OLD | NEW |
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 core class for intelligibility enhancer. | |
13 // | |
14 // Details of the model and algorithm can be found in the original paper: | |
15 // http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6882788 | |
16 // | |
17 | |
18 #include "webrtc/modules/audio_processing/intelligibility/intelligibility_enhanc
er.h" | 11 #include "webrtc/modules/audio_processing/intelligibility/intelligibility_enhanc
er.h" |
19 | 12 |
20 #include <cmath> | 13 #include <cmath> |
21 #include <cstdlib> | 14 #include <cstdlib> |
22 | 15 |
23 #include <algorithm> | 16 #include <algorithm> |
24 | 17 |
25 #include "webrtc/base/checks.h" | 18 #include "webrtc/base/checks.h" |
26 #include "webrtc/common_audio/vad/include/webrtc_vad.h" | 19 #include "webrtc/common_audio/vad/include/webrtc_vad.h" |
27 #include "webrtc/common_audio/window_generator.h" | 20 #include "webrtc/common_audio/window_generator.h" |
28 | 21 |
29 using std::complex; | 22 using std::complex; |
30 using std::max; | 23 using std::max; |
31 using std::min; | 24 using std::min; |
32 | 25 |
33 namespace webrtc { | 26 namespace webrtc { |
34 | 27 |
35 const int IntelligibilityEnhancer::kErbResolution = 2; | 28 const int IntelligibilityEnhancer::kErbResolution = 2; |
36 const int IntelligibilityEnhancer::kWindowSizeMs = 2; | 29 const int IntelligibilityEnhancer::kWindowSizeMs = 2; |
37 const int IntelligibilityEnhancer::kChunkSizeMs = 10; // Size provided by APM. | 30 // The size of the chunk provided by APM, in milliseconds. |
| 31 const int IntelligibilityEnhancer::kChunkSizeMs = 10; |
38 const int IntelligibilityEnhancer::kAnalyzeRate = 800; | 32 const int IntelligibilityEnhancer::kAnalyzeRate = 800; |
39 const int IntelligibilityEnhancer::kVarianceRate = 2; | 33 const int IntelligibilityEnhancer::kVarianceRate = 2; |
40 const float IntelligibilityEnhancer::kClipFreq = 200.0f; | 34 const float IntelligibilityEnhancer::kClipFreq = 200.0f; |
41 const float IntelligibilityEnhancer::kConfigRho = 0.02f; | 35 const float IntelligibilityEnhancer::kConfigRho = 0.02f; |
42 const float IntelligibilityEnhancer::kKbdAlpha = 1.5f; | 36 const float IntelligibilityEnhancer::kKbdAlpha = 1.5f; |
43 | |
44 // To disable gain update smoothing, set gain limit to be VERY high. | |
45 // TODO(ekmeyerson): Add option to disable gain smoothing altogether | |
46 // to avoid the extra computation. | |
47 const float IntelligibilityEnhancer::kGainChangeLimit = 0.0125f; | 37 const float IntelligibilityEnhancer::kGainChangeLimit = 0.0125f; |
48 | 38 |
49 using VarianceType = intelligibility::VarianceArray::StepType; | 39 using VarianceType = intelligibility::VarianceArray::StepType; |
50 | 40 |
51 IntelligibilityEnhancer::TransformCallback::TransformCallback( | 41 IntelligibilityEnhancer::TransformCallback::TransformCallback( |
52 IntelligibilityEnhancer* parent, | 42 IntelligibilityEnhancer* parent, |
53 IntelligibilityEnhancer::AudioSource source) | 43 IntelligibilityEnhancer::AudioSource source) |
54 : parent_(parent), source_(source) { | 44 : parent_(parent), |
55 } | 45 source_(source) {} |
56 | 46 |
57 void IntelligibilityEnhancer::TransformCallback::ProcessAudioBlock( | 47 void IntelligibilityEnhancer::TransformCallback::ProcessAudioBlock( |
58 const complex<float>* const* in_block, | 48 const complex<float>* const* in_block, |
