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/*
* lingot, a musical instrument tuner.
*
* Copyright (C) 2004-2011 Ibán Cereijo Graña, Jairo Chapela Martínez.
*
* This file is part of lingot.
*
* lingot is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* lingot is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with lingot; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __LINGOT_FILTER_H__
#define __LINGOT_FILTER_H__
#include <fcntl.h>
#include <stdlib.h>
#include "lingot-defs.h"
/*
digital filtering implementation.
*/
typedef struct _LingotFilter LingotFilter;
struct _LingotFilter
{
FLT* a;
FLT* b; // coefs
FLT* s; // status
unsigned int N;
};
LingotFilter
* lingot_filter_new(unsigned int Na, unsigned int Nb, FLT* a, FLT* b);
/**
* Design a Chebyshev type I low pass filter with Rp dB of pass band ripple
* with cutoff pi*wc radians.
*/
LingotFilter* lingot_filter_cheby_design(unsigned int order, FLT Rp, FLT wc);
void lingot_filter_destroy(LingotFilter*);
// Digital Filter Implementation II, in & out overlapables. Vector filtering
void lingot_filter_filter(LingotFilter*, unsigned int n, FLT* in, FLT* out);
// sample filtering
FLT lingot_filter_filter_sample(LingotFilter*, FLT in);
#endif
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