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
|
/*
* huffman.h -- structures used for huffman compression.
*
* Copyright (C) 2003 Maik Broemme <mbroemme@plusserver.de>
*
* This source was adepted from the C++ version of huffman.h included
* in stormlib. The C++ version belongs to the following authors,
*
* Ladislav Zezula <ladik.zezula.net>
* ShadowFlare <BlakFlare@hotmail.com>
*
* 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.
*/
#ifndef _HUFFMAN_H
#define _HUFFMAN_H
#define PTR_NOT(ptr) (struct huffman_tree_item *)(~(unsigned long)(ptr))
#define PTR_PTR(ptr) ((struct huffman_tree_item *)(ptr))
#define PTR_INT(ptr) (long)(ptr)
#define INSERT_ITEM 1
#define SWITCH_ITEMS 2 /* Switch the item1 and item2 */
/*
* Input stream for Huffmann decompression
*/
struct huffman_input_stream {
unsigned char *in_buf; /* 00 - Input data */
unsigned long bit_buf; /* 04 - Input bit buffer */
unsigned int bits; /* 08 - Number of bits remaining in 'byte' */
};
/*
* Huffmann tree item.
*/
struct huffman_tree_item {
struct huffman_tree_item *next; /* 00 - Pointer to next huffman_tree_item */
struct huffman_tree_item *prev; /* 04 - Pointer to prev huffman_tree_item (< 0 if none) */
unsigned long dcmp_byte; /* 08 - Index of this item in item pointer array, decompressed byte value */
unsigned long byte_value; /* 0C - Some byte value */
struct huffman_tree_item *parent; /* 10 - Pointer to parent huffman_tree_item (NULL if none) */
struct huffman_tree_item *child; /* 14 - Pointer to child huffman_tree_item */
};
/*
* Structure used for quick decompress. The 'bits' contains
* number of bits and dcmp_byte contains result decompressed byte
* value. After each walk through Huffman tree are filled all entries
* which are multiplies of number of bits loaded from input stream.
* These entries contain number of bits and result value. At the next
* 7 bits is tested this structure first. If corresponding entry found,
* decompression routine will not walk through Huffman tree and
* directly stores output byte to output stream.
*/
struct huffman_decompress {
unsigned long offs00; /* 00 - 1 if resolved */
unsigned long bits; /* 04 - Bit count */
union {
unsigned long dcmp_byte; /* 08 - Byte value for decompress (if bitCount <= 7) */
struct huffman_tree_item *p_item; /* 08 - THTreeItem (if number of bits is greater than 7 */
};
};
/*
* Structure for Huffman tree.
*/
struct huffman_tree {
unsigned long cmp0; /* 0000 - 1 if compression type 0 */
unsigned long offs0004; /* 0004 - Some flag */
struct huffman_tree_item items0008[0x203]; /* 0008 - huffman tree items */
/* Sometimes used as huffman tree item */
struct huffman_tree_item *item3050; /* 3050 - Always NULL (?) */
struct huffman_tree_item *item3054; /* 3054 - Pointer to huffman_tree_item */
struct huffman_tree_item *item3058; /* 3058 - Pointer to huffman_tree_item (< 0 if invalid) */
/* Sometimes used as huffman tree item */
struct huffman_tree_item *item305C; /* 305C - Usually NULL */
struct huffman_tree_item *first; /* 3060 - Pointer to top (first) Huffman tree item */
struct huffman_tree_item *last; /* 3064 - Pointer to bottom (last) Huffman tree item (< 0 if invalid) */
unsigned long items; /* 3068 - Number of used huffman tree items */
struct huffman_tree_item *items306C[0x102]; /* 306C - huffman_tree_item pointer array */
struct huffman_decompress qd3474[0x80]; /* 3474 - Array for quick decompression */
//unsigned char table1502A630[]; /* Some table to make struct size flexible */
};
int libmpq_huff_init_tree(struct huffman_tree *ht, struct huffman_tree_item *hi, unsigned int cmp);
int libmpq_huff_do_decompress(struct huffman_tree *ht, struct huffman_input_stream *is, unsigned char *out_buf, unsigned int out_length);
#endif /* _HUFFMAN_H */
|