59 int in_channels, | 49 int in_channels, int frames, int /* out_channels */, |
60 int frames, | |
61 int /* out_channels */, | |
62 complex<float>* const* out_block) { | 50 complex<float>* const* out_block) { |
63 DCHECK_EQ(parent_->freqs_, frames); | 51 DCHECK_EQ(parent_->freqs_, frames); |
64 for (int i = 0; i < in_channels; ++i) { | 52 for (int i = 0; i < in_channels; ++i) { |
65 parent_->DispatchAudio(source_, in_block[i], out_block[i]); | 53 parent_->DispatchAudio(source_, in_block[i], out_block[i]); |
66 } | 54 } |
67 } | 55 } |
68 | 56 |
69 IntelligibilityEnhancer::IntelligibilityEnhancer(int erb_resolution, | 57 IntelligibilityEnhancer::IntelligibilityEnhancer(int erb_resolution, |
70 int sample_rate_hz, | 58 int sample_rate_hz, |
71 int channels, | 59 int channels, |
72 int cv_type, | 60 int cv_type, float cv_alpha, |
73 float cv_alpha, | |
74 int cv_win, | 61 int cv_win, |
75 int analysis_rate, | 62 int analysis_rate, |
76 int variance_rate, | 63 int variance_rate, |
77 float gain_limit) | 64 float gain_limit) |
78 : freqs_(RealFourier::ComplexLength( | 65 : freqs_(RealFourier::ComplexLength(RealFourier::FftOrder( |
79 RealFourier::FftOrder(sample_rate_hz * kWindowSizeMs / 1000))), | 66 sample_rate_hz * kWindowSizeMs / 1000))), |
80 window_size_(1 << RealFourier::FftOrder(freqs_)), | 67 window_size_(1 << RealFourier::FftOrder(freqs_)), |
81 chunk_length_(sample_rate_hz * kChunkSizeMs / 1000), | 68 chunk_length_(sample_rate_hz * kChunkSizeMs / 1000), |
82 bank_size_(GetBankSize(sample_rate_hz, erb_resolution)), | 69 bank_size_(GetBankSize(sample_rate_hz, erb_resolution)), |
83 sample_rate_hz_(sample_rate_hz), | 70 sample_rate_hz_(sample_rate_hz), |
84 erb_resolution_(erb_resolution), | 71 erb_resolution_(erb_resolution), |
85 channels_(channels), | 72 channels_(channels), |
86 analysis_rate_(analysis_rate), | 73 analysis_rate_(analysis_rate), |
87 variance_rate_(variance_rate), | 74 variance_rate_(variance_rate), |
88 clear_variance_(freqs_, | 75 clear_variance_(freqs_, static_cast<VarianceType>(cv_type), cv_win, |
89 static_cast<VarianceType>(cv_type), | |
90 cv_win, | |
91 cv_alpha), | 76 cv_alpha), |
92 noise_variance_(freqs_, VarianceType::kStepInfinite, 475, 0.01f), | 77 noise_variance_(freqs_, VarianceType::kStepInfinite, 475, 0.01f), |
93 filtered_clear_var_(new float[bank_size_]), | 78 filtered_clear_var_(new float[bank_size_]), |
94 filtered_noise_var_(new float[bank_size_]), | 79 filtered_noise_var_(new float[bank_size_]), |
95 filter_bank_(nullptr), | 80 filter_bank_(nullptr), |
96 center_freqs_(new float[bank_size_]), | 81 center_freqs_(new float[bank_size_]), |
97 rho_(new float[bank_size_]), | 82 rho_(new float[bank_size_]), |
98 gains_eq_(new float[bank_size_]), | 83 gains_eq_(new float[bank_size_]), |
99 gain_applier_(freqs_, gain_limit), | 84 gain_applier_(freqs_, gain_limit), |
100 temp_out_buffer_(nullptr), | 85 temp_out_buffer_(nullptr), |
101 input_audio_(new float* [channels]), | 86 input_audio_(new float*[channels]), |
102 kbd_window_(new float[window_size_]), | 87 kbd_window_(new float[window_size_]), |
103 render_callback_(this, AudioSource::kRenderStream), | 88 render_callback_(this, AudioSource::kRenderStream), |
104 capture_callback_(this, AudioSource::kCaptureStream), | 89 capture_callback_(this, AudioSource::kCaptureStream), |
