1/*
2 * Header file for hardcoded mpegaudiodec tables
3 *
4 * Copyright (c) 2009 Reimar D��ffinger <Reimar.Doeffinger@gmx.de>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#ifndef MPEGAUDIO_TABLEGEN_H
24#define MPEGAUDIO_TABLEGEN_H
25
26#include <stdint.h>
27// do not use libavutil/mathematics.h since this is compiled both
28// for the host and the target and config.h is only valid for the target
29#include <math.h>
30
31#define TABLE_4_3_SIZE (8191 + 16)*4
32#if CONFIG_HARDCODED_TABLES
33#define mpegaudio_tableinit()
34#include "libavcodec/mpegaudio_tables.h"
35#else
36static int8_t   table_4_3_exp[TABLE_4_3_SIZE];
37static uint32_t table_4_3_value[TABLE_4_3_SIZE];
38static uint32_t exp_table[512];
39static uint32_t expval_table[512][16];
40
41static void mpegaudio_tableinit(void)
42{
43    int i, value, exponent;
44    for (i = 1; i < TABLE_4_3_SIZE; i++) {
45        double value = i / 4;
46        double f, fm;
47        int e, m;
48        f  = value * cbrtf(value) * pow(2, (i & 3) * 0.25);
49        fm = frexp(f, &e);
50        m  = (uint32_t)(fm * (1LL << 31) + 0.5);
51        e += FRAC_BITS - 31 + 5 - 100;
52
53        /* normalized to FRAC_BITS */
54        table_4_3_value[i] =  m;
55        table_4_3_exp[i]   = -e;
56    }
57    for (exponent = 0; exponent < 512; exponent++) {
58        for (value = 0; value < 16; value++) {
59            double f = (double)value * cbrtf(value) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5);
60            expval_table[exponent][value] = llrint(f);
61        }
62        exp_table[exponent] = expval_table[exponent][1];
63    }
64}
65#endif /* CONFIG_HARDCODED_TABLES */
66
67#endif /* MPEGAUDIO_TABLEGEN_H */
68