1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
/*
* 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 "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;
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(i=0; i<512*16; i++){
double value = i & 15;
int exponent= (i>>4);
double f= value * cbrtf(value) * pow(2, (exponent-400)*0.25 + FRAC_BITS + 5);
expval_table[exponent][i&15]= llrint(f);
if((i&15)==1)
exp_table[exponent]= llrint(f);
}
}
#endif /* CONFIG_HARDCODED_TABLES */
#endif /* MPEGAUDIO_TABLEGEN_H */
|
