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1 /* | 1 /* |
2 * Copyright (c) 2014 The WebRTC project authors. All Rights Reserved. | 2 * Copyright (c) 2014 The WebRTC project authors. All Rights Reserved. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license | 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 | 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 | 6 * tree. An additional intellectual property rights grant can be found |
7 * in the file PATENTS. All contributing project authors may | 7 * in the file PATENTS. All contributing project authors may |
8 * be found in the AUTHORS file in the root of the source tree. | 8 * be found in the AUTHORS file in the root of the source tree. |
9 */ | 9 */ |
10 | 10 |
11 // | |
12 // Implements helper functions and classes for intelligibility enhancement. | |
13 // | |
14 | |
15 #include "webrtc/modules/audio_processing/intelligibility/intelligibility_utils.
h" | 11 #include "webrtc/modules/audio_processing/intelligibility/intelligibility_utils.
h" |
16 | 12 |
17 #include <algorithm> | 13 #include <algorithm> |
18 #include <cmath> | 14 #include <cmath> |
19 #include <cstring> | 15 #include <cstring> |
20 | 16 |
21 using std::complex; | 17 using std::complex; |
22 | 18 |
23 namespace { | 19 namespace { |
24 | 20 |
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37 | 33 |
38 // std::isnormal for complex numbers. | 34 // std::isnormal for complex numbers. |
39 inline bool cplxnormal(complex<float> c) { | 35 inline bool cplxnormal(complex<float> c) { |
40 return std::isnormal(c.real()) && std::isnormal(c.imag()); | 36 return std::isnormal(c.real()) && std::isnormal(c.imag()); |
41 } | 37 } |
42 | 38 |
43 // Apply a small fudge to degenerate complex values. The numbers in the array | 39 // Apply a small fudge to degenerate complex values. The numbers in the array |
44 // were chosen randomly, so that even a series of all zeroes has some small | 40 // were chosen randomly, so that even a series of all zeroes has some small |
45 // variability. | 41 // variability. |
46 inline complex<float> zerofudge(complex<float> c) { | 42 inline complex<float> zerofudge(complex<float> c) { |
47 const static complex<float> fudge[7] = {{0.001f, 0.002f}, | 43 const static complex<float> fudge[7] = { |
48 {0.008f, 0.001f}, | 44 {0.001f, 0.002f}, {0.008f, 0.001f}, {0.003f, 0.008f}, {0.0006f, 0.0009f}, |
49 {0.003f, 0.008f}, | 45 {0.001f, 0.004f}, {0.003f, 0.004f}, {0.002f, 0.009f} |
50 {0.0006f, 0.0009f}, | 46 }; |
51 {0.001f, 0.004f}, | |
52 {0.003f, 0.004f}, | |
53 {0.002f, 0.009f}}; | |
54 static int fudge_index = 0; | 47 static int fudge_index = 0; |
55 if (cplxfinite(c) && !cplxnormal(c)) { | 48 if (cplxfinite(c) && !cplxnormal(c)) { |
56 fudge_index = (fudge_index + 1) % 7; | 49 fudge_index = (fudge_index + 1) % 7; |
57 return c + fudge[fudge_index]; | 50 return c + fudge[fudge_index]; |
58 } | 51 } |
59 return c; | 52 return c; |
60 } | 53 } |
61 | 54 |
62 // Incremental mean computation. Return the mean of the series with the | 55 // Incremental mean computation. Return the mean of the series with the |
63 // mean |mean| with added |data|. | 56 // mean |mean| with added |data|. |
64 inline complex<float> NewMean(complex<float> mean, | 57 inline complex<float> NewMean(complex<float> mean, complex<float> data, |
