1 /* 2 * Copyright (c) 2013 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 "webrtc/modules/audio_processing/aecm/aecm_core.h" 12 13 #include <assert.h> 14 #include <stddef.h> 15 #include <stdlib.h> 16 17 #include "webrtc/common_audio/signal_processing/include/real_fft.h" 18 #include "webrtc/modules/audio_processing/aecm/include/echo_control_mobile.h" 19 #include "webrtc/modules/audio_processing/utility/delay_estimator_wrapper.h" 20 #include "webrtc/modules/audio_processing/utility/ring_buffer.h" 21 #include "webrtc/system_wrappers/interface/compile_assert_c.h" 22 #include "webrtc/system_wrappers/interface/cpu_features_wrapper.h" 23 #include "webrtc/typedefs.h" 24 25 // Square root of Hanning window in Q14. 26 #if defined(WEBRTC_DETECT_ARM_NEON) || defined(WEBRTC_ARCH_ARM_NEON) 27 // Table is defined in an ARM assembly file. 28 extern const ALIGN8_BEG int16_t WebRtcAecm_kSqrtHanning[] ALIGN8_END; 29 #else 30 static const ALIGN8_BEG int16_t WebRtcAecm_kSqrtHanning[] ALIGN8_END = { 31 0, 399, 798, 1196, 1594, 1990, 2386, 2780, 3172, 32 3562, 3951, 4337, 4720, 5101, 5478, 5853, 6224, 33 6591, 6954, 7313, 7668, 8019, 8364, 8705, 9040, 34 9370, 9695, 10013, 10326, 10633, 10933, 11227, 11514, 35 11795, 12068, 12335, 12594, 12845, 13089, 13325, 13553, 36 13773, 13985, 14189, 14384, 14571, 14749, 14918, 15079, 37 15231, 15373, 15506, 15631, 15746, 15851, 15947, 16034, 38 16111, 16179, 16237, 16286, 16325, 16354, 16373, 16384 39 }; 40 #endif 41 42 #ifdef AECM_WITH_ABS_APPROX 43 //Q15 alpha = 0.99439986968132 const Factor for magnitude approximation 44 static const uint16_t kAlpha1 = 32584; 45 //Q15 beta = 0.12967166976970 const Factor for magnitude approximation 46 static const uint16_t kBeta1 = 4249; 47 //Q15 alpha = 0.94234827210087 const Factor for magnitude approximation 48 static const uint16_t kAlpha2 = 30879; 49 //Q15 beta = 0.33787806009150 const Factor for magnitude approximation 50 static const uint16_t kBeta2 = 11072; 51 //Q15 alpha = 0.82247698684306 const Factor for magnitude approximation 52 static const uint16_t kAlpha3 = 26951; 53 //Q15 beta = 0.57762063060713 const Factor for magnitude approximation 54 static const uint16_t kBeta3 = 18927; 55 #endif 56 57 static const int16_t kNoiseEstQDomain = 15; 58 static const int16_t kNoiseEstIncCount = 5; 59 60 static void ComfortNoise(AecmCore_t* aecm, 61 const uint16_t* dfa, 62 complex16_t* out, 63 const int16_t* lambda); 64 65 static void WindowAndFFT(AecmCore_t* aecm, 66 int16_t* fft, 67 const int16_t* time_signal, 68 complex16_t* freq_signal, 69 int time_signal_scaling) { 70 int i = 0; 71 72 // FFT of signal 73 for (i = 0; i < PART_LEN; i++) { 74 // Window time domain signal and insert into real part of 75 // transformation array |fft| 76 fft[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT( 77 (time_signal[i] << time_signal_scaling), 78 WebRtcAecm_kSqrtHanning[i], 79 14); 80 fft[PART_LEN + i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT( 81 (time_signal[i + PART_LEN] << time_signal_scaling), 82 WebRtcAecm_kSqrtHanning[PART_LEN - i], 83 14); 84 } 85 86 // Do forward FFT, then take only the first PART_LEN complex samples, 87 // and change signs of the imaginary parts. 