Asterisk - The Open Source Telephony Project GIT-master-f36a736
Functions
syntFilter.c File Reference
#include "iLBC_define.h"
Include dependency graph for syntFilter.c:

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Functions

void syntFilter (float *Out, float *a, int len, float *mem)
 

Function Documentation

◆ syntFilter()

void syntFilter ( float *  Out,
float *  a,
int  len,
float *  mem 
)

Definition at line 19 of file syntFilter.c.

29 {
30 int i, j;
31 float *po, *pi, *pa, *pm;
32
33 po=Out;
34
35 /* Filter first part using memory from past */
36
37 for (i=0; i<LPC_FILTERORDER; i++) {
38 pi=&Out[i-1];
39 pa=&a[1];
40 pm=&mem[LPC_FILTERORDER-1];
41 for (j=1; j<=i; j++) {
42 *po-=(*pa++)*(*pi--);
43 }
44 for (j=i+1; j<LPC_FILTERORDER+1; j++) {
45 *po-=(*pa++)*(*pm--);
46 }
47 po++;
48 }
49
50 /* Filter last part where the state is entirely in
51 the output vector */
52
53 for (i=LPC_FILTERORDER; i<len; i++) {
54 pi=&Out[i-1];
55 pa=&a[1];
56 for (j=1; j<LPC_FILTERORDER+1; j++) {
57 *po-=(*pa++)*(*pi--);
58 }
59 po++;
60 }
61
62 /* Update state vector */
63
64 memcpy(mem, &Out[len-LPC_FILTERORDER],
65 LPC_FILTERORDER*sizeof(float));
66 }
static int len(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t buflen)
#define LPC_FILTERORDER
Definition: iLBC_define.h:40
static struct test_val a

References a, len(), and LPC_FILTERORDER.

Referenced by iLBC_decode().