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Diffstat (limited to 'codecs/ilbc/enhancer.c')
| -rwxr-xr-x | codecs/ilbc/enhancer.c | 600 |
1 files changed, 600 insertions, 0 deletions
diff --git a/codecs/ilbc/enhancer.c b/codecs/ilbc/enhancer.c new file mode 100755 index 000000000..a2878cce0 --- /dev/null +++ b/codecs/ilbc/enhancer.c @@ -0,0 +1,600 @@ + +/****************************************************************** + + iLBC Speech Coder ANSI-C Source Code + + enhancer.c + + Copyright (c) 2001, + Global IP Sound AB. + All rights reserved. + +******************************************************************/ + +#include <math.h> +#include <string.h> +#include "iLBC_define.h" +#include "constants.h" +#include "filter.h" + +/*----------------------------------------------------------------* + * Find index in array such that the array element with said + * index is the element of said array closest to "value" + * according to the squared-error criterion + *---------------------------------------------------------------*/ + +void NearestNeighbor( + int *index, /* (o) index of array element closest to value */ + float *array, /* (i) data array */ + float value,/* (i) value */ + int arlength/* (i) dimension of data array */ +){ + int i; + float bestcrit,crit; + + crit=array[0]-value; + bestcrit=crit*crit; + *index=0; + for(i=1;i<arlength;i++){ + crit=array[i]-value; + crit=crit*crit; + + if(crit<bestcrit){ + bestcrit=crit; + *index=i; + } + } +} + +/*----------------------------------------------------------------* + * compute cross correlation between sequences + *---------------------------------------------------------------*/ + +void mycorr1( + float* corr, /* (o) correlation of seq1 and seq2 */ + float* seq1, /* (i) first sequence */ + int dim1, /* (i) dimension first seq1 */ + const float *seq2, /* (i) second sequence */ + int dim2 /* (i) dimension seq2 */ +){ + int i,j; + + for(i=0;i<=dim1-dim2; i++){ + corr[i]=0.0; + for(j=0;j<dim2; j++){ + corr[i] += seq1[i+j] * seq2[j]; + } + } +} + +/*----------------------------------------------------------------* + * upsample finite array assuming zeros outside bounds + *---------------------------------------------------------------*/ + +void enh_upsample( + float* useq1, /* (o) upsampled output sequence */ + float* seq1,/* (i) unupsampled sequence */ + int dim1, /* (i) dimension seq1 */ + int hfl /* (i) polyphase filter length=2*hfl+1 */ +){ + float *pu,*ps; + int i,j,k,q,filterlength,hfl2; + const float *polyp[ENH_UPS0]; /* pointers to polyphase columns */ + const float *pp; + + /* define pointers for filter */ + + filterlength=2*hfl+1; + + if( filterlength > dim1){ + hfl2=(int) (dim1/2); + for(j=0;j<ENH_UPS0; j++) { + polyp[j]=polyphaserTbl+j*filterlength+hfl-hfl2; + } + hfl=hfl2; + filterlength=2*hfl+1; + } + else { + for(j=0;j<ENH_UPS0; j++) { + polyp[j]=polyphaserTbl+j*filterlength; + } + } + + /* filtering: filter overhangs left side of sequence */ + + pu=useq1; + for(i=hfl;i<filterlength; i++){ + for(j=0;j<ENH_UPS0; j++){ + *pu=0.0; + pp = polyp[j]; + ps = seq1+i; + for(k=0;k<=i;k++) { + *pu += *ps-- * *pp++; + } + pu++; + } + } + + /* filtering: simple convolution=inner products */ + + for(i=filterlength; i<dim1; i++){ + for(j=0;j<ENH_UPS0; j++){ + *pu=0.0; + pp = polyp[j]; + ps = seq1+i; + for(k=0;k<filterlength;k++) { + *pu += *ps-- * *pp++; + } + pu++; + } + } + + /* filtering: filter overhangs right side of sequence */ + + for(q=1; q<=hfl;q++){ + for(j=0;j<ENH_UPS0; j++){ + *pu=0.0; + pp = polyp[j]+q; + ps = seq1+dim1-1; + for(k=0;k<filterlength-q;k++) { + *pu += *ps-- * *pp++; + } + pu++; + } + } +} + + +/*----------------------------------------------------------------* + * find segment starting near idata+estSegPos that has highest + * correlation with idata+centerStartPos through + * idata+centerStartPos+ENH_BLOCKL-1 segment is found at a + * resolution of ENH_UPSO times the original of the original + * sampling rate + *---------------------------------------------------------------*/ + +void refiner( + float *seg, /* (o) segment array */ + float *updStartPos, /* (o) updated start point */ + float* idata, /* (i) original data buffer */ + int idatal, /* (i) dimension of idata */ + int centerStartPos, /* (i) beginning center segment */ + float estSegPos,/* (i) estimated beginning other segment */ + float period /* (i) estimated pitch period */ +){ + int estSegPosRounded,searchSegStartPos,searchSegEndPos,corrdim; + int tloc,tloc2,i,st,en,fraction; + float vect[ENH_VECTL],corrVec[ENH_CORRDIM],maxv; + float corrVecUps[ENH_CORRDIM*ENH_UPS0]; + (void)period; + + /* defining array bounds */ + + estSegPosRounded=(int)(estSegPos - 0.5); + + searchSegStartPos=estSegPosRounded-ENH_SLOP; + + if (searchSegStartPos<0) { + searchSegStartPos=0; + } + searchSegEndPos=estSegPosRounded+ENH_SLOP; + + if(searchSegEndPos+ENH_BLOCKL >= idatal) { + searchSegEndPos=idatal-ENH_BLOCKL-1; + } + corrdim=searchSegEndPos-searchSegStartPos+1; + + /* compute upsampled correlation (corr33) and find + location of max */ + + mycorr1(corrVec,idata+searchSegStartPos, + corrdim+ENH_BLOCKL-1,idata+centerStartPos,ENH_BLOCKL); + enh_upsample(corrVecUps,corrVec,corrdim,ENH_FL0); + tloc=0; maxv=corrVecUps[0]; + for(i=1;i<ENH_UPS0*corrdim; i++){ + + if(corrVecUps[i]>maxv){ + tloc=i; + maxv=corrVecUps[i]; + } + } + + /* make vector can be upsampled without ever running outside + bounds */ + + *updStartPos= (float)searchSegStartPos + + (float)tloc/(float)ENH_UPS0+(float)1.0; + tloc2=(int)(tloc/ENH_UPS0); + + if (tloc>tloc2*ENH_UPS0) { + tloc2++; + } + st=searchSegStartPos+tloc2-ENH_FL0; + + if(st<0){ + memset(vect,0,-st*sizeof(float)); + memcpy(&vect[-st],idata, (ENH_VECTL+st)*sizeof(float)); + } + else{ + en=st+ENH_VECTL; + + if(en>idatal){ + memcpy(vect, &idata[st], + (ENH_VECTL-(en-idatal))*sizeof(float)); + memset(&vect[ENH_VECTL-(en-idatal)], 0, + (en-idatal)*sizeof(float)); + } + else { + memcpy(vect, &idata[st], ENH_VECTL*sizeof(float)); + } + } + fraction=tloc2*ENH_UPS0-tloc; + + /* compute the segment (this