LPCdecode.c File Reference

#include <math.h>
#include <string.h>
#include "helpfun.h"
#include "lsf.h"
#include "iLBC_define.h"
#include "constants.h"

Include dependency graph for LPCdecode.c:

Go to the source code of this file.

Functions
void	DecoderInterpolateLSF (float *syntdenum, float *weightdenum, float *lsfdeq, int length, iLBC_Dec_Inst_t *iLBCdec_inst)
void	LSFinterpolate2a_dec (float *a, float *lsf1, float *lsf2, float coef, int length)
void	SimplelsfDEQ (float *lsfdeq, int *index, int lpc_n)

Function Documentation

DecoderInterpolateLSF()

void DecoderInterpolateLSF	(	float *	syntdenum,
		float *	weightdenum,
		float *	lsfdeq,
		int	length,
		iLBC_Dec_Inst_t *	iLBCdec_inst
	)

Definition at line 89 of file LPCdecode.c.

References bwexpand(), LPC_CHIRP_WEIGHTDENUM, LPC_FILTERORDER, lsf_weightTbl_20ms, lsf_weightTbl_30ms, iLBC_Dec_Inst_t_::lsfdeqold, LSFinterpolate2a_dec(), iLBC_Dec_Inst_t_::mode, and iLBC_Dec_Inst_t_::nsub.

Referenced by iLBC_decode().

 {
 int i, pos, lp_length;
 float lp[LPC_FILTERORDER + 1], *lsfdeq2;






 lsfdeq2 = lsfdeq + length;
 lp_length = length + 1;

 if (iLBCdec_inst->mode==30) {
 /* sub-frame 1: Interpolation between old and first */

 LSFinterpolate2a_dec(lp, iLBCdec_inst->lsfdeqold, lsfdeq,
 lsf_weightTbl_30ms[0], length);
 memcpy(syntdenum,lp,lp_length*sizeof(float));
 bwexpand(weightdenum, lp, LPC_CHIRP_WEIGHTDENUM,
 lp_length);

 /* sub-frames 2 to 6: interpolation between first
 and last LSF */

 pos = lp_length;
 for (i = 1; i < 6; i++) {
 LSFinterpolate2a_dec(lp, lsfdeq, lsfdeq2,
 lsf_weightTbl_30ms[i], length);
 memcpy(syntdenum + pos,lp,lp_length*sizeof(float));
 bwexpand(weightdenum + pos, lp,
 LPC_CHIRP_WEIGHTDENUM, lp_length);
 pos += lp_length;
 }
 }
 else {
 pos = 0;
 for (i = 0; i < iLBCdec_inst->nsub; i++) {
 LSFinterpolate2a_dec(lp, iLBCdec_inst->lsfdeqold,
 lsfdeq, lsf_weightTbl_20ms[i], length);
 memcpy(syntdenum+pos,lp,lp_length*sizeof(float));
 bwexpand(weightdenum+pos, lp, LPC_CHIRP_WEIGHTDENUM,
 lp_length);
 pos += lp_length;
 }
 }

 /* update memory */

 if (iLBCdec_inst->mode==30)
 memcpy(iLBCdec_inst->lsfdeqold, lsfdeq2,
 length*sizeof(float));
 else
 memcpy(iLBCdec_inst->lsfdeqold, lsfdeq,
 length*sizeof(float));

 }

LSFinterpolate2a_dec()

void LSFinterpolate2a_dec	(	float *	a,
		float *	lsf1,
		float *	lsf2,
		float	coef,
		int	length
	)

Definition at line 25 of file LPCdecode.c.

References interpolate(), LPC_FILTERORDER, and lsf2a().

Referenced by DecoderInterpolateLSF().

 {
 float lsftmp[LPC_FILTERORDER];

 interpolate(lsftmp, lsf1, lsf2, coef, length);
 lsf2a(a, lsftmp);
 }

SimplelsfDEQ()

void SimplelsfDEQ	(	float *	lsfdeq,
		int *	index,
		int	lpc_n
	)

Definition at line 42 of file LPCdecode.c.

References dim_lsfCbTbl, LPC_FILTERORDER, LSF_NSPLIT, lsfCbTbl, and size_lsfCbTbl.

Referenced by iLBC_decode().

 {
 int i, j, pos, cb_pos;





 /* decode first LSF */

 pos = 0;
 cb_pos = 0;
 for (i = 0; i < LSF_NSPLIT; i++) {
 for (j = 0; j < dim_lsfCbTbl[i]; j++) {
 lsfdeq[pos + j] = lsfCbTbl[cb_pos +
 (long)(index[i])*dim_lsfCbTbl[i] + j];
 }
 pos += dim_lsfCbTbl[i];
 cb_pos += size_lsfCbTbl[i]*dim_lsfCbTbl[i];
 }

 if (lpc_n>1) {

 /* decode last LSF */

 pos = 0;
 cb_pos = 0;
 for (i = 0; i < LSF_NSPLIT; i++) {
 for (j = 0; j < dim_lsfCbTbl[i]; j++) {
 lsfdeq[LPC_FILTERORDER + pos + j] =
 lsfCbTbl[cb_pos +
 (long)(index[LSF_NSPLIT + i])*
 dim_lsfCbTbl[i] + j];
 }
 pos += dim_lsfCbTbl[i];
 cb_pos += size_lsfCbTbl[i]*dim_lsfCbTbl[i];
 }
 }
 }