invsefilt.c

来自「speech signal process tools」· C语言 代码 · 共 28 行

	/* perform inverse filtering */
/*
| This material contains proprietary software of Entropic Processing, Inc.   
| Any reproduction, distribution, or publication without the the prior	   
| written permission of Entropic Processing, Inc. is strictly prohibited.
| Any public distribution of copies of this work authorized in writing by
| Entropic Processing, Inc. must bear the notice			
|								
|              "Copyright 1986 Entropic Processing, Inc."
*/
#ifdef SCCS
static char *sccs_id = "@(#)invsefilt.c	1.2 4/29/86";
#endif
float   invse_filter (c, state, order, input)
float   c[], state[], input;
int     order;
{
    int     j;
    double  t = input;

    for (j = 1; j <= order; j++)
	t -= c[j] * state[j];
    for (j = order; j > 1; j--)
	state[j] = state[j - 1];
    state[1] = input;
    return (t);
}