ref: c03e7777e63a0202d21f99fa08039ac65f8c581f
dir: /src/spectral/fft.h/
/* Copyright (C) 2003-2009 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 Fast Fourier Transform object */ #ifndef FFT_H_ #define FFT_H_ #ifdef __cplusplus extern "C" { #endif /** 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_