StateConstructW.c File Reference

#include <math.h>
#include <string.h>
#include "iLBC_define.h"
#include "constants.h"
#include "filter.h"

Include dependency graph for StateConstructW.c:

Go to the source code of this file.

Functions
void	StateConstructW (int idxForMax, int *idxVec, float *syntDenum, float *out, int len)

Function Documentation

StateConstructW()

void StateConstructW	(	int	idxForMax,
		int *	idxVec,
		float *	syntDenum,
		float *	out,
		int	len
	)

Definition at line 24 of file StateConstructW.c.

References len(), LPC_FILTERORDER, state_frgqTbl, STATE_LEN, state_sq3Tbl, tmp(), and ZeroPoleFilter().

Referenced by Decode(), and iLBC_encode().

 {
 float maxVal, tmpbuf[LPC_FILTERORDER+2*STATE_LEN], *tmp,
 numerator[LPC_FILTERORDER+1];
 float foutbuf[LPC_FILTERORDER+2*STATE_LEN], *fout;
 int k,tmpi;

 /* decoding of the maximum value */

 maxVal = state_frgqTbl[idxForMax];
 maxVal = (float)pow(10,maxVal)/(float)4.5;

 /* initialization of buffers and coefficients */

 memset(tmpbuf, 0, LPC_FILTERORDER*sizeof(float));
 memset(foutbuf, 0, LPC_FILTERORDER*sizeof(float));
 for (k=0; k<LPC_FILTERORDER; k++) {
 numerator[k]=syntDenum[LPC_FILTERORDER-k];
 }
 numerator[LPC_FILTERORDER]=syntDenum[0];
 tmp = &tmpbuf[LPC_FILTERORDER];
 fout = &foutbuf[LPC_FILTERORDER];

 /* decoding of the sample values */

 for (k=0; k<len; k++) {
 tmpi = len-1-k;
 /* maxVal = 1/scal */
 tmp[k] = maxVal*state_sq3Tbl[idxVec[tmpi]];
 }

 /* circular convolution with all-pass filter */

 memset(tmp+len, 0, len*sizeof(float));
 ZeroPoleFilter(tmp, numerator, syntDenum, 2*len,
 LPC_FILTERORDER, fout);
 for (k=0;k<len;k++) {
 out[k] = fout[len-1-k]+fout[2*len-1-k];
 }
 }