view aubioFullOSXUni/include/aubio/filter.h @ 0:572c856e38ac

Starting up openFrameworks project for audio time warping. The ofxFileReader goes in addons of your OF folder, the libraries and source (chromogram, fftw and source code src+ timewarp) are probably best kept in the repository, then dragged into the project afresh. That way, as we update the repository, the code that the openFrameworks project looks for will be updated.

/*
	 Copyright (C) 2003 Paul Brossier

	 This program 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.

	 This program 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 this program; if not, write to the Free Software
	 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#ifndef FILTER_H
#define FILTER_H

/** \file 

  Infinite Impulse Response filter

  This file implements IIR filters of any order:
 
  \f$ y[n] = b_1 x[n] + ... + b_{order} x[n-order] -
       a_2 y[n-1] - ... - a_{order} y[n-order]\f$

  The filtfilt version runs the filter twice, forward and backward, to
  compensate the phase shifting of the forward operation.

*/

#ifdef __cplusplus
extern "C" {
#endif

/** IIR filter object */
typedef struct _aubio_filter_t aubio_filter_t;

/** filter input vector (in-place)

  \param b biquad object as returned by new_aubio_biquad
  \param in input vector to filter

*/
void aubio_filter_do(aubio_filter_t * b, fvec_t * in);
/** filter input vector (out-of-place)

  \param b biquad object as returned by new_aubio_biquad
  \param in input vector to filter
  \param out output vector to store filtered input

*/
void aubio_filter_do_outplace(aubio_filter_t * b, fvec_t * in, fvec_t * out);
/** filter input vector forward and backward

  \param b biquad object as returned by new_aubio_biquad
  \param in input vector to filter
  \param tmp memory space to use for computation

*/
void aubio_filter_do_filtfilt(aubio_filter_t * b, fvec_t * in, fvec_t * tmp);
/** create new IIR filter

  \param samplerate signal sampling rate
  \param order order of the filter (number of coefficients)

*/
aubio_filter_t * new_aubio_filter(ba_uint_t samplerate, ba_uint_t order);
/** create a new A-design filter 

  \param samplerate sampling-rate of the signal to filter 

*/
aubio_filter_t * new_aubio_adsgn_filter(ba_uint_t samplerate);
/** create a new C-design filter 

  \param samplerate sampling-rate of the signal to filter 

*/
aubio_filter_t * new_aubio_cdsgn_filter(ba_uint_t samplerate);
/** delete a filter object
 
  \param f filter object to delete

*/
void del_aubio_filter(aubio_filter_t * f);

#ifdef __cplusplus
}
#endif

#endif /*FILTER_H*/