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/*
* Copyright (c) 2015 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/remote_bitrate_estimator/test/estimators/nada.h"
#include <math.h>
#include <stddef.h>
#include <algorithm>
#include <memory>
#include "modules/remote_bitrate_estimator/test/packet.h"
#include "rtc_base/arraysize.h"
#include "test/gtest.h"
namespace webrtc {
namespace testing {
namespace bwe {
class FilterTest : public ::testing::Test {
public:
void MedianFilterConstantArray() {
std::fill_n(raw_signal_, kNumElements, kSignalValue);
for (int i = 0; i < kNumElements; ++i) {
int size = std::min(5, i + 1);
median_filtered_[i] =
NadaBweReceiver::MedianFilter(&raw_signal_[i + 1 - size], size);
}
}
void MedianFilterIntermittentNoise() {
const int kValue = 500;
const int kNoise = 100;
for (int i = 0; i < kNumElements; ++i) {
raw_signal_[i] = kValue + kNoise * (i % 10 == 9 ? 1 : 0);
}
for (int i = 0; i < kNumElements; ++i) {
int size = std::min(5, i + 1);
median_filtered_[i] =
NadaBweReceiver::MedianFilter(&raw_signal_[i + 1 - size], size);
EXPECT_EQ(median_filtered_[i], kValue);
}
}
void ExponentialSmoothingFilter(const int64_t raw_signal_[],
int num_elements,
int64_t exp_smoothed[]) {
exp_smoothed[0] =
NadaBweReceiver::ExponentialSmoothingFilter(raw_signal_[0], -1, kAlpha);
for (int i = 1; i < num_elements; ++i) {
exp_smoothed[i] = NadaBweReceiver::ExponentialSmoothingFilter(
raw_signal_[i], exp_smoothed[i - 1], kAlpha);
}
}
void ExponentialSmoothingConstantArray(int64_t exp_smoothed[]) {
std::fill_n(raw_signal_, kNumElements, kSignalValue);
ExponentialSmoothingFilter(raw_signal_, kNumElements, exp_smoothed);
}
protected:
static const int kNumElements = 1000;
static const int64_t kSignalValue;
static const float kAlpha;
int64_t raw_signal_[kNumElements];
int64_t median_filtered_[kNumElements];
};
const int64_t FilterTest::kSignalValue = 200;
const float FilterTest::kAlpha = 0.1f;
class TestBitrateObserver : public BitrateObserver {
public:
TestBitrateObserver()
: last_bitrate_(0), last_fraction_loss_(0), last_rtt_(0) {}
virtual void OnNetworkChanged(uint32_t bitrate,
uint8_t fraction_loss,
int64_t rtt) {
last_bitrate_ = bitrate;
last_fraction_loss_ = fraction_loss;
last_rtt_ = rtt;
}
uint32_t last_bitrate_;
uint8_t last_fraction_loss_;
int64_t last_rtt_;
};
class NadaSenderSideTest : public ::testing::Test {
public:
NadaSenderSideTest()
: observer_(),
simulated_clock_(0),
nada_sender_(&observer_, &simulated_clock_) {}
~NadaSenderSideTest() {}
private:
TestBitrateObserver observer_;
SimulatedClock simulated_clock_;
protected:
NadaBweSender nada_sender_;
};
class NadaReceiverSideTest : public ::testing::Test {
public:
NadaReceiverSideTest() : nada_receiver_(kFlowId) {}
~NadaReceiverSideTest() {}
protected:
const int kFlowId = 1; // Arbitrary.
NadaBweReceiver nada_receiver_;
};
class NadaFbGenerator {
public:
NadaFbGenerator();
static NadaFeedback NotCongestedFb(size_t receiving_rate,
int64_t ref_signal_ms,
int64_t send_time_ms) {
int64_t exp_smoothed_delay_ms = ref_signal_ms;
int64_t est_queuing_delay_signal_ms = ref_signal_ms;
int64_t congestion_signal_ms = ref_signal_ms;
float derivative = 0.0f;
return NadaFeedback(kFlowId, kNowMs, exp_smoothed_delay_ms,
est_queuing_delay_signal_ms, congestion_signal_ms,
derivative, receiving_rate, send_time_ms);
}
static NadaFeedback CongestedFb(size_t receiving_rate, int64_t send_time_ms) {
int64_t exp_smoothed_delay_ms = 1000;
int64_t est_queuing_delay_signal_ms = 800;
int64_t congestion_signal_ms = 1000;
float derivative = 1.0f;
return NadaFeedback(kFlowId, kNowMs, exp_smoothed_delay_ms,
est_queuing_delay_signal_ms, congestion_signal_ms,
derivative, receiving_rate, send_time_ms);
}
static NadaFeedback ExtremelyCongestedFb(size_t receiving_rate,
int64_t send_time_ms) {
int64_t exp_smoothed_delay_ms = 100000;
int64_t est_queuing_delay_signal_ms = 0;
int64_t congestion_signal_ms = 100000;
float derivative = 10000.0f;
return NadaFeedback(kFlowId, kNowMs, exp_smoothed_delay_ms,
est_queuing_delay_signal_ms, congestion_signal_ms,
derivative, receiving_rate, send_time_ms);
}
private:
// Arbitrary values, won't change these test results.