65 complex<float> data, | 58 int count) { |
66 int count) { | |
67 return mean + (data - mean) / static_cast<float>(count); | 59 return mean + (data - mean) / static_cast<float>(count); |
68 } | 60 } |
69 | 61 |
70 inline void AddToMean(complex<float> data, int count, complex<float>* mean) { | 62 inline void AddToMean(complex<float> data, int count, complex<float>* mean) { |
71 (*mean) = NewMean(*mean, data, count); | 63 (*mean) = NewMean(*mean, data, count); |
72 } | 64 } |
73 | 65 |
74 } // namespace | 66 } // namespace |
75 | 67 |
76 using std::min; | 68 using std::min; |
77 | 69 |
78 namespace webrtc { | 70 namespace webrtc { |
79 | 71 |
80 namespace intelligibility { | 72 namespace intelligibility { |
81 | 73 |
82 static const int kWindowBlockSize = 10; | 74 static const int kWindowBlockSize = 10; |
83 | 75 |
84 VarianceArray::VarianceArray(int freqs, | 76 VarianceArray::VarianceArray(int freqs, StepType type, int window_size, |
85 StepType type, | |
86 int window_size, | |
87 float decay) | 77 float decay) |
88 : running_mean_(new complex<float>[freqs]()), | 78 : running_mean_(new complex<float>[freqs]()), |
89 running_mean_sq_(new complex<float>[freqs]()), | 79 running_mean_sq_(new complex<float>[freqs]()), |
90 sub_running_mean_(new complex<float>[freqs]()), | 80 sub_running_mean_(new complex<float>[freqs]()), |
91 sub_running_mean_sq_(new complex<float>[freqs]()), | 81 sub_running_mean_sq_(new complex<float>[freqs]()), |
92 variance_(new float[freqs]()), | 82 variance_(new float[freqs]()), |
93 conj_sum_(new float[freqs]()), | 83 conj_sum_(new float[freqs]()), |
94 freqs_(freqs), | 84 freqs_(freqs), |
95 window_size_(window_size), | 85 window_size_(window_size), |
96 decay_(decay), | 86 decay_(decay), |
97 history_cursor_(0), | 87 history_cursor_(0), |
98 count_(0), | 88 count_(0), |
99 array_mean_(0.0f) { | 89 array_mean_(0.0f) { |
100 history_.reset(new rtc::scoped_ptr<complex<float>[]>[freqs_]()); | 90 history_.reset(new scoped_ptr<complex<float>[]>[freqs_]()); |
101 for (int i = 0; i < freqs_; ++i) { | 91 for (int i = 0; i < freqs_; ++i) { |
102 history_[i].reset(new complex<float>[window_size_]()); | 92 history_[i].reset(new complex<float>[window_size_]()); |
103 } | 93 } |
104 subhistory_.reset(new rtc::scoped_ptr<complex<float>[]>[freqs_]()); | 94 subhistory_.reset(new scoped_ptr<complex<float>[]>[freqs_]()); |
105 for (int i = 0; i < freqs_; ++i) { | 95 for (int i = 0; i < freqs_; ++i) { |
106 subhistory_[i].reset(new complex<float>[window_size_]()); | 96 subhistory_[i].reset(new complex<float>[window_size_]()); |
107 } | 97 } |
108 subhistory_sq_.reset(new rtc::scoped_ptr<complex<float>[]>[freqs_]()); | 98 subhistory_sq_.reset(new scoped_ptr<complex<float>[]>[freqs_]()); |
109 for (int i = 0; i < freqs_; ++i) { | 99 for (int i = 0; i < freqs_; ++i) { |
110 subhistory_sq_[i].reset(new complex<float>[window_size_]()); | 100 subhistory_sq_[i].reset(new complex<float>[window_size_]()); |
111 } | 101 } |
112 switch (type) { | 102 switch (type) { |
113 case kStepInfinite: | 103 case kStepInfinite: |
114 step_func_ = &VarianceArray::InfiniteStep; | 104 step_func_ = &VarianceArray::InfiniteStep; |
115 break; | 105 break; |
116 case kStepDecaying: | 106 case kStepDecaying: |
117 step_func_ = &VarianceArray::DecayStep; | 107 step_func_ = &VarianceArray::DecayStep; |
118 break; | 108 break; |
