aubio
0.4.1
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00001 /* 00002 Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org> 00003 00004 This file is part of aubio. 00005 00006 aubio is free software: you can redistribute it and/or modify 00007 it under the terms of the GNU General Public License as published by 00008 the Free Software Foundation, either version 3 of the License, or 00009 (at your option) any later version. 00010 00011 aubio is distributed in the hope that it will be useful, 00012 but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 GNU General Public License for more details. 00015 00016 You should have received a copy of the GNU General Public License 00017 along with aubio. If not, see <http://www.gnu.org/licenses/>. 00018 00019 */ 00020 00021 /** \file 00022 00023 Fast Fourier Transform 00024 00025 Depending on how aubio was compiled, FFT are computed using one of: 00026 - [Ooura](http://www.kurims.kyoto-u.ac.jp/~ooura/fft.html) 00027 - [FFTW3](http://www.fftw.org) 00028 - [vDSP](https://developer.apple.com/library/mac/#documentation/Accelerate/Reference/vDSPRef/Reference/reference.html) 00029 00030 \example src/spectral/test-fft.c 00031 00032 */ 00033 00034 #ifndef _AUBIO_FFT_H 00035 #define _AUBIO_FFT_H 00036 00037 #ifdef __cplusplus 00038 extern "C" { 00039 #endif 00040 00041 /** FFT object 00042 00043 This object computes forward and backward FFTs. 00044 00045 */ 00046 typedef struct _aubio_fft_t aubio_fft_t; 00047 00048 /** create new FFT computation object 00049 00050 \param size length of the FFT 00051 00052 */ 00053 aubio_fft_t * new_aubio_fft (uint_t size); 00054 /** delete FFT object 00055 00056 \param s fft object as returned by new_aubio_fft 00057 00058 */ 00059 void del_aubio_fft(aubio_fft_t * s); 00060 00061 /** compute forward FFT 00062 00063 \param s fft object as returned by new_aubio_fft 00064 \param input input signal 00065 \param spectrum output spectrum 00066 00067 */ 00068 void aubio_fft_do (aubio_fft_t *s, fvec_t * input, cvec_t * spectrum); 00069 /** compute backward (inverse) FFT 00070 00071 \param s fft object as returned by new_aubio_fft 00072 \param spectrum input spectrum 00073 \param output output signal 00074 00075 */ 00076 void aubio_fft_rdo (aubio_fft_t *s, cvec_t * spectrum, fvec_t * output); 00077 00078 /** compute forward FFT 00079 00080 \param s fft object as returned by new_aubio_fft 00081 \param input real input signal 00082 \param compspec complex output fft real/imag 00083 00084 */ 00085 void aubio_fft_do_complex (aubio_fft_t *s, fvec_t * input, fvec_t * compspec); 00086 /** compute backward (inverse) FFT from real/imag 00087 00088 \param s fft object as returned by new_aubio_fft 00089 \param compspec real/imag input fft array 00090 \param output real output array 00091 00092 */ 00093 void aubio_fft_rdo_complex (aubio_fft_t *s, fvec_t * compspec, fvec_t * output); 00094 00095 /** convert real/imag spectrum to norm/phas spectrum 00096 00097 \param compspec real/imag input fft array 00098 \param spectrum cvec norm/phas output array 00099 00100 */ 00101 void aubio_fft_get_spectrum(fvec_t * compspec, cvec_t * spectrum); 00102 /** convert real/imag spectrum to norm/phas spectrum 00103 00104 \param compspec real/imag input fft array 00105 \param spectrum cvec norm/phas output array 00106 00107 */ 00108 void aubio_fft_get_realimag(cvec_t * spectrum, fvec_t * compspec); 00109 00110 /** compute phas spectrum from real/imag parts 00111 00112 \param compspec real/imag input fft array 00113 \param spectrum cvec norm/phas output array 00114 00115 */ 00116 void aubio_fft_get_phas(fvec_t * compspec, cvec_t * spectrum); 00117 /** compute imaginary part from the norm/phas cvec 00118 00119 \param spectrum norm/phas input array 00120 \param compspec real/imag output fft array 00121 00122 */ 00123 void aubio_fft_get_imag(cvec_t * spectrum, fvec_t * compspec); 00124 00125 /** compute norm component from real/imag parts 00126 00127 \param compspec real/imag input fft array 00128 \param spectrum cvec norm/phas output array 00129 00130 */ 00131 void aubio_fft_get_norm(fvec_t * compspec, cvec_t * spectrum); 00132 /** compute real part from norm/phas components 00133 00134 \param spectrum norm/phas input array 00135 \param compspec real/imag output fft array 00136 00137 */ 00138 void aubio_fft_get_real(cvec_t * spectrum, fvec_t * compspec); 00139 00140 #ifdef __cplusplus 00141 } 00142 #endif 00143 00144 #endif /* _AUBIO_FFT_H */