ref: 04ceeab0124ab3e08530e0ebbf93179c3ba7d31d
dir: /src/spectral/fft.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.
*/
/** \file
Fast Fourier Transform object
*/
#ifndef FFT_H_
#define FFT_H_
/* note that <complex.h> is not included here but only in aubio_priv.h, so that
* c++ projects can still use their own complex definition. */
#include <fftw3.h>
#ifdef HAVE_COMPLEX_H
#if HAVE_FFTW3F
#define FFTW_TYPE fftwf_complex
#else
#define FFTW_TYPE fftw_complex
#endif
#else
#if HAVE_FFTW3F
/** fft data type */
#define FFTW_TYPE float
#else
/** fft data type */
#define FFTW_TYPE double
#endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
/** fft data type */
typedef FFTW_TYPE fft_data_t;
/** FFT object
This object computes forward and backward FFTs, using the complex type to
store the results. The phase vocoder or aubio_mfft_t objects should be
preferred to using directly aubio_fft_t. The FFT are computed using FFTW3
(although support for another library could be added).
*/
typedef struct _aubio_fft_t aubio_fft_t;
/** create new FFT computation object
\param size length of the FFT
\param channels number of channels
*/
aubio_fft_t * new_aubio_fft(uint_t size, uint_t channels);
/** delete FFT object
\param s fft object as returned by new_aubio_fft
*/
void del_aubio_fft(aubio_fft_t * s);
/** compute forward FFT
\param s fft object as returned by new_aubio_fft
\param input input signal
\param spectrum output spectrum
*/
void aubio_fft_do (aubio_fft_t *s, fvec_t * input, cvec_t * spectrum);
/** compute backward (inverse) FFT
\param s fft object as returned by new_aubio_fft
\param spectrum input spectrum
\param output output signal
*/
void aubio_fft_rdo (aubio_fft_t *s, cvec_t * spectrum, fvec_t * output);
/** compute forward FFT
\param s fft object as returned by new_aubio_fft
\param input real input signal
\param compspec complex output fft real/imag
*/
void aubio_fft_do_complex (aubio_fft_t *s, fvec_t * input, fvec_t * compspec);
/** compute backward (inverse) FFT from real/imag
\param s fft object as returned by new_aubio_fft
\param compspec real/imag input fft array
\param output real output array
*/
void aubio_fft_rdo_complex (aubio_fft_t *s, fvec_t * compspec, fvec_t * output);
/** convert real/imag spectrum to norm/phas spectrum
\param compspec real/imag input fft array
\param spectrum cvec norm/phas output array
*/
void aubio_fft_get_spectrum(fvec_t * compspec, cvec_t * spectrum);
/** convert real/imag spectrum to norm/phas spectrum
\param compspec real/imag input fft array
\param spectrum cvec norm/phas output array
*/
void aubio_fft_get_realimag(cvec_t * spectrum, fvec_t * compspec);
/** compute phas spectrum from real/imag parts
\param compspec real/imag input fft array
\param spectrum cvec norm/phas output array
*/
void aubio_fft_get_phas(fvec_t * compspec, cvec_t * spectrum);
/** compute imaginary part from the norm/phas cvec
\param spectrum norm/phas input array
\param compspec real/imag output fft array
*/
void aubio_fft_get_imag(cvec_t * spectrum, fvec_t * compspec);
/** compute norm component from real/imag parts
\param compspec real/imag input fft array
\param spectrum cvec norm/phas output array
*/
void aubio_fft_get_norm(fvec_t * compspec, cvec_t * spectrum);
/** compute real part from norm/phas components
\param spectrum norm/phas input array
\param compspec real/imag output fft array
*/
void aubio_fft_get_real(cvec_t * spectrum, fvec_t * compspec);
#ifdef __cplusplus
}
#endif
#endif // FFT_H_