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Diffstat (limited to 'third_party/webrtc/src/webrtc/modules/audio_processing/aecm/aecm_core_c.c')
| -rw-r--r-- | third_party/webrtc/src/webrtc/modules/audio_processing/aecm/aecm_core_c.c | 771 |
1 files changed, 771 insertions, 0 deletions
diff --git a/third_party/webrtc/src/webrtc/modules/audio_processing/aecm/aecm_core_c.c b/third_party/webrtc/src/webrtc/modules/audio_processing/aecm/aecm_core_c.c new file mode 100644 index 00000000..eb2bd918 --- /dev/null +++ b/third_party/webrtc/src/webrtc/modules/audio_processing/aecm/aecm_core_c.c @@ -0,0 +1,771 @@ +/* + * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#include "webrtc/modules/audio_processing/aecm/aecm_core.h" + +#include <assert.h> +#include <stddef.h> +#include <stdlib.h> + +#include "webrtc/common_audio/ring_buffer.h" +#include "webrtc/common_audio/signal_processing/include/real_fft.h" +#include "webrtc/modules/audio_processing/aecm/include/echo_control_mobile.h" +#include "webrtc/modules/audio_processing/utility/delay_estimator_wrapper.h" +#include "webrtc/system_wrappers/interface/compile_assert_c.h" +#include "webrtc/system_wrappers/interface/cpu_features_wrapper.h" +#include "webrtc/typedefs.h" + +// Square root of Hanning window in Q14. +#if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON) +// Table is defined in an ARM assembly file. +extern const ALIGN8_BEG int16_t WebRtcAecm_kSqrtHanning[] ALIGN8_END; +#else +static const ALIGN8_BEG int16_t WebRtcAecm_kSqrtHanning[] ALIGN8_END = { + 0, 399, 798, 1196, 1594, 1990, 2386, 2780, 3172, + 3562, 3951, 4337, 4720, 5101, 5478, 5853, 6224, + 6591, 6954, 7313, 7668, 8019, 8364, 8705, 9040, + 9370, 9695, 10013, 10326, 10633, 10933, 11227, 11514, + 11795, 12068, 12335, 12594, 12845, 13089, 13325, 13553, + 13773, 13985, 14189, 14384, 14571, 14749, 14918, 15079, + 15231, 15373, 15506, 15631, 15746, 15851, 15947, 16034, + 16111, 16179, 16237, 16286, 16325, 16354, 16373, 16384 +}; +#endif + +#ifdef AECM_WITH_ABS_APPROX +//Q15 alpha = 0.99439986968132 const Factor for magnitude approximation +static const uint16_t kAlpha1 = 32584; +//Q15 beta = 0.12967166976970 const Factor for magnitude approximation +static const uint16_t kBeta1 = 4249; +//Q15 alpha = 0.94234827210087 const Factor for magnitude approximation +static const uint16_t kAlpha2 = 30879; +//Q15 beta = 0.33787806009150 const Factor for magnitude approximation +static const uint16_t kBeta2 = 11072; +//Q15 alpha = 0.82247698684306 const Factor for magnitude approximation +static const uint16_t kAlpha3 = 26951; +//Q15 beta = 0.57762063060713 const Factor for magnitude approximation +static const uint16_t kBeta3 = 18927; +#endif + +static const int16_t kNoiseEstQDomain = 15; +static const int16_t kNoiseEstIncCount = 5; + +static void ComfortNoise(AecmCore* aecm, + const uint16_t* dfa, + ComplexInt16* out, + const int16_t* lambda); + +static void WindowAndFFT(AecmCore* aecm, + int16_t* fft, + const int16_t* time_signal, + ComplexInt16* freq_signal, + int time_signal_scaling) { + int i = 0; + + // FFT of signal + for (i = 0; i < PART_LEN; i++) { + // Window