source: src/spectral/fft.h @ 554a9cb

feature/autosinkfeature/cnnfeature/cnn_orgfeature/constantqfeature/crepefeature/crepe_orgfeature/pitchshiftfeature/pydocstringsfeature/timestretchfix/ffmpeg5pitchshiftsamplertimestretchyinfft+
Last change on this file since 554a9cb was 32d6958, checked in by Paul Brossier <piem@piem.org>, 17 years ago

src/: more moving and splitting

  • Property mode set to 100644
File size: 4.1 KB
Line 
1/*
2   Copyright (C) 2003 Paul Brossier
3
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.
8
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.
13
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.
17   
18*/
19
20/** \file
21
22  Fast Fourier Transform object
23
24*/
25
26#ifndef FFT_H_
27#define FFT_H_
28
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. */
31#include <fftw3.h>
32
33#ifdef HAVE_COMPLEX_H
34#if FFTW3F_SUPPORT
35#define FFTW_TYPE fftwf_complex
36#else
37#define FFTW_TYPE fftw_complex
38#endif
39#else
40#if FFTW3F_SUPPORT
41/** fft data type */
42#define FFTW_TYPE float
43#else
44/** fft data type */
45#define FFTW_TYPE double
46#endif
47#endif
48
49#ifdef __cplusplus
50extern "C" {
51#endif
52
53/** fft data type */
54typedef FFTW_TYPE fft_data_t;
55
56/** FFT object
57 
58  This object computes forward and backward FFTs, using the complex type to
59  store the results. The phase vocoder or aubio_mfft_t objects should be
60  preferred to using directly aubio_fft_t. The FFT are computed using FFTW3
61  (although support for another library could be added).
62
63*/
64typedef struct _aubio_fft_t aubio_fft_t;
65
66/** create new FFT computation object
67
68  \param size length of the FFT
69  \param channels number of channels
70
71*/
72aubio_fft_t * new_aubio_fft(uint_t size, uint_t channels);
73/** delete FFT object
74
75  \param s fft object as returned by new_aubio_fft
76
77*/
78void del_aubio_fft(aubio_fft_t * s);
79
80/** compute forward FFT
81
82  \param s fft object as returned by new_aubio_fft
83  \param input input signal
84  \param spectrum output spectrum
85
86*/
87void aubio_fft_do (aubio_fft_t *s, fvec_t * input, cvec_t * spectrum);
88/** compute backward (inverse) FFT
89
90  \param s fft object as returned by new_aubio_fft
91  \param spectrum input spectrum
92  \param output output signal
93
94*/
95void aubio_fft_rdo (aubio_fft_t *s, cvec_t * spectrum, fvec_t * output);
96
97/** compute forward FFT
98
99  \param s fft object as returned by new_aubio_fft
100  \param input real input signal
101  \param compspec complex output fft real/imag
102
103*/
104void aubio_fft_do_complex (aubio_fft_t *s, fvec_t * input, fvec_t * compspec);
105/** compute backward (inverse) FFT from real/imag
106
107  \param s fft object as returned by new_aubio_fft
108  \param compspec real/imag input fft array
109  \param output real output array
110
111*/
112void aubio_fft_rdo_complex (aubio_fft_t *s, fvec_t * compspec, fvec_t * output);
113
114/** convert real/imag spectrum to norm/phas spectrum
115
116  \param compspec real/imag input fft array
117  \param spectrum cvec norm/phas output array
118
119*/
120void aubio_fft_get_spectrum(fvec_t * compspec, cvec_t * spectrum);
121/** convert real/imag spectrum to norm/phas spectrum
122
123  \param compspec real/imag input fft array
124  \param spectrum cvec norm/phas output array
125
126*/
127void aubio_fft_get_realimag(cvec_t * spectrum, fvec_t * compspec);
128
129/** compute phas spectrum from real/imag parts
130
131  \param compspec real/imag input fft array
132  \param spectrum cvec norm/phas output array
133
134*/
135void aubio_fft_get_phas(fvec_t * compspec, cvec_t * spectrum);
136/** compute imaginary part from the norm/phas cvec
137
138  \param spectrum norm/phas input array
139  \param compspec real/imag output fft array
140
141*/
142void aubio_fft_get_imag(cvec_t * spectrum, fvec_t * compspec);
143
144/** compute norm component from real/imag parts
145
146  \param compspec real/imag input fft array
147  \param spectrum cvec norm/phas output array
148
149*/
150void aubio_fft_get_norm(fvec_t * compspec, cvec_t * spectrum);
151/** compute real part from norm/phas components
152
153  \param spectrum norm/phas input array
154  \param compspec real/imag output fft array
155
156*/
157void aubio_fft_get_real(cvec_t * spectrum, fvec_t * compspec);
158
159#ifdef __cplusplus
160}
161#endif
162
163#endif // FFT_H_
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