mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-25 08:42:39 +00:00
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
/*
|
|
* Header file for hardcoded AAC cube-root table
|
|
*
|
|
* Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
|
|
*
|
|
* 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_CBRT_TABLEGEN_H
|
|
#define AVCODEC_CBRT_TABLEGEN_H
|
|
|
|
#include <stdint.h>
|
|
#include <math.h>
|
|
|
|
#if CONFIG_HARDCODED_TABLES
|
|
#define cbrt_tableinit()
|
|
#include "libavcodec/cbrt_tables.h"
|
|
#else
|
|
static uint32_t cbrt_tab[1 << 13];
|
|
|
|
static void cbrt_tableinit(void)
|
|
{
|
|
if (!cbrt_tab[(1<<13) - 1]) {
|
|
int i;
|
|
/* cbrtf() isn't available on all systems, so we use powf(). */
|
|
for (i = 0; i < 1<<13; i++) {
|
|
union {
|
|
float f;
|
|
uint32_t i;
|
|
} f;
|
|
f.f = pow(i, 1.0 / 3.0) * i;
|
|
cbrt_tab[i] = f.i;
|
|
}
|
|
}
|
|
}
|
|
#endif /* CONFIG_HARDCODED_TABLES */
|
|
|
|
#endif /* AVCODEC_CBRT_TABLEGEN_H */
|