1 /*
2 * Copyright (c) 2018 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/reverb_model_estimator.h"
12
13 #include <algorithm>
14 #include <array>
15 #include <cmath>
16 #include <numeric>
17 #include <vector>
18
19 #include "absl/types/optional.h"
20 #include "api/array_view.h"
21 #include "api/audio/echo_canceller3_config.h"
22 #include "modules/audio_processing/aec3/aec3_common.h"
23 #include "modules/audio_processing/aec3/aec3_fft.h"
24 #include "modules/audio_processing/aec3/fft_data.h"
25 #include "rtc_base/checks.h"
26 #include "test/gtest.h"
27
28 namespace webrtc {
29
30 namespace {
31
CreateConfigForTest(float default_decay)32 EchoCanceller3Config CreateConfigForTest(float default_decay) {
33 EchoCanceller3Config cfg;
34 cfg.ep_strength.default_len = default_decay;
35 cfg.filter.refined.length_blocks = 40;
36 return cfg;
37 }
38
39 constexpr int kFilterDelayBlocks = 2;
40
41 } // namespace
42
43 class ReverbModelEstimatorTest {
44 public:
ReverbModelEstimatorTest(float default_decay,size_t num_capture_channels)45 ReverbModelEstimatorTest(float default_decay, size_t num_capture_channels)
46 : aec3_config_(CreateConfigForTest(default_decay)),
47 estimated_decay_(default_decay),
48 h_(num_capture_channels,
49 std::vector<float>(
50 aec3_config_.filter.refined.length_blocks * kBlockSize,
51 0.f)),
52 H2_(num_capture_channels,
53 std::vector<std::array<float, kFftLengthBy2Plus1>>(
54 aec3_config_.filter.refined.length_blocks)),
55 quality_linear_(num_capture_channels, 1.0f) {
56 CreateImpulseResponseWithDecay();
57 }
58 void RunEstimator();
GetDecay()59 float GetDecay() { return estimated_decay_; }
GetTrueDecay()60 float GetTrueDecay() { return kTruePowerDecay; }
GetPowerTailDb()61 float GetPowerTailDb() { return 10.f * std::log10(estimated_power_tail_); }
GetTruePowerTailDb()62 float GetTruePowerTailDb() { return 10.f * std::log10(true_power_tail_); }
63
64 private:
65 void CreateImpulseResponseWithDecay();
66 static constexpr bool kStationaryBlock = false;
67 static constexpr float kTruePowerDecay = 0.5f;
68 const EchoCanceller3Config aec3_config_;
69 float estimated_decay_;
70 float estimated_power_tail_ = 0.f;
71 float true_power_tail_ = 0.f;
72 std::vector<std::vector<float>> h_;
73 std::vector<std::vector<std::array<float, kFftLengthBy2Plus1>>> H2_;
74 std::vector<absl::optional<float>> quality_linear_;
75 };
76
CreateImpulseResponseWithDecay()77 void ReverbModelEstimatorTest::CreateImpulseResponseWithDecay() {
78 const Aec3Fft fft;
79 for (const auto& h_k : h_) {
80 RTC_DCHECK_EQ(h_k.size(),
81 aec3_config_.filter.refined.length_blocks * kBlockSize);
82 }
83 for (const auto& H2_k : H2_) {
84 RTC_DCHECK_EQ(H2_k.size(), aec3_config_.filter.refined.length_blocks);
85 }
86 RTC_DCHECK_EQ(kFilterDelayBlocks, 2);
87
88 float decay_sample = std::sqrt(powf(kTruePowerDecay, 1.f / kBlockSize));
89 const size_t filter_delay_coefficients = kFilterDelayBlocks * kBlockSize;
90 for (auto& h_i : h_) {
91 std::fill(h_i.begin(), h_i.end(), 0.f);
92 h_i[filter_delay_coefficients] = 1.f;
93 for (size_t k = filter_delay_coefficients + 1; k < h_i.size(); ++k) {
94 h_i[k] = h_i[k - 1] * decay_sample;
95 }
96 }
97
98 for (size_t ch = 0; ch < H2_.size(); ++ch) {
99 for (size_t j = 0, k = 0; j < H2_[ch].size(); ++j, k += kBlockSize) {
100 std::array<float, kFftLength> fft_data;
101 fft_data.fill(0.f);
102 std::copy(h_[ch].begin() + k, h_[ch].begin() + k + kBlockSize,
103 fft_data.begin());
104 FftData H_j;
105 fft.Fft(&fft_data, &H_j);
106 H_j.Spectrum(Aec3Optimization::kNone, H2_[ch][j]);
107 }
108 }
109 rtc::ArrayView<float> H2_tail(H2_[0][H2_[0].size() - 1]);
110 true_power_tail_ = std::accumulate(H2_tail.begin(), H2_tail.end(), 0.f);
111 }
RunEstimator()112 void ReverbModelEstimatorTest::RunEstimator() {
113 const size_t num_capture_channels = H2_.size();
114 constexpr bool kUsableLinearEstimate = true;
115 ReverbModelEstimator estimator(aec3_config_, num_capture_channels);
116 std::vector<bool> usable_linear_estimates(num_capture_channels,
117 kUsableLinearEstimate);
118 std::vector<int> filter_delay_blocks(num_capture_channels,
119 kFilterDelayBlocks);
120 for (size_t k = 0; k < 3000; ++k) {
121 estimator.Update(h_, H2_, quality_linear_, filter_delay_blocks,
122 usable_linear_estimates, kStationaryBlock);
123 }
124 estimated_decay_ = estimator.ReverbDecay();
125 auto freq_resp_tail = estimator.GetReverbFrequencyResponse();
126 estimated_power_tail_ =
127 std::accumulate(freq_resp_tail.begin(), freq_resp_tail.end(), 0.f);
128 }
129
TEST(ReverbModelEstimatorTests,NotChangingDecay)130 TEST(ReverbModelEstimatorTests, NotChangingDecay) {
131 constexpr float kDefaultDecay = 0.9f;
132 for (size_t num_capture_channels : {1, 2, 4, 8}) {
133 ReverbModelEstimatorTest test(kDefaultDecay, num_capture_channels);
134 test.RunEstimator();
135 EXPECT_EQ(test.GetDecay(), kDefaultDecay);
136 EXPECT_NEAR(test.GetPowerTailDb(), test.GetTruePowerTailDb(), 5.f);
137 }
138 }
139
TEST(ReverbModelEstimatorTests,ChangingDecay)140 TEST(ReverbModelEstimatorTests, ChangingDecay) {
141 constexpr float kDefaultDecay = -0.9f;
142 for (size_t num_capture_channels : {1, 2, 4, 8}) {
143 ReverbModelEstimatorTest test(kDefaultDecay, num_capture_channels);
144 test.RunEstimator();
145 EXPECT_NEAR(test.GetDecay(), test.GetTrueDecay(), 0.1);
146 EXPECT_NEAR(test.GetPowerTailDb(), test.GetTruePowerTailDb(), 5.f);
147 }
148 }
149
150 } // namespace webrtc
151