.h"
#include "test/explicit_key_value_config.h"
#include "test/field_trial.h"
#include "test/gmock.h"
#include "test/gtest.h"
using ::testing::_;
using ::testing::Field;
using ::testing::Pointee;
using ::testing::Property;
using ::testing::Return;
namespace webrtc {
namespace test {
namespace {
constexpr DataRate kFirstClusterRate = DataRate::KilobitsPerSec(900);
constexpr DataRate kSecondClusterRate = DataRate::KilobitsPerSec(1800);
// The error stems from truncating the time interval of probe packets to integer
// values. This results in probing slightly higher than the target bitrate.
// For 1.8 Mbps, this comes to be about 120 kbps with 1200 probe packets.
constexpr DataRate kProbingErrorMargin = DataRate::KilobitsPerSec(150);
const float kPaceMultiplier = 2.5f;
constexpr uint32_t kAudioSsrc = 12345;
constexpr uint32_t kVideoSsrc = 234565;
constexpr uint32_t kVideoRtxSsrc = 34567;
constexpr uint32_t kFlexFecSsrc = 45678;
constexpr DataRate kTargetRate = DataRate::KilobitsPerSec(800);
std::unique_ptr<RtpPacketToSend> BuildPacket(RtpPacketMediaType type,
uint32_t ssrc,
uint16_t sequence_number,
int64_t capture_time_ms,
size_t size) {
auto packet = std::make_unique<RtpPacketToSend>(nullptr);
packet->set_packet_type(type);
packet->SetSsrc(ssrc);
packet->SetSequenceNumber(sequence_number);
packet->set_capture_time_ms(capture_time_ms);
packet->SetPayloadSize(size);
return packet;
}
} // namespace
// Mock callback proxy, where both new and old api redirects to common mock
// methods that focus on core aspects.
class MockPacingControllerCallback : public PacingController::PacketSender {
public:
void SendPacket(std::unique_ptr<RtpPacketToSend> packet,
const PacedPacketInfo& cluster_info) override {
SendPacket(packet->Ssrc(), packet->SequenceNumber(),
packet->capture_time_ms(),
packet->packet_type() == RtpPacketMediaType::kRetransmission,
packet->packet_type() == RtpPacketMediaType::kPadding);
}
std::vector<std::unique_ptr<RtpPacketToSend>> GeneratePadding(
DataSize target_size) override {
std::vector<std::unique_ptr<RtpPacketToSend>> ret;
size_t padding_size = SendPadding(target_size.bytes());
if (padding_size > 0) {
auto packet = std::make_unique<RtpPacketToSend>(nullptr);
packet->SetPayloadSize(padding_size);
packet->set_packet_type(RtpPacketMediaType::kPadding);
ret.emplace_back(std::move(packet));
}
return ret;
}
MOCK_METHOD(void,
SendPacket,
(uint32_t ssrc,
uint16_t sequence_number,
int64_t capture_timestamp,
bool retransmission,
bool padding));
MOCK_METHOD(std::vector<std::unique_ptr<RtpPacketToSend>>,
FetchFec,
(),
(override));
MOCK_METHOD(size_t, SendPadding, (size_t target_size));
};
// Mock callback implementing the raw api.
class MockPacketSender : public PacingController::PacketSender {
public:
MOCK_METHOD(void,
SendPacket,
(std::unique_ptr<RtpPacketToSend> packet,
const PacedPacketInfo& cluster_info),
(override));
MOCK_METHOD(std::vector<std::unique_ptr<RtpPacketToSend>>,
FetchFec,
(),
(override));
MOCK_METHOD(std::vector<std::unique_ptr<RtpPacketToSend>>,
GeneratePadding,
(DataSize target_size),
(override));
};
class PacingControllerPadding : public PacingController::PacketSender {
public:
static const size_t kPaddingPacketSize = 224;
PacingControllerPadding() : padding_sent_(0), total_bytes_sent_(0) {}
void SendPacket(std::unique_ptr<RtpPacketToSend> packet,
const PacedPacketInfo& pacing_info) override {
total_bytes_sent_ += packet->payload_size();
}
std::vector<std::unique_ptr<RtpPacketToSend>> FetchFec() override {
return {};
}
std::vector<std::unique_ptr<RtpPacketToSend>> GeneratePadding(
DataSize target_size) override {
size_t num_packets =
(target_size.bytes() + kPaddingPacketSize - 1) / kPaddingPacketSize;
std::vector<std::unique_ptr<RtpPacketToSend>> packets;
for (size_t i = 0; i < num_packets; ++i) {
packets.emplace_back(std::make_unique<RtpPacketToSend>(nullptr));
packets.back()->SetPadding(kPaddingPacketSize);
packets.back()->set_packet_type(RtpPacketMediaType::kPadding);
padding_sent_ += kPaddingPacketSize;
}
return packets;
}
size_t padding_sent() { return padding_sent_; }
size_t total_bytes_sent() { return total_bytes_sent_; }
private:
size_t padding_sent_;
size_t total_bytes_sent_;
};
class PacingControllerProbing : public PacingController::PacketSender {
public:
PacingControllerProbing() : packets_sent_(0), padding_sent_(0) {}
void SendPacket(std::unique_ptr<RtpPacketToSend> packet,
const PacedPacketInfo& pacing_info) override {
if (packet->packet_type() != RtpPacketMediaType::kPadding) {
++packets_sent_;
}
last_pacing_info_ = pacing_info;
}
std::vector<std::unique_ptr<RtpPacketToSend>> FetchFec() override {
return {};
}
std::vector<std::unique_ptr<RtpPacketToSend>> GeneratePadding(
DataSize target_size) override {
// From RTPSender:
// Max in the RFC 3550 is 255 bytes, we limit it to be modulus 32 for SRTP.
const DataSize kMaxPadding = DataSize::Bytes(224);
std::vector<std::unique_ptr<RtpPacketToSend>> packets;
while (target_size > DataSize::Zero()) {
DataSize padding_size = std::min(kMaxPadding, target_size);
packets.emplace_back(std::make_unique<RtpPacketToSend>(nullptr));
packets.back()->SetPadding(padding_size.bytes());
packets.back()->set_packet_type(RtpPacketMediaType::kPadding);
padding_sent_ += padding_size.bytes();
target_size -= padding_size;
}
return packets;
}
int packets_sent() const { return packets_sent_; }
int padding_sent() const { return padding_sent_; }
int total_packets_sent() const { return packets_sent_ + padding_sent_; }
PacedPacketInfo last_pacing_info() const { return last_pacing_info_; }
private:
int packets_sent_;
int padding_sent_;
PacedPacketInfo last_pacing_info_;
};
class PacingControllerTest
: public ::testing::TestWithParam<PacingController::ProcessMode> {
protected:
PacingControllerTest() : clock_(123456) {}
void SetUp() override {
srand(0);
// Need to initialize PacingController after we initialize clock.
pacer_ = std::make_unique<PacingController>(&clock_, &callback_, nullptr,
nullptr, GetParam());
Init();
}
bool PeriodicProcess() const {
return GetParam() == PacingController::ProcessMode::kPeriodic;
}
void Init() {
pacer_->CreateProbeCluster(kFirstClusterRate, /*cluster_id=*/0);
pacer_->CreateProbeCluster(kSecondClusterRate, /*cluster_id=*/1);
// Default to bitrate probing disabled for testing purposes. Probing tests
// have to enable probing, either by creating a new PacingController
// instance or by calling SetProbingEnabled(true).
pacer_->SetProbingEnabled(false);
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, DataRate::Zero());
clock_.AdvanceTime(TimeUntilNextProcess());
}
void Send(RtpPacketMediaType type,
uint32_t ssrc,
uint16_t sequence_number,
int64_t capture_time_ms,
size_t size) {
pacer_->EnqueuePacket(
BuildPacket(type, ssrc, sequence_number, capture_time_ms, size));
}
void SendAndExpectPacket(RtpPacketMediaType type,
uint32_t ssrc,
uint16_t sequence_number,
int64_t capture_time_ms,
size_t size) {
Send(type, ssrc, sequence_number, capture_time_ms, size);
EXPECT_CALL(callback_,
SendPacket(ssrc, sequence_number, capture_time_ms,
type == RtpPacketMediaType::kRetransmission, false))
.Times(1);
}
std::unique_ptr<RtpPacketToSend> BuildRtpPacket(RtpPacketMediaType type) {
auto packet = std::make_unique<RtpPacketToSend>(nullptr);
packet->set_packet_type(type);
switch (type) {
case RtpPacketMediaType::kAudio:
packet->SetSsrc(kAudioSsrc);
break;
case RtpPacketMediaType::kVideo:
packet->SetSsrc(kVideoSsrc);
break;
case RtpPacketMediaType::kRetransmission:
case RtpPacketMediaType::kPadding:
packet->SetSsrc(kVideoRtxSsrc);
break;
case RtpPacketMediaType::kForwardErrorCorrection:
packet->SetSsrc(kFlexFecSsrc);
break;
}
packet->SetPayloadSize(234);
return packet;
}
TimeDelta TimeUntilNextProcess() {
Timestamp now = clock_.CurrentTime();
return std::max(pacer_->NextSendTime() - now, TimeDelta::Zero());
}
void AdvanceTimeAndProcess() {
Timestamp now = clock_.CurrentTime();
Timestamp next_send_time = pacer_->NextSendTime();
clock_.AdvanceTime(std::max(TimeDelta::Zero(), next_send_time - now));
pacer_->ProcessPackets();
}
void ConsumeInitialBudget() {
const uint32_t kSsrc = 54321;
uint16_t sequence_number = 1234;
int64_t capture_time_ms = clock_.TimeInMilliseconds();
const size_t kPacketSize = 250;
EXPECT_EQ(TimeDelta::Zero(), pacer_->OldestPacketWaitTime());
// Due to the multiplicative factor we can send 5 packets during a send
// interval. (network capacity * multiplier / (8 bits per byte *
// (packet size * #send intervals per second)
const size_t packets_to_send_per_interval =
kTargetRate.bps() * kPaceMultiplier / (8 * kPacketSize * 200);
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, kSsrc, sequence_number++,
capture_time_ms, kPacketSize);
}
while (pacer_->QueueSizePackets() > 0) {
if (PeriodicProcess()) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
AdvanceTimeAndProcess();
}
}
}
SimulatedClock clock_;
::testing::NiceMock<MockPacingControllerCallback> callback_;
std::unique_ptr<PacingController> pacer_;
};
class PacingControllerFieldTrialTest
: public ::testing::TestWithParam<PacingController::ProcessMode> {
protected:
struct MediaStream {
const RtpPacketMediaType type;
const uint32_t ssrc;
const size_t packet_size;
uint16_t seq_num;
};
const int kProcessIntervalsPerSecond = 1000 / 5;
PacingControllerFieldTrialTest() : clock_(123456) {}
void InsertPacket(PacingController* pacer, MediaStream* stream) {
pacer->EnqueuePacket(
BuildPacket(stream->type, stream->ssrc, stream->seq_num++,
clock_.TimeInMilliseconds(), stream->packet_size));
}
void ProcessNext(PacingController* pacer) {
if (GetParam() == PacingController::ProcessMode::kPeriodic) {
TimeDelta process_interval = TimeDelta::Millis(5);
clock_.AdvanceTime(process_interval);
pacer->ProcessPackets();
return;
}
Timestamp now = clock_.CurrentTime();
Timestamp next_send_time = pacer->NextSendTime();
TimeDelta wait_time = std::max(TimeDelta::Zero(), next_send_time - now);
clock_.AdvanceTime(wait_time);
pacer->ProcessPackets();
}
MediaStream audio{/*type*/ RtpPacketMediaType::kAudio,
/*ssrc*/ 3333, /*packet_size*/ 100, /*seq_num*/ 1000};
MediaStream video{/*type*/ RtpPacketMediaType::kVideo,
/*ssrc*/ 4444, /*packet_size*/ 1000, /*seq_num*/ 1000};
SimulatedClock clock_;
MockPacingControllerCallback callback_;
};
TEST_P(PacingControllerFieldTrialTest, DefaultNoPaddingInSilence) {
PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
pacer.SetPacingRates(kTargetRate, DataRate::Zero());
// Video packet to reset last send time and provide padding data.