time domain signal and insert into real part of + // transformation array |fft| + int16_t scaled_time_signal = time_signal[i] << time_signal_scaling; + fft[i] = (int16_t)((scaled_time_signal * WebRtcAecm_kSqrtHanning[i]) >> 14); + scaled_time_signal = time_signal[i + PART_LEN] << time_signal_scaling; + fft[PART_LEN + i] = (int16_t)(( + scaled_time_signal * WebRtcAecm_kSqrtHanning[PART_LEN - i]) >> 14); + } + + // Do forward FFT, then take only the first PART_LEN complex samples, + // and change signs of the imaginary parts. + WebRtcSpl_RealForwardFFT(aecm->real_fft, fft, (int16_t*)freq_signal); + for (i = 0; i < PART_LEN; i++) { + freq_signal[i].imag = -freq_signal[i].imag; + } +} + +static void InverseFFTAndWindow(AecmCore* aecm, + int16_t* fft, + ComplexInt16* efw, + int16_t* output, + const int16_t* nearendClean) { + int i, j, outCFFT; + int32_t tmp32no1; + // Reuse |efw| for the inverse FFT output after transferring + // the contents to |fft|. + int16_t* ifft_out = (int16_t*)efw; + + // Synthesis + for (i = 1, j = 2; i < PART_LEN; i += 1, j += 2) { + fft[j] = efw[i].real; + fft[j + 1] = -efw[i].imag; + } + fft[0] = efw[0].real; + fft[1] = -efw[0].imag; + + fft[PART_LEN2] = efw[PART_LEN].real; + fft[PART_LEN2 + 1] = -efw[PART_LEN].imag; + + // Inverse FFT. Keep outCFFT to scale the samples in the next block. + outCFFT = WebRtcSpl_RealInverseFFT(aecm->real_fft, fft, ifft_out); + for (i = 0; i < PART_LEN; i++) { + ifft_out[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND( + ifft_out[i], WebRtcAecm_kSqrtHanning[i], 14); + tmp32no1 = WEBRTC_SPL_SHIFT_W32((int32_t)ifft_out[i], + outCFFT - aecm->dfaCleanQDomain); + output[i] = (int16_t)WEBRTC_SPL_SAT(WEBRTC_SPL_WORD16_MAX, + tmp32no1 + aecm->outBuf[i], + WEBRTC_SPL_WORD16_MIN); + + tmp32no1 = (ifft_out[PART_LEN + i] * + WebRtcAecm_kSqrtHanning[PART_LEN - i]) >> 14; + tmp32no1 = WEBRTC_SPL_SHIFT_W32(tmp32no1, + outCFFT - aecm->dfaCleanQDomain); + aecm->outBuf[i] = (int16_t)WEBRTC_SPL_SAT(WEBRTC_SPL_WORD16_MAX, + tmp32no1, + WEBRTC_SPL_WORD16_MIN); + } + + // Copy the current block to the old position + // (aecm->outBuf is shifted elsewhere) + memcpy(aecm->xBuf, aecm->xBuf + PART_LEN, sizeof(int16_t) * PART_LEN); + memcpy(aecm->dBufNoisy, + aecm->dBufNoisy + PART_LEN, + sizeof(int16_t) * PART_LEN); + if (nearendClean != NULL) + { + memcpy(aecm->dBufClean, + aecm->dBufClean + PART_LEN, + sizeof(int16_t) * PART_LEN); + } +} + +// Transforms a time domain signal into the frequency domain, outputting the +// complex valued signal, absolute value and sum of absolute values. +// +// time_signal [in] Pointer to time domain signal +// freq_signal_real [out] Pointer to real part of frequency domain array +// freq_signal_imag [out] Pointer to imaginary part of frequency domain +// array +// freq_signal_abs [out] Pointer to absolute value of frequency domain +// array +// freq_signal_sum_abs [out] Pointer to the sum of all absolute values in +// the frequency domain array +// return value The Q-domain of current frequency values +// +static int TimeToFrequencyDomain(AecmCore* aecm, + const