65 lines
1.3 KiB
C
65 lines
1.3 KiB
C
|
|
/******************************************************************
|
|
|
|
iLBC Speech Coder ANSI-C Source Code
|
|
|
|
|
|
|
|
|
|
|
|
hpInput.c
|
|
|
|
Copyright (C) The Internet Society (2004).
|
|
All Rights Reserved.
|
|
|
|
******************************************************************/
|
|
|
|
#include "constants.h"
|
|
|
|
/*----------------------------------------------------------------*
|
|
* Input high-pass filter
|
|
*---------------------------------------------------------------*/
|
|
|
|
void hpInput(
|
|
float *In, /* (i) vector to filter */
|
|
int len, /* (i) length of vector to filter */
|
|
float *Out, /* (o) the resulting filtered vector */
|
|
float *mem /* (i/o) the filter state */
|
|
){
|
|
int i;
|
|
float *pi, *po;
|
|
|
|
/* all-zero section*/
|
|
|
|
pi = &In[0];
|
|
po = &Out[0];
|
|
for (i=0; i<len; i++) {
|
|
*po = hpi_zero_coefsTbl[0] * (*pi);
|
|
*po += hpi_zero_coefsTbl[1] * mem[0];
|
|
*po += hpi_zero_coefsTbl[2] * mem[1];
|
|
|
|
mem[1] = mem[0];
|
|
mem[0] = *pi;
|
|
po++;
|
|
pi++;
|
|
|
|
}
|
|
|
|
/* all-pole section*/
|
|
|
|
po = &Out[0];
|
|
for (i=0; i<len; i++) {
|
|
*po -= hpi_pole_coefsTbl[1] * mem[2];
|
|
*po -= hpi_pole_coefsTbl[2] * mem[3];
|
|
|
|
mem[3] = mem[2];
|
|
mem[2] = *po;
|
|
po++;
|
|
|
|
|
|
|
|
|
|
|
|
}
|
|
}
|