88 WebRtcSpl_RealForwardFFT(aecm->real_fft, fft, (int16_t*)freq_signal); 89 for (i = 0; i < PART_LEN; i++) { 90 freq_signal[i].imag = -freq_signal[i].imag; 91 } 92 } 93 94 static void InverseFFTAndWindow(AecmCore_t* aecm, 95 int16_t* fft, 96 complex16_t* efw, 97 int16_t* output, 98 const int16_t* nearendClean) 99 { 100 int i, j, outCFFT; 101 int32_t tmp32no1; 102 // Reuse |efw| for the inverse FFT output after transferring 103 // the contents to |fft|. 104 int16_t* ifft_out = (int16_t*)efw; 105 106 // Synthesis 107 for (i = 1, j = 2; i < PART_LEN; i += 1, j += 2) { 108 fft[j] = efw[i].real; 109 fft[j + 1] = -efw[i].imag; 110 } 111 fft[0] = efw[0].real; 112 fft[1] = -efw[0].imag; 113 114 fft[PART_LEN2] = efw[PART_LEN].real; 115 fft[PART_LEN2 + 1] = -efw[PART_LEN].imag; 116 117 // Inverse FFT. Keep outCFFT to scale the samples in the next block. 118 outCFFT = WebRtcSpl_RealInverseFFT(aecm->real_fft, fft, ifft_out); 119 for (i = 0; i < PART_LEN; i++) { 120 ifft_out[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND( 121 ifft_out[i], WebRtcAecm_kSqrtHanning[i], 14); 122 tmp32no1 = WEBRTC_SPL_SHIFT_W32((int32_t)ifft_out[i], 123 outCFFT - aecm->dfaCleanQDomain); 124 output[i] = (int16_t)WEBRTC_SPL_SAT(WEBRTC_SPL_WORD16_MAX, 125 tmp32no1 + aecm->outBuf[i], 126 WEBRTC_SPL_WORD16_MIN); 127 128 tmp32no1 = WEBRTC_SPL_MUL_16_16_RSFT(ifft_out[PART_LEN + i], 129 WebRtcAecm_kSqrtHanning[PART_LEN - i], 130 14); 131 tmp32no1 = WEBRTC_SPL_SHIFT_W32(tmp32no1, 132 outCFFT - aecm->dfaCleanQDomain); 133 aecm->outBuf[i] = (int16_t)WEBRTC_SPL_SAT(WEBRTC_SPL_WORD16_MAX, 134 tmp32no1, 135 WEBRTC_SPL_WORD16_MIN); 136 } 137 138 // Copy the current block to the old position 139 // (aecm->outBuf is shifted elsewhere) 140 memcpy(aecm->xBuf, aecm->xBuf + PART_LEN, sizeof(int16_t) * PART_LEN); 141 memcpy(aecm->dBufNoisy, 142 aecm->dBufNoisy + PART_LEN, 143 sizeof(int16_t) * PART_LEN); 144 if (nearendClean != NULL) 145 { 146 memcpy(aecm->dBufClean, 147 aecm->dBufClean + PART_LEN, 148 sizeof(int16_t) * PART_LEN); 149 } 150 } 151 152 // Transforms a time domain signal into the frequency domain, outputting the 153 // complex valued signal, absolute value and sum of absolute values. 154 // 155 // time_signal [in] Pointer to time domain signal 156 // freq_signal_real [out] Pointer to real part of frequency domain array 157 // freq_signal_imag [out] Pointer to imaginary part of frequency domain 158 // array 159 // freq_signal_abs [out] Pointer to absolute value of frequency domain 160 // array 161 // freq_signal_sum_abs [out] Pointer to the sum of all absolute values in 162 // the frequency domain array 163 // return value The Q-domain of current frequency values 164 // 165 static int TimeToFrequencyDomain(AecmCore_t* aecm, 166 const int16_t* time_signal, 167 complex16_t* freq_signal, 168 uint16_t* freq_signal_abs, 169 uint32_t* freq_signal_sum_abs) 170 { 171 int i = 0; 172 int time_signal_scaling = 0; 173 174 int32_t tmp32no1 = 0; 175 int32_t tmp32no2 = 0; 176 177 // In fft_buf, +16 for 32-byte alignment. 