blob: 4d2128ee0e8410311e059e1f276138a768d41ab3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
/******************************************************************
iLBC Speech Coder ANSI-C Source Code
hpOutput.c
Copyright (C) The Internet Society (2004).
All Rights Reserved.
******************************************************************/
#include "constants.h"
/*----------------------------------------------------------------*
* Output high-pass filter
*---------------------------------------------------------------*/
void hpOutput(
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 = hpo_zero_coefsTbl[0] * (*pi);
*po += hpo_zero_coefsTbl[1] * mem[0];
*po += hpo_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 -= hpo_pole_coefsTbl[1] * mem[2];
*po -= hpo_pole_coefsTbl[2] * mem[3];
mem[3] = mem[2];
mem[2] = *po;
po++;
}
}
|
