ref: 8eecb9f21796dba241e6c8292166fe085eb90d8e
dir: /src/spectral/filterbank.h/
/*
Copyright (C) 2007-2013 Paul Brossier <piem@aubio.org>
and Amaury Hazan <ahazan@iua.upf.edu>
This file is part of aubio.
aubio 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 3 of the License, or
(at your option) any later version.
aubio 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 aubio. If not, see <http://www.gnu.org/licenses/>.
*/
/** \file
Filterbank object
General-purpose spectral filterbank object.
\example spectral/test-filterbank.c
*/
#ifndef AUBIO_FILTERBANK_H
#define AUBIO_FILTERBANK_H
#ifdef __cplusplus
extern "C"
{
#endif
/** filterbank object
This object stores a matrix of spectral filter coefficients.
*/
typedef struct _aubio_filterbank_t aubio_filterbank_t;
/** create filterbank object
\param n_filters number of filters to create
\param win_s size of analysis buffer (and length the FFT transform)
*/
aubio_filterbank_t *new_aubio_filterbank (uint_t n_filters, uint_t win_s);
/** destroy filterbank object
\param f filterbank object, as returned by new_aubio_filterbank()
*/
void del_aubio_filterbank (aubio_filterbank_t * f);
/** compute filterbank
\param f filterbank object, as returned by new_aubio_filterbank()
\param in input spectrum containing an input spectrum of length `win_s`
\param out output vector containing the energy found in each band, `nfilt` output values
*/
void aubio_filterbank_do (aubio_filterbank_t * f, const cvec_t * in, fvec_t * out);
/** return a pointer to the matrix object containing all filter coefficients
\param f filterbank object, as returned by new_aubio_filterbank()
*/
fmat_t *aubio_filterbank_get_coeffs (const aubio_filterbank_t * f);
/** copy filter coefficients to the filterbank
\param f filterbank object, as returned by new_aubio_filterbank()
\param filters filter bank coefficients to copy from
*/
uint_t aubio_filterbank_set_coeffs (aubio_filterbank_t * f, const fmat_t * filters);
/** set norm parameter
\param f filterbank object, as returned by new_aubio_filterbank()
\param norm `1` to norm the filters, `0` otherwise.
If set to `0`, the filters will not be normalized. If set to `1`,
each filter will be normalized to one. Defaults to `1`.
This function should be called *before* setting the filters with one of
aubio_filterbank_set_triangle_bands(), aubio_filterbank_set_mel_coeffs(),
aubio_filterbank_set_mel_coeffs_htk(), or
aubio_filterbank_set_mel_coeffs_slaney().
*/
uint_t aubio_filterbank_set_norm (aubio_filterbank_t *f, smpl_t norm);
/** get norm parameter
\param f filterbank object, as returned by new_aubio_filterbank()
\returns `1` if norm is set, `0` otherwise. Defaults to `1`.
*/
smpl_t aubio_filterbank_get_norm (aubio_filterbank_t *f);
/** set power parameter
\param f filterbank object, as returned by new_aubio_filterbank()
\param power Raise norm of the input spectrum norm to this power before
computing filterbank. Defaults to `1`.
*/
uint_t aubio_filterbank_set_power (aubio_filterbank_t *f, smpl_t power);
/** get power parameter
\param f filterbank object, as returned by new_aubio_filterbank()
\return current power parameter. Defaults to `1`.
*/
smpl_t aubio_filterbank_get_power (aubio_filterbank_t *f);
#ifdef __cplusplus
}
#endif
#endif /* AUBIO_FILTERBANK_H */