105 block_count_(0), | 90 block_count_(0), |
106 analysis_step_(0), | 91 analysis_step_(0), |
107 vad_high_(WebRtcVad_Create()), | 92 vad_high_(nullptr), |
108 vad_low_(WebRtcVad_Create()), | 93 vad_low_(nullptr), |
109 vad_tmp_buffer_(new int16_t[chunk_length_]) { | 94 vad_tmp_buffer_(new int16_t[chunk_length_]) { |
110 DCHECK_LE(kConfigRho, 1.0f); | 95 DCHECK_LE(kConfigRho, 1.0f); |
111 | 96 |
112 CreateErbBank(); | 97 CreateErbBank(); |
113 | 98 |
| 99 WebRtcVad_Create(&vad_high_); |
114 WebRtcVad_Init(vad_high_); | 100 WebRtcVad_Init(vad_high_); |
115 WebRtcVad_set_mode(vad_high_, 0); // High likelihood of speech. | 101 WebRtcVad_set_mode(vad_high_, 0); // high likelihood of speech |
| 102 WebRtcVad_Create(&vad_low_); |
116 WebRtcVad_Init(vad_low_); | 103 WebRtcVad_Init(vad_low_); |
117 WebRtcVad_set_mode(vad_low_, 3); // Low likelihood of speech. | 104 WebRtcVad_set_mode(vad_low_, 3); // low likelihood of speech |
118 | 105 |
119 temp_out_buffer_ = static_cast<float**>( | 106 temp_out_buffer_ = static_cast<float**>(malloc( |
120 malloc(sizeof(*temp_out_buffer_) * channels_ + | 107 sizeof(*temp_out_buffer_) * channels_ + |
121 sizeof(**temp_out_buffer_) * chunk_length_ * channels_)); | 108 sizeof(**temp_out_buffer_) * chunk_length_ * channels_)); |
122 for (int i = 0; i < channels_; ++i) { | 109 for (int i = 0; i < channels_; ++i) { |
123 temp_out_buffer_[i] = | 110 temp_out_buffer_[i] = reinterpret_cast<float*>(temp_out_buffer_ + channels_) |
124 reinterpret_cast<float*>(temp_out_buffer_ + channels_) + | 111 + chunk_length_ * i; |
125 chunk_length_ * i; | |
126 } | 112 } |
127 | 113 |
128 // Assumes all rho equal. | |
129 for (int i = 0; i < bank_size_; ++i) { | 114 for (int i = 0; i < bank_size_; ++i) { |
130 rho_[i] = kConfigRho * kConfigRho; | 115 rho_[i] = kConfigRho * kConfigRho; |
131 } | 116 } |
132 | 117 |
133 float freqs_khz = kClipFreq / 1000.0f; | 118 float freqs_khz = kClipFreq / 1000.0f; |
134 int erb_index = static_cast<int>(ceilf( | 119 int erb_index = static_cast<int>(ceilf(11.17f * logf((freqs_khz + 0.312f) / |
135 11.17f * logf((freqs_khz + 0.312f) / (freqs_khz + 14.6575f)) + 43.0f)); | 120 (freqs_khz + 14.6575f)) |
| 121 + 43.0f)); |
136 start_freq_ = max(1, erb_index * kErbResolution); | 122 start_freq_ = max(1, erb_index * kErbResolution); |
137 | 123 |
138 WindowGenerator::KaiserBesselDerived(kKbdAlpha, window_size_, | 124 WindowGenerator::KaiserBesselDerived(kKbdAlpha, window_size_, |
139 kbd_window_.get()); | 125 kbd_window_.get()); |
140 render_mangler_.reset(new LappedTransform( | 126 render_mangler_.reset(new LappedTransform(channels_, channels_, |
141 channels_, channels_, chunk_length_, kbd_window_.get(), window_size_, | 127 chunk_length_, |
142 window_size_ / 2, &render_callback_)); | 128 kbd_window_.get(), |
143 capture_mangler_.reset(new LappedTransform( | 129 window_size_, |
144 channels_, channels_, chunk_length_, kbd_window_.get(), window_size_, | 130 window_size_ / 2, |
145 window_size_ / 2, &capture_callback_)); | 131 &render_callback_)); |
| 132 capture_mangler_.reset(new LappedTransform(channels_, channels_, |
| 133 chunk_length_, |
| 134 kbd_window_.get(), |
| 135 window_size_, |
| 136 window_size_ / 2, |
| 137 &capture_callback_)); |
146 } | 138 } |
147 | 139 |