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134 complex<float> sample = data[i]; | 124 complex<float> sample = data[i]; |
135 if (!skip_fudge) { | 125 if (!skip_fudge) { |
136 sample = zerofudge(sample); | 126 sample = zerofudge(sample); |
137 } | 127 } |
138 if (count_ == 1) { | 128 if (count_ == 1) { |
139 running_mean_[i] = sample; | 129 running_mean_[i] = sample; |
140 variance_[i] = 0.0f; | 130 variance_[i] = 0.0f; |
141 } else { | 131 } else { |
142 float old_sum = conj_sum_[i]; | 132 float old_sum = conj_sum_[i]; |
143 complex<float> old_mean = running_mean_[i]; | 133 complex<float> old_mean = running_mean_[i]; |
144 running_mean_[i] = | 134 running_mean_[i] = old_mean + (sample - old_mean) / |
145 old_mean + (sample - old_mean) / static_cast<float>(count_); | 135 static_cast<float>(count_); |
146 conj_sum_[i] = | 136 conj_sum_[i] = (old_sum + std::conj(sample - old_mean) * |
147 (old_sum + std::conj(sample - old_mean) * (sample - running_mean_[i])) | 137 (sample - running_mean_[i])).real(); |
148 .real(); | 138 variance_[i] = conj_sum_[i] / (count_ - 1); // + fudge[fudge_index].real()
; |
149 variance_[i] = | |
150 conj_sum_[i] / (count_ - 1); // + fudge[fudge_index].real(); | |
151 if (skip_fudge && false) { | 139 if (skip_fudge && false) { |
152 // variance_[i] -= fudge[fudge_index].real(); | 140 //variance_[i] -= fudge[fudge_index].real(); |
153 } | 141 } |
154 } | 142 } |
155 array_mean_ += (variance_[i] - array_mean_) / (i + 1); | 143 array_mean_ += (variance_[i] - array_mean_) / (i + 1); |
156 } | 144 } |
157 } | 145 } |
158 | 146 |
159 // Compute the variance from the beginning, with exponential decaying of the | 147 // Compute the variance from the beginning, with exponential decaying of the |
160 // series data. | 148 // series data. |
161 void VarianceArray::DecayStep(const complex<float>* data, bool /*dummy*/) { | 149 void VarianceArray::DecayStep(const complex<float>* data, bool /*dummy*/) { |
162 array_mean_ = 0.0f; | 150 array_mean_ = 0.0f; |
163 ++count_; | 151 ++count_; |
164 for (int i = 0; i < freqs_; ++i) { | 152 for (int i = 0; i < freqs_; ++i) { |
165 complex<float> sample = data[i]; | 153 complex<float> sample = data[i]; |
166 sample = zerofudge(sample); | 154 sample = zerofudge(sample); |
167 | 155 |
168 if (count_ == 1) { | 156 if (count_ == 1) { |
169 running_mean_[i] = sample; | 157 running_mean_[i] = sample; |
170 running_mean_sq_[i] = sample * std::conj(sample); | 158 running_mean_sq_[i] = sample * std::conj(sample); |
171 variance_[i] = 0.0f; | 159 variance_[i] = 0.0f; |
172 } else { | 160 } else { |
173 complex<float> prev = running_mean_[i]; | 161 complex<float> prev = running_mean_[i]; |
174 complex<float> prev2 = running_mean_sq_[i]; | 162 complex<float> prev2 = running_mean_sq_[i]; |
175 running_mean_[i] = decay_ * prev + (1.0f - decay_) * sample; | 163 running_mean_[i] = decay_ * prev + (1.0f - decay_) * sample; |
176 running_mean_sq_[i] = | 164 running_mean_sq_[i] = decay_ * prev2 + |
177 decay_ * prev2 + (1.0f - decay_) * sample * std::conj(sample); | 165 (1.0f - decay_) * sample * std::conj(sample); |
178 // variance_[i] = decay_ * variance_[i] + (1.0f - decay_) * ( | 166 //variance_[i] = decay_ * variance_[i] + (1.0f - decay_) * ( |
179 // (sample - running_mean_[i]) * std::conj(sample - | 167 // (sample - running_mean_[i]) * std::conj(sample - running_mean_[i])).re