178 int16_t fft_buf[PART_LEN4 + 16]; 179 int16_t *fft = (int16_t *) (((uintptr_t) fft_buf + 31) & ~31); 180 181 int16_t tmp16no1; 182 #ifndef WEBRTC_ARCH_ARM_V7 183 int16_t tmp16no2; 184 #endif 185 #ifdef AECM_WITH_ABS_APPROX 186 int16_t max_value = 0; 187 int16_t min_value = 0; 188 uint16_t alpha = 0; 189 uint16_t beta = 0; 190 #endif 191 192 #ifdef AECM_DYNAMIC_Q 193 tmp16no1 = WebRtcSpl_MaxAbsValueW16(time_signal, PART_LEN2); 194 time_signal_scaling = WebRtcSpl_NormW16(tmp16no1); 195 #endif 196 197 WindowAndFFT(aecm, fft, time_signal, freq_signal, time_signal_scaling); 198 199 // Extract imaginary and real part, calculate the magnitude for 200 // all frequency bins 201 freq_signal[0].imag = 0; 202 freq_signal[PART_LEN].imag = 0; 203 freq_signal_abs[0] = (uint16_t)WEBRTC_SPL_ABS_W16(freq_signal[0].real); 204 freq_signal_abs[PART_LEN] = (uint16_t)WEBRTC_SPL_ABS_W16( 205 freq_signal[PART_LEN].real); 206 (*freq_signal_sum_abs) = (uint32_t)(freq_signal_abs[0]) + 207 (uint32_t)(freq_signal_abs[PART_LEN]); 208 209 for (i = 1; i < PART_LEN; i++) 210 { 211 if (freq_signal[i].real == 0) 212 { 213 freq_signal_abs[i] = (uint16_t)WEBRTC_SPL_ABS_W16(freq_signal[i].imag); 214 } 215 else if (freq_signal[i].imag == 0) 216 { 217 freq_signal_abs[i] = (uint16_t)WEBRTC_SPL_ABS_W16(freq_signal[i].real); 218 } 219 else 220 { 221 // Approximation for magnitude of complex fft output 222 // magn = sqrt(real^2 + imag^2) 223 // magn ~= alpha * max(|imag|,|real|) + beta * min(|imag|,|real|) 224 // 225 // The parameters alpha and beta are stored in Q15 226 227 #ifdef AECM_WITH_ABS_APPROX 228 tmp16no1 = WEBRTC_SPL_ABS_W16(freq_signal[i].real); 229 tmp16no2 = WEBRTC_SPL_ABS_W16(freq_signal[i].imag); 230 231 if(tmp16no1 > tmp16no2) 232 { 233 max_value = tmp16no1; 234 min_value = tmp16no2; 235 } else 236 { 237 max_value = tmp16no2; 238 min_value = tmp16no1; 239 } 240 241 // Magnitude in Q(-6) 242 if ((max_value >> 2) > min_value) 243 { 244 alpha = kAlpha1; 245 beta = kBeta1; 246 } else if ((max_value >> 1) > min_value) 247 { 248 alpha = kAlpha2; 249 beta = kBeta2; 250 } else 251 { 252 alpha = kAlpha3; 253 beta = kBeta3; 254 } 255 tmp16no1 = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(max_value, alpha, 15); 256 tmp16no2 = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(min_value, beta, 15); 257 freq_signal_abs[i] = (uint16_t)tmp16no1 + (uint16_t)tmp16no2; 258 #else 259 #ifdef WEBRTC_ARCH_ARM_V7 260 __asm __volatile( 261 "smulbb %[tmp32no1], %[real], %[real]\n\t" 262 "smlabb %[tmp32no2], %[imag], %[imag], %[tmp32no1]\n\t" 