148 IntelligibilityEnhancer::~IntelligibilityEnhancer() { | 140 IntelligibilityEnhancer::~IntelligibilityEnhancer() { |
149 WebRtcVad_Free(vad_low_); | 141 WebRtcVad_Free(vad_low_); |
150 WebRtcVad_Free(vad_high_); | 142 WebRtcVad_Free(vad_high_); |
151 free(filter_bank_); | 143 free(filter_bank_); |
152 } | 144 } |
153 | 145 |
154 void IntelligibilityEnhancer::ProcessRenderAudio(float* const* audio) { | 146 void IntelligibilityEnhancer::ProcessRenderAudio(float* const* audio) { |
155 for (int i = 0; i < chunk_length_; ++i) { | 147 for (int i = 0; i < chunk_length_; ++i) { |
156 vad_tmp_buffer_[i] = (int16_t)audio[0][i]; | 148 vad_tmp_buffer_[i] = (int16_t)audio[0][i]; |
157 } | 149 } |
158 has_voice_low_ = WebRtcVad_Process(vad_low_, sample_rate_hz_, | 150 has_voice_low_ = WebRtcVad_Process(vad_low_, sample_rate_hz_, |
159 vad_tmp_buffer_.get(), chunk_length_) == 1; | 151 vad_tmp_buffer_.get(), chunk_length_) == 1; |
160 | 152 |
161 // Process and enhance chunk of |audio| | |
162 render_mangler_->ProcessChunk(audio, temp_out_buffer_); | 153 render_mangler_->ProcessChunk(audio, temp_out_buffer_); |
163 | |
164 for (int i = 0; i < channels_; ++i) { | 154 for (int i = 0; i < channels_; ++i) { |
165 memcpy(audio[i], temp_out_buffer_[i], | 155 memcpy(audio[i], temp_out_buffer_[i], |
166 chunk_length_ * sizeof(**temp_out_buffer_)); | 156 chunk_length_ * sizeof(**temp_out_buffer_)); |
167 } | 157 } |
168 } | 158 } |
169 | 159 |
170 void IntelligibilityEnhancer::ProcessCaptureAudio(float* const* audio) { | 160 void IntelligibilityEnhancer::ProcessCaptureAudio(float* const* audio) { |
171 for (int i = 0; i < chunk_length_; ++i) { | 161 for (int i = 0; i < chunk_length_; ++i) { |
172 vad_tmp_buffer_[i] = (int16_t)audio[0][i]; | 162 vad_tmp_buffer_[i] = (int16_t)audio[0][i]; |
173 } | 163 } |
174 // TODO(bercic): The VAD was always detecting voice in the noise stream, | 164 // TODO(bercic): the VAD was always detecting voice in the noise stream, |
175 // no matter what the aggressiveness, so it was temporarily disabled here. | 165 // no matter what the aggressiveness, so it was temporarily disabled here |
176 | 166 |
177 #if 0 | 167 //if (WebRtcVad_Process(vad_high_, sample_rate_hz_, vad_tmp_buffer_.get(), |
178 if (WebRtcVad_Process(vad_high_, sample_rate_hz_, vad_tmp_buffer_.get(), | 168 // chunk_length_) == 1) { |
179 chunk_length_) == 1) { | 169 // printf("capture HAS speech\n"); |
180 printf("capture HAS speech\n"); | 170 // return; |
181 return; | 171 //} |
182 } | 172 //printf("capture NO speech\n"); |
183 printf("capture NO speech\n"); | |
184 #endif | |
185 | |
186 capture_mangler_->ProcessChunk(audio, temp_out_buffer_); | 173 capture_mangler_->ProcessChunk(audio, temp_out_buffer_); |
187 } | 174 } |
188 | 175 |
189 void IntelligibilityEnhancer::DispatchAudio( | 176 void IntelligibilityEnhancer::DispatchAudio( |
190 IntelligibilityEnhancer::AudioSource source, | 177 IntelligibilityEnhancer::AudioSource source, |
191 const complex<float>* in_block, | 178 const complex<float>* in_block, complex<float>* out_block) { |
192 complex<float>* out_block) { | |
193 switch (source) { | 179 switch (source) { |
194 case kRenderStream: | 180 case kRenderStream: |
195 ProcessClearBlock(in_block, out_block); | 181 ProcessClearBlock(in_block, out_block); |
196 break; | 182 break; |
197 case kCaptureStream: | 183 case kCaptureStream: |