InsertPacket(&pacer, &video);
EXPECT_CALL(callback_, SendPacket).Times(1);
clock_.AdvanceTimeMilliseconds(5);
pacer.ProcessPackets();
EXPECT_CALL(callback_, SendPadding).Times(0);
// Waiting 500 ms should not trigger sending of padding.
clock_.AdvanceTimeMilliseconds(500);
pacer.ProcessPackets();
}
TEST_P(PacingControllerFieldTrialTest, PaddingInSilenceWithTrial) {
ScopedFieldTrials trial("WebRTC-Pacer-PadInSilence/Enabled/");
PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
pacer.SetPacingRates(kTargetRate, DataRate::Zero());
// Video packet to reset last send time and provide padding data.
InsertPacket(&pacer, &video);
EXPECT_CALL(callback_, SendPacket).Times(2);
clock_.AdvanceTimeMilliseconds(5);
pacer.ProcessPackets();
EXPECT_CALL(callback_, SendPadding).WillOnce(Return(1000));
// Waiting 500 ms should trigger sending of padding.
clock_.AdvanceTimeMilliseconds(500);
pacer.ProcessPackets();
}
TEST_P(PacingControllerFieldTrialTest, CongestionWindowAffectsAudioInTrial) {
ScopedFieldTrials trial("WebRTC-Pacer-BlockAudio/Enabled/");
EXPECT_CALL(callback_, SendPadding).Times(0);
PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
pacer.SetPacingRates(DataRate::KilobitsPerSec(10000), DataRate::Zero());
pacer.SetCongestionWindow(DataSize::Bytes(video.packet_size - 100));
pacer.UpdateOutstandingData(DataSize::Zero());
// Video packet fills congestion window.
InsertPacket(&pacer, &video);
EXPECT_CALL(callback_, SendPacket).Times(1);
ProcessNext(&pacer);
// Audio packet blocked due to congestion.
InsertPacket(&pacer, &audio);
EXPECT_CALL(callback_, SendPacket).Times(0);
if (GetParam() == PacingController::ProcessMode::kDynamic) {
// Without interval budget we'll forward time to where we send keep-alive.
EXPECT_CALL(callback_, SendPadding(1)).Times(2);
}
ProcessNext(&pacer);
ProcessNext(&pacer);
// Audio packet unblocked when congestion window clear.
::testing::Mock::VerifyAndClearExpectations(&callback_);
pacer.UpdateOutstandingData(DataSize::Zero());
EXPECT_CALL(callback_, SendPacket).Times(1);
ProcessNext(&pacer);
}
TEST_P(PacingControllerFieldTrialTest,
DefaultCongestionWindowDoesNotAffectAudio) {
EXPECT_CALL(callback_, SendPadding).Times(0);
PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
pacer.SetPacingRates(DataRate::BitsPerSec(10000000), DataRate::Zero());
pacer.SetCongestionWindow(DataSize::Bytes(800));
pacer.UpdateOutstandingData(DataSize::Zero());
// Video packet fills congestion window.
InsertPacket(&pacer, &video);
EXPECT_CALL(callback_, SendPacket).Times(1);
ProcessNext(&pacer);
// Audio not blocked due to congestion.
InsertPacket(&pacer, &audio);
EXPECT_CALL(callback_, SendPacket).Times(1);
ProcessNext(&pacer);
}
TEST_P(PacingControllerFieldTrialTest, BudgetAffectsAudioInTrial) {
ScopedFieldTrials trial("WebRTC-Pacer-BlockAudio/Enabled/");
PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
DataRate pacing_rate = DataRate::BitsPerSec(video.packet_size / 3 * 8 *
kProcessIntervalsPerSecond);
pacer.SetPacingRates(pacing_rate, DataRate::Zero());
// Video fills budget for following process periods.
InsertPacket(&pacer, &video);
EXPECT_CALL(callback_, SendPacket).Times(1);
ProcessNext(&pacer);
// Audio packet blocked due to budget limit.
InsertPacket(&pacer, &audio);
Timestamp wait_start_time = clock_.CurrentTime();
Timestamp wait_end_time = Timestamp::MinusInfinity();
EXPECT_CALL(callback_, SendPacket)
.WillOnce([&](uint32_t ssrc, uint16_t sequence_number,
int64_t capture_timestamp, bool retransmission,
bool padding) { wait_end_time = clock_.CurrentTime(); });
while (!wait_end_time.IsFinite()) {
ProcessNext(&pacer);
}
const TimeDelta expected_wait_time =
DataSize::Bytes(video.packet_size) / pacing_rate;
// Verify delay is near expectation, within timing margin.
EXPECT_LT(((wait_end_time - wait_start_time) - expected_wait_time).Abs(),
GetParam() == PacingController::ProcessMode::kPeriodic
? TimeDelta::Millis(5)
: PacingController::kMinSleepTime);
}
TEST_P(PacingControllerFieldTrialTest, DefaultBudgetDoesNotAffectAudio) {
EXPECT_CALL(callback_, SendPadding).Times(0);
PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
pacer.SetPacingRates(DataRate::BitsPerSec(video.packet_size / 3 * 8 *
kProcessIntervalsPerSecond),
DataRate::Zero());
// Video fills budget for following process periods.
InsertPacket(&pacer, &video);
EXPECT_CALL(callback_, SendPacket).Times(1);
ProcessNext(&pacer);
// Audio packet not blocked due to budget limit.
EXPECT_CALL(callback_, SendPacket).Times(1);
InsertPacket(&pacer, &audio);
ProcessNext(&pacer);
}
INSTANTIATE_TEST_SUITE_P(WithAndWithoutIntervalBudget,
PacingControllerFieldTrialTest,
::testing::Values(false, true));
TEST_P(PacingControllerTest, FirstSentPacketTimeIsSet) {
uint16_t sequence_number = 1234;
const uint32_t kSsrc = 12345;
const size_t kSizeBytes = 250;
const size_t kPacketToSend = 3;
const Timestamp kStartTime = clock_.CurrentTime();
// No packet sent.
EXPECT_FALSE(pacer_->FirstSentPacketTime().has_value());
for (size_t i = 0; i < kPacketToSend; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, kSsrc, sequence_number++,
clock_.TimeInMilliseconds(), kSizeBytes);
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
}
EXPECT_EQ(kStartTime, pacer_->FirstSentPacketTime());
}
TEST_P(PacingControllerTest, QueuePacket) {
if (!PeriodicProcess()) {
// This test checks behavior applicable only when using interval budget.
return;
}
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
// Due to the multiplicative factor we can send 5 packets during a 5ms send
// interval. (network capacity * multiplier / (8 bits per byte *
// (packet size * #send intervals per second)
const size_t kPacketsToSend =
kTargetRate.bps() * kPaceMultiplier / (8 * 250 * 200);
for (size_t i = 0; i < kPacketsToSend; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), 250);
}
EXPECT_CALL(callback_, SendPadding).Times(0);
// Enqueue one extra packet.
int64_t queued_packet_timestamp = clock_.TimeInMilliseconds();
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number,
queued_packet_timestamp, 250);
EXPECT_EQ(kPacketsToSend + 1, pacer_->QueueSizePackets());
// The first kPacketsToSend packets will be sent with budget from the
// initial 5ms interval.
pacer_->ProcessPackets();
EXPECT_EQ(1u, pacer_->QueueSizePackets());
// Advance time to next interval, make sure the last packet is sent.
clock_.AdvanceTimeMilliseconds(5);
EXPECT_CALL(callback_, SendPacket(ssrc, sequence_number++,
queued_packet_timestamp, false, false))
.Times(1);
pacer_->ProcessPackets();
sequence_number++;
EXPECT_EQ(0u, pacer_->QueueSizePackets());
// We can send packets_to_send -1 packets of size 250 during the current
// interval since one packet has already been sent.
