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/*
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 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
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 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav 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 GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; 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 AVCODEC_FFT_H
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#define AVCODEC_FFT_H
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#include <stdint.h>
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#include "config.h"
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#include "libavutil/mem.h"
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#include "avfft.h"
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/* FFT computation */
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struct FFTContext {
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    int nbits;
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    int inverse;
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    uint16_t *revtab;
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    FFTComplex *tmp_buf;
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    int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
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    int mdct_bits; /* n = 2^nbits */
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    /* pre/post rotation tables */
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    FFTSample *tcos;
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    FFTSample *tsin;
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    /**
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     * Do the permutation needed BEFORE calling fft_calc().
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     */
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    void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
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    /**
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     * Do a complex FFT with the parameters defined in ff_fft_init(). The
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     * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
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     */
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    void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
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    void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
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    void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
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    void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
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    int fft_permutation;
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#define FF_FFT_PERM_DEFAULT   0
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#define FF_FFT_PERM_SWAP_LSBS 1
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    int mdct_permutation;
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#define FF_MDCT_PERM_NONE       0
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#define FF_MDCT_PERM_INTERLEAVE 1
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};
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#if CONFIG_HARDCODED_TABLES
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#define COSTABLE_CONST const
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#else
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#define COSTABLE_CONST
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#endif
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#define COSTABLE(size) \
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    COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
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extern COSTABLE(16);
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extern COSTABLE(32);
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extern COSTABLE(64);
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extern COSTABLE(128);
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extern COSTABLE(256);
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extern COSTABLE(512);
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extern COSTABLE(1024);
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extern COSTABLE(2048);
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extern COSTABLE(4096);
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extern COSTABLE(8192);
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extern COSTABLE(16384);
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extern COSTABLE(32768);
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extern COSTABLE(65536);
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extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
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/**
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 * Initialize the cosine table in ff_cos_tabs[index]
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 * \param index index in ff_cos_tabs array of the table to initialize
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 */
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void ff_init_ff_cos_tabs(int index);
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/**
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 * Set up a complex FFT.
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 * @param nbits           log2 of the length of the input array
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 * @param inverse         if 0 perform the forward transform, if 1 perform the inverse
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 */
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int ff_fft_init(FFTContext *s, int nbits, int inverse);
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void ff_fft_init_altivec(FFTContext *s);
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void ff_fft_init_mmx(FFTContext *s);
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void ff_fft_init_arm(FFTContext *s);
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void ff_fft_end(FFTContext *s);
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int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
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void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
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void ff_mdct_end(FFTContext *s);
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#endif /* AVCODEC_FFT_H */