198 ProcessNoiseBlock(in_block, out_block); | 184 ProcessNoiseBlock(in_block, out_block); |
199 break; | 185 break; |
200 } | 186 } |
201 } | 187 } |
202 | 188 |
203 void IntelligibilityEnhancer::ProcessClearBlock(const complex<float>* in_block, | 189 void IntelligibilityEnhancer::ProcessClearBlock(const complex<float>* in_block, |
204 complex<float>* out_block) { | 190 complex<float>* out_block) { |
205 float power_target; | 191 float power_target; |
206 | 192 |
207 if (block_count_ < 2) { | 193 if (block_count_ < 2) { |
208 memset(out_block, 0, freqs_ * sizeof(*out_block)); | 194 memset(out_block, 0, freqs_ * sizeof(*out_block)); |
209 ++block_count_; | 195 ++block_count_; |
210 return; | 196 return; |
211 } | 197 } |
212 | 198 |
213 // For now, always assumes enhancement is necessary. | |
214 // TODO(ekmeyerson): Change to only enhance if necessary, | |
215 // based on experiments with different cutoffs. | |
216 if (has_voice_low_ || true) { | 199 if (has_voice_low_ || true) { |
217 clear_variance_.Step(in_block, false); | 200 clear_variance_.Step(in_block, false); |
218 power_target = std::accumulate(clear_variance_.variance(), | 201 power_target = std::accumulate(clear_variance_.variance(), |
219 clear_variance_.variance() + freqs_, 0.0f); | 202 clear_variance_.variance() + freqs_, 0.0f); |
220 | 203 |
221 if (block_count_ % analysis_rate_ == analysis_rate_ - 1) { | 204 if (block_count_ % analysis_rate_ == analysis_rate_ - 1) { |
222 AnalyzeClearBlock(power_target); | 205 AnalyzeClearBlock(power_target); |
223 ++analysis_step_; | 206 ++analysis_step_; |
224 if (analysis_step_ == variance_rate_) { | 207 if (analysis_step_ == variance_rate_) { |
225 analysis_step_ = 0; | 208 analysis_step_ = 0; |
226 clear_variance_.Clear(); | 209 clear_variance_.Clear(); |
227 noise_variance_.Clear(); | 210 noise_variance_.Clear(); |
228 } | 211 } |
229 } | 212 } |
230 ++block_count_; | 213 ++block_count_; |
231 } | 214 } |
232 | 215 |
233 /* efidata(n,:) = sqrt(b(n)) * fidata(n,:) */ | 216 /* efidata(n,:) = sqrt(b(n)) * fidata(n,:) */ |
234 gain_applier_.Apply(in_block, out_block); | 217 gain_applier_.Apply(in_block, out_block); |
235 } | 218 } |
236 | 219 |
237 void IntelligibilityEnhancer::AnalyzeClearBlock(float power_target) { | 220 void IntelligibilityEnhancer::AnalyzeClearBlock(float power_target) { |
238 FilterVariance(clear_variance_.variance(), filtered_clear_var_.get()); | 221 FilterVariance(clear_variance_.variance(), filtered_clear_var_.get()); |
239 FilterVariance(noise_variance_.variance(), filtered_noise_var_.get()); | 222 FilterVariance(noise_variance_.variance(), filtered_noise_var_.get()); |
240 | 223 |
241 // Bisection search for optimal |lambda| | 224 /* lambda binary search */ |
242 | 225 |
243 float lambda_bot = -1.0f, lambda_top = -10e-18f, lambda; | 226 float lambda_bot = -1.0f, lambda_top = -10e-18f, lambda; |
244 float power_bot, power_top, power; | 227 float power_bot, power_top, power; |
245 SolveForGainsGivenLambda(lambda_top, start_freq_, gains_eq_.get()); | 228 SolveEquation14(lambda_top, start_freq_, gains_eq_.get()); |
246 power_top = | 229 power_top = DotProduct(gains_eq_.get(), filtered_clear_var_.get(), |
247 DotProduct(gains_eq_.get(), filtered_clear_var_.get(), bank_size_); | 230 bank_size_); |
248 SolveForGainsGivenLambda(lambda_bot, start_freq_, gains_eq_.get()); | 231 SolveEquation14(lambda_bot, start_freq_, gains_eq_.get()); |