static const int kFlowId = 2;
static const int64_t kNowMs = 1000;
};
// Verify if AcceleratedRampUp is called and that bitrate increases.
TEST_F(NadaSenderSideTest, AcceleratedRampUp) {
const int64_t kRefSignalMs = 1;
const int64_t kOneWayDelayMs = 50;
int original_bitrate = 2 * NadaBweSender::kMinNadaBitrateKbps;
size_t receiving_rate = static_cast<size_t>(original_bitrate);
int64_t send_time_ms = nada_sender_.NowMs() - kOneWayDelayMs;
NadaFeedback not_congested_fb = NadaFbGenerator::NotCongestedFb(
receiving_rate, kRefSignalMs, send_time_ms);
nada_sender_.set_original_operating_mode(true);
nada_sender_.set_bitrate_kbps(original_bitrate);
// Trigger AcceleratedRampUp mode.
nada_sender_.GiveFeedback(not_congested_fb);
int bitrate_1_kbps = nada_sender_.bitrate_kbps();
EXPECT_GT(bitrate_1_kbps, original_bitrate);
// Updates the bitrate according to the receiving rate and other constant
// parameters.
nada_sender_.AcceleratedRampUp(not_congested_fb);
EXPECT_EQ(nada_sender_.bitrate_kbps(), bitrate_1_kbps);
nada_sender_.set_original_operating_mode(false);
nada_sender_.set_bitrate_kbps(original_bitrate);
// Trigger AcceleratedRampUp mode.
nada_sender_.GiveFeedback(not_congested_fb);
bitrate_1_kbps = nada_sender_.bitrate_kbps();
EXPECT_GT(bitrate_1_kbps, original_bitrate);
nada_sender_.AcceleratedRampUp(not_congested_fb);
EXPECT_EQ(nada_sender_.bitrate_kbps(), bitrate_1_kbps);
}
// Verify if AcceleratedRampDown is called and if bitrate decreases.
TEST_F(NadaSenderSideTest, AcceleratedRampDown) {
const int64_t kOneWayDelayMs = 50;
int original_bitrate = 3 * NadaBweSender::kMinNadaBitrateKbps;
size_t receiving_rate = static_cast<size_t>(original_bitrate);
int64_t send_time_ms = nada_sender_.NowMs() - kOneWayDelayMs;
NadaFeedback congested_fb =
NadaFbGenerator::CongestedFb(receiving_rate, send_time_ms);
nada_sender_.set_original_operating_mode(false);
nada_sender_.set_bitrate_kbps(original_bitrate);
nada_sender_.GiveFeedback(congested_fb); // Trigger AcceleratedRampDown mode.
int bitrate_1_kbps = nada_sender_.bitrate_kbps();
EXPECT_LE(bitrate_1_kbps, original_bitrate * 0.9f + 0.5f);
EXPECT_LT(bitrate_1_kbps, original_bitrate);
// Updates the bitrate according to the receiving rate and other constant
// parameters.
