1 /*
2 * Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "webrtc/modules/remote_bitrate_estimator/test/metric_recorder.h"
12
13 #include <math.h>
14 #include <algorithm>
15 #include <vector>
16
17 #include "testing/gtest/include/gtest/gtest.h"
18
19 namespace webrtc {
20 namespace testing {
21 namespace bwe {
22
23 class MetricRecorderTest : public ::testing::Test {
24 public:
MetricRecorderTest()25 MetricRecorderTest() : metric_recorder_("Test", 0, nullptr, nullptr) {}
26
~MetricRecorderTest()27 ~MetricRecorderTest() {}
28
29 protected:
30 MetricRecorder metric_recorder_;
31 };
32
TEST_F(MetricRecorderTest,NoPackets)33 TEST_F(MetricRecorderTest, NoPackets) {
34 EXPECT_EQ(metric_recorder_.AverageBitrateKbps(0), 0);
35 EXPECT_EQ(metric_recorder_.DelayStdDev(), 0.0);
36 EXPECT_EQ(metric_recorder_.NthDelayPercentile(0), 0);
37 EXPECT_EQ(metric_recorder_.NthDelayPercentile(5), 0);
38 EXPECT_EQ(metric_recorder_.NthDelayPercentile(95), 0);
39 EXPECT_EQ(metric_recorder_.NthDelayPercentile(100), 0);
40 }
41
TEST_F(MetricRecorderTest,RegularPackets)42 TEST_F(MetricRecorderTest, RegularPackets) {
43 const size_t kPayloadSizeBytes = 1200;
44 const int64_t kDelayMs = 20;
45 const int64_t kInterpacketGapMs = 5;
46 const int kNumPackets = 1000;
47
48 for (int i = 0; i < kNumPackets; ++i) {
49 int64_t arrival_time_ms = kInterpacketGapMs * i + kDelayMs;
50 metric_recorder_.UpdateTimeMs(arrival_time_ms);
51 metric_recorder_.PushDelayMs(kDelayMs, arrival_time_ms);
52 metric_recorder_.PushThroughputBytes(kPayloadSizeBytes, arrival_time_ms);
53 }
54
55 EXPECT_NEAR(
56 metric_recorder_.AverageBitrateKbps(0),
57 static_cast<uint32_t>(kPayloadSizeBytes * 8) / (kInterpacketGapMs), 10);
58
59 EXPECT_EQ(metric_recorder_.DelayStdDev(), 0.0);
60
61 EXPECT_EQ(metric_recorder_.NthDelayPercentile(0), kDelayMs);
62 EXPECT_EQ(metric_recorder_.NthDelayPercentile(5), kDelayMs);
63 EXPECT_EQ(metric_recorder_.NthDelayPercentile(95), kDelayMs);
64 EXPECT_EQ(metric_recorder_.NthDelayPercentile(100), kDelayMs);
65 }
66
TEST_F(MetricRecorderTest,VariableDelayPackets)67 TEST_F(MetricRecorderTest, VariableDelayPackets) {
68 const size_t kPayloadSizeBytes = 1200;
69 const int64_t kInterpacketGapMs = 2000;
70 const int kNumPackets = 1000;
71
72 std::vector<int64_t> delays_ms;
73 for (int i = 0; i < kNumPackets; ++i) {
74 delays_ms.push_back(static_cast<int64_t>(i + 1));
75 }
76 // Order of packets should not matter here.
77 std::random_shuffle(delays_ms.begin(), delays_ms.end());
78
79 int first_received_ms = delays_ms[0];
80 int64_t last_received_ms = 0;
81 for (int i = 0; i < kNumPackets; ++i) {
82 int64_t arrival_time_ms = kInterpacketGapMs * i + delays_ms[i];
83 last_received_ms = std::max(last_received_ms, arrival_time_ms);
84 metric_recorder_.UpdateTimeMs(arrival_time_ms);
85 metric_recorder_.PushDelayMs(delays_ms[i], arrival_time_ms);
86 metric_recorder_.PushThroughputBytes(kPayloadSizeBytes, arrival_time_ms);
87 }
88
89 size_t received_bits = kPayloadSizeBytes * 8 * kNumPackets;
90 EXPECT_NEAR(metric_recorder_.AverageBitrateKbps(0),
91 static_cast<uint32_t>(received_bits) /
92 ((last_received_ms - first_received_ms)),
93 10);
94
95 double expected_x = (kNumPackets + 1) / 2.0;
96 double expected_x2 = ((kNumPackets + 1) * (2 * kNumPackets + 1)) / 6.0;
97 double var = expected_x2 - pow(expected_x, 2.0);
98 EXPECT_NEAR(metric_recorder_.DelayStdDev(), sqrt(var), kNumPackets / 1000.0);
99
100 EXPECT_EQ(metric_recorder_.NthDelayPercentile(0), 1);
101 EXPECT_EQ(metric_recorder_.NthDelayPercentile(5), (5 * kNumPackets) / 100);
102 EXPECT_EQ(metric_recorder_.NthDelayPercentile(95), (95 * kNumPackets) / 100);
103 EXPECT_EQ(metric_recorder_.NthDelayPercentile(100), kNumPackets);
104 }
105
106 } // namespace bwe
107 } // namespace testing
108 } // namespace webrtc
109