root/trunk/contrib/extractor/libmpq/huffman.h @ 177

Revision 2, 4.4 kB (checked in by yumileroy, 17 years ago)

[svn] * Proper SVN structure

Original author: Neo2003
Date: 2008-10-02 16:23:55-05:00
Line 
1/*
2 *  huffman.h -- structures used for huffman compression.
3 *
4 *  Copyright (C) 2003 Maik Broemme <mbroemme@plusserver.de>
5 *
6 *  This source was adepted from the C++ version of huffman.h included
7 *  in stormlib. The C++ version belongs to the following authors,
8 *
9 *  Ladislav Zezula <ladik.zezula.net>
10 *  ShadowFlare <BlakFlare@hotmail.com>
11 *
12 *  This program is free software; you can redistribute it and/or modify
13 *  it under the terms of the GNU General Public License as published by
14 *  the Free Software Foundation; either version 2 of the License, or
15 *  (at your option) any later version.
16 *
17 *  This program is distributed in the hope that it will be useful,
18 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20 *  GNU General Public License for more details.
21 *
22 *  You should have received a copy of the GNU General Public License
23 *  along with this program; if not, write to the Free Software
24 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
27#ifndef _HUFFMAN_H
28#define _HUFFMAN_H
29
30#define PTR_NOT(ptr)    (struct huffman_tree_item *)(~(unsigned long)(ptr))
31#define PTR_PTR(ptr)    ((struct huffman_tree_item *)(ptr))
32#define PTR_INT(ptr)    (long)(ptr)
33
34#define INSERT_ITEM     1
35#define SWITCH_ITEMS    2                               /* Switch the item1 and item2 */
36
37/*
38 *  Input stream for Huffmann decompression
39 */
40struct huffman_input_stream {
41        unsigned char *in_buf;                          /* 00 - Input data */
42        unsigned long bit_buf;                          /* 04 - Input bit buffer */
43        unsigned int bits;                              /* 08 - Number of bits remaining in 'byte' */
44};
45
46/*
47 *  Huffmann tree item.
48 */
49struct huffman_tree_item {
50        struct huffman_tree_item *next;                 /* 00 - Pointer to next huffman_tree_item */
51        struct huffman_tree_item *prev;                 /* 04 - Pointer to prev huffman_tree_item (< 0 if none) */
52        unsigned long dcmp_byte;                        /* 08 - Index of this item in item pointer array, decompressed byte value */
53        unsigned long byte_value;                       /* 0C - Some byte value */
54        struct huffman_tree_item *parent;               /* 10 - Pointer to parent huffman_tree_item (NULL if none) */
55        struct huffman_tree_item *child;                /* 14 - Pointer to child huffman_tree_item */
56};
57
58/*
59 *  Structure used for quick decompress. The 'bits' contains
60 *  number of bits and dcmp_byte contains result decompressed byte
61 *  value. After each walk through Huffman tree are filled all entries
62 *  which are multiplies of number of bits loaded from input stream.
63 *  These entries contain number of bits and result value. At the next
64 *  7 bits is tested this structure first. If corresponding entry found,
65 *  decompression routine will not walk through Huffman tree and
66 *  directly stores output byte to output stream.
67 */
68struct huffman_decompress {
69        unsigned long offs00;                           /* 00 - 1 if resolved */
70        unsigned long bits;                             /* 04 - Bit count */
71        union {
72                unsigned long dcmp_byte;                /* 08 - Byte value for decompress (if bitCount <= 7) */
73                struct huffman_tree_item *p_item;       /* 08 - THTreeItem (if number of bits is greater than 7 */
74        };
75};
76
77/*
78 *  Structure for Huffman tree.
79 */
80struct huffman_tree {
81        unsigned long cmp0;                             /* 0000 - 1 if compression type 0 */
82        unsigned long offs0004;                         /* 0004 - Some flag */
83
84        struct huffman_tree_item items0008[0x203];      /* 0008 - huffman tree items */
85
86        /* Sometimes used as huffman tree item */
87        struct huffman_tree_item *item3050;             /* 3050 - Always NULL (?) */
88        struct huffman_tree_item *item3054;             /* 3054 - Pointer to huffman_tree_item */
89        struct huffman_tree_item *item3058;             /* 3058 - Pointer to huffman_tree_item (< 0 if invalid) */
90
91        /* Sometimes used as huffman tree item */
92        struct huffman_tree_item *item305C;             /* 305C - Usually NULL */
93        struct huffman_tree_item *first;                /* 3060 - Pointer to top (first) Huffman tree item */
94        struct huffman_tree_item *last;                 /* 3064 - Pointer to bottom (last) Huffman tree item (< 0 if invalid) */
95        unsigned long items;                            /* 3068 - Number of used huffman tree items */
96
97        struct huffman_tree_item *items306C[0x102];     /* 306C - huffman_tree_item pointer array */
98        struct huffman_decompress qd3474[0x80];         /* 3474 - Array for quick decompression */
99
100        //unsigned char table1502A630[];                        /* Some table to make struct size flexible */
101};
102
103int libmpq_huff_init_tree(struct huffman_tree *ht, struct huffman_tree_item *hi, unsigned int cmp);
104int libmpq_huff_do_decompress(struct huffman_tree *ht, struct huffman_input_stream *is, unsigned char *out_buf, unsigned int out_length);
105#endif                  /* _HUFFMAN_H */
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