1 /*
2  *  Copyright (c) 2017 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 "modules/audio_processing/aec3/render_signal_analyzer.h"
12 
13 #include <math.h>
14 
15 #include <array>
16 #include <cmath>
17 #include <vector>
18 
19 #include "api/array_view.h"
20 #include "modules/audio_processing/aec3/aec3_common.h"
21 #include "modules/audio_processing/aec3/aec3_fft.h"
22 #include "modules/audio_processing/aec3/fft_data.h"
23 #include "modules/audio_processing/aec3/render_delay_buffer.h"
24 #include "modules/audio_processing/test/echo_canceller_test_tools.h"
25 #include "rtc_base/random.h"
26 #include "rtc_base/strings/string_builder.h"
27 #include "test/gtest.h"
28 
29 namespace webrtc {
30 namespace {
31 
32 constexpr float kPi = 3.141592f;
33 
ProduceSinusoidInNoise(int sample_rate_hz,size_t sinusoid_channel,float sinusoidal_frequency_hz,Random * random_generator,size_t * sample_counter,std::vector<std::vector<std::vector<float>>> * x)34 void ProduceSinusoidInNoise(int sample_rate_hz,
35                             size_t sinusoid_channel,
36                             float sinusoidal_frequency_hz,
37                             Random* random_generator,
38                             size_t* sample_counter,
39                             std::vector<std::vector<std::vector<float>>>* x) {
40   // Fill x with low-amplitude noise.
41   for (auto& band : *x) {
42     for (auto& channel : band) {
43       RandomizeSampleVector(random_generator, channel,
44                             /*amplitude=*/500.f);
45     }
46   }
47   // Produce a sinusoid of the specified frequency in the specified channel.
48   for (size_t k = *sample_counter, j = 0; k < (*sample_counter + kBlockSize);
49        ++k, ++j) {
50     (*x)[0][sinusoid_channel][j] +=
51         32000.f *
52         std::sin(2.f * kPi * sinusoidal_frequency_hz * k / sample_rate_hz);
53   }
54   *sample_counter = *sample_counter + kBlockSize;
55 }
56 
RunNarrowBandDetectionTest(size_t num_channels)57 void RunNarrowBandDetectionTest(size_t num_channels) {
58   RenderSignalAnalyzer analyzer(EchoCanceller3Config{});
59   Random random_generator(42U);
60   constexpr int kSampleRateHz = 48000;
61   constexpr size_t kNumBands = NumBandsForRate(kSampleRateHz);
62   std::vector<std::vector<std::vector<float>>> x(
63       kNumBands, std::vector<std::vector<float>>(
64                      num_channels, std::vector<float>(kBlockSize, 0.f)));
65   std::array<float, kBlockSize> x_old;
66   Aec3Fft fft;
67   EchoCanceller3Config config;
68   std::unique_ptr<RenderDelayBuffer> render_delay_buffer(
69       RenderDelayBuffer::Create(config, kSampleRateHz, num_channels));
70 
71   std::array<float, kFftLengthBy2Plus1> mask;
72   x_old.fill(0.f);
73   constexpr int kSinusFrequencyBin = 32;
74 
75   auto generate_sinusoid_test = [&](bool known_delay) {
76     size_t sample_counter = 0;
77     for (size_t k = 0; k < 100; ++k) {
78       ProduceSinusoidInNoise(16000, num_channels - 1,
79                              16000 / 2 * kSinusFrequencyBin / kFftLengthBy2,
80                              &random_generator, &sample_counter, &x);
81 
82       render_delay_buffer->Insert(x);
83       if (k == 0) {
84         render_delay_buffer->Reset();
85       }
86       render_delay_buffer->PrepareCaptureProcessing();
87 
88       analyzer.Update(*render_delay_buffer->GetRenderBuffer(),
89                       known_delay ? absl::optional<size_t>(0) : absl::nullopt);
90     }
91   };
92 
93   generate_sinusoid_test(true);
94   mask.fill(1.f);
95   analyzer.MaskRegionsAroundNarrowBands(&mask);
96   for (int k = 0; k < static_cast<int>(mask.size()); ++k) {
97     EXPECT_EQ(abs(k - kSinusFrequencyBin) <= 2 ? 0.f : 1.f, mask[k]);
98   }
99   EXPECT_TRUE(analyzer.PoorSignalExcitation());
100   EXPECT_TRUE(static_cast<bool>(analyzer.NarrowPeakBand()));
101   EXPECT_EQ(*analyzer.NarrowPeakBand(), 32);
102 
103   // Verify that no bands are detected as narrow when the delay is unknown.