for (size_t i = 0; i < kPacketsToSend - 1; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), 250);
}
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), 250);
EXPECT_EQ(kPacketsToSend, pacer_->QueueSizePackets());
pacer_->ProcessPackets();
EXPECT_EQ(1u, pacer_->QueueSizePackets());
}
TEST_P(PacingControllerTest, QueueAndPacePackets) {
if (PeriodicProcess()) {
// This test checks behavior when not using interval budget.
return;
}
const uint32_t kSsrc = 12345;
uint16_t sequence_number = 1234;
const DataSize kPackeSize = DataSize::Bytes(250);
const TimeDelta kSendInterval = TimeDelta::Millis(5);
// Due to the multiplicative factor we can send 5 packets during a 5ms send
// interval. (send interval * network capacity * multiplier / packet size)
const size_t kPacketsToSend = (kSendInterval * kTargetRate).bytes() *
kPaceMultiplier / kPackeSize.bytes();
for (size_t i = 0; i < kPacketsToSend; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, kSsrc, sequence_number++,
clock_.TimeInMilliseconds(), kPackeSize.bytes());
}
EXPECT_CALL(callback_, SendPadding).Times(0);
// Enqueue one extra packet.
int64_t queued_packet_timestamp = clock_.TimeInMilliseconds();
Send(RtpPacketMediaType::kVideo, kSsrc, sequence_number,
queued_packet_timestamp, kPackeSize.bytes());
EXPECT_EQ(kPacketsToSend + 1, pacer_->QueueSizePackets());
// Send packets until the initial kPacketsToSend packets are done.
Timestamp start_time = clock_.CurrentTime();
while (pacer_->QueueSizePackets() > 1) {
AdvanceTimeAndProcess();
}
EXPECT_LT(clock_.CurrentTime() - start_time, kSendInterval);
// Proceed till last packet can be sent.
EXPECT_CALL(callback_, SendPacket(kSsrc, sequence_number,
queued_packet_timestamp, false, false))
.Times(1);
AdvanceTimeAndProcess();
EXPECT_GE(clock_.CurrentTime() - start_time, kSendInterval);
EXPECT_EQ(pacer_->QueueSizePackets(), 0u);
}
TEST_P(PacingControllerTest, PaceQueuedPackets) {
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
const size_t kPacketSize = 250;
// Due to the multiplicative factor we can send 5 packets during a send
// interval. (network capacity * multiplier / (8 bits per byte *
// (packet size * #send intervals per second)
const size_t packets_to_send_per_interval =
kTargetRate.bps() * kPaceMultiplier / (8 * kPacketSize * 200);
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
for (size_t j = 0; j < packets_to_send_per_interval * 10; ++j) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
EXPECT_EQ(packets_to_send_per_interval + packets_to_send_per_interval * 10,
pacer_->QueueSizePackets());
if (PeriodicProcess()) {
pacer_->ProcessPackets();
} else {
while (pacer_->QueueSizePackets() > packets_to_send_per_interval * 10) {
AdvanceTimeAndProcess();
}
}
EXPECT_EQ(pacer_->QueueSizePackets(), packets_to_send_per_interval * 10);
EXPECT_CALL(callback_, SendPadding).Times(0);
EXPECT_CALL(callback_, SendPacket(ssrc, _, _, false, false))
.Times(pacer_->QueueSizePackets());
const TimeDelta expected_pace_time =
DataSize::Bytes(pacer_->QueueSizePackets() * kPacketSize) /
(kPaceMultiplier * kTargetRate);
Timestamp start_time = clock_.CurrentTime();
while (pacer_->QueueSizePackets() > 0) {
if (PeriodicProcess()) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
AdvanceTimeAndProcess();
}
}
const TimeDelta actual_pace_time = clock_.CurrentTime() - start_time;
EXPECT_LT((actual_pace_time - expected_pace_time).Abs(),
PeriodicProcess() ? TimeDelta::Millis(5)
: PacingController::kMinSleepTime);
EXPECT_EQ(0u, pacer_->QueueSizePackets());
clock_.AdvanceTime(TimeUntilNextProcess());
EXPECT_EQ(0u, pacer_->QueueSizePackets());
pacer_->ProcessPackets();
// Send some more packet, just show that we can..?
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), 250);
}
EXPECT_EQ(packets_to_send_per_interval, pacer_->QueueSizePackets());
if (PeriodicProcess()) {
pacer_->ProcessPackets();
} else {
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
AdvanceTimeAndProcess();
}
}
EXPECT_EQ(0u, pacer_->QueueSizePackets());
}
TEST_P(PacingControllerTest, RepeatedRetransmissionsAllowed) {
// Send one packet, then two retransmissions of that packet.
for (size_t i = 0; i < 3; i++) {
constexpr uint32_t ssrc = 333;
constexpr uint16_t sequence_number = 444;
constexpr size_t bytes = 250;
bool is_retransmission = (i != 0); // Original followed by retransmissions.
SendAndExpectPacket(is_retransmission ? RtpPacketMediaType::kRetransmission
: RtpPacketMediaType::kVideo,
ssrc, sequence_number, clock_.TimeInMilliseconds(),
bytes);
clock_.AdvanceTimeMilliseconds(5);
}
if (PeriodicProcess()) {
pacer_->ProcessPackets();
} else {
while (pacer_->QueueSizePackets() > 0) {
AdvanceTimeAndProcess();
}
}
}
TEST_P(PacingControllerTest,
CanQueuePacketsWithSameSequenceNumberOnDifferentSsrcs) {
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number,
clock_.TimeInMilliseconds(), 250);
// Expect packet on second ssrc to be queued and sent as well.
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc + 1, sequence_number,
clock_.TimeInMilliseconds(), 250);
clock_.AdvanceTimeMilliseconds(1000);
if (PeriodicProcess()) {
pacer_->ProcessPackets();
} else {
while (pacer_->QueueSizePackets() > 0) {
AdvanceTimeAndProcess();
}
}
}
TEST_P(PacingControllerTest, Padding) {
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
const size_t kPacketSize = 250;
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, kTargetRate);
if (PeriodicProcess()) {
ConsumeInitialBudget();
// 5 milliseconds later should not send padding since we filled the buffers
// initially.
EXPECT_CALL(callback_, SendPadding(kPacketSize)).Times(0);
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
// 5 milliseconds later we have enough budget to send some padding.
EXPECT_CALL(callback_, SendPadding(250)).WillOnce(Return(kPacketSize));
EXPECT_CALL(callback_, SendPacket(_, _, _, _, true)).Times(1);
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
const size_t kPacketsToSend = 20;
for (size_t i = 0; i < kPacketsToSend; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
const TimeDelta expected_pace_time =
DataSize::Bytes(pacer_->QueueSizePackets() * kPacketSize) /
(kPaceMultiplier * kTargetRate);
EXPECT_CALL(callback_, SendPadding).Times(0);
// Only the media packets should be sent.
Timestamp start_time = clock_.CurrentTime();
while (pacer_->QueueSizePackets() > 0) {
AdvanceTimeAndProcess();
}
const TimeDelta actual_pace_time = clock_.CurrentTime() - start_time;
EXPECT_LE((actual_pace_time - expected_pace_time).Abs(),
PacingController::kMinSleepTime);
// Pacing media happens at 2.5x, but padding was configured with 1.0x
// factor. We have to wait until the padding debt is gone before we start
// sending padding.
const TimeDelta time_to_padding_debt_free =
(expected_pace_time * kPaceMultiplier) - actual_pace_time;
clock_.AdvanceTime(time_to_padding_debt_free -
PacingController::kMinSleepTime);
pacer_->ProcessPackets();
// Send 10 padding packets.
const size_t kPaddingPacketsToSend = 10;
DataSize padding_sent = DataSize::Zero();
size_t packets_sent = 0;
Timestamp first_send_time = Timestamp::MinusInfinity();
Timestamp last_send_time = Timestamp::MinusInfinity();
EXPECT_CALL(callback_, SendPadding)
.Times(kPaddingPacketsToSend)
.WillRepeatedly([&](size_t target_size) {
++packets_sent;
if (packets_sent < kPaddingPacketsToSend) {
// Don't count bytes of last packet, instead just
// use this as the time the last packet finished
// sending.
padding_sent += DataSize::Bytes(target_size);
}
if (first_send_time.IsInfinite()) {
first_send_time = clock_.CurrentTime();
} else {
last_send_time = clock_.CurrentTime();
}
return target_size;
});
EXPECT_CALL(callback_, SendPacket(_, _, _, false, true))
.Times(kPaddingPacketsToSend);
while (packets_sent < kPaddingPacketsToSend) {
AdvanceTimeAndProcess();
}
// Verify rate of sent padding.
