2 Copyright (C) 2003 Paul Brossier
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 Fast Fourier Transform object
29 /* note that <complex.h> is not included here but only in aubio_priv.h, so that
30 * c++ projects can still use their own complex definition. */
34 #define FFTW_TYPE fftwf_complex
36 #define FFTW_TYPE fftw_complex
43 typedef FFTW_TYPE fft_data_t;
47 This object computes forward and backward FFTs, using the complex type to
48 store the results. The phase vocoder or aubio_mfft_t objects should be
49 preferred to using directly aubio_fft_t. The FFT are computed using FFTW3
50 (although support for another library could be added).
53 typedef struct _aubio_fft_t aubio_fft_t;
55 /** create new FFT computation object
57 \param size length of the FFT
60 aubio_fft_t * new_aubio_fft(uint_t size);
63 \param s fft object as returned by new_aubio_fft
66 void del_aubio_fft(aubio_fft_t * s);
67 /** compute forward FFT
69 \param s fft object as returned by new_aubio_fft
70 \param data input signal
71 \param spectrum output spectrum
72 \param size length of the input vector
75 void aubio_fft_do (const aubio_fft_t *s, const smpl_t * data,
76 fft_data_t * spectrum, const uint_t size);
77 /** compute backward (inverse) FFT
79 \param s fft object as returned by new_aubio_fft
80 \param spectrum input spectrum
81 \param data output signal
82 \param size length of the input vector
85 void aubio_fft_rdo(const aubio_fft_t *s, const fft_data_t * spectrum,
86 smpl_t * data, const uint_t size);
87 /** compute norm vector from input spectrum
89 \param norm magnitude vector output
90 \param spectrum spectral data input
91 \param size size of the vectors
94 void aubio_fft_getnorm(smpl_t * norm, fft_data_t * spectrum, uint_t size);
95 /** compute phase vector from input spectrum
97 \param phase phase vector output
98 \param spectrum spectral data input
99 \param size size of the vectors
102 void aubio_fft_getphas(smpl_t * phase, fft_data_t * spectrum, uint_t size);
104 /** FFT object (using cvec)
106 This object works similarly as aubio_fft_t, except the spectral data is
107 stored in a cvec_t as two vectors, magnitude and phase.
110 typedef struct _aubio_mfft_t aubio_mfft_t;
112 /** create new FFT computation object
114 \param winsize length of the FFT
115 \param channels number of channels
118 aubio_mfft_t * new_aubio_mfft(uint_t winsize, uint_t channels);
119 /** compute forward FFT
121 \param fft fft object as returned by new_aubio_mfft
122 \param in input signal
123 \param fftgrain output spectrum
126 void aubio_mfft_do (aubio_mfft_t * fft,fvec_t * in,cvec_t * fftgrain);
127 /** compute backward (inverse) FFT
129 \param fft fft object as returned by new_aubio_mfft
130 \param fftgrain input spectrum (cvec)
131 \param out output signal
134 void aubio_mfft_rdo(aubio_mfft_t * fft,cvec_t * fftgrain, fvec_t * out);
135 /** delete FFT object
137 \param fft fft object as returned by new_aubio_mfft
140 void del_aubio_mfft(aubio_mfft_t * fft);