nada_sender_.AcceleratedRampDown(congested_fb);
int bitrate_2_kbps =
std::max(nada_sender_.bitrate_kbps(), NadaBweSender::kMinNadaBitrateKbps);
EXPECT_EQ(bitrate_2_kbps, bitrate_1_kbps);
}
TEST_F(NadaSenderSideTest, GradualRateUpdate) {
const int64_t kDeltaSMs = 20;
const int64_t kRefSignalMs = 20;
const int64_t kOneWayDelayMs = 50;
int original_bitrate = 5 * NadaBweSender::kMinNadaBitrateKbps;
size_t receiving_rate = static_cast<size_t>(original_bitrate);
int64_t send_time_ms = nada_sender_.NowMs() - kOneWayDelayMs;
NadaFeedback congested_fb =
NadaFbGenerator::CongestedFb(receiving_rate, send_time_ms);
NadaFeedback not_congested_fb = NadaFbGenerator::NotCongestedFb(
original_bitrate, kRefSignalMs, send_time_ms);
nada_sender_.set_bitrate_kbps(original_bitrate);
double smoothing_factor = 0.0;
nada_sender_.GradualRateUpdate(congested_fb, kDeltaSMs, smoothing_factor);
EXPECT_EQ(nada_sender_.bitrate_kbps(), original_bitrate);
smoothing_factor = 1.0;
nada_sender_.GradualRateUpdate(congested_fb, kDeltaSMs, smoothing_factor);
EXPECT_LT(nada_sender_.bitrate_kbps(), original_bitrate);
nada_sender_.set_bitrate_kbps(original_bitrate);
nada_sender_.GradualRateUpdate(not_congested_fb, kDeltaSMs, smoothing_factor);
EXPECT_GT(nada_sender_.bitrate_kbps(), original_bitrate);
}
// Sending bitrate should decrease and reach its Min bound.
TEST_F(NadaSenderSideTest, VeryLowBandwith) {
const int64_t kOneWayDelayMs = 50;
size_t receiving_rate =
static_cast<size_t>(NadaBweSender::kMinNadaBitrateKbps);
int64_t send_time_ms = nada_sender_.NowMs() - kOneWayDelayMs;
NadaFeedback extremely_congested_fb =
NadaFbGenerator::ExtremelyCongestedFb(receiving_rate, send_time_ms);
NadaFeedback congested_fb =
NadaFbGenerator::CongestedFb(receiving_rate, send_time_ms);
nada_sender_.set_bitrate_kbps(5 * NadaBweSender::kMinNadaBitrateKbps);
nada_sender_.set_original_operating_mode(true);
for (int i = 0; i < 100; ++i) {
// Trigger GradualRateUpdate mode.
nada_sender_.GiveFeedback(extremely_congested_fb);
}
// The original implementation doesn't allow the bitrate to stay at kMin,
// even if the congestion signal is very high.
EXPECT_GE(nada_sender_.bitrate_kbps(), NadaBweSender::kMinNadaBitrateKbps);
nada_sender_.set_original_operating_mode(false);
nada_sender_.set_bitrate_kbps(5 * NadaBweSender::kMinNadaBitrateKbps);
for (int i = 0; i < 1000; ++i) {
int previous_bitrate = nada_sender_.bitrate_kbps();
// Trigger AcceleratedRampDown mode.
nada_sender_.GiveFeedback(congested_fb);
EXPECT_LE(nada_sender_.bitrate_kbps(), previous_bitrate);
}
EXPECT_EQ(nada_sender_.bitrate_kbps(), NadaBweSender::kMinNadaBitrateKbps);
}
// Sending bitrate should increase and reach its Max bound.
TEST_F(NadaSenderSideTest, VeryHighBandwith) {
const int64_t kOneWayDelayMs = 50;
const size_t kRecentReceivingRate = static_cast<size_t>(kMaxBitrateKbps);
const int64_t kRefSignalMs = 1;
int64_t send_time_ms = nada_sender_.NowMs() - kOneWayDelayMs;
NadaFeedback not_congested_fb = NadaFbGenerator::NotCongestedFb(
kRecentReceivingRate, kRefSignalMs, send_time_ms);
nada_sender_.set_original_operating_mode(true);
for (int i = 0; i < 100; ++i) {
int previous_bitrate = nada_sender_.bitrate_kbps();
nada_sender_.GiveFeedback(not_congested_fb);
EXPECT_GE(nada_sender_.bitrate_kbps(), previous_bitrate);
}
EXPECT_EQ(nada_sender_.bitrate_kbps(), kMaxBitrateKbps);
nada_sender_.set_original_operating_mode(false);
nada_sender_.set_bitrate_kbps(NadaBweSender::kMinNadaBitrateKbps);
for (int i = 0; i < 100; ++i) {
int previous_bitrate = nada_sender_.bitrate_kbps();
nada_sender_.GiveFeedback(not_congested_fb);
EXPECT_GE(nada_sender_.bitrate_kbps(), previous_bitrate);
}
EXPECT_EQ(nada_sender_.bitrate_kbps(), kMaxBitrateKbps);
}
TEST_F(NadaReceiverSideTest, FeedbackInitialCases) {
std::unique_ptr<NadaFeedback> nada_feedback(
static_cast<NadaFeedback*>(nada_receiver_.GetFeedback(0)));
EXPECT_EQ(nada_feedback, nullptr);
nada_feedback.reset(
static_cast<NadaFeedback*>(nada_receiver_.GetFeedback(100)));
EXPECT_EQ(nada_feedback->exp_smoothed_delay_ms(), -1);
EXPECT_EQ(nada_feedback->est_queuing_delay_signal_ms(), 0L);
EXPECT_EQ(nada_feedback->congestion_signal(), 0L);
EXPECT_EQ(nada_feedback->derivative(), 0.0f);
EXPECT_EQ(nada_feedback->receiving_rate(), 0.0f);
}
TEST_F(NadaReceiverSideTest, FeedbackEmptyQueues) {
const int64_t kTimeGapMs = 50; // Between each packet.