263 :[tmp32no1]"+&r"(tmp32no1), 264 [tmp32no2]"=r"(tmp32no2) 265 :[real]"r"(freq_signal[i].real), 266 [imag]"r"(freq_signal[i].imag) 267 ); 268 #else 269 tmp16no1 = WEBRTC_SPL_ABS_W16(freq_signal[i].real); 270 tmp16no2 = WEBRTC_SPL_ABS_W16(freq_signal[i].imag); 271 tmp32no1 = WEBRTC_SPL_MUL_16_16(tmp16no1, tmp16no1); 272 tmp32no2 = WEBRTC_SPL_MUL_16_16(tmp16no2, tmp16no2); 273 tmp32no2 = WEBRTC_SPL_ADD_SAT_W32(tmp32no1, tmp32no2); 274 #endif // WEBRTC_ARCH_ARM_V7 275 tmp32no1 = WebRtcSpl_SqrtFloor(tmp32no2); 276 277 freq_signal_abs[i] = (uint16_t)tmp32no1; 278 #endif // AECM_WITH_ABS_APPROX 279 } 280 (*freq_signal_sum_abs) += (uint32_t)freq_signal_abs[i]; 281 } 282 283 return time_signal_scaling; 284 } 285 286 int WebRtcAecm_ProcessBlock(AecmCore_t * aecm, 287 const int16_t * farend, 288 const int16_t * nearendNoisy, 289 const int16_t * nearendClean, 290 int16_t * output) 291 { 292 int i; 293 294 uint32_t xfaSum; 295 uint32_t dfaNoisySum; 296 uint32_t dfaCleanSum; 297 uint32_t echoEst32Gained; 298 uint32_t tmpU32; 299 300 int32_t tmp32no1; 301 302 uint16_t xfa[PART_LEN1]; 303 uint16_t dfaNoisy[PART_LEN1]; 304 uint16_t dfaClean[PART_LEN1]; 305 uint16_t* ptrDfaClean = dfaClean; 306 const uint16_t* far_spectrum_ptr = NULL; 307 308 // 32 byte aligned buffers (with +8 or +16). 309 // TODO (kma): define fft with complex16_t. 310 int16_t fft_buf[PART_LEN4 + 2 + 16]; // +2 to make a loop safe. 311 int32_t echoEst32_buf[PART_LEN1 + 8]; 312 int32_t dfw_buf[PART_LEN2 + 8]; 313 int32_t efw_buf[PART_LEN2 + 8]; 314 315 int16_t* fft = (int16_t*) (((uintptr_t) fft_buf + 31) & ~ 31); 316 int32_t* echoEst32 = (int32_t*) (((uintptr_t) echoEst32_buf + 31) & ~ 31); 317 complex16_t* dfw = (complex16_t*) (((uintptr_t) dfw_buf + 31) & ~ 31); 318 complex16_t* efw = (complex16_t*) (((uintptr_t) efw_buf + 31) & ~ 31); 319 320 int16_t hnl[PART_LEN1]; 321 int16_t numPosCoef = 0; 322 int16_t nlpGain = ONE_Q14; 323 int delay; 324 int16_t tmp16no1; 325 int16_t tmp16no2; 326 int16_t mu; 327 int16_t supGain; 328 int16_t zeros32, zeros16; 329 int16_t zerosDBufNoisy, zerosDBufClean, zerosXBuf; 330 int far_q; 331 int16_t resolutionDiff, qDomainDiff; 332 333 const int kMinPrefBand = 4; 334 const int kMaxPrefBand = 24; 335 int32_t avgHnl32 = 0; 336 337 // Determine startup state. There are three states: 338 // (0) the first CONV_LEN blocks 339 // (1) another CONV_LEN blocks 340 // (2) the rest 341 342 if (aecm->startupState < 2) 343 { 344 aecm->startupState = (aecm->totCount >= CONV_LEN) + 345 (aecm->totCount >= CONV_LEN2); 346 } 347 // END: Determine startup state 348 349 // Buffer near and far end signals 350 memcpy(aecm->xBuf + PART_LEN, farend, sizeof(int16_t) * PART_LEN); 351 memcpy(aecm->dBufNoisy + PART_LEN, nearendNoisy, sizeof(int16_t) * PART_LEN); 352 if (nearendClean != NULL) 353 { 354 memcpy(aecm->dBufClean + PART_LEN, 355 nearendClean, 356 sizeof(int16_t) * PART_LEN); 357 } 358 359 // Transform far end signal from time domain to frequency domain. 