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| /****************************************************************** |
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| iLBC Speech Coder ANSI-C Source Code |
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| iCBSearch.c |
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| Copyright (C) The Internet Society (2004). |
| All Rights Reserved. |
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| ******************************************************************/ |
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| #include <math.h> |
| #include <string.h> |
| |
| #include "iLBC_define.h" |
| #include "gainquant.h" |
| #include "createCB.h" |
| #include "filter.h" |
| #include "constants.h" |
| |
| /*----------------------------------------------------------------* |
| * Search routine for codebook encoding and gain quantization. |
| *---------------------------------------------------------------*/ |
| |
| void iCBSearch( |
| iLBC_Enc_Inst_t *iLBCenc_inst, |
| /* (i) the encoder state structure */ |
| int *index, /* (o) Codebook indices */ |
| int *gain_index,/* (o) Gain quantization indices */ |
| |
| |
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| |
| |
| float *intarget,/* (i) Target vector for encoding */ |
| float *mem, /* (i) Buffer for codebook construction */ |
| int lMem, /* (i) Length of buffer */ |
| int lTarget, /* (i) Length of vector */ |
| int nStages, /* (i) Number of codebook stages */ |
| float *weightDenum, /* (i) weighting filter coefficients */ |
| float *weightState, /* (i) weighting filter state */ |
| int block /* (i) the sub-block number */ |
| ){ |
| int i, j, icount, stage, best_index, range, counter; |
| float max_measure, gain, measure, crossDot, ftmp; |
| float gains[CB_NSTAGES]; |
| float target[SUBL]; |
| int base_index, sInd, eInd, base_size; |
| int sIndAug=0, eIndAug=0; |
| float buf[CB_MEML+SUBL+2*LPC_FILTERORDER]; |
| float invenergy[CB_EXPAND*128], energy[CB_EXPAND*128]; |
| float *pp, *ppi=0, *ppo=0, *ppe=0; |
| float cbvectors[CB_MEML]; |
| float tene, cene, cvec[SUBL]; |
| float aug_vec[SUBL]; |
| |
| memset(cvec,0,SUBL*sizeof(float)); |
| |
| /* Determine size of codebook sections */ |
| |
| base_size=lMem-lTarget+1; |
| |
| if (lTarget==SUBL) { |
| base_size=lMem-lTarget+1+lTarget/2; |
| } |
| |
| /* setup buffer for weighting */ |
| |
| memcpy(buf,weightState,sizeof(float)*LPC_FILTERORDER); |
| memcpy(buf+LPC_FILTERORDER,mem,lMem*sizeof(float)); |
| memcpy(buf+LPC_FILTERORDER+lMem,intarget,lTarget*sizeof(float)); |
| |
| /* weighting */ |
| |
| AllPoleFilter(buf+LPC_FILTERORDER, weightDenum, |
| lMem+lTarget, LPC_FILTERORDER); |
| |
| /* Construct the codebook and target needed */ |
| |
| memcpy(target, buf+LPC_FILTERORDER+lMem, lTarget*sizeof(float)); |
| |
| tene=0.0; |
| |
| |
| |
| |
| |
| for (i=0; i<lTarget; i++) { |
| tene+=target[i]*target[i]; |
| } |
| |
| /* Prepare search over one more codebook section. This section |
| is created by filtering the original buffer with a filter. */ |
| |
| filteredCBvecs(cbvectors, buf+LPC_FILTERORDER, lMem); |
| |
| /* The Main Loop over stages */ |
| |
| for (stage=0; stage<nStages; stage++) { |
| |
| range = search_rangeTbl[block][stage]; |
| |
| /* initialize search measure */ |
| |
| max_measure = (float)-10000000.0; |
| gain = (float)0.0; |
| best_index = 0; |
| |
| /* Compute cross dot product between the target |
| and the CB memory */ |
| |
| crossDot=0.0; |
| pp=buf+LPC_FILTERORDER+lMem-lTarget; |
| for (j=0; j<lTarget; j++) { |
| crossDot += target[j]*(*pp++); |
| } |
| |
| if (stage==0) { |
| |
| /* Calculate energy in the first block of |
| 'lTarget' samples. */ |
| ppe = energy; |
| ppi = buf+LPC_FILTERORDER+lMem-lTarget-1; |
