asterisk/codecs/ilbc/getCBvec.c

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2023-05-25 18:45:57 +00:00
/******************************************************************
iLBC Speech Coder ANSI-C Source Code
getCBvec.c
Copyright (C) The Internet Society (2004).
All Rights Reserved.
******************************************************************/
#include "iLBC_define.h"
#include "constants.h"
#include <string.h>
/*----------------------------------------------------------------*
* Construct codebook vector for given index.
*---------------------------------------------------------------*/
void getCBvec(
float *cbvec, /* (o) Constructed codebook vector */
float *mem, /* (i) Codebook buffer */
int index, /* (i) Codebook index */
int lMem, /* (i) Length of codebook buffer */
int cbveclen/* (i) Codebook vector length */
){
int j, k, n, memInd, sFilt;
float tmpbuf[CB_MEML];
int base_size;
int ilow, ihigh;
float alfa, alfa1;
/* Determine size of codebook sections */
base_size=lMem-cbveclen+1;
if (cbveclen==SUBL) {
base_size+=cbveclen/2;
}
/* No filter -> First codebook section */
if (index<lMem-cbveclen+1) {
/* first non-interpolated vectors */
k=index+cbveclen;
/* get vector */
memcpy(cbvec, mem+lMem-k, cbveclen*sizeof(float));
} else if (index < base_size) {
k=2*(index-(lMem-cbveclen+1))+cbveclen;
ihigh=k/2;
ilow=ihigh-5;
/* Copy first noninterpolated part */
memcpy(cbvec, mem+lMem-k/2, ilow*sizeof(float));
/* interpolation */
alfa1=(float)0.2;
alfa=0.0;
for (j=ilow; j<ihigh; j++) {
cbvec[j]=((float)1.0-alfa)*mem[lMem-k/2+j]+
alfa*mem[lMem-k+j];
alfa+=alfa1;
}
/* Copy second noninterpolated part */
memcpy(cbvec+ihigh, mem+lMem-k+ihigh,
(cbveclen-ihigh)*sizeof(float));
}
/* Higher codebook section based on filtering */
else {
/* first non-interpolated vectors */
if (index-base_size<lMem-cbveclen+1) {
float tempbuff2[CB_MEML+CB_FILTERLEN+1];
float *pos;
float *pp, *pp1;
memset(tempbuff2, 0,
CB_HALFFILTERLEN*sizeof(float));
memcpy(&tempbuff2[CB_HALFFILTERLEN], mem,
lMem*sizeof(float));
memset(&tempbuff2[lMem+CB_HALFFILTERLEN], 0,
(CB_HALFFILTERLEN+1)*sizeof(float));
k=index-base_size+cbveclen;
sFilt=lMem-k;
memInd=sFilt+1-CB_HALFFILTERLEN;
/* do filtering */
pos=cbvec;
memset(pos, 0, cbveclen*sizeof(float));
for (n=0; n<cbveclen; n++) {
pp=&tempbuff2[memInd+n+CB_HALFFILTERLEN];
pp1=&cbfiltersTbl[CB_FILTERLEN-1];
for (j=0; j<CB_FILTERLEN; j++) {
(*pos)+=(*pp++)*(*pp1--);
}
pos++;
}
}
/* interpolated vectors */
else {
float tempbuff2[CB_MEML+CB_FILTERLEN+1];
float *pos;
float *pp, *pp1;
int i;
memset(tempbuff2, 0,
CB_HALFFILTERLEN*sizeof(float));
memcpy(&tempbuff2[CB_HALFFILTERLEN], mem,
lMem*sizeof(float));
memset(&tempbuff2[lMem+CB_HALFFILTERLEN], 0,
(CB_HALFFILTERLEN+1)*sizeof(float));
k=2*(index-base_size-
(lMem-cbveclen+1))+cbveclen;
sFilt=lMem-k;
memInd=sFilt+1-CB_HALFFILTERLEN;
/* do filtering */
pos=&tmpbuf[sFilt];
memset(pos, 0, k*sizeof(float));
for (i=0; i<k; i++) {
pp=&tempbuff2[memInd+i+CB_HALFFILTERLEN];
pp1=&cbfiltersTbl[CB_FILTERLEN-1];
for (j=0; j<CB_FILTERLEN; j++) {
(*pos)+=(*pp++)*(*pp1--);
}
pos++;
}
ihigh=k/2;
ilow=ihigh-5;
/* Copy first noninterpolated part */
memcpy(cbvec, tmpbuf+lMem-k/2,
ilow*sizeof(float));
/* interpolation */
alfa1=(float)0.2;
alfa=0.0;
for (j=ilow; j<ihigh; j++) {
cbvec[j]=((float)1.0-alfa)*
tmpbuf[lMem-k/2+j]+alfa*tmpbuf[lMem-k+j];
alfa+=alfa1;
}
/* Copy second noninterpolated part */
memcpy(cbvec+ihigh, tmpbuf+lMem-k+ihigh,
(cbveclen-ihigh)*sizeof(float));
}
}
}