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59352a07d8
cbrtf() took floats but it represented 1/3 exactly and even if not more precission should be better in theory for the table generation Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
53 lines
1.5 KiB
C
53 lines
1.5 KiB
C
/*
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* Header file for hardcoded AAC cube-root table
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*
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* Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg 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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* FFmpeg 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 FFmpeg; 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_CBRT_TABLEGEN_H
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#define AVCODEC_CBRT_TABLEGEN_H
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#include <stdint.h>
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#include <math.h>
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#if CONFIG_HARDCODED_TABLES
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#define cbrt_tableinit()
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#include "libavcodec/cbrt_tables.h"
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#else
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static uint32_t cbrt_tab[1 << 13];
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static void cbrt_tableinit(void)
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{
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if (!cbrt_tab[(1<<13) - 1]) {
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int i;
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/* cbrtf() isn't available on all systems, so we use powf(). */
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for (i = 0; i < 1<<13; i++) {
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union {
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float f;
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uint32_t i;
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} f;
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f.f = pow(i, 1.0 / 3.0) * i;
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cbrt_tab[i] = f.i;
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}
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}
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}
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#endif /* CONFIG_HARDCODED_TABLES */
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#endif /* AVCODEC_CBRT_TABLEGEN_H */
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