rctoc.c

speech signal process tools

/*
| 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."
|
| Written by:  S. Shankar Narayan
|
| Module:	rctoc.c
| 
*/

#ifdef SCCS
static char *sccs_id = "@(#)rctoc.c	1.2 4/21/86 (rctoc.c)";
#endif
rctoc(rc,order,c,pgain)
	/* convert reflection coefficients to filter coefficients */
float rc[],c[],*pgain;
int order;
{
    float   tmp,
            ctmp[1000],
            gain = 1.0;
    int     i,
            j;
    for (i = 1; i <= order; i++) {
	tmp = rc[i];
	gain = gain * (1.0 - tmp * tmp);

    /* 	printf("rc(%d) = %f, gain = %f\n",i,tmp,gain); */

	if (i != 1) {
	    for (j = 1; j < i; j++)
		ctmp[j] = c[j] - tmp * c[i - j];
	}
	ctmp[i] = tmp;
	for (j = 1; j <= i; j++)
	    c[j] = ctmp[j];
    }
    *pgain = gain;
}