const int64_t kOneWayDelayMs = 50;
// No added latency, delay = kOneWayDelayMs.
for (int i = 1; i < 10; ++i) {
int64_t send_time_us = i * kTimeGapMs * 1000;
int64_t arrival_time_ms = send_time_us / 1000 + kOneWayDelayMs;
uint16_t sequence_number = static_cast<uint16_t>(i);
// Payload sizes are not important here.
const MediaPacket media_packet(kFlowId, send_time_us, 0, sequence_number);
nada_receiver_.ReceivePacket(arrival_time_ms, media_packet);
}
// Baseline delay will be equal kOneWayDelayMs.
std::unique_ptr<NadaFeedback> nada_feedback(
static_cast<NadaFeedback*>(nada_receiver_.GetFeedback(500)));
EXPECT_EQ(nada_feedback->exp_smoothed_delay_ms(), 0L);
EXPECT_EQ(nada_feedback->est_queuing_delay_signal_ms(), 0L);
EXPECT_EQ(nada_feedback->congestion_signal(), 0L);
EXPECT_EQ(nada_feedback->derivative(), 0.0f);
}
TEST_F(NadaReceiverSideTest, FeedbackIncreasingDelay) {
// Since packets are 100ms apart, each one corresponds to a feedback.
const int64_t kTimeGapMs = 100; // Between each packet.
// Raw delays are = [10 20 30 40 50 60 70 80] ms.
// Baseline delay will be 50 ms.
// Delay signals should be: [0 10 20 30 40 50 60 70] ms.
const int64_t kMedianFilteredDelaysMs[] = {0, 5, 10, 15, 20, 30, 40, 50};
const int kNumPackets = arraysize(kMedianFilteredDelaysMs);
const float kAlpha = 0.1f; // Used for exponential smoothing.
int64_t exp_smoothed_delays_ms[kNumPackets];
exp_smoothed_delays_ms[0] = kMedianFilteredDelaysMs[0];
for (int i = 1; i < kNumPackets; ++i) {
exp_smoothed_delays_ms[i] = static_cast<int64_t>(
kAlpha * kMedianFilteredDelaysMs[i] +
(1.0f - kAlpha) * exp_smoothed_delays_ms[i - 1] + 0.5f);
}
for (int i = 0; i < kNumPackets; ++i) {
int64_t send_time_us = (i + 1) * kTimeGapMs * 1000;
int64_t arrival_time_ms = send_time_us / 1000 + 10 * (i + 1);
uint16_t sequence_number = static_cast<uint16_t>(i + 1);
// Payload sizes are not important here.
const MediaPacket media_packet(kFlowId, send_time_us, 0, sequence_number);
nada_receiver_.ReceivePacket(arrival_time_ms, media_packet);
std::unique_ptr<NadaFeedback> nada_feedback(static_cast<NadaFeedback*>(
nada_receiver_.GetFeedback(arrival_time_ms)));
EXPECT_EQ(nada_feedback->exp_smoothed_delay_ms(),
exp_smoothed_delays_ms[i]);
// Since delay signals are lower than 50ms, they will not be non-linearly
// warped.
