1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
/* Copyright (c) 2014 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 "webrtc/modules/video_coding/jitter_estimator.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "webrtc/system_wrappers/include/clock.h"
namespace webrtc {
class TestEstimator : public VCMJitterEstimator {
public:
explicit TestEstimator(bool exp_enabled)
: VCMJitterEstimator(&fake_clock_, 0, 0),
fake_clock_(0),
exp_enabled_(exp_enabled) {}
virtual bool LowRateExperimentEnabled() { return exp_enabled_; }
void AdvanceClock(int64_t microseconds) {
fake_clock_.AdvanceTimeMicroseconds(microseconds);
}
private:
SimulatedClock fake_clock_;
const bool exp_enabled_;
};
class TestVCMJitterEstimator : public ::testing::Test {
protected:
TestVCMJitterEstimator()
: regular_estimator_(false), low_rate_estimator_(true) {}
virtual void SetUp() { regular_estimator_.Reset(); }
TestEstimator regular_estimator_;
TestEstimator low_rate_estimator_;
};
// Generates some simple test data in the form of a sawtooth wave.
class ValueGenerator {
public:
ValueGenerator(int32_t amplitude) : amplitude_(amplitude), counter_(0) {}
virtual ~ValueGenerator() {}
int64_t Delay() { return ((counter_ % 11) - 5) * amplitude_; }
uint32_t FrameSize() { return 1000 + Delay(); }
void Advance() { ++counter_; }
private:
const int32_t amplitude_;
int64_t counter_;
};
// 5 fps, disable jitter delay altogether.
TEST_F(TestVCMJitterEstimator, TestLowRate) {
ValueGenerator gen(10);
uint64_t time_delta = 1000000 / 5;
for (int i = 0; i < 60; ++i) {
regular_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
regular_estimator_.AdvanceClock(time_delta);
low_rate_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
low_rate_estimator_.AdvanceClock(time_delta);
EXPECT_GT(regular_estimator_.GetJitterEstimate(0), 0);
if (i > 2)
EXPECT_EQ(low_rate_estimator_.GetJitterEstimate(0), 0);
gen.Advance();
}
}
// 8 fps, steady state estimate should be in interpolated interval between 0
// and value of previous method.
TEST_F(TestVCMJitterEstimator, TestMidRate) {
ValueGenerator gen(10);
uint64_t time_delta = 1000000 / 8;
for (int i = 0; i < 60; ++i) {
regular_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
regular_estimator_.AdvanceClock(time_delta);
low_rate_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
low_rate_estimator_.AdvanceClock(time_delta);
EXPECT_GT(regular_estimator_.GetJitterEstimate(0), 0);
EXPECT_GT(low_rate_estimator_.GetJitterEstimate(0), 0);
EXPECT_GE(regular_estimator_.GetJitterEstimate(0),
low_rate_estimator_.GetJitterEstimate(0));
gen.Advance();
}
}
// 30 fps, steady state estimate should be same as previous method.
TEST_F(TestVCMJitterEstimator, TestHighRate) {
ValueGenerator gen(10);
uint64_t time_delta = 1000000 / 30;
for (int i = 0; i < 60; ++i) {
regular_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
regular_estimator_.AdvanceClock(time_delta);
low_rate_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
low_rate_estimator_.AdvanceClock(time_delta);
EXPECT_EQ(regular_estimator_.GetJitterEstimate(0),
low_rate_estimator_.GetJitterEstimate(0));
gen.Advance();
}
}
// 10 fps, high jitter then low jitter. Low rate estimator should converge
// faster to low noise estimate.
TEST_F(TestVCMJitterEstimator, TestConvergence) {
// Reach a steady state with high noise.
ValueGenerator gen(50);
uint64_t time_delta = 1000000 / 10;
for (int i = 0; i < 100; ++i) {
regular_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
regular_estimator_.AdvanceClock(time_delta * 2);
low_rate_estimator_.UpdateEstimate(gen.Delay(), gen.FrameSize());
low_rate_estimator_.AdvanceClock(time_delta * 2);
gen.Advance();
}
int threshold = regular_estimator_.GetJitterEstimate(0) / 2;
// New generator with zero noise.
ValueGenerator low_gen(0);
int regular_iterations = 0;
int low_rate_iterations = 0;
for (int i = 0; i < 500; ++i) {
if (regular_iterations == 0) {
regular_estimator_.UpdateEstimate(low_gen.Delay(), low_gen.FrameSize());
regular_estimator_.AdvanceClock(time_delta);
if (regular_estimator_.GetJitterEstimate(0) < threshold) {
regular_iterations = i;
}
}
if (low_rate_iterations == 0) {
low_rate_estimator_.UpdateEstimate(low_gen.Delay(), low_gen.FrameSize());
low_rate_estimator_.AdvanceClock(time_delta);
if (low_rate_estimator_.GetJitterEstimate(0) < threshold) {
low_rate_iterations = i;
}
}
if (regular_iterations != 0 && low_rate_iterations != 0) {
break;
}
gen.Advance();
}
EXPECT_NE(regular_iterations, 0);
EXPECT_NE(low_rate_iterations, 0);
EXPECT_LE(low_rate_iterations, regular_iterations);
}
}
|