249 power_bot = | 232 power_bot = DotProduct(gains_eq_.get(), filtered_clear_var_.get(), |
250 DotProduct(gains_eq_.get(), filtered_clear_var_.get(), bank_size_); | 233 bank_size_); |
251 DCHECK(power_target >= power_bot && power_target <= power_top); | 234 DCHECK(power_target >= power_bot && power_target <= power_top); |
252 | 235 |
253 float power_ratio = 2.0f; // Ratio of achieved power to target power. | 236 float power_ratio = 2.0f; |
254 const float kConvergeThresh = 0.001f; // TODO(ekmeyerson): Find best values | |
255 const int kMaxIters = 100; // for these, based on experiments. | |
256 int iters = 0; | 237 int iters = 0; |
257 while (fabs(power_ratio - 1.0f) > kConvergeThresh && iters <= kMaxIters) { | 238 while (fabs(power_ratio - 1.0f) > 0.001f && iters <= 100) { |
258 lambda = lambda_bot + (lambda_top - lambda_bot) / 2.0f; | 239 lambda = lambda_bot + (lambda_top - lambda_bot) / 2.0f; |
259 SolveForGainsGivenLambda(lambda, start_freq_, gains_eq_.get()); | 240 SolveEquation14(lambda, start_freq_, gains_eq_.get()); |
260 power = DotProduct(gains_eq_.get(), filtered_clear_var_.get(), bank_size_); | 241 power = DotProduct(gains_eq_.get(), filtered_clear_var_.get(), bank_size_); |
261 if (power < power_target) { | 242 if (power < power_target) { |
262 lambda_bot = lambda; | 243 lambda_bot = lambda; |
263 } else { | 244 } else { |
264 lambda_top = lambda; | 245 lambda_top = lambda; |
265 } | 246 } |
266 power_ratio = fabs(power / power_target); | 247 power_ratio = fabs(power / power_target); |
267 ++iters; | 248 ++iters; |
268 } | 249 } |
269 | 250 |
270 // (ERB gain) = filterbank' * (freq gain) | 251 /* b = filterbank' * b */ |
271 float* gains = gain_applier_.target(); | 252 float* gains = gain_applier_.target(); |
272 for (int i = 0; i < freqs_; ++i) { | 253 for (int i = 0; i < freqs_; ++i) { |
273 gains[i] = 0.0f; | 254 gains[i] = 0.0f; |
274 for (int j = 0; j < bank_size_; ++j) { | 255 for (int j = 0; j < bank_size_; ++j) { |
275 gains[i] = fmaf(filter_bank_[j][i], gains_eq_[j], gains[i]); | 256 gains[i] = fmaf(filter_bank_[j][i], gains_eq_[j], gains[i]); |
276 } | 257 } |
277 } | 258 } |
278 } | 259 } |
279 | 260 |
280 void IntelligibilityEnhancer::ProcessNoiseBlock(const complex<float>* in_block, | 261 void IntelligibilityEnhancer::ProcessNoiseBlock(const complex<float>* in_block, |
281 complex<float>* /*out_block*/) { | 262 complex<float>* /*out_block*/) { |
282 noise_variance_.Step(in_block); | 263 noise_variance_.Step(in_block); |
283 } | 264 } |
284 | 265 |
285 int IntelligibilityEnhancer::GetBankSize(int sample_rate, int erb_resolution) { | 266 int IntelligibilityEnhancer::GetBankSize(int sample_rate, int erb_resolution) { |
286 float freq_limit = sample_rate / 2000.0f; | 267 float freq_limit = sample_rate / 2000.0f; |
287 int erb_scale = ceilf( | 268 int erb_scale = ceilf(11.17f * logf((freq_limit + 0.312f) / |
288 11.17f * logf((freq_limit + 0.312f) / (freq_limit + 14.6575f)) + 43.0f); | 269 (freq_limit + 14.6575f)) + 43.0f); |
289 return erb_scale * erb_resolution; | 270 return erb_scale * erb_resolution; |
290 } | 271 } |
291 | 272 |
292 void IntelligibilityEnhancer::CreateErbBank() { | 273 void IntelligibilityEnhancer::CreateErbBank() { |
293 int lf = 1, rf = 4; | 274 int lf = 1, rf = 4; |
294 | 275 |
