ref: b1c948bece6ebed49f1906e2542edd8e7f05cea0
dir: /src/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 FFTW3F_SUPPORT
#define FFTW_TYPE fftwf_complex
#else
#define FFTW_TYPE fftw_complex
#endif
#else
#if FFTW3F_SUPPORT
/** 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
*/
aubio_fft_t * new_aubio_fft(uint_t size);
/** 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 data input signal
\param spectrum output spectrum
\param size length of the input vector
*/
void aubio_fft_do (const aubio_fft_t *s, const smpl_t * data,
fft_data_t * spectrum, const uint_t size);
/** compute backward (inverse) FFT
\param s fft object as returned by new_aubio_fft
\param spectrum input spectrum
\param data output signal
\param size length of the input vector
*/
void aubio_fft_rdo(const aubio_fft_t *s, const fft_data_t * spectrum,
smpl_t * data, const uint_t size);
/** compute norm vector from input spectrum
\param norm magnitude vector output
\param spectrum spectral data input
\param size size of the vectors
*/
void aubio_fft_getnorm(smpl_t * norm, fft_data_t * spectrum, uint_t size);
/** compute phase vector from input spectrum
\param phase phase vector output
\param spectrum spectral data input
\param size size of the vectors
*/
void aubio_fft_getphas(smpl_t * phase, fft_data_t * spectrum, uint_t size);
/** FFT object (using cvec)
This object works similarly as aubio_fft_t, except the spectral data is
stored in a cvec_t as two vectors, magnitude and phase.
*/
typedef struct _aubio_mfft_t aubio_mfft_t;
/** create new FFT computation object
\param winsize length of the FFT
\param channels number of channels
*/
aubio_mfft_t * new_aubio_mfft(uint_t winsize, uint_t channels);
/** compute forward FFT
\param fft fft object as returned by new_aubio_mfft
\param in input signal
\param fftgrain output spectrum
*/
void aubio_mfft_do (aubio_mfft_t * fft,fvec_t * in,cvec_t * fftgrain);
/** compute backward (inverse) FFT
\param fft fft object as returned by new_aubio_mfft
\param fftgrain input spectrum (cvec)
\param out output signal
*/
void aubio_mfft_rdo(aubio_mfft_t * fft,cvec_t * fftgrain, fvec_t * out);
/** delete FFT object
\param fft fft object as returned by new_aubio_mfft
*/
void del_aubio_mfft(aubio_mfft_t * fft);
#ifdef __cplusplus
}
#endif
#endif