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
|
/*
* 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.
*/
// MSVC++ requires this to be set before any other includes to get M_PI.
#define _USE_MATH_DEFINES
#include <cmath>
#include "testing/gtest/include/gtest/gtest.h"
#include "webrtc/common_audio/channel_buffer.h"
#include "webrtc/modules/audio_processing/splitting_filter.h"
namespace webrtc {
namespace {
const size_t kSamplesPer16kHzChannel = 160;
const size_t kSamplesPer48kHzChannel = 480;
} // namespace
// Generates a signal from presence or absence of sine waves of different
// frequencies.
// Splits into 3 bands and checks their presence or absence.
// Recombines the bands.
// Calculates the delay.
// Checks that the cross correlation of input and output is high enough at the
// calculated delay.
TEST(SplittingFilterTest, SplitsIntoThreeBandsAndReconstructs) {
static const int kChannels = 1;
static const int kSampleRateHz = 48000;
static const size_t kNumBands = 3;
static const int kFrequenciesHz[kNumBands] = {1000, 12000, 18000};
static const float kAmplitude = 8192.f;
static const size_t kChunks = 8;
SplittingFilter splitting_filter(kChannels,
kNumBands,
kSamplesPer48kHzChannel);
IFChannelBuffer in_data(kSamplesPer48kHzChannel, kChannels, kNumBands);
IFChannelBuffer bands(kSamplesPer48kHzChannel, kChannels, kNumBands);
IFChannelBuffer out_data(kSamplesPer48kHzChannel, kChannels, kNumBands);
for (size_t i = 0; i < kChunks; ++i) {
// Input signal generation.
bool is_present[kNumBands];
memset(in_data.fbuf()->channels()[0],
0,
kSamplesPer48kHzChannel * sizeof(in_data.fbuf()->channels()[0][0]));
for (size_t j = 0; j < kNumBands; ++j) {
is_present[j] = i & (static_cast<size_t>(1) << j);
float amplitude = is_present[j] ? kAmplitude : 0.f;
for (size_t k = 0; k < kSamplesPer48kHzChannel; ++k) {
in_data.fbuf()->channels()[0][k] +=
amplitude * sin(2.f * M_PI * kFrequenciesHz[j] *
(i * kSamplesPer48kHzChannel + k) / kSampleRateHz);
}
}
// Three band splitting filter.
splitting_filter.Analysis(&in_data, &bands);
// Energy calculation.
float energy[kNumBands];
for (size_t j = 0; j < kNumBands; ++j) {
energy[j] = 0.f;
for (size_t k = 0; k < kSamplesPer16kHzChannel; ++k) {
energy[j] += bands.fbuf_const()->channels(j)[0][k] *
bands.fbuf_const()->channels(j)[0][k];
}
energy[j] /= kSamplesPer16kHzChannel;
if (is_present[j]) {
EXPECT_GT(energy[j], kAmplitude * kAmplitude / 4);
} else {
EXPECT_LT(energy[j], kAmplitude * kAmplitude / 4);
}
}
// Three band merge.
splitting_filter.Synthesis(&bands, &out_data);
// Delay and cross correlation estimation.
float xcorr = 0.f;
for (size_t delay = 0; delay < kSamplesPer48kHzChannel; ++delay) {
float tmpcorr = 0.f;
for (size_t j = delay; j < kSamplesPer48kHzChannel; ++j) {
tmpcorr += in_data.fbuf_const()->channels()[0][j - delay] *
out_data.fbuf_const()->channels()[0][j];
}
tmpcorr /= kSamplesPer48kHzChannel;
if (tmpcorr > xcorr) {
xcorr = tmpcorr;
}
}
// High cross correlation check.
bool any_present = false;
for (size_t j = 0; j < kNumBands; ++j) {
any_present |= is_present[j];
}
if (any_present) {
EXPECT_GT(xcorr, kAmplitude * kAmplitude / 4);
}
}
}
} // namespace webrtc
|
