1 /* Libvisual-plugins - Standard plugins for libvisual
2  *
3  * Copyright (C) 2004, 2005, 2006 Antti Silvast <asilvast@iki.fi>
4  *
5  * Authors: Antti Silvast <asilvast@iki.fi>
6  *	    Dennis Smit <ds@nerds-incorporated.org>
7  *
8  * $Id: notch.h,v 1.3 2006/01/22 13:25:26 synap Exp $
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2
13  * of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23  */
24 
25 typedef struct {
26     float cutoff;
27     float a0;
28     float b1;
29     float b2;
30     float x1;
31     float x2;
32 } NOTCH_FILTER;
33 
34 #define SAMPLING_RATE 44100
35 
36 NOTCH_FILTER *  init_notch(float cutoff);
37 float process_notch(NOTCH_FILTER * l, float x0);
38