LPCencode.c File Reference

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

Include dependency graph for LPCencode.c:

Go to the source code of this file.

Functions
void	LPCencode (float *syntdenum, float *weightdenum, int *lsf_index, float *data, iLBC_Enc_Inst_t *iLBCenc_inst)
void	LSFinterpolate2a_enc (float *a, float *lsf1, float *lsf2, float coef, long length)
void	SimpleAnalysis (float *lsf, float *data, iLBC_Enc_Inst_t *iLBCenc_inst)
void	SimpleInterpolateLSF (float *syntdenum, float *weightdenum, float *lsf, float *lsfdeq, float *lsfold, float *lsfdeqold, int length, iLBC_Enc_Inst_t *iLBCenc_inst)
void	SimplelsfQ (float *lsfdeq, int *index, float *lsf, int lpc_n)

Function Documentation

LPCencode()

void LPCencode	(	float *	syntdenum,
		float *	weightdenum,
		int *	lsf_index,
		float *	data,
		iLBC_Enc_Inst_t *	iLBCenc_inst
	)

Definition at line 214 of file LPCencode.c.

References LPC_FILTERORDER, iLBC_Enc_Inst_t_::lpc_n, LPC_N_MAX, LSF_check(), iLBC_Enc_Inst_t_::lsfdeqold, iLBC_Enc_Inst_t_::lsfold, SimpleAnalysis(), SimpleInterpolateLSF(), and SimplelsfQ().

Referenced by iLBC_encode().

 {
 float lsf[LPC_FILTERORDER * LPC_N_MAX];
 float lsfdeq[LPC_FILTERORDER * LPC_N_MAX];

 SimpleAnalysis(lsf, data, iLBCenc_inst);
 SimplelsfQ(lsfdeq, lsf_index, lsf, iLBCenc_inst->lpc_n);




 LSF_check(lsfdeq, LPC_FILTERORDER, iLBCenc_inst->lpc_n);
 SimpleInterpolateLSF(syntdenum, weightdenum,
 lsf, lsfdeq, iLBCenc_inst->lsfold,
 iLBCenc_inst->lsfdeqold, LPC_FILTERORDER, iLBCenc_inst);
 }

LSFinterpolate2a_enc()

void LSFinterpolate2a_enc	(	float *	a,
		float *	lsf1,
		float *	lsf2,
		float	coef,
		long	length
	)

Definition at line 81 of file LPCencode.c.

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

Referenced by SimpleInterpolateLSF().

 {
 float lsftmp[LPC_FILTERORDER];

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

SimpleAnalysis()

void SimpleAnalysis	(	float *	lsf,
		float *	data,
		iLBC_Enc_Inst_t *	iLBCenc_inst
	)

Definition at line 28 of file LPCencode.c.

References a2lsf(), autocorr(), iLBC_Enc_Inst_t_::blockl, BLOCKL_MAX, bwexpand(), levdurb(), lpc_asymwinTbl, iLBC_Enc_Inst_t_::lpc_buffer, LPC_CHIRP_SYNTDENUM, LPC_FILTERORDER, lpc_lagwinTbl, LPC_LOOKBACK, iLBC_Enc_Inst_t_::lpc_n, lpc_winTbl, and window.

Referenced by LPCencode().

 {
 int k, is;
 float temp[BLOCKL_MAX], lp[LPC_FILTERORDER + 1];
 float lp2[LPC_FILTERORDER + 1];
 float r[LPC_FILTERORDER + 1];

 is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
 memcpy(iLBCenc_inst->lpc_buffer+is,data,
 iLBCenc_inst->blockl*sizeof(float));

 /* No lookahead, last window is asymmetric */

 for (k = 0; k < iLBCenc_inst->lpc_n; k++) {

 is = LPC_LOOKBACK;

 if (k < (iLBCenc_inst->lpc_n - 1)) {
 window(temp, lpc_winTbl,
 iLBCenc_inst->lpc_buffer, BLOCKL_MAX);
 } else {
 window(temp, lpc_asymwinTbl,
 iLBCenc_inst->lpc_buffer + is, BLOCKL_MAX);
 }

 autocorr(r, temp, BLOCKL_MAX, LPC_FILTERORDER);
 window(r, r, lpc_lagwinTbl, LPC_FILTERORDER + 1);

 levdurb(lp, temp, r, LPC_FILTERORDER);
 bwexpand(lp2, lp, LPC_CHIRP_SYNTDENUM, LPC_FILTERORDER+1);

 a2lsf(lsf + k*LPC_FILTERORDER, lp2);
 }
 is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
 memmove(iLBCenc_inst->lpc_buffer,
 iLBCenc_inst->lpc_buffer+LPC_LOOKBACK+BLOCKL_MAX-is,
 is*sizeof(float));
 }

