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/*
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_FFT_H
#define AVCODEC_FFT_H
#include <stdint.h>
#include "config.h"
#include "libavutil/mem.h"
#include "avfft.h"
/* FFT computation */
struct FFTContext {
int nbits;
int inverse;
uint16_t *revtab;
FFTComplex *tmp_buf;
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;
/**
* Do the permutation needed BEFORE calling fft_calc().
*/
void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
/**
* Do a complex FFT with the parameters defined in ff_fft_init(). The
* input data must be permuted before. No 1.0/sqrt(n) normalization is done.
*/
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 fft_permutation;
#define FF_FFT_PERM_DEFAULT 0
#define FF_FFT_PERM_SWAP_LSBS 1
int mdct_permutation;
#define FF_MDCT_PERM_NONE 0
#define FF_MDCT_PERM_INTERLEAVE 1
};
#if CONFIG_HARDCODED_TABLES
#define COSTABLE_CONST const
#else
#define COSTABLE_CONST
#endif
#define COSTABLE(size) \
COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
extern COSTABLE(16);
extern COSTABLE(32);
extern COSTABLE(64);
extern COSTABLE(128);
extern COSTABLE(256);
extern COSTABLE(512);
extern COSTABLE(1024);
extern COSTABLE(2048);
extern COSTABLE(4096);
extern COSTABLE(8192);
extern COSTABLE(16384);
extern COSTABLE(32768);
extern COSTABLE(65536);
extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
/**
* Initialize the cosine table in ff_cos_tabs[index]
* \param index index in ff_cos_tabs array of the table to initialize
*/
void ff_init_ff_cos_tabs(int index);
/**
* Set up a complex FFT.
* @param nbits log2 of the length of the input array
* @param inverse if 0 perform the forward transform, if 1 perform the inverse
*/
int ff_fft_init(FFTContext *s, int nbits, int inverse);
void ff_fft_init_altivec(FFTContext *s);
void ff_fft_init_mmx(FFTContext *s);
void ff_fft_init_arm(FFTContext *s);
void ff_fft_end(FFTContext *s);
int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
void ff_mdct_end(FFTContext *s);
#endif /* AVCODEC_FFT_H */
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