al(); |
180 // running_mean_[i])).real(); | 168 variance_[i] = (running_mean_sq_[i] - running_mean_[i] * std::conj(running
_mean_[i])).real(); |
181 variance_[i] = (running_mean_sq_[i] - | |
182 running_mean_[i] * std::conj(running_mean_[i])).real(); | |
183 } | 169 } |
184 | 170 |
185 array_mean_ += (variance_[i] - array_mean_) / (i + 1); | 171 array_mean_ += (variance_[i] - array_mean_) / (i + 1); |
186 } | 172 } |
187 } | 173 } |
188 | 174 |
189 // Windowed variance computation. On each step, the variances for the | 175 // Windowed variance computation. On each step, the variances for the |
190 // window are recomputed from scratch, using Welford's algorithm. | 176 // window are recomputed from scratch, using Welford's algorithm. |
191 void VarianceArray::WindowedStep(const complex<float>* data, bool /*dummy*/) { | 177 void VarianceArray::WindowedStep(const complex<float>* data, bool /*dummy*/) { |
192 int num = min(count_ + 1, window_size_); | 178 int num = min(count_ + 1, window_size_); |
193 array_mean_ = 0.0f; | 179 array_mean_ = 0.0f; |
194 for (int i = 0; i < freqs_; ++i) { | 180 for (int i = 0; i < freqs_; ++i) { |
195 complex<float> mean; | 181 complex<float> mean; |
196 float conj_sum = 0.0f; | 182 float conj_sum = 0.0f; |
197 | 183 |
198 history_[i][history_cursor_] = data[i]; | 184 history_[i][history_cursor_] = data[i]; |
199 | 185 |
200 mean = history_[i][history_cursor_]; | 186 mean = history_[i][history_cursor_]; |
201 variance_[i] = 0.0f; | 187 variance_[i] = 0.0f; |
202 for (int j = 1; j < num; ++j) { | 188 for (int j = 1; j < num; ++j) { |
203 complex<float> sample = | 189 complex<float> sample = zerofudge( |
204 zerofudge(history_[i][(history_cursor_ + j) % window_size_]); | 190 history_[i][(history_cursor_ + j) % window_size_]); |
205 sample = history_[i][(history_cursor_ + j) % window_size_]; | 191 sample = history_[i][(history_cursor_ + j) % window_size_]; |
206 float old_sum = conj_sum; | 192 float old_sum = conj_sum; |
207 complex<float> old_mean = mean; | 193 complex<float> old_mean = mean; |
208 | 194 |
209 mean = old_mean + (sample - old_mean) / static_cast<float>(j + 1); | 195 mean = old_mean + (sample - old_mean) / static_cast<float>(j + 1); |
210 conj_sum = | 196 conj_sum = (old_sum + std::conj(sample - old_mean) * |
211 (old_sum + std::conj(sample - old_mean) * (sample - mean)).real(); | 197 (sample - mean)).real(); |
212 variance_[i] = conj_sum / (j); | 198 variance_[i] = conj_sum / (j); |
213 } | 199 } |
214 array_mean_ += (variance_[i] - array_mean_) / (i + 1); | 200 array_mean_ += (variance_[i] - array_mean_) / (i + 1); |
215 } | 201 } |
216 history_cursor_ = (history_cursor_ + 1) % window_size_; | 202 history_cursor_ = (history_cursor_ + 1) % window_size_; |
217 ++count_; | 203 ++count_; |
218 } | 204 } |
219 | 205 |
220 // Variance with a window of blocks. Within each block, the variances are | 206 // Variance with a window of blocks. Within each block, the variances are |
221 // recomputed from scratch at every stp, using |Var(X) = E(X^2) - E^2(X)|. | 207 // recomputed from scratch at every stp, using |Var(X) = E(X^2) - E^2(X)|. |
222 // Once a block is filled with kWindowBlockSize samples, it is added to the | 208 // Once a block is filled with kWindowBlockSize samples, it is added to the |