295 for (int i = 0; i < bank_size_; ++i) { | 276 for (int i = 0; i < bank_size_; ++i) { |
296 float abs_temp = fabsf((i + 1.0f) / static_cast<float>(erb_resolution_)); | 277 float abs_temp = fabsf((i + 1.0f) / static_cast<float>(erb_resolution_)); |
297 center_freqs_[i] = 676170.4f / (47.06538f - expf(0.08950404f * abs_temp)); | 278 center_freqs_[i] = 676170.4f / (47.06538f - expf(0.08950404f * abs_temp)); |
298 center_freqs_[i] -= 14678.49f; | 279 center_freqs_[i] -= 14678.49f; |
299 } | 280 } |
300 float last_center_freq = center_freqs_[bank_size_ - 1]; | 281 float last_center_freq = center_freqs_[bank_size_ - 1]; |
301 for (int i = 0; i < bank_size_; ++i) { | 282 for (int i = 0; i < bank_size_; ++i) { |
302 center_freqs_[i] *= 0.5f * sample_rate_hz_ / last_center_freq; | 283 center_freqs_[i] *= 0.5f * sample_rate_hz_ / last_center_freq; |
303 } | 284 } |
304 | 285 |
305 filter_bank_ = static_cast<float**>( | 286 filter_bank_ = static_cast<float**>(malloc( |
306 malloc(sizeof(*filter_bank_) * bank_size_ + | 287 sizeof(*filter_bank_) * bank_size_ + |
307 sizeof(**filter_bank_) * freqs_ * bank_size_)); | 288 sizeof(**filter_bank_) * freqs_ * bank_size_)); |
308 for (int i = 0; i < bank_size_; ++i) { | 289 for (int i = 0; i < bank_size_; ++i) { |
309 filter_bank_[i] = | 290 filter_bank_[i] = reinterpret_cast<float*>(filter_bank_ + bank_size_) + |
310 reinterpret_cast<float*>(filter_bank_ + bank_size_) + freqs_ * i; | 291 freqs_ * i; |
311 } | 292 } |
312 | 293 |
313 for (int i = 1; i <= bank_size_; ++i) { | 294 for (int i = 1; i <= bank_size_; ++i) { |
314 int lll, ll, rr, rrr; | 295 int lll, ll, rr, rrr; |
315 lll = round(center_freqs_[max(1, i - lf) - 1] * freqs_ / | 296 lll = round(center_freqs_[max(1, i - lf) - 1] * freqs_ / |
316 (0.5f * sample_rate_hz_)); | 297 (0.5f * sample_rate_hz_)); |
317 ll = | 298 ll = round(center_freqs_[max(1, i ) - 1] * freqs_ / |
318 round(center_freqs_[max(1, i) - 1] * freqs_ / (0.5f * sample_rate_hz_)); | 299 (0.5f * sample_rate_hz_)); |
319 lll = min(freqs_, max(lll, 1)) - 1; | 300 lll = min(freqs_, max(lll, 1)) - 1; |
320 ll = min(freqs_, max(ll, 1)) - 1; | 301 ll = min(freqs_, max(ll, 1)) - 1; |
321 | 302 |
322 rrr = round(center_freqs_[min(bank_size_, i + rf) - 1] * freqs_ / | 303 rrr = round(center_freqs_[min(bank_size_, i + rf) - 1] * freqs_ / |
323 (0.5f * sample_rate_hz_)); | 304 (0.5f * sample_rate_hz_)); |
324 rr = round(center_freqs_[min(bank_size_, i + 1) - 1] * freqs_ / | 305 rr = round(center_freqs_[min(bank_size_, i + 1) - 1] * freqs_ / |
325 (0.5f * sample_rate_hz_)); | 306 (0.5f * sample_rate_hz_)); |
326 rrr = min(freqs_, max(rrr, 1)) - 1; | 307 rrr = min(freqs_, max(rrr, 1)) - 1; |
327 rr = min(freqs_, max(rr, 1)) - 1; | 308 rr = min(freqs_, max(rr, 1)) - 1; |
328 | 309 |
329 float step, element; | 310 float step, element; |
330 | 311 |
331 step = 1.0f / (ll - lll); | 312 step = 1.0f / (ll - lll); |
332 element = 0.0f; | 313 element = 0.0f; |
333 for (int j = lll; j <= ll; ++j) { | 314 for (int j = lll; j <= ll; ++j) { |
334 filter_bank_[i - 1][j] = element; | 315 filter_bank_[i - 1][j] = element; |
335 element += step; | 316 element += step; |
336 } | 317 } |
337 step = 1.0f / (rrr - rr); | 318 step = 1.0f / (rrr - rr); |
(...skipping 12 matching lines...) Expand all Loading... |
350 sum = 0.0f; | 331 sum = 0.0f; |
