16adf6de8c
This patch includes the iLBC source code for distribution with Asterisk. Clarification regarding the iLBC source code was provided by Google, and the appropriate licenses have been included in the codecs/ilbc folder. Review: https://reviewboard.asterisk.org/r/1675 Review: https://reviewboard.asterisk.org/r/1649 (closes issue: ASTERISK-18943) Reporter: Leif Madsen Tested by: Matt Jordan ........ Merged revisions 351450 from http://svn.asterisk.org/svn/asterisk/branches/1.8 ........ Merged revisions 351451 from http://svn.asterisk.org/svn/asterisk/branches/10 git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@351452 65c4cc65-6c06-0410-ace0-fbb531ad65f3
159 lines
4.7 KiB
C
159 lines
4.7 KiB
C
|
|
/******************************************************************
|
|
|
|
iLBC Speech Coder ANSI-C Source Code
|
|
|
|
LPC_decode.c
|
|
|
|
Copyright (C) The Internet Society (2004).
|
|
All Rights Reserved.
|
|
|
|
******************************************************************/
|
|
|
|
#include <math.h>
|
|
#include <string.h>
|
|
|
|
#include "helpfun.h"
|
|
#include "lsf.h"
|
|
#include "iLBC_define.h"
|
|
#include "constants.h"
|
|
|
|
/*---------------------------------------------------------------*
|
|
* interpolation of lsf coefficients for the decoder
|
|
*--------------------------------------------------------------*/
|
|
|
|
void LSFinterpolate2a_dec(
|
|
float *a, /* (o) lpc coefficients for a sub-frame */
|
|
float *lsf1, /* (i) first lsf coefficient vector */
|
|
float *lsf2, /* (i) second lsf coefficient vector */
|
|
float coef, /* (i) interpolation weight */
|
|
int length /* (i) length of lsf vectors */
|
|
){
|
|
float lsftmp[LPC_FILTERORDER];
|
|
|
|
interpolate(lsftmp, lsf1, lsf2, coef, length);
|
|
lsf2a(a, lsftmp);
|
|
}
|
|
|
|
/*---------------------------------------------------------------*
|
|
* obtain dequantized lsf coefficients from quantization index
|
|
*--------------------------------------------------------------*/
|
|
|
|
void SimplelsfDEQ(
|
|
float *lsfdeq, /* (o) dequantized lsf coefficients */
|
|
int *index, /* (i) quantization index */
|
|
int lpc_n /* (i) number of LPCs */
|
|
){
|
|
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];
|
|
}
|
|
}
|
|
}
|
|
|
|
/*----------------------------------------------------------------*
|
|
* obtain synthesis and weighting filters form lsf coefficients
|
|
*---------------------------------------------------------------*/
|
|
|
|
void DecoderInterpolateLSF(
|
|
float *syntdenum, /* (o) synthesis filter coefficients */
|
|
float *weightdenum, /* (o) weighting denumerator
|
|
coefficients */
|
|
float *lsfdeq, /* (i) dequantized lsf coefficients */
|
|
int length, /* (i) length of lsf coefficient vector */
|
|
iLBC_Dec_Inst_t *iLBCdec_inst
|
|
/* (i) the decoder state structure */
|
|
){
|
|
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));
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|