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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
// MSVC++ requires this to be set before any other includes to get M_PI.
#define _USE_MATH_DEFINES
#include "modules/audio_processing/rms_level.h"
#include <cmath>
#include <memory>
#include <vector>
#include "api/array_view.h"
#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "test/gtest.h"
namespace webrtc {
namespace {
constexpr int kSampleRateHz = 48000;
constexpr size_t kBlockSizeSamples = kSampleRateHz / 100;
std::unique_ptr<RmsLevel> RunTest(ArrayView<const int16_t> input) {
std::unique_ptr<RmsLevel> level(new RmsLevel);
for (size_t n = 0; n + kBlockSizeSamples <= input.size();
n += kBlockSizeSamples) {
level->Analyze(input.subview(n, kBlockSizeSamples));
}
return level;
}
std::unique_ptr<RmsLevel> RunTest(ArrayView<const float> input) {
std::unique_ptr<RmsLevel> level(new RmsLevel);
for (size_t n = 0; n + kBlockSizeSamples <= input.size();
n += kBlockSizeSamples) {
level->Analyze(input.subview(n, kBlockSizeSamples));
}
return level;
}
std::vector<int16_t> CreateInt16Sinusoid(int frequency_hz,
int amplitude,
size_t num_samples) {
std::vector<int16_t> x(num_samples);
for (size_t n = 0; n < num_samples; ++n) {
x[n] = saturated_cast<int16_t>(
amplitude * std::sin(2 * M_PI * n * frequency_hz / kSampleRateHz));
}
return x;
}
std::vector<float> CreateFloatSinusoid(int frequency_hz,
int amplitude,
size_t num_samples) {
std::vector<int16_t> x16 =
CreateInt16Sinusoid(frequency_hz, amplitude, num_samples);
std::vector<float> x(x16.size());
for (size_t n = 0; n < x.size(); ++n) {
x[n] = x16[n];
}
return x;
}
} // namespace
TEST(RmsLevelTest, VerifyIndentityBetweenFloatAndFix) {
auto x_f = CreateFloatSinusoid(1000, INT16_MAX, kSampleRateHz);
auto x_i = CreateFloatSinusoid(1000, INT16_MAX, kSampleRateHz);
auto level_f = RunTest(x_f);
auto level_i = RunTest(x_i);
int avg_i = level_i->Average();
int avg_f = level_f->Average();
EXPECT_EQ(3, avg_i); // -3 dBFS
EXPECT_EQ(avg_f, avg_i);
}
TEST(RmsLevelTest, Run1000HzFullScale) {
auto x = CreateInt16Sinusoid(1000, INT16_MAX, kSampleRateHz);
auto level = RunTest(x);
EXPECT_EQ(3, level->Average()); // -3 dBFS
}
TEST(RmsLevelTest, Run1000HzFullScaleAverageAndPeak) {
auto x = CreateInt16Sinusoid(1000, INT16_MAX, kSampleRateHz);
auto level = RunTest(x);
auto stats = level->AverageAndPeak();
EXPECT_EQ(3, stats.average); // -3 dBFS
EXPECT_EQ(3, stats.peak);
}
TEST(RmsLevelTest, Run1000HzHalfScale) {
auto x = CreateInt16Sinusoid(1000, INT16_MAX / 2, kSampleRateHz);
auto level = RunTest(x);
EXPECT_EQ(9, level->Average()); // -9 dBFS
}
TEST(RmsLevelTest, RunZeros) {
std::vector<int16_t> x(kSampleRateHz, 0); // 1 second of pure silence.
auto level = RunTest(x);
EXPECT_EQ(127, level->Average());
}
TEST(RmsLevelTest, RunZerosAverageAndPeak) {
std::vector<int16_t> x(kSampleRateHz, 0); // 1 second of pure silence.
auto level = RunTest(x);
auto stats = level->AverageAndPeak();
EXPECT_EQ(127, stats.average);
EXPECT_EQ(127, stats.peak);
}
TEST(RmsLevelTest, NoSamples) {
RmsLevel level;
EXPECT_EQ(127, level.Average()); // Return minimum if no samples are given.
}
TEST(RmsLevelTest, NoSamplesAverageAndPeak) {
RmsLevel level;
auto stats = level.AverageAndPeak();
EXPECT_EQ(127, stats.average);
EXPECT_EQ(127, stats.peak);
}
TEST(RmsLevelTest, PollTwice) {
auto x = CreateInt16Sinusoid(1000, INT16_MAX, kSampleRateHz);
auto level = RunTest(x);
level->Average();
EXPECT_EQ(127, level->Average()); // Stats should be reset at this point.
}
TEST(RmsLevelTest, Reset) {
auto x = CreateInt16Sinusoid(1000, INT16_MAX, kSampleRateHz);
auto level = RunTest(x);
level->Reset();
EXPECT_EQ(127, level->Average()); // Stats should be reset at this point.
}
// Inserts 1 second of full-scale sinusoid, followed by 1 second of muted.
TEST(RmsLevelTest, ProcessMuted) {
auto x = CreateInt16Sinusoid(1000, INT16_MAX, kSampleRateHz);
auto level = RunTest(x);
const size_t kBlocksPerSecond =
CheckedDivExact(static_cast<size_t>(kSampleRateHz), kBlockSizeSamples);
for (size_t i = 0; i < kBlocksPerSecond; ++i) {
level->AnalyzeMuted(kBlockSizeSamples);
}
EXPECT_EQ(6, level->Average()); // Average RMS halved due to the silence.
}
// Digital silence must yield 127 and anything else should yield 126 or lower.
TEST(RmsLevelTest, OnlyDigitalSilenceIs127) {
std::vector<int16_t> test_buffer(kSampleRateHz, 0);
auto level = RunTest(test_buffer);
EXPECT_EQ(127, level->Average());
// Change one sample to something other than 0 to make the buffer not strictly
// represent digital silence.
test_buffer[0] = 1;
level = RunTest(test_buffer);
EXPECT_LT(level->Average(), 127);
}
// Inserts 1 second of half-scale sinusoid, follwed by 10 ms of full-scale, and
// finally 1 second of half-scale again. Expect the average to be -9 dBFS due
// to the vast majority of the signal being half-scale, and the peak to be
// -3 dBFS.
TEST(RmsLevelTest, RunHalfScaleAndInsertFullScale) {
auto half_scale = CreateInt16Sinusoid(1000, INT16_MAX / 2, kSampleRateHz);
auto full_scale = CreateInt16Sinusoid(1000, INT16_MAX, kSampleRateHz / 100);
auto x = half_scale;
x.insert(x.end(), full_scale.begin(), full_scale.end());
x.insert(x.end(), half_scale.begin(), half_scale.end());
ASSERT_EQ(static_cast<size_t>(2 * kSampleRateHz + kSampleRateHz / 100),
x.size());
auto level = RunTest(x);
auto stats = level->AverageAndPeak();
EXPECT_EQ(9, stats.average);
EXPECT_EQ(3, stats.peak);
}
TEST(RmsLevelTest, ResetOnBlockSizeChange) {
auto x = CreateInt16Sinusoid(1000, INT16_MAX, kSampleRateHz);
auto level = RunTest(x);
// Create a new signal with half amplitude, but double block length.
auto y = CreateInt16Sinusoid(1000, INT16_MAX / 2, kBlockSizeSamples * 2);
level->Analyze(y);
auto stats = level->AverageAndPeak();
// Expect all stats to only be influenced by the last signal (y), since the
// changed block size should reset the stats.
EXPECT_EQ(9, stats.average);
EXPECT_EQ(9, stats.peak);
}
} // namespace webrtc
|
