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Diffstat (limited to 'trunk/codecs/ilbc/iCBSearch.c')
-rw-r--r-- | trunk/codecs/ilbc/iCBSearch.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/trunk/codecs/ilbc/iCBSearch.c b/trunk/codecs/ilbc/iCBSearch.c new file mode 100644 index 000000000..c047297e3 --- /dev/null +++ b/trunk/codecs/ilbc/iCBSearch.c @@ -0,0 +1,480 @@ + +/****************************************************************** + + iLBC Speech Coder ANSI-C Source Code + + iCBSearch.c + + Copyright (C) The Internet Society (2004). + All Rights Reserved. + +******************************************************************/ + +#include <math.h> +#include <string.h> + +#include "iLBC_define.h" +#include "iCBSearch.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 */ + 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' sampels. */ + 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) { + sInd=0; + eInd=range-1; + sIndAug=20; + eIndAug=39; + } + + /* restriced 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; + } + } + } + + /* 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; +} + + |