1 #ifndef _Sound_and_Spectrum_dft_h_
2 #define _Sound_and_Spectrum_dft_h_
3 /* Sound_and_Spectrum_dft.h
4  *
5  * Copyright (C) 2021 David Weenink
6  *
7  * This code is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or (at
10  * your option) any later version.
11  *
12  * This code is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this work. If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "Sound.h"
22 #include "Spectrum.h"
23 
24 /*
25 	Speed up the DFT calculations by using the FFT on a resampled signal that has
26 	exactly a power of 2 samples.
27 	(after a suggestion by Ton Wempe).
28 */
29 autoSpectrum Sound_to_Spectrum_dft (Sound me, integer interpolationDepth);
30 
31 autoSound Spectrum_to_Sound_dft (Spectrum me, integer interpolationDepth);
32 
33 #endif /* _Sound_and_Spectrum_dft_h_ */
34