aubio: spectral/fft.h Source File

aubio 0.4.9

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fft.h
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1/*
2 Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org>
3
4 This file is part of aubio.
5
6 aubio is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
10
11 aubio is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with aubio. If not, see <http://www.gnu.org/licenses/>.
18
19*/
20
21/** \file
22
23 Fast Fourier Transform
24
25 Depending on how aubio was compiled, FFT are computed using one of:
26 - [Ooura](http://www.kurims.kyoto-u.ac.jp/~ooura/fft.html)
27 - [FFTW3](http://www.fftw.org)
28 - [vDSP](https://developer.apple.com/library/mac/#documentation/Accelerate/Reference/vDSPRef/Reference/reference.html)
29
30 \example spectral/test-fft.c
31
32*/
33
34#ifndef AUBIO_FFT_H
35#define AUBIO_FFT_H
36
37#ifdef __cplusplus
38extern "C" {
39#endif
40
41/** FFT object
42
43 This object computes forward and backward FFTs.
44
45*/
46 typedef struct _aubio_fft_t aubio_fft_t;
47
48/** create new FFT computation object
49
50 \param size length of the FFT
51
52*/
53 aubio_fft_t * new_aubio_fft (uint_t size);
54/** delete FFT object
55
56 \param s fft object as returned by new_aubio_fft
57
58*/
59 void del_aubio_fft(aubio_fft_t * s);
60
61/** compute forward FFT
62
63 \param s fft object as returned by new_aubio_fft
64 \param input input signal
65 \param spectrum output spectrum
66
67*/
68 void aubio_fft_do (aubio_fft_t *s, const fvec_t * input, cvec_t * spectrum);
69/** compute backward (inverse) FFT
70
71 \param s fft object as returned by new_aubio_fft
72 \param spectrum input spectrum
73 \param output output signal
74
75*/
76 void aubio_fft_rdo (aubio_fft_t *s, const cvec_t * spectrum, fvec_t * output);
77
78/** compute forward FFT
79
80 \param s fft object as returned by new_aubio_fft
81 \param input real input signal
82 \param compspec complex output fft real/imag
83
84*/
85 void aubio_fft_do_complex (aubio_fft_t *s, const fvec_t * input, fvec_t * compspec);
86/** compute backward (inverse) FFT from real/imag
87
88 \param s fft object as returned by new_aubio_fft
89 \param compspec real/imag input fft array
90 \param output real output array
91
92*/
93 void aubio_fft_rdo_complex (aubio_fft_t *s, const fvec_t * compspec, fvec_t * output);
94
95/** convert real/imag spectrum to norm/phas spectrum
96
97 \param compspec real/imag input fft array
98 \param spectrum cvec norm/phas output array
99
100*/
101 void aubio_fft_get_spectrum(const fvec_t * compspec, cvec_t * spectrum);
102/** convert real/imag spectrum to norm/phas spectrum
103
104 \param compspec real/imag input fft array
105 \param spectrum cvec norm/phas output array
106
107*/
108 void aubio_fft_get_realimag(const cvec_t * spectrum, fvec_t * compspec);
109
110/** compute phas spectrum from real/imag parts
111
112 \param compspec real/imag input fft array
113 \param spectrum cvec norm/phas output array
114
115*/
116 void aubio_fft_get_phas(const fvec_t * compspec, cvec_t * spectrum);
117/** compute imaginary part from the norm/phas cvec
118
119 \param spectrum norm/phas input array
120 \param compspec real/imag output fft array
121
122*/
123 void aubio_fft_get_imag(const cvec_t * spectrum, fvec_t * compspec);
124
125/** compute norm component from real/imag parts
126
127 \param compspec real/imag input fft array
128 \param spectrum cvec norm/phas output array
129
130*/
131 void aubio_fft_get_norm(const fvec_t * compspec, cvec_t * spectrum);
132/** compute real part from norm/phas components
133
134 \param spectrum norm/phas input array
135 \param compspec real/imag output fft array
136
137*/
138 void aubio_fft_get_real(const cvec_t * spectrum, fvec_t * compspec);
139
140#ifdef __cplusplus
141}
142#endif
143
144#endif /* AUBIO_FFT_H */
new_aubio_fft
aubio_fft_t * new_aubio_fft(uint_t size)
create new FFT computation object
aubio_fft_rdo
void aubio_fft_rdo(aubio_fft_t *s, const cvec_t *spectrum, fvec_t *output)
compute backward (inverse) FFT
aubio_fft_rdo_complex
void aubio_fft_rdo_complex(aubio_fft_t *s, const fvec_t *compspec, fvec_t *output)
compute backward (inverse) FFT from real/imag
aubio_fft_get_real
void aubio_fft_get_real(const cvec_t *spectrum, fvec_t *compspec)
compute real part from norm/phas components
aubio_fft_get_spectrum
void aubio_fft_get_spectrum(const fvec_t *compspec, cvec_t *spectrum)
convert real/imag spectrum to norm/phas spectrum
del_aubio_fft
void del_aubio_fft(aubio_fft_t *s)
delete FFT object
aubio_fft_get_imag
void aubio_fft_get_imag(const cvec_t *spectrum, fvec_t *compspec)
compute imaginary part from the norm/phas cvec
aubio_fft_do_complex
void aubio_fft_do_complex(aubio_fft_t *s, const fvec_t *input, fvec_t *compspec)
compute forward FFT
aubio_fft_t
struct _aubio_fft_t aubio_fft_t
FFT object.
Definition: fft.h:46
aubio_fft_get_realimag
void aubio_fft_get_realimag(const cvec_t *spectrum, fvec_t *compspec)
convert real/imag spectrum to norm/phas spectrum
aubio_fft_get_phas
void aubio_fft_get_phas(const fvec_t *compspec, cvec_t *spectrum)
compute phas spectrum from real/imag parts
aubio_fft_do
void aubio_fft_do(aubio_fft_t *s, const fvec_t *input, cvec_t *spectrum)
compute forward FFT
aubio_fft_get_norm
void aubio_fft_get_norm(const fvec_t *compspec, cvec_t *spectrum)
compute norm component from real/imag parts
cvec_t
Vector of real-valued phase and spectrum data.
Definition: cvec.h:63
fvec_t
Buffer for real data.
Definition: fvec.h:67
uint_t
unsigned int uint_t
unsigned integer
Definition: types.h:60