view libs/aubioFullOSXUni/include/aubio/biquad.h @ 1:ba2a17cf81bf

first working version of audio file loder. Loads bach clip from the apps->audio-file-loader->bin->data->sounds foler. Three classes: SoundFileLoader does the loading and parsing of thefile with libSndFile. audio samples are kept in AudioFile and analysis of features are kept in AudioAnalysis, at this stage just chromagramm and basic energy

/*
	 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 BIQUAD_H
#define BIQUAD_H

/** \file 

  Second order Infinite Impulse Response filter

  This file implements a normalised biquad filter (second order IIR):
 
  \f$ y[n] = b_1 x[n] + b_2 x[n-1] + b_3 x[n-2] - a_2 y[n-1] - a_3 y[n-2] \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

/** biquad filter object */
typedef struct _aubio_biquad_t aubio_biquad_t;

/** filter input vector

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

*/
void aubio_biquad_do(aubio_biquad_t * b, fvec_t * in);
/** 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_biquad_do_filtfilt(aubio_biquad_t * b, fvec_t * in, fvec_t * tmp);
/** create new biquad filter

  \param b1 forward filter coefficient
  \param b2 forward filter coefficient
  \param b3 forward filter coefficient
  \param a2 feedback filter coefficient
  \param a3 feedback filter coefficient

*/
aubio_biquad_t * new_aubio_biquad(lsmp_t b1, lsmp_t b2, lsmp_t b3, lsmp_t a2, lsmp_t a3);

/** delete biquad filter 
 
  \param b biquad object to delete 

*/
void del_aubio_biquad(aubio_biquad_t * b);

#ifdef __cplusplus
}
#endif

#endif /*BIQUAD_H*/