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Diffstat (limited to '')
| -rw-r--r-- | third_party/libwebrtc/modules/audio_coding/codecs/ilbc/do_plc.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/do_plc.c b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/do_plc.c new file mode 100644 index 0000000000..9ca6ca48e9 --- /dev/null +++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/do_plc.c @@ -0,0 +1,309 @@ +/* + * Copyright (c) 2011 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. + */ + +/****************************************************************** + + iLBC Speech Coder ANSI-C Source Code + + WebRtcIlbcfix_DoThePlc.c + +******************************************************************/ + +#include "modules/audio_coding/codecs/ilbc/do_plc.h" + +#include "modules/audio_coding/codecs/ilbc/bw_expand.h" +#include "modules/audio_coding/codecs/ilbc/comp_corr.h" +#include "modules/audio_coding/codecs/ilbc/constants.h" +#include "modules/audio_coding/codecs/ilbc/defines.h" + +/*----------------------------------------------------------------* + * Packet loss concealment routine. Conceals a residual signal + * and LP parameters. If no packet loss, update state. + *---------------------------------------------------------------*/ + +void WebRtcIlbcfix_DoThePlc( + int16_t *PLCresidual, /* (o) concealed residual */ + int16_t *PLClpc, /* (o) concealed LP parameters */ + int16_t PLI, /* (i) packet loss indicator + 0 - no PL, 1 = PL */ + int16_t *decresidual, /* (i) decoded residual */ + int16_t *lpc, /* (i) decoded LPC (only used for no PL) */ + size_t inlag, /* (i) pitch lag */ + IlbcDecoder *iLBCdec_inst + /* (i/o) decoder instance */ + ){ + size_t i; + int32_t cross, ener, cross_comp, ener_comp = 0; + int32_t measure, maxMeasure, energy; + int32_t noise_energy_threshold_30dB; + int16_t max, crossSquareMax, crossSquare; + size_t j, lag, randlag; + int16_t tmp1, tmp2; + int16_t shift1, shift2, shift3, shiftMax; + int16_t scale3; + size_t corrLen; + int32_t tmpW32, tmp2W32; + int16_t use_gain; + int16_t tot_gain; + int16_t max_perSquare; + int16_t scale1, scale2; + int16_t totscale; + int32_t nom; + int16_t denom; + int16_t pitchfact; + size_t use_lag; + int ind; + int16_t randvec[BLOCKL_MAX]; + + /* Packet Loss */ + if (PLI == 1) { + + (*iLBCdec_inst).consPLICount += 1; + + /* if previous frame not lost, + determine pitch pred. gain */ + + if (iLBCdec_inst->prevPLI != 1) { + + /* Maximum 60 samples are correlated, preserve as high accuracy + as possible without getting overflow */ + max = WebRtcSpl_MaxAbsValueW16((*iLBCdec_inst).prevResidual, + iLBCdec_inst->blockl); + scale3 = (WebRtcSpl_GetSizeInBits(max)<<1) - 25; + if (scale3 < 0) { + scale3 = 0; + } + + /* Store scale for use when interpolating between the + * concealment and the received packet */ + iLBCdec_inst->prevScale = scale3; + + /* Search around the previous lag +/-3 to find the + best pitch period */ + lag = inlag - 3; + + /* Guard against getting outside the frame */ + corrLen = (size_t)WEBRTC_SPL_MIN(60, iLBCdec_inst->blockl-(inlag+3)); + + WebRtcIlbcfix_CompCorr( &cross, &ener, + iLBCdec_inst->prevResidual, lag, iLBCdec_inst->blockl, corrLen, scale3); + + /* Normalize and store cross^2 and the number of shifts */ + shiftMax = WebRtcSpl_GetSizeInBits(WEBRTC_SPL_ABS_W32(cross))-15; + crossSquareMax = (int16_t)(( + (int16_t)WEBRTC_SPL_SHIFT_W32(cross, -shiftMax) * + (int16_t)WEBRTC_SPL_SHIFT_W32(cross, -shiftMax)) >> 15); + + for (j=inlag-2;j<=inlag+3;j++) { + WebRtcIlbcfix_CompCorr( &cross_comp, &ener_comp, + iLBCdec_inst->prevResidual, j, iLBCdec_inst->blockl, corrLen, scale3); + + /* Use the criteria (corr*corr)/energy to compare if + this lag is better or not. To avoid the division, + do a cross multiplication */ + shift1 = WebRtcSpl_GetSizeInBits(WEBRTC_SPL_ABS_W32(cross_comp))-15; + crossSquare = (int16_t)(( + (int16_t)WEBRTC_SPL_SHIFT_W32(cross_comp, -shift1) * + (int16_t)WEBRTC_SPL_SHIFT_W32(cross_comp, -shift1)) >> 15); + + shift2 = WebRtcSpl_GetSizeInBits(ener)-15; + measure = (int16_t)WEBRTC_SPL_SHIFT_W32(ener, -shift2) * crossSquare; + + shift3 = WebRtcSpl_GetSizeInBits(ener_comp)-15; + maxMeasure = (int16_t)WEBRTC_SPL_SHIFT_W32(ener_comp, -shift3) * + crossSquareMax; + + /* Calculate shift value, so that the two measures can + be put in the same Q domain */ + if(2 * shiftMax + shift3 > 2 * shift1 + shift2) { + tmp1 = + WEBRTC_SPL_MIN(31, 2 * shiftMax + shift3 - 2 * shift1 - shift2); + tmp2 = 0; + } else { + tmp1 = 0; + tmp2 = + WEBRTC_SPL_MIN(31, 2 * shift1 + shift2 - 2 * shiftMax - shift3); + } + + if ((measure>>tmp1) > (maxMeasure>>tmp2)) { + /* New lag is better => record lag, measure and domain */ + lag = j; + crossSquareMax = crossSquare; + cross = cross_comp; + shiftMax = shift1; + ener = ener_comp; + } + } + + /* Calculate the periodicity for the lag with the maximum correlation. + + Definition of the periodicity: + abs(corr(vec1, vec2))/(sqrt(energy(vec1))*sqrt(energy(vec2))) + + Work in the Square domain to simplify the calculations + max_perSquare is less than 1 (in Q15) + */ + tmp2W32=WebRtcSpl_DotProductWithScale(&iLBCdec_inst->prevResidual[iLBCdec_inst->blockl-corrLen], + &iLBCdec_inst->prevResidual[iLBCdec_inst->blockl-corrLen], + corrLen, scale3); + + if ((tmp2W32>0)&&(ener_comp>0)) { + /* norm energies to int16_t, compute the product of the energies and + use the upper int16_t as the denominator */ + + scale1=(int16_t)WebRtcSpl_NormW32(tmp2W32)-16; + tmp1=(int16_t)WEBRTC_SPL_SHIFT_W32(tmp2W32, scale1); + + scale2=(int16_t)WebRtcSpl_NormW32(ener)-16; + tmp2=(int16_t)WEBRTC_SPL_SHIFT_W32(ener, scale2); + denom = (int16_t)((tmp1 * tmp2) >> 16); /* in Q(scale1+scale2-16) */ + + /* Square the cross correlation and norm it such that max_perSquare + will be in Q15 after the division */ + + totscale = scale1+scale2-1; + tmp1 = (int16_t)WEBRTC_SPL_SHIFT_W32(cross, (totscale>>1)); + tmp2 = (int16_t)WEBRTC_SPL_SHIFT_W32(cross, totscale-(totscale>>1)); + + nom = tmp1 * tmp2; + max_perSquare = (int16_t)WebRtcSpl_DivW32W16(nom, denom); + + } else { + max_perSquare = 0; + } + } + + /* previous frame lost, use recorded lag and gain */ + + else { + lag = iLBCdec_inst->prevLag; + max_perSquare = iLBCdec_inst->perSquare; + } + + /* Attenuate signal and scale down pitch pred gain if + several frames lost consecutively */ + + use_gain = 32767; /* 1.0 in Q15 */ + + if (iLBCdec_inst->consPLICount*iLBCdec_inst->blockl>320) { + use_gain = 29491; /* 0.9 in Q15 */ + } else if (iLBCdec_inst->consPLICount*iLBCdec_inst->blockl>640) { + use_gain = 22938; /* 0.7 in Q15 */ + } else if (iLBCdec_inst->consPLICount*iLBCdec_inst->blockl>960) { + use_gain = 