int16_t* time_signal, + ComplexInt16* freq_signal, + uint16_t* freq_signal_abs, + uint32_t* freq_signal_sum_abs) { + int i = 0; + int time_signal_scaling = 0; + + int32_t tmp32no1 = 0; + int32_t tmp32no2 = 0; + + // In fft_buf, +16 for 32-byte alignment. + int16_t fft_buf[PART_LEN4 + 16]; + int16_t *fft = (int16_t *) (((uintptr_t) fft_buf + 31) & ~31); + + int16_t tmp16no1; +#ifndef WEBRTC_ARCH_ARM_V7 + int16_t tmp16no2; +#endif +#ifdef AECM_WITH_ABS_APPROX + int16_t max_value = 0; + int16_t min_value = 0; + uint16_t alpha = 0; + uint16_t beta = 0; +#endif + +#ifdef AECM_DYNAMIC_Q + tmp16no1 = WebRtcSpl_MaxAbsValueW16(time_signal, PART_LEN2); + time_signal_scaling = WebRtcSpl_NormW16(tmp16no1); +#endif + + WindowAndFFT(aecm, fft, time_signal, freq_signal, time_signal_scaling); + + // Extract imaginary and real part, calculate the magnitude for + // all frequency bins + freq_signal[0].imag = 0; + freq_signal[PART_LEN].imag = 0; + freq_signal_abs[0] = (uint16_t)WEBRTC_SPL_ABS_W16(freq_signal[0].real); + freq_signal_abs[PART_LEN] = (uint16_t)WEBRTC_SPL_ABS_W16( + freq_signal[PART_LEN].real); + (*freq_signal_sum_abs) = (uint32_t)(freq_signal_abs[0]) + + (uint32_t)(freq_signal_abs[PART_LEN]); + + for (i = 1; i < PART_LEN; i++) + { + if (freq_signal[i].real == 0) + { + freq_signal_abs[i] = (uint16_t)WEBRTC_SPL_ABS_W16(freq_signal[i].imag); + } + else if (freq_signal[i].imag == 0) + { + freq_signal_abs[i] = (uint16_t)WEBRTC_SPL_ABS_W16(freq_signal[i].real); + } + else + { + // Approximation for magnitude of complex fft output + // magn = sqrt(real^2 + imag^2) + // magn ~= alpha * max(|imag|,|real|) + beta * min(|imag|,|real|) + // + // The parameters alpha and beta are stored in Q15 + +#ifdef AECM_WITH_ABS_APPROX + tmp16no1 = WEBRTC_SPL_ABS_W16(freq_signal[i].real); + tmp16no2 = WEBRTC_SPL_ABS_W16(freq_signal[i].imag); + + if(tmp16no1 > tmp16no2) + { + max_value = tmp16no1; + min_value = tmp16no2; + } else + { + max_value = tmp16no2; + min_value = tmp16no1; + } + + // Magnitude in Q(-6) + if ((max_value >> 2) > min_value) + { + alpha = kAlpha1; + beta = kBeta1; + } else if ((max_value >> 1) > min_value) + { + alpha = kAlpha2; + beta = kBeta2; + } else + { + alpha = kAlpha3; + beta = kBeta3; + } + tmp16no1 = (int16_t)((max_value * alpha) >> 15); + tmp16no2 = (int16_t)((min_value * beta) >> 15); + freq_signal_abs[i] = (uint16_t)tmp16no1 + (uint16_t)tmp16no2; +#else +#ifdef WEBRTC_ARCH_ARM_V7 + __asm __volatile( + "smulbb %[tmp32no1], %[real], %[real]\n\t" + "smlabb %[tmp32no2], %[imag], %[imag], %[tmp32no1]\n\t" + :[tmp32no1]"+&r"(tmp32no1), + [tmp32no2]"=r"(tmp32no2) + :[real]"r"(freq_signal[i].real), + [imag]"r"(freq_signal[i].imag) + ); +#else + tmp16no1 = WEBRTC_SPL_ABS_W16(freq_signal[i].real); + tmp16no2 = WEBRTC_SPL_ABS_W16(freq_signal[i].imag); + tmp32no1 = tmp16no1 * tmp16no1; + tmp32no2 = tmp16no2 * tmp16no2; + tmp32no2 = WebRtcSpl_AddSatW32(tmp32no1, tmp32no2); +#endif // WEBRTC_ARCH_ARM_V7 + tmp32no1 = WebRtcSpl_SqrtFloor(tmp32no2); + + freq_signal_abs[i] = (uint16_t)tmp32no1; +#endif // AECM_WITH_ABS_APPROX + } + (*freq_signal_sum_abs) += (uint32_t)freq_signal_abs[i]; + } + + return time_signal_scaling; +} + +int