ref: 598fbb0861db85b5046479921d5909b79a316c31
dir: /src/spectral/dct.h/
/*
Copyright (C) 2017 Paul Brossier <piem@aubio.org>
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
Discrete Cosine Transform
Functions aubio_dct_do() and aubio_dct_rdo() are equivalent to MATLAB/Octave
dct() and idct() functions, as well as scipy.fftpack.dct(x, norm='ortho') and
scipy.fftpack.idct(x, norm='ortho')
\example spectral/test-dct.c
*/
#ifndef AUBIO_DCT_H
#define AUBIO_DCT_H
#ifdef __cplusplus
extern "C" {
#endif
/** DCT object
This object computes forward and backward DCT type 2 with orthonormal
scaling.
*/
typedef struct _aubio_dct_t aubio_dct_t;
/** create new DCT computation object
\param size length of the DCT
*/
aubio_dct_t * new_aubio_dct(uint_t size);
/** compute forward DCT
\param s dct object as returned by new_aubio_dct
\param input input signal
\param dct_output transformed input array
*/
void aubio_dct_do (aubio_dct_t *s, const fvec_t * input, fvec_t * dct_output);
/** compute backward DCT
\param s dct object as returned by new_aubio_dct
\param input input signal
\param idct_output transformed input array
*/
void aubio_dct_rdo (aubio_dct_t *s, const fvec_t * input, fvec_t * idct_output);
/** delete DCT object
\param s dct object as returned by new_aubio_dct
*/
void del_aubio_dct (aubio_dct_t *s);
#ifdef __cplusplus
}
#endif
#endif /* AUBIO_DCT_H */