SimpleInterpolateLSF()

void SimpleInterpolateLSF	(	float *	syntdenum,
		float *	weightdenum,
		float *	lsf,
		float *	lsfdeq,
		float *	lsfold,
		float *	lsfdeqold,
		int	length,
		iLBC_Enc_Inst_t *	iLBCenc_inst
	)

Definition at line 99 of file LPCencode.c.

References bwexpand(), LPC_CHIRP_WEIGHTDENUM, LPC_FILTERORDER, lsf_weightTbl_20ms, lsf_weightTbl_30ms, LSFinterpolate2a_enc(), iLBC_Enc_Inst_t_::mode, and iLBC_Enc_Inst_t_::nsub.

Referenced by LPCencode().

 {
 int i, pos, lp_length;
 float lp[LPC_FILTERORDER + 1], *lsf2, *lsfdeq2;

 lsf2 = lsf + length;
 lsfdeq2 = lsfdeq + length;
 lp_length = length + 1;

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





 set of lsf coefficients */

 LSFinterpolate2a_enc(lp, lsfdeqold, lsfdeq,
 lsf_weightTbl_30ms[0], length);
 memcpy(syntdenum,lp,lp_length*sizeof(float));
 LSFinterpolate2a_enc(lp, lsfold, lsf,
 lsf_weightTbl_30ms[0], length);
 bwexpand(weightdenum, lp, LPC_CHIRP_WEIGHTDENUM, lp_length);

 /* sub-frame 2 to 6: Interpolation between first
 and second set of lsf coefficients */

 pos = lp_length;
 for (i = 1; i < iLBCenc_inst->nsub; i++) {
 LSFinterpolate2a_enc(lp, lsfdeq, lsfdeq2,
 lsf_weightTbl_30ms[i], length);
 memcpy(syntdenum + pos,lp,lp_length*sizeof(float));

 LSFinterpolate2a_enc(lp, lsf, lsf2,
 lsf_weightTbl_30ms[i], length);
 bwexpand(weightdenum + pos, lp,
 LPC_CHIRP_WEIGHTDENUM, lp_length);
 pos += lp_length;
 }
 }
 else {
 pos = 0;
 for (i = 0; i < iLBCenc_inst->nsub; i++) {
 LSFinterpolate2a_enc(lp, lsfdeqold, lsfdeq,
 lsf_weightTbl_20ms[i], length);
 memcpy(syntdenum+pos,lp,lp_length*sizeof(float));
 LSFinterpolate2a_enc(lp, lsfold, lsf,
 lsf_weightTbl_20ms[i], length);
 bwexpand(weightdenum+pos, lp,
 LPC_CHIRP_WEIGHTDENUM, lp_length);
 pos += lp_length;
 }
 }

 /* update memory */

 if (iLBCenc_inst->mode==30) {
 memcpy(lsfold, lsf2, length*sizeof(float));
 memcpy(lsfdeqold, lsfdeq2, length*sizeof(float));
 }
 else {
 memcpy(lsfold, lsf, length*sizeof(float));
 memcpy(lsfdeqold, lsfdeq, length*sizeof(float));





 }
 }

SimplelsfQ()

void SimplelsfQ	(	float *	lsfdeq,
		int *	index,
		float *	lsf,
		int	lpc_n
	)

Definition at line 190 of file LPCencode.c.

References dim_lsfCbTbl, LPC_FILTERORDER, LSF_NSPLIT, lsfCbTbl, size_lsfCbTbl, and SplitVQ().

Referenced by LPCencode().

 {
 /* Quantize first LSF with memoryless split VQ */
 SplitVQ(lsfdeq, index, lsf, lsfCbTbl, LSF_NSPLIT,
 dim_lsfCbTbl, size_lsfCbTbl);

 if (lpc_n==2) {
 /* Quantize second LSF with memoryless split VQ */
 SplitVQ(lsfdeq + LPC_FILTERORDER, index + LSF_NSPLIT,
 lsf + LPC_FILTERORDER, lsfCbTbl, LSF_NSPLIT,
 dim_lsfCbTbl, size_lsfCbTbl);
 }
 }