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55 lines
1.9 KiB
55 lines
1.9 KiB
/*****************************************************************************
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* fft.h: Headers for iterative implementation of a FFT
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*****************************************************************************
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*
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* Mainly taken from XMMS's code
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*
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* Authors: Richard Boulton <richard@tartarus.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
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*****************************************************************************/
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#ifndef VLC_VISUAL_FFT_H_
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#define VLC_VISUAL_FFT_H_
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#define FFT_BUFFER_SIZE_LOG 8
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#define FFT_BUFFER_SIZE (1 << FFT_BUFFER_SIZE_LOG)
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/* sound sample - should be an signed 16 bit value */
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typedef short int sound_sample;
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struct _struct_fft_state {
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/* Temporary data stores to perform FFT in. */
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float real[FFT_BUFFER_SIZE];
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float imag[FFT_BUFFER_SIZE];
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/* */
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unsigned int bitReverse[FFT_BUFFER_SIZE];
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/* The next two tables could be made to use less space in memory, since they
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* overlap hugely, but hey. */
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float sintable[FFT_BUFFER_SIZE / 2];
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float costable[FFT_BUFFER_SIZE / 2];
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};
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/* FFT prototypes */
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typedef struct _struct_fft_state fft_state;
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fft_state *visual_fft_init (void);
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void fft_perform (const sound_sample *input, float *output, fft_state *state);
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void fft_close (fft_state *state);
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#endif /* include-guard */
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