ref: f218f29b032d1e2390a9be25dfd633732b6bd9f1
dir: /src/filter.h/
/* 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(uint_t samplerate, 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(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(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*/