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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
/*
** FAAD - Freeware Advanced Audio Decoder
** Copyright (C) 2002 M. Bakker
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** $Id: bits.h,v 1.1 2002/07/14 23:43:01 miguelfreitas Exp $
**/
#ifndef __BITS_H__
#define __BITS_H__
#ifdef __cplusplus
extern "C" {
#endif
#include "analysis.h"
#ifdef ANALYSIS
#include <stdio.h>
#endif
#define BYTE_NUMBIT 8
#define bit2byte(a) ((a+7)/BYTE_NUMBIT)
typedef struct _bitfile
{
/* bit input */
uint32_t bufa;
uint32_t bufb;
uint32_t pos;
uint32_t *tail;
uint32_t *start;
} bitfile;
#if defined(_WIN32)
#define BSWAP(a) __asm mov eax,a __asm bswap eax __asm mov a, eax
#elif defined(LINUX) || defined(DJGPP)
#define BSWAP(a) __asm__ ( "bswapl %0\n" : "=r" (a) : "0" (a) )
#else
#define BSWAP(a) \
((a) = ( ((a)&0xff)<<24) | (((a)&0xff00)<<8) | (((a)>>8)&0xff00) | (((a)>>24)&0xff))
#endif
void faad_initbits(bitfile *ld, void *buffer);
uint8_t faad_byte_align(bitfile *ld);
uint32_t faad_get_processed_bits(bitfile *ld);
static INLINE uint32_t faad_showbits(bitfile *ld, uint8_t bits)
{
int32_t nbit = (bits + ld->pos) - 32;
if (nbit > 0)
{
return ((ld->bufa & (0xffffffff >> ld->pos)) << nbit) |
(ld->bufb >> (32 - nbit));
} else {
return (ld->bufa & (0xffffffff >> ld->pos)) >> (32 - ld->pos - bits);
}
}
static INLINE void faad_flushbits(bitfile *ld, uint8_t bits)
{
ld->pos += bits;
if (ld->pos >= 32)
{
uint32_t tmp;
ld->bufa = ld->bufb;
tmp = *(uint32_t*)ld->tail;
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
ld->bufb = tmp;
ld->tail++;
ld->pos -= 32;
}
}
/* return next n bits (right adjusted) */
static INLINE uint32_t faad_getbits(bitfile *ld, uint8_t n DEBUGDEC)
{
uint32_t ret = faad_showbits(ld, n);
faad_flushbits(ld, n);
#ifdef ANALYSIS
if (print)
fprintf(stdout, "%4d %2d bits, val: %4d, variable: %d %s\n", dbg_count++, n, ret, var, dbg);
#endif
return ret;
}
static INLINE uint8_t faad_get1bit(bitfile *ld DEBUGDEC)
{
return (uint8_t)faad_getbits(ld, 1 DEBUGVAR(print,var,dbg));
}
#ifdef __cplusplus
}
#endif
#endif
|
