FFmpeg/libavcodec/mpegaudio_tablegen.h
Måns Rullgård 4f898e77fb Revert "Add required header #include to fix 'make checkheaders'."
config.h must not be included in that file.  The table generator runs
on the host system, but config.h describes the target.

Originally committed as revision 20620 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-11-26 10:06:41 +00:00

68 lines
2.3 KiB
C

/*
* Header file for hardcoded mpegaudiodec tables
*
* Copyright (c) 2009 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 MPEGAUDIO_TABLEGEN_H
#define MPEGAUDIO_TABLEGEN_H
#include <stdint.h>
// do not use libavutil/mathematics.h since this is compiled both
// for the host and the target and config.h is only valid for the target
#include <math.h>
#define TABLE_4_3_SIZE (8191 + 16)*4
#if CONFIG_HARDCODED_TABLES
#define mpegaudio_tableinit()
#include "libavcodec/mpegaudio_tables.h"
#else
static int8_t table_4_3_exp[TABLE_4_3_SIZE];
static uint32_t table_4_3_value[TABLE_4_3_SIZE];
static uint32_t exp_table[512];
static uint32_t expval_table[512][16];
static void mpegaudio_tableinit(void)
{
int i, value, exponent;
for (i = 1; i < TABLE_4_3_SIZE; i++) {
double value = i / 4;
double f, fm;
int e, m;
f = value * cbrtf(value) * pow(2, (i & 3) * 0.25);
fm = frexp(f, &e);
m = (uint32_t)(fm * (1LL << 31) + 0.5);
e += FRAC_BITS - 31 + 5 - 100;
/* normalized to FRAC_BITS */
table_4_3_value[i] = m;
table_4_3_exp[i] = -e;
}
for (exponent = 0; exponent < 512; exponent++) {
for (value = 0; value < 16; value++) {
double f = (double)value * cbrtf(value) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5);
expval_table[exponent][value] = llrint(f);
}
exp_table[exponent] = expval_table[exponent][1];
}
}
#endif /* CONFIG_HARDCODED_TABLES */
#endif /* MPEGAUDIO_TABLEGEN_H */