TimeDelta padding_duration = last_send_time - first_send_time;
DataRate padding_rate = padding_sent / padding_duration;
EXPECT_EQ(padding_rate, kTargetRate);
}
}
TEST_P(PacingControllerTest, NoPaddingBeforeNormalPacket) {
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, kTargetRate);
EXPECT_CALL(callback_, SendPadding).Times(0);
pacer_->ProcessPackets();
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
clock_.AdvanceTime(TimeUntilNextProcess());
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
int64_t capture_time_ms = 56789;
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
capture_time_ms, 250);
bool padding_sent = false;
EXPECT_CALL(callback_, SendPadding).WillOnce([&](size_t padding) {
padding_sent = true;
return padding;
});
EXPECT_CALL(callback_, SendPacket(_, _, _, _, true)).Times(1);
if (PeriodicProcess()) {
pacer_->ProcessPackets();
} else {
while (!padding_sent) {
AdvanceTimeAndProcess();
}
}
}
TEST_P(PacingControllerTest, VerifyPaddingUpToBitrate) {
if (!PeriodicProcess()) {
// Already tested in PacingControllerTest.Padding.
return;
}
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
int64_t capture_time_ms = 56789;
const int kTimeStep = 5;
const int64_t kBitrateWindow = 100;
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, kTargetRate);
int64_t start_time = clock_.TimeInMilliseconds();
while (clock_.TimeInMilliseconds() - start_time < kBitrateWindow) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
capture_time_ms, 250);
EXPECT_CALL(callback_, SendPadding(250)).WillOnce(Return(250));
EXPECT_CALL(callback_, SendPacket(_, _, _, _, true)).Times(1);
pacer_->ProcessPackets();
clock_.AdvanceTimeMilliseconds(kTimeStep);
}
}
TEST_P(PacingControllerTest, VerifyAverageBitrateVaryingMediaPayload) {
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
int64_t capture_time_ms = 56789;
const int kTimeStep = 5;
const TimeDelta kAveragingWindowLength = TimeDelta::Seconds(10);
PacingControllerPadding callback;
pacer_ = std::make_unique<PacingController>(&clock_, &callback, nullptr,
nullptr, GetParam());
pacer_->SetProbingEnabled(false);
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, kTargetRate);
Timestamp start_time = clock_.CurrentTime();
size_t media_bytes = 0;
while (clock_.CurrentTime() - start_time < kAveragingWindowLength) {
// Maybe add some new media packets corresponding to expected send rate.
int rand_value = rand(); // NOLINT (rand_r instead of rand)
while (
media_bytes <
(kTargetRate * (clock_.CurrentTime() - start_time)).bytes<size_t>()) {
size_t media_payload = rand_value % 400 + 800; // [400, 1200] bytes.
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++, capture_time_ms,
media_payload);
media_bytes += media_payload;
}
if (PeriodicProcess()) {
clock_.AdvanceTimeMilliseconds(kTimeStep);
pacer_->ProcessPackets();
} else {
AdvanceTimeAndProcess();
}
}
EXPECT_NEAR(
kTargetRate.bps(),
(DataSize::Bytes(callback.total_bytes_sent()) / kAveragingWindowLength)
.bps(),
(kTargetRate * 0.01 /* 1% error marging */).bps());
}
TEST_P(PacingControllerTest, Priority) {
uint32_t ssrc_low_priority = 12345;
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
int64_t capture_time_ms = 56789;
int64_t capture_time_ms_low_priority = 1234567;
ConsumeInitialBudget();
// Expect normal and low priority to be queued and high to pass through.
Send(RtpPacketMediaType::kVideo, ssrc_low_priority, sequence_number++,
capture_time_ms_low_priority, 250);
const size_t packets_to_send_per_interval =
kTargetRate.bps() * kPaceMultiplier / (8 * 250 * 200);
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
Send(RtpPacketMediaType::kRetransmission, ssrc, sequence_number++,
capture_time_ms, 250);
}
Send(RtpPacketMediaType::kAudio, ssrc, sequence_number++, capture_time_ms,
250);
// Expect all high and normal priority to be sent out first.
EXPECT_CALL(callback_, SendPadding).Times(0);
EXPECT_CALL(callback_, SendPacket(ssrc, _, capture_time_ms, _, _))
.Times(packets_to_send_per_interval + 1);
if (PeriodicProcess()) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
while (pacer_->QueueSizePackets() > 1) {
AdvanceTimeAndProcess();
}
}
EXPECT_EQ(1u, pacer_->QueueSizePackets());
EXPECT_CALL(callback_, SendPacket(ssrc_low_priority, _,
capture_time_ms_low_priority, _, _))
.Times(1);
if (PeriodicProcess()) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
AdvanceTimeAndProcess();
}
}
TEST_P(PacingControllerTest, RetransmissionPriority) {
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
int64_t capture_time_ms = 45678;
int64_t capture_time_ms_retransmission = 56789;
// Due to the multiplicative factor we can send 5 packets during a send
// interval. (network capacity * multiplier / (8 bits per byte *
// (packet size * #send intervals per second)
const size_t packets_to_send_per_interval =
kTargetRate.bps() * kPaceMultiplier / (8 * 250 * 200);
pacer_->ProcessPackets();
EXPECT_EQ(0u, pacer_->QueueSizePackets());
// Alternate retransmissions and normal packets.
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++, capture_time_ms,
250);
Send(RtpPacketMediaType::kRetransmission, ssrc, sequence_number++,
capture_time_ms_retransmission, 250);
}
EXPECT_EQ(2 * packets_to_send_per_interval, pacer_->QueueSizePackets());
// Expect all retransmissions to be sent out first despite having a later
// capture time.
EXPECT_CALL(callback_, SendPadding).Times(0);
EXPECT_CALL(callback_, SendPacket(_, _, _, false, _)).Times(0);
EXPECT_CALL(callback_,
SendPacket(ssrc, _, capture_time_ms_retransmission, true, _))
.Times(packets_to_send_per_interval);
if (PeriodicProcess()) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
while (pacer_->QueueSizePackets() > packets_to_send_per_interval) {
AdvanceTimeAndProcess();
}
}
EXPECT_EQ(packets_to_send_per_interval, pacer_->QueueSizePackets());
// Expect the remaining (non-retransmission) packets to be sent.
EXPECT_CALL(callback_, SendPadding).Times(0);
EXPECT_CALL(callback_, SendPacket(_, _, _, true, _)).Times(0);
EXPECT_CALL(callback_, SendPacket(ssrc, _, capture_time_ms, false, _))
.Times(packets_to_send_per_interval);
if (PeriodicProcess()) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
while (pacer_->QueueSizePackets() > 0) {
AdvanceTimeAndProcess();
}
}
EXPECT_EQ(0u, pacer_->QueueSizePackets());
}
TEST_P(PacingControllerTest, HighPrioDoesntAffectBudget) {
const size_t kPacketSize = 250;
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
int64_t capture_time_ms = 56789;
// As high prio packets doesn't affect the budget, we should be able to send
// a high number of them at once.
const size_t kNumAudioPackets = 25;
for (size_t i = 0; i < kNumAudioPackets; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kAudio, ssrc, sequence_number++,
capture_time_ms, kPacketSize);
}
pacer_->ProcessPackets();
// Low prio packets does affect the budget.
// Due to the multiplicative factor we can send 5 packets during a send
// interval. (network capacity * multiplier / (8 bits per byte *
// (packet size * #send intervals per second)
const size_t kPacketsToSendPerInterval =
kTargetRate.bps() * kPaceMultiplier / (8 * kPacketSize * 200);
for (size_t i = 0; i < kPacketsToSendPerInterval; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
// Send all packets and measure pace time.
Timestamp start_time = clock_.CurrentTime();
while (pacer_->QueueSizePackets() > 0) {
if (PeriodicProcess()) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
} else {
AdvanceTimeAndProcess();
}
}
// Measure pacing time. Expect only low-prio packets to affect this.
TimeDelta pacing_time = clock_.CurrentTime() - start_time;
TimeDelta expected_pacing_time =
DataSize::Bytes(kPacketsToSendPerInterval * kPacketSize) /
(kTargetRate * kPaceMultiplier);
EXPECT_NEAR(pacing_time.us<double>(), expected_pacing_time.us<double>(),
PeriodicProcess() ? 5000.0
: PacingController::kMinSleepTime.us<double>());
}
TEST_P(PacingControllerTest, SendsOnlyPaddingWhenCongested) {
uint32_t ssrc = 202020;
uint16_t sequence_number = 1000;
int kPacketSize = 250;
int kCongestionWindow = kPacketSize * 10;
pacer_->UpdateOutstandingData(DataSize::Zero());
pacer_->SetCongestionWindow(DataSize::Bytes(kCongestionWindow));
int sent_data = 0;
while (sent_data < kCongestionWindow) {
sent_data += kPacketSize;
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
AdvanceTimeAndProcess();
}
::testing::Mock::VerifyAndClearExpectations(&callback_);
EXPECT_CALL(callback_, SendPacket).Times(0);
EXPECT_CALL(callback_, SendPadding).Times(0);
size_t blocked_packets = 0;
int64_t expected_time_until_padding = 500;
while (expected_time_until_padding > 5) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
blocked_packets++;
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
expected_time_until_padding -= 5;
}
::testing::Mock::VerifyAndClearExpectations(&callback_);
EXPECT_CALL(callback_, SendPadding(1)).WillOnce(Return(1));
EXPECT_CALL(callback_, SendPacket(_, _, _, _, true)).Times(1);
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
EXPECT_EQ(blocked_packets, pacer_->QueueSizePackets());
}
TEST_P(PacingControllerTest, DoesNotAllowOveruseAfterCongestion) {
uint32_t ssrc = 202020;
uint16_t seq_num = 1000;
int size = 1000;
auto now_ms = [this] { return clock_.TimeInMilliseconds(); };
EXPECT_CALL(callback_, SendPadding).Times(0);
// The pacing rate is low enough that the budget should not allow two packets
// to be sent in a row.
pacer_->SetPacingRates(DataRate::BitsPerSec(400 * 8 * 1000 / 5),
DataRate::Zero());
// The congestion window is small enough to only let one packet through.
pacer_->SetCongestionWindow(DataSize::Bytes(800));
pacer_->UpdateOutstandingData(DataSize::Zero());
// Not yet budget limited or congested, packet is sent.
Send(RtpPacketMediaType::kVideo, ssrc, seq_num++, now_ms(), size);
EXPECT_CALL(callback_, SendPacket).Times(1);
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
// Packet blocked due to congestion.
Send(RtpPacketMediaType::kVideo, ssrc, seq_num++, now_ms(), size);
EXPECT_CALL(callback_, SendPacket).Times(0);
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
// Packet blocked due to congestion.
Send(RtpPacketMediaType::kVideo, ssrc, seq_num++, now_ms(), size);
EXPECT_CALL(callback_, SendPacket).Times(0);
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
// Congestion removed and budget has recovered, packet is sent.