EXPECT_EQ(nada_feedback->est_queuing_delay_signal_ms(),
exp_smoothed_delays_ms[i]);
// Zero loss, congestion signal = queuing_delay
EXPECT_EQ(nada_feedback->congestion_signal(), exp_smoothed_delays_ms[i]);
if (i == 0) {
EXPECT_NEAR(nada_feedback->derivative(),
static_cast<float>(exp_smoothed_delays_ms[i]) / kTimeGapMs,
0.005f);
} else {
EXPECT_NEAR(nada_feedback->derivative(),
static_cast<float>(exp_smoothed_delays_ms[i] -
exp_smoothed_delays_ms[i - 1]) /
kTimeGapMs,
0.005f);
}
}
}
int64_t Warp(int64_t input) {
const int64_t kMinThreshold = 50; // Referred as d_th.
const int64_t kMaxThreshold = 400; // Referred as d_max.
if (input < kMinThreshold) {
return input;
} else if (input < kMaxThreshold) {
return static_cast<int64_t>(
pow((static_cast<double>(kMaxThreshold - input)) /
(kMaxThreshold - kMinThreshold),
4.0) *
kMinThreshold);
} else {
return 0L;
}
}
TEST_F(NadaReceiverSideTest, FeedbackWarpedDelay) {
// Since packets are 100ms apart, each one corresponds to a feedback.
const int64_t kTimeGapMs = 100; // Between each packet.
// Raw delays are = [50 250 450 650 850 1050 1250 1450] ms.
// Baseline delay will be 50 ms.
// Delay signals should be: [0 200 400 600 800 1000 1200 1400] ms.
const int64_t kMedianFilteredDelaysMs[] = {0, 100, 200, 300,
400, 600, 800, 1000};
const int kNumPackets = arraysize(kMedianFilteredDelaysMs);
const float kAlpha = 0.1f; // Used for exponential smoothing.
int64_t exp_smoothed_delays_ms[kNumPackets];
exp_smoothed_delays_ms[0] = kMedianFilteredDelaysMs[0];
for (int i = 1; i < kNumPackets; ++i) {
exp_smoothed_delays_ms[i] = static_cast<int64_t>(
kAlpha * kMedianFilteredDelaysMs[i] +
(1.0f - kAlpha) * exp_smoothed_delays_ms[i - 1] + 0.5f);
}
for (int i = 0; i < kNumPackets; ++i) {
int64_t send_time_us = (i + 1) * kTimeGapMs * 1000;
int64_t arrival_time_ms = send_time_us / 1000 + 50 + 200 * i;
uint16_t sequence_number = static_cast<uint16_t>(i + 1);
// Payload sizes are not important here.
const MediaPacket media_packet(kFlowId, send_time_us, 0, sequence_number);
nada_receiver_.ReceivePacket(arrival_time_ms, media_packet);
std::unique_ptr<NadaFeedback> nada_feedback(static_cast<NadaFeedback*>(
nada_receiver_.GetFeedback(arrival_time_ms)));
EXPECT_EQ(nada_feedback->exp_smoothed_delay_ms(),
exp_smoothed_delays_ms[i]);
// Delays can be non-linearly warped.
EXPECT_EQ(nada_feedback->est_queuing_delay_signal_ms(),
Warp(exp_smoothed_delays_ms[i]));
// Zero loss, congestion signal = queuing_delay
EXPECT_EQ(nada_feedback->congestion_signal(),
Warp(exp_smoothed_delays_ms[i]));
}
}
TEST_F(FilterTest, MedianConstantArray) {
MedianFilterConstantArray();
for (int i = 0; i < kNumElements; ++i) {
EXPECT_EQ(median_filtered_[i], raw_signal_[i]);
}
}
TEST_F(FilterTest, MedianIntermittentNoise) {
MedianFilterIntermittentNoise();
}
TEST_F(FilterTest, ExponentialSmoothingConstantArray) {
int64_t exp_smoothed[kNumElements];
ExponentialSmoothingConstantArray(exp_smoothed);
for (int i = 0; i < kNumElements; ++i) {
EXPECT_EQ(exp_smoothed[i], kSignalValue);
}
}
TEST_F(FilterTest, ExponentialSmoothingInitialPertubation) {
const int64_t kSignal[] = {90000, 0, 0, 0, 0, 0};
const int kNumElements = arraysize(kSignal);
int64_t exp_smoothed[kNumElements];
ExponentialSmoothingFilter(kSignal, kNumElements, exp_smoothed);
for (int i = 1; i < kNumElements; ++i) {
EXPECT_EQ(
exp_smoothed[i],
static_cast<int64_t>(exp_smoothed[i - 1] * (1.0f - kAlpha) + 0.5f));
}
}
} // namespace bwe
} // namespace testing
} // namespace webrtc