2 * Header file for hardcoded mpegaudiodec tables
4 * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
6 * This file is part of FFmpeg.
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.
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.
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
23 #ifndef MPEGAUDIO_TABLEGEN_H
24 #define MPEGAUDIO_TABLEGEN_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
31 #define TABLE_4_3_SIZE (8191 + 16)*4
32 #if CONFIG_HARDCODED_TABLES
33 #define mpegaudio_tableinit()
34 #include "libavcodec/mpegaudio_tables.h"
36 static int8_t table_4_3_exp
[TABLE_4_3_SIZE
];
37 static uint32_t table_4_3_value
[TABLE_4_3_SIZE
];
38 static uint32_t exp_table
[512];
39 static uint32_t expval_table
[512][16];
41 static void mpegaudio_tableinit(void)
43 int i
, value
, exponent
;
44 for(i
=1;i
<TABLE_4_3_SIZE
;i
++) {
48 f
= value
* cbrtf(value
) * pow(2, (i
&3)*0.25);
50 m
= (uint32_t)(fm
*(1LL<<31) + 0.5);
51 e
+= FRAC_BITS
- 31 + 5 - 100;
53 /* normalized to FRAC_BITS */
54 table_4_3_value
[i
] = m
;
55 table_4_3_exp
[i
] = -e
;
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
);
62 exp_table
[exponent
]= expval_table
[exponent
][1];
65 #endif /* CONFIG_HARDCODED_TABLES */
67 #endif /* MPEGAUDIO_TABLEGEN_H */