is actually a convolution) */ + + mycorr1(seg,vect,ENH_VECTL,polyphaserTbl+(2*ENH_FL0+1)*fraction, + 2*ENH_FL0+1); +} + +/*----------------------------------------------------------------* + * find the smoothed output data + *---------------------------------------------------------------*/ + +void smath( + float *odata, /* (o) smoothed output */ + float *sseq,/* (i) said second sequence of waveforms */ + int hl, /* (i) 2*hl+1 is sseq dimension */ + float alpha0/* (i) max smoothing energy fraction */ +){ + int i,k; + float w00,w10,w11,A,B,C,*psseq,err,errs; + float surround[BLOCKL]; /* shape contributed by other than + current */ + float wt[2*ENH_HL+1]; /* waveform weighting to get surround + shape */ + float denom; + + /* create shape of contribution from all waveforms except the + current one */ + + for(i=1;i<=2*hl+1; i++) { + wt[i-1] = (float)0.5*(1 - (float)cos(2*PI*i/(2*hl+2))); + } + wt[hl]=0.0; /* for clarity, not used */ + for(i=0;i<ENH_BLOCKL; i++) { + surround[i]=sseq[i]*wt[0]; + } + for(k=1;k<hl; k++){ + psseq=sseq+k*ENH_BLOCKL; + for(i=0;i<ENH_BLOCKL; i++) { + surround[i]+=psseq[i]*wt[k]; + } + } + for(k=hl+1;k<=2*hl; k++){ + psseq=sseq+k*ENH_BLOCKL; + for(i=0;i<ENH_BLOCKL; i++) { + surround[i]+=psseq[i]*wt[k]; + } + } + + /* compute some inner products */ + + w00 = w10 = w11 = 0.0; + psseq=sseq+hl*ENH_BLOCKL; /* current block */ + for(i=0;i<ENH_BLOCKL;i++) { + w00+=psseq[i]*psseq[i]; + w11+=surround[i]*surround[i]; + w10+=surround[i]*psseq[i]; + } + + if( fabs(w11) < 1.0) { + w11=1.0; + } + C = (float)sqrt( w00/w11); + + /* first try enhancement without power-constraint */ + + errs=0.0; + psseq=sseq+hl*ENH_BLOCKL; + for(i=0;i<ENH_BLOCKL;i++) { + odata[i]=C*surround[i]; + err=psseq[i]-odata[i]; + errs+=err*err; + } + + /* if constraint violated by first try, add constraint */ + + if( errs > alpha0 * w00){ + if( w00 < 1) { + w00=1; + } + denom = (w11*w00-w10*w10)/(w00*w00); + + if( denom > 0.0001){ /* eliminates numerical problems + for if smooth */ + A = (float)sqrt( (alpha0- alpha0*alpha0/4)/denom); + B = -alpha0/2 - A * w10/w00; + B = B+1; + } + else{ /* essentially no difference between cycles; + smoothing not needed */ + A= 0.0; + B= 1.0; + } + + /* create smoothed sequence */ + + psseq=sseq+hl*ENH_BLOCKL; + for(i=0;i<ENH_BLOCKL;i++) { + odata[i]=A*surround[i]+B*psseq[i]; + } + } +} + +/*----------------------------------------------------------------* + * get the pitch-synchronous sample sequence + *---------------------------------------------------------------*/ + +void getsseq( + float *sseq, /* (o) the pitch-synchronous sequence */ + float *idata, /* (i) original data */ + int idatal, /* (i) dimension of data */ + int centerStartPos, /* (i) where current block starts */ + float *period, /* (i) rough-pitch-period array */ + float *plocs, /* (i) where periods of period array + are taken */ + int periodl, /* (i) dimension period array */ + int hl /* (i)( 2*hl+1 is the number of sequences */ +){ + int i,centerEndPos,q; + float blockStartPos[2*ENH_HL+1]; + int