WebRtcAecm_ProcessBlock(AecmCore* aecm, + const int16_t* farend, + const int16_t* nearendNoisy, + const int16_t* nearendClean, + int16_t* output) { + int i; + + uint32_t xfaSum; + uint32_t dfaNoisySum; + uint32_t dfaCleanSum; + uint32_t echoEst32Gained; + uint32_t tmpU32; + + int32_t tmp32no1; + + uint16_t xfa[PART_LEN1]; + uint16_t dfaNoisy[PART_LEN1]; + uint16_t dfaClean[PART_LEN1]; + uint16_t* ptrDfaClean = dfaClean; + const uint16_t* far_spectrum_ptr = NULL; + + // 32 byte aligned buffers (with +8 or +16). + // TODO(kma): define fft with ComplexInt16. + int16_t fft_buf[PART_LEN4 + 2 + 16]; // +2 to make a loop safe. + int32_t echoEst32_buf[PART_LEN1 + 8]; + int32_t dfw_buf[PART_LEN2 + 8]; + int32_t efw_buf[PART_LEN2 + 8]; + + int16_t* fft = (int16_t*) (((uintptr_t) fft_buf + 31) & ~ 31); + int32_t* echoEst32 = (int32_t*) (((uintptr_t) echoEst32_buf + 31) & ~ 31); + ComplexInt16* dfw = (ComplexInt16*)(((uintptr_t)dfw_buf + 31) & ~31); + ComplexInt16* efw = (ComplexInt16*)(((uintptr_t)efw_buf + 31) & ~31); + + int16_t hnl[PART_LEN1]; + int16_t numPosCoef = 0; + int16_t nlpGain = ONE_Q14; + int delay; + int16_t tmp16no1; + int16_t tmp16no2; + int16_t mu; + int16_t supGain; + int16_t zeros32, zeros16; + int16_t zerosDBufNoisy, zerosDBufClean, zerosXBuf; + int far_q; + int16_t resolutionDiff, qDomainDiff, dfa_clean_q_domain_diff; + + const int kMinPrefBand = 4; + const int kMaxPrefBand = 24; + int32_t avgHnl32 = 0; + + // Determine startup state. There are three states: + // (0) the first CONV_LEN blocks + // (1) another CONV_LEN blocks + // (2) the rest + + if (aecm->startupState < 2) + { + aecm->startupState = (aecm->totCount >= CONV_LEN) + + (aecm->totCount >= CONV_LEN2); + } + // END: Determine startup state + + // Buffer near and far end signals + memcpy(aecm->xBuf + PART_LEN, farend, sizeof(int16_t) * PART_LEN); + memcpy(aecm->dBufNoisy + PART_LEN, nearendNoisy, sizeof(int16_t) * PART_LEN); + if (nearendClean != NULL) + { + memcpy(aecm->dBufClean + PART_LEN, + nearendClean, + sizeof(int16_t) * PART_LEN); + } + + // Transform far end signal from time domain to frequency domain. + far_q = TimeToFrequencyDomain(aecm, + aecm->xBuf, + dfw, + xfa, + &xfaSum); + + // Transform noisy near end signal from time domain to frequency domain. + zerosDBufNoisy = TimeToFrequencyDomain(aecm, + aecm->dBufNoisy, + dfw, + dfaNoisy, + &dfaNoisySum); + aecm->dfaNoisyQDomainOld = aecm->dfaNoisyQDomain; + aecm->dfaNoisyQDomain = (int16_t)zerosDBufNoisy; + + + if (nearendClean == NULL) + { + ptrDfaClean = dfaNoisy; + aecm->dfaCleanQDomainOld = aecm->dfaNoisyQDomainOld; + aecm->dfaCleanQDomain = aecm->dfaNoisyQDomain; + dfaCleanSum = dfaNoisySum; + } else + { + // Transform clean near end signal from time domain to frequency domain. + zerosDBufClean = TimeToFrequencyDomain(aecm, + aecm->dBufClean, + dfw, + dfaClean, + &dfaCleanSum); + aecm->dfaCleanQDomainOld = aecm->dfaCleanQDomain; + aecm->dfaCleanQDomain = (int16_t)zerosDBufClean; + } + + // Get the delay + // Save far-end history and estimate delay + WebRtcAecm_UpdateFarHistory(aecm, xfa, far_q); + if (WebRtc_AddFarSpectrumFix(aecm->delay_estimator_farend, + xfa, + PART_LEN1, + far_q) == -1) { + return -1; + } + delay = WebRtc_DelayEstimatorProcessFix(aecm->delay_estimator, + dfaNoisy, + PART_LEN1, + zerosDBufNoisy); + if (delay == -1) + { + return -1; + } + else if (delay == -2) + { + // If the delay is unknown, we assume zero. + // NOTE: this will have to be adjusted if we ever add lookahead. + delay = 0; + } + + if (aecm->fixedDelay >= 0) + { + // Use fixed delay + delay = aecm->fixedDelay; + } + + // Get aligned far end spectrum + far_spectrum_ptr = WebRtcAecm_AlignedFarend(aecm, &far_q, delay); + zerosXBuf = (int16_t) far_q; + if (far_spectrum_ptr == NULL) + { + return -1; + } + + // Calculate log(energy) and update energy threshold levels + WebRtcAecm_CalcEnergies(aecm, + far_spectrum_ptr, + zerosXBuf, + dfaNoisySum, + echoEst32); + + // Calculate stepsize + mu = WebRtcAecm_CalcStepSize(aecm); + + // Update counters + aecm->totCount++; + + // This is the channel estimation algorithm. + // It is base on NLMS but has a variable step length, + // which was calculated above. + WebRtcAecm_UpdateChannel(aecm, + far_spectrum_ptr, + zerosXBuf, + dfaNoisy, + mu, + echoEst32); + supGain = WebRtcAecm_CalcSuppressionGain(aecm); + + + // Calculate Wiener filter hnl[] + for (i = 0; i < PART_LEN1; i++) + { + // Far end signal through channel estimate in Q8 + // How much can we shift right to preserve resolution + tmp32no1 = echoEst32[i] - aecm->echoFilt[i]; + aecm->echoFilt[i] += (tmp32no1 * 50) >> 8; + + zeros32 = WebRtcSpl_NormW32(aecm->echoFilt[i]) + 1; + zeros16 = WebRtcSpl_NormW16(supGain) + 1; + if (zeros32 + zeros16 > 16) + { + // Multiplication is safe + // Result in + // Q(RESOLUTION_CHANNEL+RESOLUTION_SUPGAIN+ + // aecm->xfaQDomainBuf[diff]) + echoEst32Gained = WEBRTC_SPL_UMUL_32_16((uint32_t)aecm->echoFilt[i], + (uint16_t)supGain); + resolutionDiff = 14 - RESOLUTION_CHANNEL16 - RESOLUTION_SUPGAIN; + resolutionDiff += (aecm->dfaCleanQDomain - zerosXBuf); + } else + { + tmp16no1 = 17 - zeros32 - zeros16; + resolutionDiff = 14 + tmp16no1 - RESOLUTION_CHANNEL16 - + RESOLUTION_SUPGAIN; + resolutionDiff += (aecm->dfaCleanQDomain - zerosXBuf); + if (zeros32 > tmp16no1) + { + echoEst32Gained = WEBRTC_SPL_UMUL_32_16((uint32_t)aecm->echoFilt[i], + supGain >> tmp16no1); + } else + { + // Result in Q-(RESOLUTION_CHANNEL+RESOLUTION_SUPGAIN-16) + echoEst32Gained = (aecm->echoFilt[i] >> tmp16no1) * supGain; + } + } + + zeros16 = WebRtcSpl_NormW16(aecm->nearFilt[i]); + assert(zeros16 >= 0); // |zeros16| is a norm, hence non-negative. + dfa_clean_q_domain_diff = aecm->dfaCleanQDomain - aecm->dfaCleanQDomainOld; + if (zeros16 < dfa_clean_q_domain_diff && aecm->nearFilt[i]) { + tmp16no1 = aecm->nearFilt[i] << zeros16; + qDomainDiff = zeros16 - dfa_clean_q_domain_diff; + tmp16no2 = ptrDfaClean[i] >> -qDomainDiff; + } else { + tmp16no1 = dfa_clean_q_domain_diff < 0 + ? aecm->nearFilt[i] >> -dfa_clean_q_domain_diff + : aecm->nearFilt[i] << dfa_clean_q_domain_diff; + qDomainDiff = 0; + tmp16no2 = ptrDfaClean[i]; + } + tmp32no1 = (int32_t)(tmp16no2 - tmp16no1); + tmp16no2 = (int16_t)(tmp32no1 >> 4); + tmp16no2 += tmp16no1; + zeros16 = WebRtcSpl_NormW16(tmp16no2); + if ((tmp16no2) & (-qDomainDiff > zeros16)) { + aecm->nearFilt[i] = WEBRTC_SPL_WORD16_MAX; + } else { + aecm->nearFilt[i] = qDomainDiff < 0 ? tmp16no2 << -qDomainDiff + : tmp16no2 >> qDomainDiff; + } + + // Wiener filter coefficients, resulting hnl in Q14 + if (echoEst32Gained == 0) + { + hnl[i] = ONE_Q14; + } else if (aecm->nearFilt[i] == 0) + { + hnl[i] = 0; + } else + { + // Multiply the suppression gain + // Rounding + echoEst32Gained += (uint32_t)(aecm->nearFilt[i] >> 1); + tmpU32 = WebRtcSpl_DivU32U16(echoEst32Gained, + (uint16_t)aecm->nearFilt[i]); + + // Current resolution is + // Q-(RESOLUTION_CHANNEL+RESOLUTION_SUPGAIN- max(0,17-zeros16- zeros32)) + // Make sure we are in Q14 + tmp32no1 = (int32_t)WEBRTC_SPL_SHIFT_W32(tmpU32, resolutionDiff); + if (tmp32no1 > ONE_Q14) + { + hnl[i] = 0; + } else if (tmp32no1 < 0) + { + hnl[i] = ONE_Q14; + } else + { + // 1-echoEst/dfa + hnl[i] = ONE_Q14 - (int16_t)tmp32no1; + if (hnl[i] < 0) + { + hnl[i] = 0; + } + } + } + if (hnl[i]) + { + numPosCoef++; + } + } + // Only in wideband. Prevent the gain in upper band from being larger than + // in lower band. + if (aecm->mult == 2) + { + // TODO(bjornv): Investigate if the scaling of hnl[i] below can cause + // speech distortion in double-talk. + for (i = 0; i < PART_LEN1; i++) + { + hnl[i] = (int16_t)((hnl[i] * hnl[i]) >> 14); + } + + for (i = kMinPrefBand; i <= kMaxPrefBand; i++) + { + avgHnl32 += (int32_t)hnl[i]; + } + assert(kMaxPrefBand - kMinPrefBand + 1 > 0); + avgHnl32 /= (kMaxPrefBand - kMinPrefBand + 1); + + for (i = kMaxPrefBand; i < PART_LEN1; i++) + { + if (hnl[i] > (int16_t)avgHnl32) + { + hnl[i] = (int16_t)avgHnl32; + } + } + } + + // Calculate NLP gain, result is in Q14 + if (aecm->nlpFlag) + { + for (i = 0; i < PART_LEN1; i++) + { + // Truncate values close to zero and one. + if (hnl[i] > NLP_COMP_HIGH) + { + hnl[i] = ONE_Q14; + } else if (hnl[i] < NLP_COMP_LOW) + { + hnl[i] = 0; + } + + // Remove outliers + if (numPosCoef < 3) + { + nlpGain = 0; + } else + { + nlpGain = ONE_Q14; + } + + // NLP + if ((hnl[i] == ONE_Q14) && (nlpGain == ONE_Q14)) + { + hnl[i] = ONE_Q14; + } else + { + hnl[i] = (int16_t)((hnl[i] * nlpGain) >> 14); + } + + // multiply with Wiener coefficients + efw[i].real = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].real, + hnl[i], 14)); + efw[i].imag = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].imag, + hnl[i], 14)); + } + } + else + { + // multiply with Wiener coefficients + for (i = 0; i < PART_LEN1; i++) + { + efw[i].real = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].real, + hnl[i], 14)); + efw[i].imag = (int16_t)(WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(dfw[i].imag, + hnl[i], 14)); + } + } + + if (aecm->cngMode == AecmTrue) + { + ComfortNoise(aecm, ptrDfaClean, efw, hnl); + } + + InverseFFTAndWindow(aecm, fft, efw, output, nearendClean); + + return 0; +} + +static void ComfortNoise(AecmCore* aecm, + const uint16_t* dfa, + ComplexInt16* out, + const int16_t* lambda) { + int16_t i; + int16_t tmp16; + int32_t tmp32; + + int16_t randW16[PART_LEN]; + int16_t