mirror of https://github.com/asterisk/asterisk
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
513 lines
14 KiB
513 lines
14 KiB
|
|
/******************************************************************
|
|
|
|
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 "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' 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++, pp++) {
|
|
*ppe+=(*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;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* 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;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* 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++, pp++) {
|
|
*ppe+=(*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;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|