223 // history window and a new block is started. The variances for the window | 209 // history window and a new block is started. The variances for the window |
224 // are recomputed from scratch at each of these transitions. | 210 // are recomputed from scratch at each of these transitions. |
225 void VarianceArray::BlockedStep(const complex<float>* data, bool /*dummy*/) { | 211 void VarianceArray::BlockedStep(const complex<float>* data, bool /*dummy*/) { |
226 int blocks = min(window_size_, history_cursor_); | 212 int blocks = min(window_size_, history_cursor_); |
227 for (int i = 0; i < freqs_; ++i) { | 213 for (int i = 0; i < freqs_; ++i) { |
228 AddToMean(data[i], count_ + 1, &sub_running_mean_[i]); | 214 AddToMean(data[i], count_ + 1, &sub_running_mean_[i]); |
229 AddToMean(data[i] * std::conj(data[i]), count_ + 1, | 215 AddToMean(data[i] * std::conj(data[i]), count_ + 1, |
230 &sub_running_mean_sq_[i]); | 216 &sub_running_mean_sq_[i]); |
231 subhistory_[i][history_cursor_ % window_size_] = sub_running_mean_[i]; | 217 subhistory_[i][history_cursor_ % window_size_] = sub_running_mean_[i]; |
232 subhistory_sq_[i][history_cursor_ % window_size_] = sub_running_mean_sq_[i]; | 218 subhistory_sq_[i][history_cursor_ % window_size_] = sub_running_mean_sq_[i]; |
233 | 219 |
234 variance_[i] = | 220 variance_[i] = (NewMean(running_mean_sq_[i], sub_running_mean_sq_[i], |
235 (NewMean(running_mean_sq_[i], sub_running_mean_sq_[i], blocks) - | 221 blocks) - |
236 NewMean(running_mean_[i], sub_running_mean_[i], blocks) * | 222 NewMean(running_mean_[i], sub_running_mean_[i], blocks) * |
237 std::conj(NewMean(running_mean_[i], sub_running_mean_[i], blocks))) | 223 std::conj(NewMean(running_mean_[i], sub_running_mean_[i], |
238 .real(); | 224 blocks))).real(); |
239 if (count_ == kWindowBlockSize - 1) { | 225 if (count_ == kWindowBlockSize - 1) { |
240 sub_running_mean_[i] = complex<float>(0.0f, 0.0f); | 226 sub_running_mean_[i] = complex<float>(0.0f, 0.0f); |
241 sub_running_mean_sq_[i] = complex<float>(0.0f, 0.0f); | 227 sub_running_mean_sq_[i] = complex<float>(0.0f, 0.0f); |
242 running_mean_[i] = complex<float>(0.0f, 0.0f); | 228 running_mean_[i] = complex<float>(0.0f, 0.0f); |
243 running_mean_sq_[i] = complex<float>(0.0f, 0.0f); | 229 running_mean_sq_[i] = complex<float>(0.0f, 0.0f); |
244 for (int j = 0; j < min(window_size_, history_cursor_); ++j) { | 230 for (int j = 0; j < min(window_size_, history_cursor_); ++j) { |
245 AddToMean(subhistory_[i][j], j, &running_mean_[i]); | 231 AddToMean(subhistory_[i][j], j, &running_mean_[i]); |
246 AddToMean(subhistory_sq_[i][j], j, &running_mean_sq_[i]); | 232 AddToMean(subhistory_sq_[i][j], j, &running_mean_sq_[i]); |
247 } | 233 } |
248 ++history_cursor_; | 234 ++history_cursor_; |
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291 factor = 1.0f; | 277 factor = 1.0f; |
292 } | 278 } |
293 out_block[i] = factor * in_block[i]; | 279 out_block[i] = factor * in_block[i]; |
294 current_[i] = UpdateFactor(target_[i], current_[i], change_limit_); | 280 current_[i] = UpdateFactor(target_[i], current_[i], change_limit_); |
295 } | 281 } |
296 } | 282 } |
297 | 283 |
298 } // namespace intelligibility | 284 } // namespace intelligibility |
299 | 285 |
300 } // namespace webrtc | 286 } // namespace webrtc |
| 287 |
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