Send(RtpPacketMediaType::kVideo, ssrc, seq_num++, now_ms(), size);
EXPECT_CALL(callback_, SendPacket).Times(1);
clock_.AdvanceTimeMilliseconds(5);
pacer_->UpdateOutstandingData(DataSize::Zero());
pacer_->ProcessPackets();
// Should be blocked due to budget limitation as congestion has be removed.
Send(RtpPacketMediaType::kVideo, ssrc, seq_num++, now_ms(), size);
EXPECT_CALL(callback_, SendPacket).Times(0);
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
}
TEST_P(PacingControllerTest, ResumesSendingWhenCongestionEnds) {
uint32_t ssrc = 202020;
uint16_t sequence_number = 1000;
int64_t kPacketSize = 250;
int64_t kCongestionCount = 10;
int64_t kCongestionWindow = kPacketSize * kCongestionCount;
int64_t kCongestionTimeMs = 1000;
pacer_->UpdateOutstandingData(DataSize::Zero());
pacer_->SetCongestionWindow(DataSize::Bytes(kCongestionWindow));
int sent_data = 0;
while (sent_data < kCongestionWindow) {
sent_data += kPacketSize;
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
}
::testing::Mock::VerifyAndClearExpectations(&callback_);
EXPECT_CALL(callback_, SendPacket).Times(0);
int unacked_packets = 0;
for (int duration = 0; duration < kCongestionTimeMs; duration += 5) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
unacked_packets++;
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
}
::testing::Mock::VerifyAndClearExpectations(&callback_);
// First mark half of the congested packets as cleared and make sure that just
// as many are sent
int ack_count = kCongestionCount / 2;
EXPECT_CALL(callback_, SendPacket(ssrc, _, _, false, _)).Times(ack_count);
pacer_->UpdateOutstandingData(
DataSize::Bytes(kCongestionWindow - kPacketSize * ack_count));
for (int duration = 0; duration < kCongestionTimeMs; duration += 5) {
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
}
unacked_packets -= ack_count;
::testing::Mock::VerifyAndClearExpectations(&callback_);
// Second make sure all packets are sent if sent packets are continuously
// marked as acked.
EXPECT_CALL(callback_, SendPacket(ssrc, _, _, false, _))
.Times(unacked_packets);
for (int duration = 0; duration < kCongestionTimeMs; duration += 5) {
pacer_->UpdateOutstandingData(DataSize::Zero());
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
}
}
TEST_P(PacingControllerTest, Pause) {
uint32_t ssrc_low_priority = 12345;
uint32_t ssrc = 12346;
uint32_t ssrc_high_priority = 12347;
uint16_t sequence_number = 1234;
EXPECT_EQ(TimeDelta::Zero(), pacer_->OldestPacketWaitTime());
ConsumeInitialBudget();
pacer_->Pause();
int64_t capture_time_ms = clock_.TimeInMilliseconds();
const size_t packets_to_send_per_interval =
kTargetRate.bps() * kPaceMultiplier / (8 * 250 * 200);
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
Send(RtpPacketMediaType::kVideo, ssrc_low_priority, sequence_number++,
capture_time_ms, 250);
Send(RtpPacketMediaType::kRetransmission, ssrc, sequence_number++,
capture_time_ms, 250);
Send(RtpPacketMediaType::kAudio, ssrc_high_priority, sequence_number++,
capture_time_ms, 250);
}
clock_.AdvanceTimeMilliseconds(10000);
int64_t second_capture_time_ms = clock_.TimeInMilliseconds();
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
Send(RtpPacketMediaType::kVideo, ssrc_low_priority, sequence_number++,
second_capture_time_ms, 250);
Send(RtpPacketMediaType::kRetransmission, ssrc, sequence_number++,
second_capture_time_ms, 250);
Send(RtpPacketMediaType::kAudio, ssrc_high_priority, sequence_number++,
second_capture_time_ms, 250);
}
// Expect everything to be queued.
EXPECT_EQ(TimeDelta::Millis(second_capture_time_ms - capture_time_ms),
pacer_->OldestPacketWaitTime());
// Process triggers keep-alive packet.
EXPECT_CALL(callback_, SendPadding).WillOnce([](size_t padding) {
return padding;
});
EXPECT_CALL(callback_, SendPacket(_, _, _, _, true)).Times(1);
pacer_->ProcessPackets();
// Verify no packets sent for the rest of the paused process interval.
const TimeDelta kProcessInterval = TimeDelta::Millis(5);
TimeDelta expected_time_until_send = PacingController::kPausedProcessInterval;
EXPECT_CALL(callback_, SendPadding).Times(0);
while (expected_time_until_send >= kProcessInterval) {
pacer_->ProcessPackets();
clock_.AdvanceTime(kProcessInterval);
expected_time_until_send -= kProcessInterval;
}
// New keep-alive packet.
::testing::Mock::VerifyAndClearExpectations(&callback_);
EXPECT_CALL(callback_, SendPadding).WillOnce([](size_t padding) {
return padding;
});
EXPECT_CALL(callback_, SendPacket(_, _, _, _, true)).Times(1);
clock_.AdvanceTime(kProcessInterval);
pacer_->ProcessPackets();
::testing::Mock::VerifyAndClearExpectations(&callback_);
// Expect high prio packets to come out first followed by normal
// prio packets and low prio packets (all in capture order).
{
::testing::InSequence sequence;
EXPECT_CALL(callback_,
SendPacket(ssrc_high_priority, _, capture_time_ms, _, _))
.Times(packets_to_send_per_interval);
EXPECT_CALL(callback_,
SendPacket(ssrc_high_priority, _, second_capture_time_ms, _, _))
.Times(packets_to_send_per_interval);
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
EXPECT_CALL(callback_, SendPacket(ssrc, _, capture_time_ms, _, _))
.Times(1);
}
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
EXPECT_CALL(callback_, SendPacket(ssrc, _, second_capture_time_ms, _, _))
.Times(1);
}
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
EXPECT_CALL(callback_,
SendPacket(ssrc_low_priority, _, capture_time_ms, _, _))
.Times(1);
}
for (size_t i = 0; i < packets_to_send_per_interval; ++i) {
EXPECT_CALL(callback_, SendPacket(ssrc_low_priority, _,
second_capture_time_ms, _, _))
.Times(1);
}
}
pacer_->Resume();
if (PeriodicProcess()) {
// The pacer was resumed directly after the previous process call finished.
// It will therefore wait 5 ms until next process.
clock_.AdvanceTime(TimeUntilNextProcess());
for (size_t i = 0; i < 4; i++) {
pacer_->ProcessPackets();
clock_.AdvanceTime(TimeUntilNextProcess());
}
} else {
while (pacer_->QueueSizePackets() > 0) {
AdvanceTimeAndProcess();
}
}
EXPECT_EQ(TimeDelta::Zero(), pacer_->OldestPacketWaitTime());
}
TEST_P(PacingControllerTest, InactiveFromStart) {
// Recreate the pacer without the inital time forwarding.
pacer_ = std::make_unique<PacingController>(&clock_, &callback_, nullptr,
nullptr, GetParam());
pacer_->SetProbingEnabled(false);
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, kTargetRate);
if (PeriodicProcess()) {
// In period mode, pause the pacer to check the same idle behavior as
// dynamic.
pacer_->Pause();
}
// No packets sent, there should be no keep-alives sent either.
EXPECT_CALL(callback_, SendPadding).Times(0);
EXPECT_CALL(callback_, SendPacket).Times(0);
pacer_->ProcessPackets();
const Timestamp start_time = clock_.CurrentTime();
// Determine the margin need so we can advance to the last possible moment
// that will not cause a process event.
const TimeDelta time_margin =
(GetParam() == PacingController::ProcessMode::kDynamic
? PacingController::kMinSleepTime
: TimeDelta::Zero()) +
TimeDelta::Micros(1);
EXPECT_EQ(pacer_->NextSendTime() - start_time,
PacingController::kPausedProcessInterval);
clock_.AdvanceTime(PacingController::kPausedProcessInterval - time_margin);
pacer_->ProcessPackets();
EXPECT_EQ(pacer_->NextSendTime() - start_time,
PacingController::kPausedProcessInterval);
clock_.AdvanceTime(time_margin);
pacer_->ProcessPackets();
EXPECT_EQ(pacer_->NextSendTime() - start_time,
2 * PacingController::kPausedProcessInterval);
}
TEST_P(PacingControllerTest, ExpectedQueueTimeMs) {
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
const size_t kNumPackets = 60;
const size_t kPacketSize = 1200;
const int32_t kMaxBitrate = kPaceMultiplier * 30000;
EXPECT_EQ(TimeDelta::Zero(), pacer_->OldestPacketWaitTime());
pacer_->SetPacingRates(DataRate::BitsPerSec(30000 * kPaceMultiplier),
DataRate::Zero());
for (size_t i = 0; i < kNumPackets; ++i) {
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
// Queue in ms = 1000 * (bytes in queue) *8 / (bits per second)
TimeDelta queue_time =
TimeDelta::Millis(1000 * kNumPackets * kPacketSize * 8 / kMaxBitrate);
EXPECT_EQ(queue_time, pacer_->ExpectedQueueTime());
const Timestamp time_start = clock_.CurrentTime();
while (pacer_->QueueSizePackets() > 0) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
}
TimeDelta duration = clock_.CurrentTime() - time_start;
EXPECT_EQ(TimeDelta::Zero(), pacer_->ExpectedQueueTime());
// Allow for aliasing, duration should be within one pack of max time limit.
const TimeDelta deviation =
duration - PacingController::kMaxExpectedQueueLength;
EXPECT_LT(deviation.Abs(),
TimeDelta::Millis(1000 * kPacketSize * 8 / kMaxBitrate));
}
TEST_P(PacingControllerTest, QueueTimeGrowsOverTime) {
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
EXPECT_EQ(TimeDelta::Zero(), pacer_->OldestPacketWaitTime());
pacer_->SetPacingRates(DataRate::BitsPerSec(30000 * kPaceMultiplier),
DataRate::Zero());
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number,
clock_.TimeInMilliseconds(), 1200);
clock_.AdvanceTimeMilliseconds(500);
EXPECT_EQ(TimeDelta::Millis(500), pacer_->OldestPacketWaitTime());
pacer_->ProcessPackets();
EXPECT_EQ(TimeDelta::Zero(), pacer_->OldestPacketWaitTime());
}
TEST_P(PacingControllerTest, ProbingWithInsertedPackets) {
const size_t kPacketSize = 1200;
const int kInitialBitrateBps = 300000;
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
PacingControllerProbing packet_sender;
pacer_ = std::make_unique<PacingController>(&clock_, &packet_sender, nullptr,
nullptr, GetParam());
pacer_->CreateProbeCluster(kFirstClusterRate,
/*cluster_id=*/0);
pacer_->CreateProbeCluster(kSecondClusterRate,
/*cluster_id=*/1);
pacer_->SetPacingRates(
DataRate::BitsPerSec(kInitialBitrateBps * kPaceMultiplier),
DataRate::Zero());
for (int i = 0; i < 10; ++i) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
int64_t start = clock_.TimeInMilliseconds();
while (packet_sender.packets_sent() < 5) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
}
int packets_sent = packet_sender.packets_sent();
// Validate first cluster bitrate. Note that we have to account for number
// of intervals and hence (packets_sent - 1) on the first cluster.