| ppo = buf+LPC_FILTERORDER+lMem-1; |
| |
| *ppe=0.0; |
| pp=buf+LPC_FILTERORDER+lMem-lTarget; |
| for (j=0; j<lTarget; j++) { |
| *ppe+=(*pp)*(*pp); |
| ++pp; |
| } |
| |
| if (*ppe>0.0) { |
| invenergy[0] = (float) 1.0 / (*ppe + EPS); |
| } else { |
| invenergy[0] = (float) 0.0; |
| |
| |
| |
| |
| |
| } |
| ppe++; |
| |
| measure=(float)-10000000.0; |
| |
| if (crossDot > 0.0) { |
| measure = crossDot*crossDot*invenergy[0]; |
| } |
| } |
| else { |
| measure = crossDot*crossDot*invenergy[0]; |
| } |
| |
| /* check if measure is better */ |
| ftmp = crossDot*invenergy[0]; |
| |
| if ((measure>max_measure) && (fabs(ftmp)<CB_MAXGAIN)) { |
| best_index = 0; |
| max_measure = measure; |
| gain = ftmp; |
| } |
| |
| /* loop over the main first codebook section, |
| full search */ |
| |
| for (icount=1; icount<range; icount++) { |
| |
| /* calculate measure */ |
| |
| crossDot=0.0; |
| pp = buf+LPC_FILTERORDER+lMem-lTarget-icount; |
| |
| for (j=0; j<lTarget; j++) { |
| crossDot += target[j]*(*pp++); |
| } |
| |
| if (stage==0) { |
| *ppe++ = energy[icount-1] + (*ppi)*(*ppi) - |
| (*ppo)*(*ppo); |
| ppo--; |
| ppi--; |
| |
| if (energy[icount]>0.0) { |
| invenergy[icount] = |
| (float)1.0/(energy[icount]+EPS); |
| } else { |
| invenergy[icount] = (float) 0.0; |
| } |
| |
| |
| |
| |
| |
| measure=(float)-10000000.0; |
| |
| if (crossDot > 0.0) { |
| measure = crossDot*crossDot*invenergy[icount]; |
| } |
| } |
| else { |
| measure = crossDot*crossDot*invenergy[icount]; |
| } |
| |
| /* check if measure is better */ |
| ftmp = crossDot*invenergy[icount]; |
| |
| if ((measure>max_measure) && (fabs(ftmp)<CB_MAXGAIN)) { |
| best_index = icount; |
| max_measure = measure; |
| gain = ftmp; |
| } |
| } |
| |
| /* Loop over augmented part in the first codebook |
| * section, full search. |
| * The vectors are interpolated. |
| */ |
| |
| if (lTarget==SUBL) { |
| |
| /* Search for best possible cb vector and |
| compute the CB-vectors' energy. */ |
| searchAugmentedCB(20, 39, stage, base_size-lTarget/2, |
| target, buf+LPC_FILTERORDER+lMem, |
| &max_measure, &best_index, &gain, energy, |
| invenergy); |
| } |
| |
| /* set search range for following codebook sections */ |
| |
| base_index=best_index; |
| |
| /* unrestricted search */ |
| |
| # if CB_RESRANGE == -1 |
| //if (CB_RESRANGE == -1) { |
| sInd=0; |
| eInd=range-1; |
| sIndAug=20; |
| eIndAug=39; |
| //} |
| |
| # else |
| |
| /* restricted search around best index from first |
| codebook section */ |
| |
| //else { |
| /* Initialize search indices */ |
| sIndAug=0; |
| eIndAug=0; |
| sInd=base_index-CB_RESRANGE/2; |
| eInd=sInd+CB_RESRANGE; |
| |
| if (lTarget==SUBL) { |
| |
| if (sInd<0) { |
| |
| sIndAug = 40 + sInd; |
| eIndAug = 39; |
| sInd=0; |
| |
| } else if ( base_index < (base_size-20) ) { |
| |
| if (eInd > range) { |
| sInd -= (eInd-range); |
| eInd = range; |
| } |
| } else { /* base_index >= (base_size-20) */ |
| |
| if (sInd < (base_size-20)) { |
| sIndAug = 20; |
| sInd = 0; |
| eInd = 0; |
| eIndAug = 19 + CB_RESRANGE; |
| |
| if(eIndAug > 39) { |
| eInd = eIndAug-39; |
| eIndAug = 39; |
| } |
| } else { |
| sIndAug = 20 + sInd - (base_size-20); |
| eIndAug = 39; |
| sInd = 0; |
| eInd = CB_RESRANGE - (eIndAug-sIndAug+1); |
| } |
| } |
| |
| } else { /* lTarget = 22 or 23 */ |
| |
| if (sInd < 0) { |
| eInd -= sInd; |
| |
| |
| |
| |
| |
| sInd = 0; |
| } |
| |
| if(eInd > range) { |
| sInd -= (eInd - range); |
| eInd = range; |
| } |
| } |
| |
| //} |
| # endif /* CB_RESRANGE == -1 */ |
| |
| |
| /* search of higher codebook section */ |
| |
| /* index search range */ |
| counter = sInd; |
| sInd += base_size; |
| eInd += base_size; |
| |
| |
| if (stage==0) { |
| ppe = energy+base_size; |
| *ppe=0.0; |