uReal[PART_LEN1]; + int16_t uImag[PART_LEN1]; + int32_t outLShift32; + int16_t noiseRShift16[PART_LEN1]; + + int16_t shiftFromNearToNoise = kNoiseEstQDomain - aecm->dfaCleanQDomain; + int16_t minTrackShift; + + assert(shiftFromNearToNoise >= 0); + assert(shiftFromNearToNoise < 16); + + if (aecm->noiseEstCtr < 100) + { + // Track the minimum more quickly initially. + aecm->noiseEstCtr++; + minTrackShift = 6; + } else + { + minTrackShift = 9; + } + + // Estimate noise power. + for (i = 0; i < PART_LEN1; i++) + { + // Shift to the noise domain. + tmp32 = (int32_t)dfa[i]; + outLShift32 = tmp32 << shiftFromNearToNoise; + + if (outLShift32 < aecm->noiseEst[i]) + { + // Reset "too low" counter + aecm->noiseEstTooLowCtr[i] = 0; + // Track the minimum. + if (aecm->noiseEst[i] < (1 << minTrackShift)) + { + // For small values, decrease noiseEst[i] every + // |kNoiseEstIncCount| block. The regular approach below can not + // go further down due to truncation. + aecm->noiseEstTooHighCtr[i]++; + if (aecm->noiseEstTooHighCtr[i] >= kNoiseEstIncCount) + { + aecm->noiseEst[i]--; + aecm->noiseEstTooHighCtr[i] = 0; // Reset the counter + } + } + else + { + aecm->noiseEst[i] -= ((aecm->noiseEst[i] - outLShift32) + >> minTrackShift); + } + } else + { + // Reset "too high" counter + aecm->noiseEstTooHighCtr[i] = 0; + // Ramp slowly upwards until we hit the minimum again. + if ((aecm->noiseEst[i] >> 19) > 0) + { + // Avoid overflow. + // Multiplication with 2049 will cause wrap around. Scale + // down first and then multiply + aecm->noiseEst[i] >>= 11; + aecm->noiseEst[i] *= 2049; + } + else if ((aecm->noiseEst[i] >> 11) > 0) + { + // Large enough for relative increase + aecm->noiseEst[i] *= 2049; + aecm->noiseEst[i] >>= 11; + } + else + { + // Make incremental increases based on size every + // |kNoiseEstIncCount| block + aecm->noiseEstTooLowCtr[i]++; + if (aecm->noiseEstTooLowCtr[i] >= kNoiseEstIncCount) + { + aecm->noiseEst[i] += (aecm->noiseEst[i] >> 9) + 1; + aecm->noiseEstTooLowCtr[i] = 0; // Reset counter + } + } + } + } + + for (i = 0; i < PART_LEN1; i++) + { + tmp32 = aecm->noiseEst[i] >> shiftFromNearToNoise; + if (tmp32 > 32767) + { + tmp32 = 32767; + aecm->noiseEst[i] = tmp32 << shiftFromNearToNoise; + } + noiseRShift16[i] = (int16_t)tmp32; + + tmp16 = ONE_Q14 - lambda[i]; + noiseRShift16[i] = (int16_t)((tmp16 * noiseRShift16[i]) >> 14); + } + + // Generate a uniform random array on [0 2^15-1]. + WebRtcSpl_RandUArray(randW16, PART_LEN, &aecm->seed); + + // Generate noise according to estimated energy. + uReal[0] = 0; // Reject LF noise. + uImag[0] = 0; + for (i = 1; i < PART_LEN1; i++) + { + // Get a random index for the cos and sin tables over [0 359]. + tmp16 = (int16_t)((359 * randW16[i - 1]) >> 15); + + // Tables are in Q13. + uReal[i] = (int16_t)((noiseRShift16[i] * WebRtcAecm_kCosTable[tmp16]) >> + 13); + uImag[i] = (int16_t)((-noiseRShift16[i] * WebRtcAecm_kSinTable[tmp16]) >> + 13); + } + uImag[PART_LEN] = 0; + + for (i = 0; i < PART_LEN1; i++) + { + out[i].real = WebRtcSpl_AddSatW16(out[i].real, uReal[i]); + out[i].imag = WebRtcSpl_AddSatW16(out[i].imag, uImag[i]); + } +} + |