EXPECT_NEAR((packets_sent - 1) * kPacketSize * 8000 /
(clock_.TimeInMilliseconds() - start),
kFirstClusterRate.bps(), kProbingErrorMargin.bps());
EXPECT_EQ(0, packet_sender.padding_sent());
clock_.AdvanceTime(TimeUntilNextProcess());
start = clock_.TimeInMilliseconds();
while (packet_sender.packets_sent() < 10) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
}
packets_sent = packet_sender.packets_sent() - packets_sent;
// Validate second cluster bitrate.
EXPECT_NEAR((packets_sent - 1) * kPacketSize * 8000 /
(clock_.TimeInMilliseconds() - start),
kSecondClusterRate.bps(), kProbingErrorMargin.bps());
}
TEST_P(PacingControllerTest, SkipsProbesWhenProcessIntervalTooLarge) {
const size_t kPacketSize = 1200;
const int kInitialBitrateBps = 300000;
const uint32_t ssrc = 12346;
const int kProbeClusterId = 3;
// Test with both legacy and new probe discard modes.
// TODO(bugs.webrtc.org/11780): Clean up when legacy is gone.
for (bool abort_delayed_probes : {false, true}) {
uint16_t sequence_number = 1234;
PacingControllerProbing packet_sender;
const test::ExplicitKeyValueConfig trials(
abort_delayed_probes ? "WebRTC-Bwe-ProbingBehavior/"
"abort_delayed_probes:1,max_probe_delay:2ms/"
: "WebRTC-Bwe-ProbingBehavior/"
"abort_delayed_probes:0,max_probe_delay:2ms/");
pacer_ = std::make_unique<PacingController>(&clock_, &packet_sender,
nullptr, &trials, GetParam());
pacer_->SetPacingRates(
DataRate::BitsPerSec(kInitialBitrateBps * kPaceMultiplier),
DataRate::BitsPerSec(kInitialBitrateBps));
for (int i = 0; i < 10; ++i) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
while (pacer_->QueueSizePackets() > 0) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
}
// Probe at a very high rate.
pacer_->CreateProbeCluster(DataRate::KilobitsPerSec(10000), // 10 Mbps.
/*cluster_id=*/kProbeClusterId);
// We need one packet to start the probe.
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
const int packets_sent_before_probe = packet_sender.packets_sent();
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
EXPECT_EQ(packet_sender.packets_sent(), packets_sent_before_probe + 1);
// Figure out how long between probe packets.
Timestamp start_time = clock_.CurrentTime();
clock_.AdvanceTime(TimeUntilNextProcess());
TimeDelta time_between_probes = clock_.CurrentTime() - start_time;
// Advance that distance again + 1ms.
clock_.AdvanceTime(time_between_probes);
// Send second probe packet.
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
pacer_->ProcessPackets();
EXPECT_EQ(packet_sender.packets_sent(), packets_sent_before_probe + 2);
PacedPacketInfo last_pacing_info = packet_sender.last_pacing_info();
EXPECT_EQ(last_pacing_info.probe_cluster_id, kProbeClusterId);
// We're exactly where we should be for the next probe.
const Timestamp probe_time = clock_.CurrentTime();
EXPECT_EQ(pacer_->NextSendTime(), clock_.CurrentTime());
BitrateProberConfig probing_config(&trials);
EXPECT_GT(probing_config.max_probe_delay.Get(), TimeDelta::Zero());
// Advance to within max probe delay, should still return same target.
clock_.AdvanceTime(probing_config.max_probe_delay.Get());
EXPECT_EQ(pacer_->NextSendTime(), probe_time);
// Too high probe delay, drop it!
clock_.AdvanceTime(TimeDelta::Micros(1));
int packets_sent_before_timeout = packet_sender.total_packets_sent();
if (abort_delayed_probes) {
// Expected next process time is unchanged, but calling should not
// generate new packets.
EXPECT_EQ(pacer_->NextSendTime(), probe_time);
pacer_->ProcessPackets();
EXPECT_EQ(packet_sender.total_packets_sent(),
packets_sent_before_timeout);
// Next packet sent is not part of probe.
if (PeriodicProcess()) {
do {
AdvanceTimeAndProcess();
} while (packet_sender.total_packets_sent() ==
packets_sent_before_timeout);
} else {
AdvanceTimeAndProcess();
}
const int expected_probe_id = PacedPacketInfo::kNotAProbe;
EXPECT_EQ(packet_sender.last_pacing_info().probe_cluster_id,
expected_probe_id);
} else {
// Legacy behaviour, probe "aborted" so send time moved back. Next call to
// ProcessPackets() still results in packets being marked as part of probe
// cluster.
EXPECT_GT(pacer_->NextSendTime(), probe_time);
AdvanceTimeAndProcess();
EXPECT_GT(packet_sender.total_packets_sent(),
packets_sent_before_timeout);
const int expected_probe_id = last_pacing_info.probe_cluster_id;
EXPECT_EQ(packet_sender.last_pacing_info().probe_cluster_id,
expected_probe_id);
// Time between sent packets keeps being too large, but we still mark the
// packets as being part of the cluster.
Timestamp a = clock_.CurrentTime();
AdvanceTimeAndProcess();
EXPECT_GT(packet_sender.total_packets_sent(),
packets_sent_before_timeout);
EXPECT_EQ(packet_sender.last_pacing_info().probe_cluster_id,
expected_probe_id);
EXPECT_GT(clock_.CurrentTime() - a, time_between_probes);
}
}
}
TEST_P(PacingControllerTest, ProbingWithPaddingSupport) {
const size_t kPacketSize = 1200;
const int kInitialBitrateBps = 300000;
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
PacingControllerProbing packet_sender;
pacer_ = std::make_unique<PacingController>(&clock_, &packet_sender, nullptr,
nullptr, GetParam());
pacer_->CreateProbeCluster(kFirstClusterRate,
/*cluster_id=*/0);
pacer_->SetPacingRates(
DataRate::BitsPerSec(kInitialBitrateBps * kPaceMultiplier),
DataRate::Zero());
for (int i = 0; i < 3; ++i) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
int64_t start = clock_.TimeInMilliseconds();
int process_count = 0;
while (process_count < 5) {
clock_.AdvanceTime(TimeUntilNextProcess());
pacer_->ProcessPackets();
++process_count;
}
int packets_sent = packet_sender.packets_sent();
int padding_sent = packet_sender.padding_sent();
EXPECT_GT(packets_sent, 0);
EXPECT_GT(padding_sent, 0);
// Note that the number of intervals here for kPacketSize is
// packets_sent due to padding in the same cluster.
EXPECT_NEAR((packets_sent * kPacketSize * 8000 + padding_sent) /
(clock_.TimeInMilliseconds() - start),
kFirstClusterRate.bps(), kProbingErrorMargin.bps());
}
TEST_P(PacingControllerTest, PaddingOveruse) {
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
const size_t kPacketSize = 1200;
// Initially no padding rate.
pacer_->ProcessPackets();
pacer_->SetPacingRates(DataRate::BitsPerSec(60000 * kPaceMultiplier),
DataRate::Zero());
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
pacer_->ProcessPackets();
// Add 30kbit padding. When increasing budget, media budget will increase from
// negative (overuse) while padding budget will increase from 0.
clock_.AdvanceTimeMilliseconds(5);
pacer_->SetPacingRates(DataRate::BitsPerSec(60000 * kPaceMultiplier),
DataRate::BitsPerSec(30000));
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
EXPECT_LT(TimeDelta::Millis(5), pacer_->ExpectedQueueTime());
// Don't send padding if queue is non-empty, even if padding budget > 0.
EXPECT_CALL(callback_, SendPadding).Times(0);
if (PeriodicProcess()) {
pacer_->ProcessPackets();
} else {
AdvanceTimeAndProcess();
}
}
TEST_P(PacingControllerTest, ProbeClusterId) {
MockPacketSender callback;
pacer_ = std::make_unique<PacingController>(&clock_, &callback, nullptr,
nullptr, GetParam());
Init();
uint32_t ssrc = 12346;
uint16_t sequence_number = 1234;
const size_t kPacketSize = 1200;
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, kTargetRate);
pacer_->SetProbingEnabled(true);
for (int i = 0; i < 10; ++i) {
Send(RtpPacketMediaType::kVideo, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
}
// First probing cluster.
EXPECT_CALL(callback,
SendPacket(_, Field(&PacedPacketInfo::probe_cluster_id, 0)))
.Times(5);
for (int i = 0; i < 5; ++i) {
AdvanceTimeAndProcess();
}
// Second probing cluster.