| |
| pp=cbvectors+lMem-lTarget; |
| for (j=0; j<lTarget; j++) { |
| *ppe+=(*pp)*(*pp); |
| ++pp; |
| } |
| |
| ppi = cbvectors + lMem - 1 - lTarget; |
| ppo = cbvectors + lMem - 1; |
| |
| for (j=0; j<(range-1); j++) { |
| *(ppe+1) = *ppe + (*ppi)*(*ppi) - (*ppo)*(*ppo); |
| ppo--; |
| ppi--; |
| ppe++; |
| } |
| } |
| |
| /* loop over search range */ |
| |
| for (icount=sInd; icount<eInd; icount++) { |
| |
| /* calculate measure */ |
| |
| crossDot=0.0; |
| pp=cbvectors + lMem - (counter++) - lTarget; |
| |
| for (j=0;j<lTarget;j++) { |
| |
| |
| |
| |
| |
| crossDot += target[j]*(*pp++); |
| } |
| |
| if (energy[icount]>0.0) { |
| invenergy[icount] =(float)1.0/(energy[icount]+EPS); |
| } else { |
| invenergy[icount] =(float)0.0; |
| } |
| |
| if (stage==0) { |
| |
| measure=(float)-10000000.0; |
| |
| if (crossDot > 0.0) { |
| measure = crossDot*crossDot* |
| invenergy[icount]; |
| } |
| } |
| else { |
| measure = crossDot*crossDot*invenergy[icount]; |
| } |
| |
| /* check if measure is better */ |
| ftmp = crossDot*invenergy[icount]; |
| |
| if ((measure>max_measure) && (fabs(ftmp)<CB_MAXGAIN)) { |
| best_index = icount; |
| max_measure = measure; |
| gain = ftmp; |
| } |
| } |
| |
| /* Search the augmented CB inside the limited range. */ |
| |
| if ((lTarget==SUBL)&&(sIndAug!=0)) { |
| searchAugmentedCB(sIndAug, eIndAug, stage, |
| 2*base_size-20, target, cbvectors+lMem, |
| &max_measure, &best_index, &gain, energy, |
| invenergy); |
| } |
| |
| /* record best index */ |
| |
| index[stage] = best_index; |
| |
| /* gain quantization */ |
| |
| if (stage==0){ |
| |
| |
| |
| |
| |
| |
| if (gain<0.0){ |
| gain = 0.0; |
| } |
| |
| if (gain>CB_MAXGAIN) { |
| gain = (float)CB_MAXGAIN; |
| } |
| gain = gainquant(gain, 1.0, 32, &gain_index[stage]); |
| } |
| else { |
| if (stage==1) { |
| gain = gainquant(gain, (float)fabs(gains[stage-1]), |
| 16, &gain_index[stage]); |
| } else { |
| gain = gainquant(gain, (float)fabs(gains[stage-1]), |
| 8, &gain_index[stage]); |
| } |
| } |
| |
| /* Extract the best (according to measure) |
| codebook vector */ |
| |
| if (lTarget==(STATE_LEN-iLBCenc_inst->state_short_len)) { |
| |
| if (index[stage]<base_size) { |
| pp=buf+LPC_FILTERORDER+lMem-lTarget-index[stage]; |
| } else { |
| pp=cbvectors+lMem-lTarget- |
| index[stage]+base_size; |
| } |
| } else { |
| |
| if (index[stage]<base_size) { |
| if (index[stage]<(base_size-20)) { |
| pp=buf+LPC_FILTERORDER+lMem- |
| lTarget-index[stage]; |
| } else { |
| createAugmentedVec(index[stage]-base_size+40, |
| buf+LPC_FILTERORDER+lMem,aug_vec); |
| pp=aug_vec; |
| } |
| } else { |
| int filterno, position; |
| |
| filterno=index[stage]/base_size; |
| position=index[stage]-filterno*base_size; |
| |
| |
| |
| |
| |
| |
| |
| if (position<(base_size-20)) { |
| pp=cbvectors+filterno*lMem-lTarget- |
| index[stage]+filterno*base_size; |
| } else { |
| createAugmentedVec( |
| index[stage]-(filterno+1)*base_size+40, |
| cbvectors+filterno*lMem,aug_vec); |
| pp=aug_vec; |
| } |
| } |
| } |
| |
| /* Subtract the best codebook vector, according |
| to measure, from the target vector */ |
| |
| for (j=0;j<lTarget;j++) { |
| cvec[j] += gain*(*pp); |
| target[j] -= gain*(*pp++); |
| } |
| |
| /* record quantized gain */ |
| |
| gains[stage]=gain; |
| |
| }/* end of Main Loop. for (stage=0;... */ |
| |
| /* Gain adjustment for energy matching */ |
| cene=0.0; |
| for (i=0; i<lTarget; i++) { |
| cene+=cvec[i]*cvec[i]; |
| } |
| j=gain_index[0]; |
| |
| for (i=gain_index[0]; i<32; i++) { |
| ftmp=cene*gain_sq5Tbl[i]*gain_sq5Tbl[i]; |
| |
| if ((ftmp<(tene*gains[0]*gains[0])) && |
| (gain_sq5Tbl[j]<(2.0*gains[0]))) { |
| j=i; |
| } |
| } |
| gain_index[0]=j; |
| } |
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