360 far_q = TimeToFrequencyDomain(aecm, 361 aecm->xBuf, 362 dfw, 363 xfa, 364 &xfaSum); 365 366 // Transform noisy near end signal from time domain to frequency domain. 367 zerosDBufNoisy = TimeToFrequencyDomain(aecm, 368 aecm->dBufNoisy, 369 dfw, 370 dfaNoisy, 371 &dfaNoisySum); 372 aecm->dfaNoisyQDomainOld = aecm->dfaNoisyQDomain; 373 aecm->dfaNoisyQDomain = (int16_t)zerosDBufNoisy; 374 375 376 if (nearendClean == NULL) 377 { 378 ptrDfaClean = dfaNoisy; 379 aecm->dfaCleanQDomainOld = aecm->dfaNoisyQDomainOld; 380 aecm->dfaCleanQDomain = aecm->dfaNoisyQDomain; 381 dfaCleanSum = dfaNoisySum; 382 } else 383 { 384 // Transform clean near end signal from time domain to frequency domain. 385 zerosDBufClean = TimeToFrequencyDomain(aecm, 386 aecm->dBufClean, 387 dfw, 388 dfaClean, 389 &dfaCleanSum); 390 aecm->dfaCleanQDomainOld = aecm->dfaCleanQDomain; 391 aecm->dfaCleanQDomain = (int16_t)zerosDBufClean; 392 } 393 394 // Get the delay 395 // Save far-end history and estimate delay 396 WebRtcAecm_UpdateFarHistory(aecm, xfa, far_q); 397 if (WebRtc_AddFarSpectrumFix(aecm->delay_estimator_farend, 398 xfa, 399 PART_LEN1, 400 far_q) == -1) { 401 return -1; 402 } 403 delay = WebRtc_DelayEstimatorProcessFix(aecm->delay_estimator, 404 dfaNoisy, 405 PART_LEN1, 406 zerosDBufNoisy); 407 if (delay == -1) 408 { 409 return -1; 410 } 411 else if (delay == -2) 412 { 413 // If the delay is unknown, we assume zero. 414 // NOTE: this will have to be adjusted if we ever add lookahead. 415 delay = 0; 416 } 417 418 if (aecm->fixedDelay >= 0) 419 { 420 // Use fixed delay 421 delay = aecm->fixedDelay; 422 } 423 424 // Get aligned far end spectrum 425 far_spectrum_ptr = WebRtcAecm_AlignedFarend(aecm, &far_q, delay); 426 zerosXBuf = (int16_t) far_q; 427 if (far_spectrum_ptr == NULL) 428 { 429 return -1; 430 } 431 432 // Calculate log(energy) and update energy threshold levels 433 WebRtcAecm_CalcEnergies(aecm, 434 far_spectrum_ptr, 435 zerosXBuf, 436 dfaNoisySum, 437 echoEst32); 438 439 // Calculate stepsize 440 mu = WebRtcAecm_CalcStepSize(aecm); 441 442 // Update counters 443 aecm->totCount++; 444 445 // This is the channel estimation algorithm. 446 // It is base on NLMS but has a variable step length, 447 // which was calculated above. 448 WebRtcAecm_UpdateChannel(aecm, 449 far_spectrum_ptr, 450 zerosXBuf, 451 dfaNoisy, 452 mu, 453 echoEst32); 454 supGain = WebRtcAecm_CalcSuppressionGain(aecm); 455 456 457 // Calculate Wiener filter hnl[] 458 for (i = 0; i < PART_LEN1; i++) 459 { 460 // Far end signal through channel estimate in Q8 461 // How much can we shift right to preserve resolution 462 tmp32no1 = echoEst32[i] - aecm->echoFilt[i]; 463 aecm->echoFilt[i] += WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL_32_16(tmp32no1, 464 50), 8); 465 466 zeros32 = WebRtcSpl_NormW32(aecm->echoFilt[i]) + 1; 467 zeros16 = WebRtcSpl_NormW16(supGain) + 1; 468 if (zeros32 + zeros16 > 16) 469 { 470 // Multiplication is safe 471 // Result in 472 // Q(RESOLUTION_CHANNEL+RESOLUTION_SUPGAIN+ 473 // aecm->xfaQDomainBuf[diff]) 474 echoEst32Gained = WEBRTC_SPL_UMUL_32_16((uint32_t)aecm->echoFilt[i], 475 (uint16_t)supGain); 476 resolutionDiff = 14 - RESOLUTION_CHANNEL16 - RESOLUTION_SUPGAIN; 477 resolutionDiff += (aecm->dfaCleanQDomain - zerosXBuf); 478 } else 479 { 480 tmp16no1 = 17 - zeros32 - zeros16; 481 resolutionDiff = 14 + tmp16no1 - RESOLUTION_CHANNEL16 - 482 RESOLUTION_SUPGAIN; 483 resolutionDiff += (aecm->dfaCleanQDomain - zerosXBuf); 484 if (zeros32 > tmp16no1) 485 { 486 echoEst32Gained = WEBRTC_SPL_UMUL_32_16((uint32_t)aecm->echoFilt[i], 487 (uint16_t)WEBRTC_SPL_RSHIFT_W16( 488 supGain, 489 tmp16no1) 490 ); 491 } else 492 { 493 // Result in Q-(RESOLUTION_CHANNEL+RESOLUTION_SUPGAIN-16) 494 echoEst32Gained = WEBRTC_SPL_UMUL_32_16((uint32_t)WEBRTC_SPL_RSHIFT_W32( 495 aecm->echoFilt[i], 496 tmp16no1), 497 (uint16_t)supGain); 498 } 499 } 500 501 zeros16 = WebRtcSpl_NormW16(aecm->nearFilt[i]); 502 if ((zeros16 < (aecm->dfaCleanQDomain - aecm->dfaCleanQDomainOld)) 503 & (aecm->nearFilt[i])) 504 { 505 tmp16no1 = WEBRTC_SPL_SHIFT_W16(aecm->nearFilt[i], zeros16); 506 qDomainDiff = zeros16 - aecm->dfaCleanQDomain + aecm->dfaCleanQDomainOld; 507 } else 508 { 509 tmp16no1 = WEBRTC_SPL_SHIFT_W16(aecm->nearFilt[i], 510 aecm->dfaCleanQDomain - 511 aecm->dfaCleanQDomainOld); 512 qDomainDiff = 0; 513 } 514 tmp16no2 = WEBRTC_SPL_SHIFT_W16(ptrDfaClean[i], qDomainDiff); 515 tmp32no1 = (int32_t)(tmp16no2 - tmp16no1); 516 tmp16no2 = (int16_t)WEBRTC_SPL_RSHIFT_W32(tmp32no1, 4); 517 tmp16no2 += tmp16no1; 518 zeros16 = WebRtcSpl_NormW16(tmp16no2); 519 if ((tmp16no2) & (-qDomainDiff > zeros16)) 520 { 521 aecm->nearFilt[i] = WEBRTC_SPL_WORD16_MAX; 522 } else 523 { 524 aecm->nearFilt[i] = WEBRTC_SPL_SHIFT_W16(tmp16no2, -qDomainDiff); 525 } 526 527 // Wiener filter coefficients, resulting hnl in Q14 528 if (echoEst32Gained == 0) 529 { 530 hnl[i] = ONE_Q14; 531 } else if (aecm->nearFilt[i] == 0) 532 { 533 hnl[i] = 0; 534 } else 535 { 536 // Multiply the suppression gain 537 // Rounding 538 echoEst32Gained += (uint32_t)(aecm->nearFilt[i] >> 1); 539 tmpU32 = WebRtcSpl_DivU32U16(echoEst32Gained, 540 (uint16_t)aecm->nearFilt[i]); 541 542 // Current resolution is 543 // Q-(RESOLUTION_CHANNEL+RESOLUTION_SUPGAIN- max(0,17-zeros16- zeros32)) 544 // Make sure we are in Q14 545 tmp32no1 = (int32_t)WEBRTC_SPL_SHIFT_W32(tmpU32, resolutionDiff); 546 if (tmp32no1 > ONE_Q14) 547 { 548 hnl[i] = 0; 549 } else if (tmp32no1 < 0) 550 { 551 hnl[i] = ONE_Q14; 552 } else 553 { 554 // 1-echoEst/dfa 555 hnl[i] = ONE_Q14 - (int16_t)tmp32no1; 556 if (hnl[i] < 0) 557 { 558 hnl[i] = 0; 559 } 560 } 561 } 562 if (hnl[i]) 563 { 564 numPosCoef++; 565 } 566 } 567 // Only in wideband. Prevent the gain in upper band from being larger than 568 // in lower band. 569 if (aecm->mult == 2) 570 { 571 // TODO(bjornv): Investigate if the scaling of hnl[i] below can cause 572 // speech distortion in double-talk. 573 for (i = 0; i < PART_LEN1; i++) 574 { 575 hnl[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(hnl[i], hnl[i], 14); 576 } 577 578 for (i = kMinPrefBand; i <= kMaxPrefBand; i++) 579 { 580 avgHnl32 += (int32_t)hnl[i]; 581 } 582 assert(kMaxPrefBand - kMinPrefBand + 1 > 0); 583 avgHnl32 /= (kMaxPrefBand - kMinPrefBand + 1); 584 585 for (i = kMaxPrefBand; i < PART_LEN1; i++) 586 { 587 if (hnl[i] > (int16_t)avgHnl32) 588 { 589 hnl[i] = (int16_t)avgHnl32; 590 } 591 } 592 } 593 594 // Calculate NLP gain, result is in Q14 595 if (aecm->nlpFlag) 596 { 597 for (i = 0; i < PART_LEN1; i++) 598 { 599 // Truncate values close to zero and one. 600 if (hnl[i] > NLP_COMP_HIGH) 601 { 602 hnl[i] = ONE_Q14; 603 } else if (hnl[i] < NLP_COMP_LOW) 604 { 605 hnl[i] = 0; 606 } 607 608 // Remove outliers 609 if (numPosCoef < 3) 610 { 611 nlpGain = 0; 612 } else 613 { 614 nlpGain = ONE_Q14; 615 } 616 617 // NLP 618 if ((hnl[i] == ONE_Q14) && (nlpGain == ONE_Q14)) 619 { 620 hnl[i] = ONE_Q14; 621 } else 622 { 623 hnl[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(hnl[i], nlpGain, 14); 624 } 625 626 // multiply with Wiener coefficients 627 efw[i].real = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].real, 628 hnl[i], 14)); 629 efw[i].imag = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].imag, 630 hnl[i], 14)); 631 } 632 } 633 else 634 { 635 // multiply with Wiener coefficients 636 for (i = 0; i < PART_LEN1; i++) 637 { 638 efw[i].real = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].real, 639 hnl[i], 14)); 640 efw[i].imag = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].imag, 641 hnl[i], 14)); 642 } 643 } 644 645 if (aecm->cngMode == AecmTrue) 646 { 647 ComfortNoise(aecm, ptrDfaClean, efw, hnl); 648 } 649 650 InverseFFTAndWindow(aecm, fft, efw, output, nearendClean); 651 652 return 0; 653 } 654 655 656 static void ComfortNoise(AecmCore_t* aecm, 657 const uint16_t* dfa, 658 complex16_t* out, 659 const int16_t* lambda) 660 { 661 int16_t i; 662 int16_t tmp16; 663 int32_t tmp32; 664 665 int16_t randW16[PART_LEN]; 666 int16_t uReal[PART_LEN1]; 667 int16_t uImag[PART_LEN1]; 668 int32_t outLShift32; 669 int16_t noiseRShift16[PART_LEN1]; 670 671 int16_t shiftFromNearToNoise = kNoiseEstQDomain - aecm->dfaCleanQDomain; 672 int16_t minTrackShift; 673 674 assert(shiftFromNearToNoise >= 0); 675 assert(shiftFromNearToNoise < 16); 676 677 if (aecm->noiseEstCtr < 100) 678 { 679 // Track the minimum more quickly initially. 680 aecm->noiseEstCtr++; 681 minTrackShift = 6; 682 } else 683 { 684 minTrackShift = 9; 685 } 686 687 // Estimate noise power. 688 for (i = 0; i < PART_LEN1; i++) 689 { 690 // Shift to the noise domain. 