lagBlock[2*ENH_HL+1]; + float plocs2[ENH_PLOCSL]; + float *psseq; + + centerEndPos=centerStartPos+ENH_BLOCKL-1; + + /* present */ + + NearestNeighbor(lagBlock+hl,plocs, + (float)0.5*(centerStartPos+centerEndPos),periodl); + + blockStartPos[hl]=(float)centerStartPos; + psseq=sseq+ENH_BLOCKL*hl; + memcpy(psseq, idata+centerStartPos, ENH_BLOCKL*sizeof(float)); + + /* past */ + + for(q=hl-1;q>=0;q--) { + blockStartPos[q]=blockStartPos[q+1]-period[lagBlock[q+1]]; + NearestNeighbor(lagBlock+q,plocs, + blockStartPos[q]+ENH_BLOCKL_HALF-period[lagBlock[q+1]], + periodl); + + + if(blockStartPos[q]-ENH_OVERHANG>=0) { + refiner(sseq+q*ENH_BLOCKL,blockStartPos+q,idata,idatal, + centerStartPos,blockStartPos[q], + period[lagBlock[q+1]]); + } else { + + psseq=sseq+q*ENH_BLOCKL; + memset(psseq, 0, ENH_BLOCKL*sizeof(float)); + } + } + + /* future */ + + for(i=0;i<periodl;i++) { + plocs2[i]=plocs[i]-period[i]; + } + for(q=hl+1;q<=2*hl;q++) { + NearestNeighbor(lagBlock+q,plocs2, + blockStartPos[q-1]+ENH_BLOCKL_HALF,periodl); + + blockStartPos[q]=blockStartPos[q-1]+period[lagBlock[q]]; + if( blockStartPos[q]+ENH_BLOCKL+ENH_OVERHANG<idatal) { + + refiner(sseq+ENH_BLOCKL*q,blockStartPos+q,idata,idatal, + centerStartPos,blockStartPos[q],period[lagBlock[q]]); + + } + else { + psseq=sseq+q*ENH_BLOCKL; + memset(psseq, 0, ENH_BLOCKL*sizeof(float)); + } + } +} + +/*----------------------------------------------------------------* + * perform enhancement on idata+centerStartPos through + * idata+centerStartPos+ENH_BLOCKL-1 + *---------------------------------------------------------------*/ + +void enhancer( + float *odata, /* (o) smoothed block, dimension blockl */ + float *idata, /* (i) data buffer used for enhancing */ + int idatal, /* (i) dimension idata */ + int centerStartPos, /* (i) first sample current block + within idata */ + float alpha0, /* (i) max correction-energy-fraction + (in [0,1]) */ + float *period, /* (i) pitch period array */ + float *plocs, /* (i) locations where period array + values valid */ + int periodl /* (i) dimension of period and plocs */ +){ + float sseq[(2*ENH_HL+1)*ENH_BLOCKL]; + + /* get said second sequence of segments */ + + getsseq(sseq,idata,idatal,centerStartPos,period, + plocs,periodl,ENH_HL); + + /* compute the smoothed output from said second sequence */ + + smath(odata,sseq,ENH_HL,alpha0); + +} + +/*----------------------------------------------------------------* + * cross correlation + *---------------------------------------------------------------*/ + +float xCorrCoef( + float *target, /* (i) first array */ + float *regressor, /* (i) second array */ + int subl /* (i) dimension arrays */ +){ + int i; + float ftmp1, ftmp2; + + ftmp1 = 0.0; + ftmp2 = 0.0; + for (i=0; i<subl; i++) { + ftmp1 += target[i]*regressor[i]; + ftmp2 += regressor[i]*regressor[i]; + } + + if (ftmp1 > 0.0) { + return (float)(ftmp1*ftmp1/ftmp2); + } + else { + return (float)0.0; + } +} + +/*----------------------------------------------------------------* + * interface for enhancer + *---------------------------------------------------------------*/ + +int enhancerInterface( + float *out, /* (o) enhanced signal */ + float *in, /* (i) unenhanced signal */ + iLBC_Dec_Inst_t *iLBCdec_inst /* (i) buffers etc */ +){ + float *enh_buf, *enh_period; + int iblock, isample; + int lag, ilag, i; + float cc, maxcc; + float ftmp1, ftmp2, gain; + float *inPtr, *enh_bufPtr1, *enh_bufPtr2; + + float lpState[6], downsampled[(ENH_NBLOCKS*ENH_BLOCKL+120)/2]; + int inLen=ENH_NBLOCKS*ENH_BLOCKL+120; + int start; + + enh_buf=iLBCdec_inst->enh_buf; + enh_period=iLBCdec_inst->enh_period; + + + memmove(enh_buf, &enh_buf[ENH_NBLOCKS*ENH_BLOCKL], + (ENH_NBLOCKS_EXTRA*ENH_BLOCKL)*sizeof(float)); + + memcpy(&enh_buf[ENH_NBLOCKS_EXTRA*ENH_BLOCKL], in, + (ENH_NBLOCKS*ENH_BLOCKL)*sizeof(float)); + + if (iLBCdec_inst->prev_enh_pl==1) { + /* PLC was performed on the previous packet */ + + lag = 20; + maxcc = xCorrCoef(in, in+lag, ENH_BLOCKL); + for (ilag=21; ilag<120; ilag++) { + cc = xCorrCoef(in, in+ilag, ENH_BLOCKL); + + if (cc > maxcc) { + maxcc = cc; + lag = ilag; + } + } + + ftmp1 = 0.0; + ftmp2 = 0.0; + for (i=0; i<ENH_BLOCKL; i++) { + ftmp1 += in[i]*in[i+lag]; + ftmp2 += in[i+lag]*in[i+lag]; + } + + if (ftmp1 > 0.0) { + gain=(float)(ftmp1/ftmp2); + } + else { + gain=(float)0.0; + } + if (gain>1.0) { + gain=1.0; + } else if (gain<-1.0) { + gain=-1.0; + } + + inPtr=&in[lag-1]; + + enh_bufPtr1=&enh_buf[ENH_NBLOCKS_EXTRA*ENH_BLOCKL-1]; + + if (lag>ENH_BLOCKL) { + start=ENH_BLOCKL; + } else { + start=lag; + } + + for (isample = start; isample>0; isample--) { + *enh_bufPtr1-- = gain*(*inPtr--); + } + + enh_bufPtr2=&enh_buf[ENH_NBLOCKS_EXTRA*ENH_BLOCKL-1]; + for (isample = (ENH_BLOCKL-1-lag); isample>=0; isample--) { + *enh_bufPtr1-- = gain*(*enh_bufPtr2--); + } + + } + + memmove(enh_period, &enh_period[ENH_NBLOCKS], + ENH_NBLOCKS_EXTRA*sizeof(float)); + + + /* Set state information to the 6 samples right before + the samples to be downsampled. */ + + memcpy(lpState, enh_buf+ENH_NBLOCKS_EXTRA*ENH_BLOCKL-126, + 6*sizeof(float)); + + /* Down sample a factor 2 to save computations */ + + DownSample(enh_buf+ENH_NBLOCKS_EXTRA*ENH_BLOCKL-120, + lpFilt_coefsTbl, inLen, + lpState, downsampled); + + /* Estimate the pitch in the down sampled domain. */ + for(iblock = 0; iblock<ENH_NBLOCKS; iblock++){ + + lag = 10; + maxcc = xCorrCoef(downsampled+60+iblock* + ENH_BLOCKL_HALF, downsampled+60+iblock* + ENH_BLOCKL_HALF-lag, ENH_BLOCKL_HALF); + for (ilag=11; ilag<60; ilag++) { + cc = xCorrCoef(downsampled+60+iblock* + ENH_BLOCKL_HALF, downsampled+60+iblock* + ENH_BLOCKL_HALF-ilag, ENH_BLOCKL_HALF); + + if (cc > maxcc) { + maxcc = cc; + lag = ilag; + } + } + + /* Store the estimated lag in the non-downsampled domain */ + enh_period[iblock+ENH_NBLOCKS_EXTRA] = (float)lag*2; + } + + for(iblock = 0; iblock<ENH_NBLOCKS; iblock++){ + + enhancer(out+iblock*ENH_BLOCKL, enh_buf, + ENH_BUFL, (4+iblock)*ENH_BLOCKL, + ENH_ALPHA0, enh_period, enh_plocsTbl, + ENH_NBLOCKS_TOT); + + } + return (lag*2); +} + + |