rockbox/apps/codecs/lib/fft.h

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/*
* WMA compatible decoder
* Copyright (c) 2002 The FFmpeg Project.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef CODECLIB_FFT_H_INCLUDED
#define CODECLIB_FFT_H_INCLUDED
#include <inttypes.h>
typedef int32_t fixed32;
typedef int64_t fixed64;
#define FFT_FIXED
#ifdef FFT_FIXED
typedef fixed32 FFTSample;
#else /* FFT_FIXED */
typedef float FFTSample;
#endif /* FFT_FIXED */
typedef struct FFTComplex {
FFTSample re, im;
} FFTComplex;
typedef struct FFTContext {
int nbits;
int inverse;
uint16_t *revtab;
int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
int mdct_bits; /* n = 2^nbits */
/* pre/post rotation tables */
FFTSample *tcos;
FFTSample *tsin;
void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
int split_radix;
int permutation;
#define FF_MDCT_PERM_NONE 0
#define FF_MDCT_PERM_INTERLEAVE 1
} FFTContext;
// internal api (fft<->mdct)
//int fft_calc_unscaled(FFTContext *s, FFTComplex *z);
//void ff_fft_permute_c(FFTContext *s, FFTComplex *z); // internal only?
void ff_fft_calc_c(int nbits, FFTComplex *z);
#endif // CODECLIB_FFT_H_INCLUDED