691 tmp32 = (int32_t)dfa[i]; 692 outLShift32 = WEBRTC_SPL_LSHIFT_W32(tmp32, shiftFromNearToNoise); 693 694 if (outLShift32 < aecm->noiseEst[i]) 695 { 696 // Reset "too low" counter 697 aecm->noiseEstTooLowCtr[i] = 0; 698 // Track the minimum. 699 if (aecm->noiseEst[i] < (1 << minTrackShift)) 700 { 701 // For small values, decrease noiseEst[i] every 702 // |kNoiseEstIncCount| block. The regular approach below can not 703 // go further down due to truncation. 704 aecm->noiseEstTooHighCtr[i]++; 705 if (aecm->noiseEstTooHighCtr[i] >= kNoiseEstIncCount) 706 { 707 aecm->noiseEst[i]--; 708 aecm->noiseEstTooHighCtr[i] = 0; // Reset the counter 709 } 710 } 711 else 712 { 713 aecm->noiseEst[i] -= ((aecm->noiseEst[i] - outLShift32) 714 >> minTrackShift); 715 } 716 } else 717 { 718 // Reset "too high" counter 719 aecm->noiseEstTooHighCtr[i] = 0; 720 // Ramp slowly upwards until we hit the minimum again. 721 if ((aecm->noiseEst[i] >> 19) > 0) 722 { 723 // Avoid overflow. 724 // Multiplication with 2049 will cause wrap around. Scale 725 // down first and then multiply 726 aecm->noiseEst[i] >>= 11; 727 aecm->noiseEst[i] *= 2049; 728 } 729 else if ((aecm->noiseEst[i] >> 11) > 0) 730 { 731 // Large enough for relative increase 732 aecm->noiseEst[i] *= 2049; 733 aecm->noiseEst[i] >>= 11; 734 } 735 else 736 { 737 // Make incremental increases based on size every 738 // |kNoiseEstIncCount| block 739 aecm->noiseEstTooLowCtr[i]++; 740 if (aecm->noiseEstTooLowCtr[i] >= kNoiseEstIncCount) 741 { 742 aecm->noiseEst[i] += (aecm->noiseEst[i] >> 9) + 1; 743 aecm->noiseEstTooLowCtr[i] = 0; // Reset counter 744 } 745 } 746 } 747 } 748 749 for (i = 0; i < PART_LEN1; i++) 750 { 751 tmp32 = WEBRTC_SPL_RSHIFT_W32(aecm->noiseEst[i], shiftFromNearToNoise); 752 if (tmp32 > 32767) 753 { 754 tmp32 = 32767; 755 aecm->noiseEst[i] = WEBRTC_SPL_LSHIFT_W32(tmp32, shiftFromNearToNoise); 756 } 757 noiseRShift16[i] = (int16_t)tmp32; 758 759 tmp16 = ONE_Q14 - lambda[i]; 760 noiseRShift16[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(tmp16, 761 noiseRShift16[i], 762 14); 763 } 764 765 // Generate a uniform random array on [0 2^15-1]. 766 WebRtcSpl_RandUArray(randW16, PART_LEN, &aecm->seed); 767 768 // Generate noise according to estimated energy. 769 uReal[0] = 0; // Reject LF noise. 770 uImag[0] = 0; 771 for (i = 1; i < PART_LEN1; i++) 772 { 773 // Get a random index for the cos and sin tables over [0 359]. 774 tmp16 = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(359, randW16[i - 1], 15); 775 776 // Tables are in Q13. 777 uReal[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(noiseRShift16[i], 778 WebRtcAecm_kCosTable[tmp16], 779 13); 780 uImag[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(-noiseRShift16[i], 781 WebRtcAecm_kSinTable[tmp16], 782 13); 783 } 784 uImag[PART_LEN] = 0; 785 786 for (i = 0; i < PART_LEN1; i++) 787 { 788 out[i].real = WEBRTC_SPL_ADD_SAT_W16(out[i].real, uReal[i]); 789 out[i].imag = WEBRTC_SPL_ADD_SAT_W16(out[i].imag, uImag[i]); 790 } 791 } 792 793