104   generate_sinusoid_test(false);
105   mask.fill(1.f);
106   analyzer.MaskRegionsAroundNarrowBands(&mask);
107   std::for_each(mask.begin(), mask.end(), [](float a) { EXPECT_EQ(1.f, a); });
108   EXPECT_FALSE(analyzer.PoorSignalExcitation());
109 }
110 
ProduceDebugText(size_t num_channels)111 std::string ProduceDebugText(size_t num_channels) {
112   rtc::StringBuilder ss;
113   ss << "number of channels: " << num_channels;
114   return ss.Release();
115 }
116 }  // namespace
117 
118 #if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
119 // Verifies that the check for non-null output parameter works.
TEST(RenderSignalAnalyzerDeathTest,NullMaskOutput)120 TEST(RenderSignalAnalyzerDeathTest, NullMaskOutput) {
121   RenderSignalAnalyzer analyzer(EchoCanceller3Config{});
122   EXPECT_DEATH(analyzer.MaskRegionsAroundNarrowBands(nullptr), "");
123 }
124 
125 #endif
126 
127 // Verify that no narrow bands are detected in a Gaussian noise signal.
TEST(RenderSignalAnalyzer,NoFalseDetectionOfNarrowBands)128 TEST(RenderSignalAnalyzer, NoFalseDetectionOfNarrowBands) {
129   for (auto num_channels : {1, 2, 8}) {
130     SCOPED_TRACE(ProduceDebugText(num_channels));
131     RenderSignalAnalyzer analyzer(EchoCanceller3Config{});
132     Random random_generator(42U);
133     std::vector<std::vector<std::vector<float>>> x(
134         3, std::vector<std::vector<float>>(
135                num_channels, std::vector<float>(kBlockSize, 0.f)));
136     std::array<float, kBlockSize> x_old;
137     std::unique_ptr<RenderDelayBuffer> render_delay_buffer(
138         RenderDelayBuffer::Create(EchoCanceller3Config(), 48000, num_channels));
139     std::array<float, kFftLengthBy2Plus1> mask;
140     x_old.fill(0.f);
141 
142     for (size_t k = 0; k < 100; ++k) {
143       for (auto& band : x) {
144         for (auto& channel : band) {
145           RandomizeSampleVector(&random_generator, channel);
146         }
147       }
148 
149       render_delay_buffer->Insert(x);
150       if (k == 0) {
151         render_delay_buffer->Reset();
152       }
153       render_delay_buffer->PrepareCaptureProcessing();
154 
155       analyzer.Update(*render_delay_buffer->GetRenderBuffer(),
156                       absl::optional<size_t>(0));
157     }
158 
159     mask.fill(1.f);
160     analyzer.MaskRegionsAroundNarrowBands(&mask);
161     EXPECT_TRUE(std::all_of(mask.begin(), mask.end(),
162                             [](float a) { return a == 1.f; }));
163     EXPECT_FALSE(analyzer.PoorSignalExcitation());
164     EXPECT_FALSE(static_cast<bool>(analyzer.NarrowPeakBand()));
165   }
166 }
167 
168 // Verify that a sinusoid signal is detected as narrow bands.
TEST(RenderSignalAnalyzer,NarrowBandDetection)169 TEST(RenderSignalAnalyzer, NarrowBandDetection) {
170   for (auto num_channels : {1, 2, 8}) {
171     SCOPED_TRACE(ProduceDebugText(num_channels));
172     RunNarrowBandDetectionTest(num_channels);
173   }
174 }
175 }  // namespace webrtc
176