16384; /* 0.5 in Q15 */ + } else if (iLBCdec_inst->consPLICount*iLBCdec_inst->blockl>1280) { + use_gain = 0; /* 0.0 in Q15 */ + } + + /* Compute mixing factor of picth repeatition and noise: + for max_per>0.7 set periodicity to 1.0 + 0.4<max_per<0.7 set periodicity to (maxper-0.4)/0.7-0.4) + max_per<0.4 set periodicity to 0.0 + */ + + if (max_perSquare>7868) { /* periodicity > 0.7 (0.7^4=0.2401 in Q15) */ + pitchfact = 32767; + } else if (max_perSquare>839) { /* 0.4 < periodicity < 0.7 (0.4^4=0.0256 in Q15) */ + /* find best index and interpolate from that */ + ind = 5; + while ((max_perSquare<WebRtcIlbcfix_kPlcPerSqr[ind])&&(ind>0)) { + ind--; + } + /* pitch fact is approximated by first order */ + tmpW32 = (int32_t)WebRtcIlbcfix_kPlcPitchFact[ind] + + ((WebRtcIlbcfix_kPlcPfSlope[ind] * + (max_perSquare - WebRtcIlbcfix_kPlcPerSqr[ind])) >> 11); + + pitchfact = (int16_t)WEBRTC_SPL_MIN(tmpW32, 32767); /* guard against overflow */ + + } else { /* periodicity < 0.4 */ + pitchfact = 0; + } + + /* avoid repetition of same pitch cycle (buzzyness) */ + use_lag = lag; + if (lag<80) { + use_lag = 2*lag; + } + + /* compute concealed residual */ + noise_energy_threshold_30dB = (int32_t)iLBCdec_inst->blockl * 900; + energy = 0; + for (i=0; i<iLBCdec_inst->blockl; i++) { + + /* noise component - 52 < randlagFIX < 117 */ + iLBCdec_inst->seed = (int16_t)(iLBCdec_inst->seed * 31821 + 13849); + randlag = 53 + (iLBCdec_inst->seed & 63); + if (randlag > i) { + randvec[i] = + iLBCdec_inst->prevResidual[iLBCdec_inst->blockl + i - randlag]; + } else { + randvec[i] = iLBCdec_inst->prevResidual[i - randlag]; + } + + /* pitch repeatition component */ + if (use_lag > i) { + PLCresidual[i] = + iLBCdec_inst->prevResidual[iLBCdec_inst->blockl + i - use_lag]; + } else { + PLCresidual[i] = PLCresidual[i - use_lag]; + } + + /* Attinuate total gain for each 10 ms */ + if (i<80) { + tot_gain=use_gain; + } else if (i<160) { + tot_gain = (int16_t)((31130 * use_gain) >> 15); /* 0.95*use_gain */ + } else { + tot_gain = (int16_t)((29491 * use_gain) >> 15); /* 0.9*use_gain */ + } + + + /* mix noise and pitch repeatition */ + PLCresidual[i] = (int16_t)((tot_gain * + ((pitchfact * PLCresidual[i] + (32767 - pitchfact) * randvec[i] + + 16384) >> 15)) >> 15); + + /* Compute energy until threshold for noise energy is reached */ + if (energy < noise_energy_threshold_30dB) { + energy += PLCresidual[i] * PLCresidual[i]; + } + } + + /* less than 30 dB, use only noise */ + if (energy < noise_energy_threshold_30dB) { + for (i=0; i<iLBCdec_inst->blockl; i++) { + PLCresidual[i] = randvec[i]; + } + } + + /* use the old LPC */ + WEBRTC_SPL_MEMCPY_W16(PLClpc, (*iLBCdec_inst).prevLpc, LPC_FILTERORDER+1); + + /* Update state in case there are multiple frame losses */ + iLBCdec_inst->prevLag = lag; + iLBCdec_inst->perSquare = max_perSquare; + } + + /* no packet loss, copy input */ + + else { + WEBRTC_SPL_MEMCPY_W16(PLCresidual, decresidual, iLBCdec_inst->blockl); + WEBRTC_SPL_MEMCPY_W16(PLClpc, lpc, (LPC_FILTERORDER+1)); + iLBCdec_inst->consPLICount = 0; + } + + /* update state */ + iLBCdec_inst->prevPLI = PLI; + WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->prevLpc, PLClpc, (LPC_FILTERORDER+1)); + WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->prevResidual, PLCresidual, iLBCdec_inst->blockl); + + return; +} |