351 for (int j = 0; j < bank_size_; ++j) { | 332 for (int j = 0; j < bank_size_; ++j) { |
352 sum += filter_bank_[j][i]; | 333 sum += filter_bank_[j][i]; |
353 } | 334 } |
354 for (int j = 0; j < bank_size_; ++j) { | 335 for (int j = 0; j < bank_size_; ++j) { |
355 filter_bank_[j][i] /= sum; | 336 filter_bank_[j][i] /= sum; |
356 } | 337 } |
357 } | 338 } |
358 } | 339 } |
359 | 340 |
360 void IntelligibilityEnhancer::SolveForGainsGivenLambda(float lambda, | 341 void IntelligibilityEnhancer::SolveEquation14(float lambda, int start_freq, |
361 int start_freq, | 342 float* sols) { |
362 float* sols) { | |
363 bool quadratic = (kConfigRho < 1.0f); | 343 bool quadratic = (kConfigRho < 1.0f); |
364 const float* var_x0 = filtered_clear_var_.get(); | 344 const float* var_x0 = filtered_clear_var_.get(); |
365 const float* var_n0 = filtered_noise_var_.get(); | 345 const float* var_n0 = filtered_noise_var_.get(); |
366 | 346 |
367 for (int n = 0; n < start_freq; ++n) { | 347 for (int n = 0; n < start_freq; ++n) { |
368 sols[n] = 1.0f; | 348 sols[n] = 1.0f; |
369 } | 349 } |
370 | |
371 // Analytic solution for optimal gains. See paper for derivation. | |
372 for (int n = start_freq - 1; n < bank_size_; ++n) { | 350 for (int n = start_freq - 1; n < bank_size_; ++n) { |
373 float alpha0, beta0, gamma0; | 351 float alpha0, beta0, gamma0; |
374 gamma0 = 0.5f * rho_[n] * var_x0[n] * var_n0[n] + | 352 gamma0 = 0.5f * rho_[n] * var_x0[n] * var_n0[n] + |
375 lambda * var_x0[n] * var_n0[n] * var_n0[n]; | 353 lambda * var_x0[n] * var_n0[n] * var_n0[n]; |
376 beta0 = lambda * var_x0[n] * (2 - rho_[n]) * var_x0[n] * var_n0[n]; | 354 beta0 = lambda * var_x0[n] * (2 - rho_[n]) * var_x0[n] * var_n0[n]; |
377 if (quadratic) { | 355 if (quadratic) { |
378 alpha0 = lambda * var_x0[n] * (1 - rho_[n]) * var_x0[n] * var_x0[n]; | 356 alpha0 = lambda * var_x0[n] * (1 - rho_[n]) * var_x0[n] * var_x0[n]; |
379 sols[n] = | 357 sols[n] = (-beta0 - sqrtf(beta0 * beta0 - 4 * alpha0 * gamma0)) |
380 (-beta0 - sqrtf(beta0 * beta0 - 4 * alpha0 * gamma0)) / (2 * alpha0); | 358 / (2 * alpha0); |
381 } else { | 359 } else { |
382 sols[n] = -gamma0 / beta0; | 360 sols[n] = -gamma0 / beta0; |
383 } | 361 } |
384 sols[n] = fmax(0, sols[n]); | 362 sols[n] = fmax(0, sols[n]); |
385 } | 363 } |
386 } | 364 } |
387 | 365 |
388 void IntelligibilityEnhancer::FilterVariance(const float* var, float* result) { | 366 void IntelligibilityEnhancer::FilterVariance(const float* var, float* result) { |
389 for (int i = 0; i < bank_size_; ++i) { | 367 for (int i = 0; i < bank_size_; ++i) { |
390 result[i] = DotProduct(filter_bank_[i], var, freqs_); | 368 result[i] = DotProduct(filter_bank_[i], var, freqs_); |
391 } | 369 } |
392 } | 370 } |
393 | 371 |
394 float IntelligibilityEnhancer::DotProduct(const float* a, | 372 float IntelligibilityEnhancer::DotProduct(const float* a, const float* b, |
395 const float* b, | 373 int length) { |
396 int length) { | |
397 float ret = 0.0f; | 374 float ret = 0.0f; |
398 | 375 |
399 for (int i = 0; i < length; ++i) { | 376 for (int i = 0; i < length; ++i) { |
400 ret = fmaf(a[i], b[i], ret); | 377 ret = fmaf(a[i], b[i], ret); |
401 } | 378 } |
402 return ret; | 379 return ret; |
403 } | 380 } |
404 | 381 |
405 } // namespace webrtc | 382 } // namespace webrtc |
| 383 |
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