EXPECT_CALL(callback,
SendPacket(_, Field(&PacedPacketInfo::probe_cluster_id, 1)))
.Times(5);
for (int i = 0; i < 5; ++i) {
AdvanceTimeAndProcess();
}
// Needed for the Field comparer below.
const int kNotAProbe = PacedPacketInfo::kNotAProbe;
// No more probing packets.
EXPECT_CALL(callback, GeneratePadding).WillOnce([&](DataSize padding_size) {
std::vector<std::unique_ptr<RtpPacketToSend>> padding_packets;
padding_packets.emplace_back(
BuildPacket(RtpPacketMediaType::kPadding, ssrc, sequence_number++,
clock_.TimeInMilliseconds(), padding_size.bytes()));
return padding_packets;
});
bool non_probe_packet_seen = false;
EXPECT_CALL(callback, SendPacket)
.WillOnce([&](std::unique_ptr<RtpPacketToSend> packet,
const PacedPacketInfo& cluster_info) {
EXPECT_EQ(cluster_info.probe_cluster_id, kNotAProbe);
non_probe_packet_seen = true;
});
while (!non_probe_packet_seen) {
AdvanceTimeAndProcess();
}
}
TEST_P(PacingControllerTest, OwnedPacketPrioritizedOnType) {
MockPacketSender callback;
pacer_ = std::make_unique<PacingController>(&clock_, &callback, nullptr,
nullptr, GetParam());
Init();
// Insert a packet of each type, from low to high priority. Since priority
// is weighted higher than insert order, these should come out of the pacer
// in backwards order with the exception of FEC and Video.
for (RtpPacketMediaType type :
{RtpPacketMediaType::kPadding,
RtpPacketMediaType::kForwardErrorCorrection, RtpPacketMediaType::kVideo,
RtpPacketMediaType::kRetransmission, RtpPacketMediaType::kAudio}) {
pacer_->EnqueuePacket(BuildRtpPacket(type));
}
::testing::InSequence seq;
EXPECT_CALL(
callback,
SendPacket(Pointee(Property(&RtpPacketToSend::Ssrc, kAudioSsrc)), _));
EXPECT_CALL(
callback,
SendPacket(Pointee(Property(&RtpPacketToSend::Ssrc, kVideoRtxSsrc)), _));
// FEC and video actually have the same priority, so will come out in
// insertion order.
EXPECT_CALL(
callback,
SendPacket(Pointee(Property(&RtpPacketToSend::Ssrc, kFlexFecSsrc)), _));
EXPECT_CALL(
callback,
SendPacket(Pointee(Property(&RtpPacketToSend::Ssrc, kVideoSsrc)), _));
EXPECT_CALL(
callback,
SendPacket(Pointee(Property(&RtpPacketToSend::Ssrc, kVideoRtxSsrc)), _));
while (pacer_->QueueSizePackets() > 0) {
if (PeriodicProcess()) {
clock_.AdvanceTimeMilliseconds(5);
pacer_->ProcessPackets();
} else {
AdvanceTimeAndProcess();
}
}
}
TEST_P(PacingControllerTest, SmallFirstProbePacket) {
ScopedFieldTrials trial("WebRTC-Pacer-SmallFirstProbePacket/Enabled/");
MockPacketSender callback;
pacer_ = std::make_unique<PacingController>(&clock_, &callback, nullptr,
nullptr, GetParam());
pacer_->CreateProbeCluster(kFirstClusterRate, /*cluster_id=*/0);
pacer_->SetPacingRates(kTargetRate * kPaceMultiplier, DataRate::Zero());
// Add high prio media.
pacer_->EnqueuePacket(BuildRtpPacket(RtpPacketMediaType::kAudio));
// Expect small padding packet to be requested.
EXPECT_CALL(callback, GeneratePadding(DataSize::Bytes(1)))
.WillOnce([&](DataSize padding_size) {
std::vector<std::unique_ptr<RtpPacketToSend>> padding_packets;
padding_packets.emplace_back(
BuildPacket(RtpPacketMediaType::kPadding, kAudioSsrc, 1,
clock_.TimeInMilliseconds(), 1));
return padding_packets;
});
size_t packets_sent = 0;
bool media_seen = false;
EXPECT_CALL(callback, SendPacket)
.Times(::testing::AnyNumber())
.WillRepeatedly([&](std::unique_ptr<RtpPacketToSend> packet,
const PacedPacketInfo& cluster_info) {
if (packets_sent == 0) {
EXPECT_EQ(packet->packet_type(), RtpPacketMediaType::kPadding);
} else {
if (packet->packet_type() == RtpPacketMediaType::kAudio) {
media_seen = true;
}
}
packets_sent++;
});
while (!media_seen) {
pacer_->ProcessPackets();
clock_.AdvanceTimeMilliseconds(5);
}
}
TEST_P(PacingControllerTest, TaskLate) {
if (PeriodicProcess()) {
// This test applies only when NOT using interval budget.
return;
}
// Set a low send rate to more easily test timing issues.
DataRate kSendRate = DataRate::KilobitsPerSec(30);
pacer_->SetPacingRates(kSendRate, DataRate::Zero());
// Add four packets of equal size and priority.
pacer_->EnqueuePacket(BuildRtpPacket(RtpPacketMediaType::kVideo));
pacer_->EnqueuePacket(BuildRtpPacket(RtpPacketMediaType::kVideo));
pacer_->EnqueuePacket(BuildRtpPacket(RtpPacketMediaType::kVideo));
pacer_->EnqueuePacket(BuildRtpPacket(RtpPacketMediaType::kVideo));
// Process packets, only first should be sent.
EXPECT_CALL(callback_, SendPacket).Times(1);
pacer_->ProcessPackets();
Timestamp next_send_time = pacer_->NextSendTime();
// Determine time between packets (ca 62ms)
const TimeDelta time_between_packets = next_send_time - clock_.CurrentTime();
// Simulate a late process call, executed just before we allow sending the
// fourth packet.
const TimeDelta kOffset = TimeDelta::Millis(1);
clock_.AdvanceTime((time_between_packets * 3) - kOffset);
EXPECT_CALL(callback_, SendPacket).Times(2);
pacer_->ProcessPackets();
// Check that next scheduled send time is in ca 1ms.
next_send_time = pacer_->NextSendTime();
const TimeDelta time_left = next_send_time - clock_.CurrentTime();
EXPECT_EQ(time_left.RoundTo(TimeDelta::Millis(1)), kOffset);
clock_.AdvanceTime(time_left);
EXPECT_CALL(callback_, SendPacket);
pacer_->ProcessPackets();
}
TEST_P(PacingControllerTest, NoProbingWhilePaused) {
uint32_t ssrc = 12345;
uint16_t sequence_number = 1234;
pacer_->SetProbingEnabled(true);
// Send at least one packet so probing can initate.
SendAndExpectPacket(RtpPacketMediaType::kVideo, ssrc, sequence_number,
clock_.TimeInMilliseconds(), 250);
while (pacer_->QueueSizePackets() > 0) {
AdvanceTimeAndProcess();
}
// Trigger probing.
pacer_->CreateProbeCluster(DataRate::KilobitsPerSec(10000), // 10 Mbps.
/*cluster_id=*/3);
// Time to next send time should be small.
EXPECT_LT(pacer_->NextSendTime() - clock_.CurrentTime(),
PacingController::kPausedProcessInterval);
// Pause pacer, time to next send time should now be the pause process
// interval.
pacer_->Pause();
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(),
PacingController::kPausedProcessInterval);
}
TEST_P(PacingControllerTest, AudioNotPacedEvenWhenAccountedFor) {
const uint32_t kSsrc = 12345;
uint16_t sequence_number = 1234;
const size_t kPacketSize = 123;
// Account for audio - so that audio packets can cause pushback on other
// types such as video. Audio packet should still be immediated passed
// through though ("WebRTC-Pacer-BlockAudio" needs to be enabled in order
// to pace audio packets).
pacer_->SetAccountForAudioPackets(true);
// Set pacing rate to 1 packet/s, no padding.
pacer_->SetPacingRates(DataSize::Bytes(kPacketSize) / TimeDelta::Seconds(1),
DataRate::Zero());
// Add and send an audio packet.
SendAndExpectPacket(RtpPacketMediaType::kAudio, kSsrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
pacer_->ProcessPackets();
// Advance time, add another audio packet and process. It should be sent
// immediately.
clock_.AdvanceTimeMilliseconds(5);
SendAndExpectPacket(RtpPacketMediaType::kAudio, kSsrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize);
pacer_->ProcessPackets();
}
TEST_P(PacingControllerTest,
PaddingResumesAfterSaturationEvenWithConcurrentAudio) {
const uint32_t kSsrc = 12345;
const DataRate kPacingDataRate = DataRate::KilobitsPerSec(125);
const DataRate kPaddingDataRate = DataRate::KilobitsPerSec(100);
const TimeDelta kMaxBufferInTime = TimeDelta::Millis(500);
const DataSize kPacketSize = DataSize::Bytes(130);
const TimeDelta kAudioPacketInterval = TimeDelta::Millis(20);
// In this test, we fist send a burst of video in order to saturate the
// padding debt level.
// We then proceed to send audio at a bitrate that is slightly lower than
// the padding rate, meaning there will be a period with audio but no
// padding sent while the debt is draining, then audio and padding will
// be interlieved.
