2
/******************************************************************
4
iLBC Speech Coder ANSI-C Source Code
8
Copyright (C) The Internet Society (2004).
11
******************************************************************/
14
#include "iLBC_define.h"
16
/*----------------------------------------------------------------*
18
*---------------------------------------------------------------*/
21
float *In, /* (i) Signal to be filtered */
22
float *a, /* (i) LP parameters */
23
int len,/* (i) Length of signal */
24
float *Out, /* (o) Filtered signal */
25
float *mem /* (i/o) Filter state */
28
float *po, *pi, *pm, *pa;
32
/* Filter first part using memory from past */
34
for (i=0; i<LPC_FILTERORDER; i++) {
36
pm = &mem[LPC_FILTERORDER-1];
44
for (j=0; j<=i; j++) {
47
for (j=i+1; j<LPC_FILTERORDER+1; j++) {
54
/* Filter last part where the state is entirely
55
in the input vector */
57
for (i=LPC_FILTERORDER; i<len; i++) {
61
for (j=0; j<LPC_FILTERORDER+1; j++) {
67
/* Update state vector */
69
memcpy(mem, &In[len-LPC_FILTERORDER],
70
LPC_FILTERORDER*sizeof(float));