// Verify both with and without accounting for audio.
for (bool account_for_audio : {false, true}) {
uint16_t sequence_number = 1234;
MockPacketSender callback;
EXPECT_CALL(callback, SendPacket).Times(::testing::AnyNumber());
pacer_ = std::make_unique<PacingController>(&clock_, &callback, nullptr,
nullptr, GetParam());
pacer_->SetAccountForAudioPackets(account_for_audio);
// First, saturate the padding budget.
pacer_->SetPacingRates(kPacingDataRate, kPaddingDataRate);
const TimeDelta kPaddingSaturationTime =
kMaxBufferInTime * kPaddingDataRate /
(kPacingDataRate - kPaddingDataRate);
const DataSize kVideoToSend = kPaddingSaturationTime * kPacingDataRate;
const DataSize kVideoPacketSize = DataSize::Bytes(1200);
DataSize video_sent = DataSize::Zero();
while (video_sent < kVideoToSend) {
pacer_->EnqueuePacket(
BuildPacket(RtpPacketMediaType::kVideo, kSsrc, sequence_number++,
clock_.TimeInMilliseconds(), kVideoPacketSize.bytes()));
video_sent += kVideoPacketSize;
}
while (pacer_->QueueSizePackets() > 0) {
AdvanceTimeAndProcess();
}
// Add a stream of audio packets at a rate slightly lower than the padding
// rate, once the padding debt is paid off we expect padding to be
// generated.
pacer_->SetPacingRates(kPacingDataRate, kPaddingDataRate);
bool padding_seen = false;
EXPECT_CALL(callback, GeneratePadding).WillOnce([&](DataSize padding_size) {
padding_seen = true;
std::vector<std::unique_ptr<RtpPacketToSend>> padding_packets;
padding_packets.emplace_back(
BuildPacket(RtpPacketMediaType::kPadding, kSsrc, sequence_number++,
clock_.TimeInMilliseconds(), padding_size.bytes()));
return padding_packets;
});
Timestamp start_time = clock_.CurrentTime();
Timestamp last_audio_time = start_time;
while (!padding_seen) {
Timestamp now = clock_.CurrentTime();
Timestamp next_send_time = pacer_->NextSendTime();
TimeDelta sleep_time =
std::min(next_send_time, last_audio_time + kAudioPacketInterval) -
now;
clock_.AdvanceTime(sleep_time);
while (clock_.CurrentTime() >= last_audio_time + kAudioPacketInterval) {
pacer_->EnqueuePacket(
BuildPacket(RtpPacketMediaType::kAudio, kSsrc, sequence_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes()));
last_audio_time += kAudioPacketInterval;
}
pacer_->ProcessPackets();
}
// Verify how long it took to drain the padding debt. Allow 2% error margin.
const DataRate kAudioDataRate = kPacketSize / kAudioPacketInterval;
const TimeDelta expected_drain_time =
account_for_audio ? (kMaxBufferInTime * kPaddingDataRate /
(kPaddingDataRate - kAudioDataRate))
: kMaxBufferInTime;
const TimeDelta actual_drain_time = clock_.CurrentTime() - start_time;
EXPECT_NEAR(actual_drain_time.ms(), expected_drain_time.ms(),
expected_drain_time.ms() * 0.02)
<< " where account_for_audio = "
<< (account_for_audio ? "true" : "false");
}
}
TEST_P(PacingControllerTest, AccountsForAudioEnqueuTime) {
if (PeriodicProcess()) {
// This test applies only when NOT using interval budget.
return;
}
const uint32_t kSsrc = 12345;
const DataRate kPacingDataRate = DataRate::KilobitsPerSec(125);
const DataRate kPaddingDataRate = DataRate::Zero();
const DataSize kPacketSize = DataSize::Bytes(130);
const TimeDelta kPacketPacingTime = kPacketSize / kPacingDataRate;
uint32_t sequnce_number = 1;
// Audio not paced, but still accounted for in budget.
pacer_->SetAccountForAudioPackets(true);
pacer_->SetPacingRates(kPacingDataRate, kPaddingDataRate);
// Enqueue two audio packets, advance clock to where one packet
// should have drained the buffer already, has they been sent
// immediately.
SendAndExpectPacket(RtpPacketMediaType::kAudio, kSsrc, sequnce_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes());
SendAndExpectPacket(RtpPacketMediaType::kAudio, kSsrc, sequnce_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes());
clock_.AdvanceTime(kPacketPacingTime);
// Now process and make sure both packets were sent.
pacer_->ProcessPackets();
::testing::Mock::VerifyAndClearExpectations(&callback_);
// Add a video packet. I can't be sent until debt from audio
// packets have been drained.
Send(RtpPacketMediaType::kVideo, kSsrc + 1, sequnce_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes());
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(), kPacketPacingTime);
}
TEST_P(PacingControllerTest, NextSendTimeAccountsForPadding) {
if (PeriodicProcess()) {
// This test applies only when NOT using interval budget.
return;
}
const uint32_t kSsrc = 12345;
const DataRate kPacingDataRate = DataRate::KilobitsPerSec(125);
const DataSize kPacketSize = DataSize::Bytes(130);
const TimeDelta kPacketPacingTime = kPacketSize / kPacingDataRate;
uint32_t sequnce_number = 1;
// Start with no padding.
pacer_->SetPacingRates(kPacingDataRate, DataRate::Zero());
// Send a single packet.
SendAndExpectPacket(RtpPacketMediaType::kVideo, kSsrc, sequnce_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes());
pacer_->ProcessPackets();
::testing::Mock::VerifyAndClearExpectations(&callback_);
// With current conditions, no need to wake until next keep-alive.
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(),
PacingController::kPausedProcessInterval);
// Enqueue a new packet, that can't be sent until previous buffer has
// drained.
SendAndExpectPacket(RtpPacketMediaType::kVideo, kSsrc, sequnce_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes());
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(), kPacketPacingTime);
clock_.AdvanceTime(kPacketPacingTime);
pacer_->ProcessPackets();
::testing::Mock::VerifyAndClearExpectations(&callback_);
// With current conditions, again no need to wake until next keep-alive.
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(),
PacingController::kPausedProcessInterval);
// Set a non-zero padding rate. Padding also can't be sent until
// previous debt has cleared. Since padding was disabled before, there
// currently is no padding debt.
pacer_->SetPacingRates(kPacingDataRate, kPacingDataRate / 2);
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(), kPacketPacingTime);
// Advance time, expect padding.
EXPECT_CALL(callback_, SendPadding).WillOnce(Return(kPacketSize.bytes()));
clock_.AdvanceTime(kPacketPacingTime);
pacer_->ProcessPackets();
::testing::Mock::VerifyAndClearExpectations(&callback_);
// Since padding rate is half of pacing rate, next time we can send
// padding is double the packet pacing time.
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(),
kPacketPacingTime * 2);
// Insert a packet to be sent, this take precedence again.
Send(RtpPacketMediaType::kVideo, kSsrc, sequnce_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes());
EXPECT_EQ(pacer_->NextSendTime() - clock_.CurrentTime(), kPacketPacingTime);
}
TEST_P(PacingControllerTest, PaddingTargetAccountsForPaddingRate) {
if (PeriodicProcess()) {
// This test applies only when NOT using interval budget.
return;
}
// Re-init pacer with an explicitly set padding target of 10ms;
const TimeDelta kPaddingTarget = TimeDelta::Millis(10);
ScopedFieldTrials field_trials(
"WebRTC-Pacer-DynamicPaddingTarget/timedelta:10ms/");
SetUp();
const uint32_t kSsrc = 12345;
const DataRate kPacingDataRate = DataRate::KilobitsPerSec(125);
const DataSize kPacketSize = DataSize::Bytes(130);
uint32_t sequnce_number = 1;
// Start with pacing and padding rate equal.
pacer_->SetPacingRates(kPacingDataRate, kPacingDataRate);
// Send a single packet.
SendAndExpectPacket(RtpPacketMediaType::kVideo, kSsrc, sequnce_number++,
clock_.TimeInMilliseconds(), kPacketSize.bytes());
AdvanceTimeAndProcess();
::testing::Mock::VerifyAndClearExpectations(&callback_);
size_t expected_padding_target_bytes =
(kPaddingTarget * kPacingDataRate).bytes();
EXPECT_CALL(callback_, SendPadding(expected_padding_target_bytes))
.WillOnce(Return(expected_padding_target_bytes));
AdvanceTimeAndProcess();
// Half the padding rate - expect half the padding target.
pacer_->SetPacingRates(kPacingDataRate, kPacingDataRate / 2);
EXPECT_CALL(callback_, SendPadding(expected_padding_target_bytes / 2))
.WillOnce(Return(expected_padding_target_bytes / 2));
AdvanceTimeAndProcess();
}
TEST_P(PacingControllerTest, SendsDeferredFecPackets) {
ScopedFieldTrials trial("WebRTC-DeferredFecGeneration/Enabled/");
SetUp();
const uint32_t kSsrc = 12345;
const uint32_t kFlexSsrc = 54321;
uint16_t sequence_number = 1234;
uint16_t flexfec_sequence_number = 4321;
const size_t kPacketSize = 123;
// Set pacing rate to 1000 packet/s, no padding.
pacer_->SetPacingRates(
DataSize::Bytes(1000 * kPacketSize) / TimeDelta::Seconds(1),
DataRate::Zero());
int64_t now = clock_.TimeInMilliseconds();
Send(RtpPacketMediaType::kVideo, kSsrc, sequence_number, now, kPacketSize);
EXPECT_CALL(callback_, SendPacket(kSsrc, sequence_number, now, false, false));
EXPECT_CALL(callback_, FetchFec).WillOnce([&]() {
EXPECT_CALL(callback_, SendPacket(kFlexSsrc, flexfec_sequence_number, now,
false, false));
EXPECT_CALL(callback_, FetchFec);
std::vector<std::unique_ptr<RtpPacketToSend>> fec_packets;
fec_packets.push_back(
BuildPacket(RtpPacketMediaType::kForwardErrorCorrection, kFlexSsrc,
flexfec_sequence_number, now, kPacketSize));
return fec_packets;
});
AdvanceTimeAndProcess();
AdvanceTimeAndProcess();
}
INSTANTIATE_TEST_SUITE_P(
WithAndWithoutIntervalBudget,
PacingControllerTest,
::testing::Values(PacingController::ProcessMode::kPeriodic,
PacingController::ProcessMode::kDynamic));
} // namespace test
} // namespace webrtc