2 * libid3tag - ID3 tag manipulation library
3 * Copyright (C) 2000-2004 Underbit Technologies, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * $Id: crc.c,v 1.11 2004/02/17 02:04:10 rob Exp $
32 unsigned long const crc_table
[256] = {
33 0x00000000L
, 0x77073096L
, 0xee0e612cL
, 0x990951baL
,
34 0x076dc419L
, 0x706af48fL
, 0xe963a535L
, 0x9e6495a3L
,
35 0x0edb8832L
, 0x79dcb8a4L
, 0xe0d5e91eL
, 0x97d2d988L
,
36 0x09b64c2bL
, 0x7eb17cbdL
, 0xe7b82d07L
, 0x90bf1d91L
,
37 0x1db71064L
, 0x6ab020f2L
, 0xf3b97148L
, 0x84be41deL
,
38 0x1adad47dL
, 0x6ddde4ebL
, 0xf4d4b551L
, 0x83d385c7L
,
39 0x136c9856L
, 0x646ba8c0L
, 0xfd62f97aL
, 0x8a65c9ecL
,
40 0x14015c4fL
, 0x63066cd9L
, 0xfa0f3d63L
, 0x8d080df5L
,
42 0x3b6e20c8L
, 0x4c69105eL
, 0xd56041e4L
, 0xa2677172L
,
43 0x3c03e4d1L
, 0x4b04d447L
, 0xd20d85fdL
, 0xa50ab56bL
,
44 0x35b5a8faL
, 0x42b2986cL
, 0xdbbbc9d6L
, 0xacbcf940L
,
45 0x32d86ce3L
, 0x45df5c75L
, 0xdcd60dcfL
, 0xabd13d59L
,
46 0x26d930acL
, 0x51de003aL
, 0xc8d75180L
, 0xbfd06116L
,
47 0x21b4f4b5L
, 0x56b3c423L
, 0xcfba9599L
, 0xb8bda50fL
,
48 0x2802b89eL
, 0x5f058808L
, 0xc60cd9b2L
, 0xb10be924L
,
49 0x2f6f7c87L
, 0x58684c11L
, 0xc1611dabL
, 0xb6662d3dL
,
51 0x76dc4190L
, 0x01db7106L
, 0x98d220bcL
, 0xefd5102aL
,
52 0x71b18589L
, 0x06b6b51fL
, 0x9fbfe4a5L
, 0xe8b8d433L
,
53 0x7807c9a2L
, 0x0f00f934L
, 0x9609a88eL
, 0xe10e9818L
,
54 0x7f6a0dbbL
, 0x086d3d2dL
, 0x91646c97L
, 0xe6635c01L
,
55 0x6b6b51f4L
, 0x1c6c6162L
, 0x856530d8L
, 0xf262004eL
,
56 0x6c0695edL
, 0x1b01a57bL
, 0x8208f4c1L
, 0xf50fc457L
,
57 0x65b0d9c6L
, 0x12b7e950L
, 0x8bbeb8eaL
, 0xfcb9887cL
,
58 0x62dd1ddfL
, 0x15da2d49L
, 0x8cd37cf3L
, 0xfbd44c65L
,
60 0x4db26158L
, 0x3ab551ceL
, 0xa3bc0074L
, 0xd4bb30e2L
,
61 0x4adfa541L
, 0x3dd895d7L
, 0xa4d1c46dL
, 0xd3d6f4fbL
,
62 0x4369e96aL
, 0x346ed9fcL
, 0xad678846L
, 0xda60b8d0L
,
63 0x44042d73L
, 0x33031de5L
, 0xaa0a4c5fL
, 0xdd0d7cc9L
,
64 0x5005713cL
, 0x270241aaL
, 0xbe0b1010L
, 0xc90c2086L
,
65 0x5768b525L
, 0x206f85b3L
, 0xb966d409L
, 0xce61e49fL
,
66 0x5edef90eL
, 0x29d9c998L
, 0xb0d09822L
, 0xc7d7a8b4L
,
67 0x59b33d17L
, 0x2eb40d81L
, 0xb7bd5c3bL
, 0xc0ba6cadL
,
69 0xedb88320L
, 0x9abfb3b6L
, 0x03b6e20cL
, 0x74b1d29aL
,
70 0xead54739L
, 0x9dd277afL
, 0x04db2615L
, 0x73dc1683L
,
71 0xe3630b12L
, 0x94643b84L
, 0x0d6d6a3eL
, 0x7a6a5aa8L
,
72 0xe40ecf0bL
, 0x9309ff9dL
, 0x0a00ae27L
, 0x7d079eb1L
,
73 0xf00f9344L
, 0x8708a3d2L
, 0x1e01f268L
, 0x6906c2feL
,
74 0xf762575dL
, 0x806567cbL
, 0x196c3671L
, 0x6e6b06e7L
,
75 0xfed41b76L
, 0x89d32be0L
, 0x10da7a5aL
, 0x67dd4accL
,
76 0xf9b9df6fL
, 0x8ebeeff9L
, 0x17b7be43L
, 0x60b08ed5L
,
78 0xd6d6a3e8L
, 0xa1d1937eL
, 0x38d8c2c4L
, 0x4fdff252L
,
79 0xd1bb67f1L
, 0xa6bc5767L
, 0x3fb506ddL
, 0x48b2364bL
,
80 0xd80d2bdaL
, 0xaf0a1b4cL
, 0x36034af6L
, 0x41047a60L
,
81 0xdf60efc3L
, 0xa867df55L
, 0x316e8eefL
, 0x4669be79L
,
82 0xcb61b38cL
, 0xbc66831aL
, 0x256fd2a0L
, 0x5268e236L
,
83 0xcc0c7795L
, 0xbb0b4703L
, 0x220216b9L
, 0x5505262fL
,
84 0xc5ba3bbeL
, 0xb2bd0b28L
, 0x2bb45a92L
, 0x5cb36a04L
,
85 0xc2d7ffa7L
, 0xb5d0cf31L
, 0x2cd99e8bL
, 0x5bdeae1dL
,
87 0x9b64c2b0L
, 0xec63f226L
, 0x756aa39cL
, 0x026d930aL
,
88 0x9c0906a9L
, 0xeb0e363fL
, 0x72076785L
, 0x05005713L
,
89 0x95bf4a82L
, 0xe2b87a14L
, 0x7bb12baeL
, 0x0cb61b38L
,
90 0x92d28e9bL
, 0xe5d5be0dL
, 0x7cdcefb7L
, 0x0bdbdf21L
,
91 0x86d3d2d4L
, 0xf1d4e242L
, 0x68ddb3f8L
, 0x1fda836eL
,
92 0x81be16cdL
, 0xf6b9265bL
, 0x6fb077e1L
, 0x18b74777L
,
93 0x88085ae6L
, 0xff0f6a70L
, 0x66063bcaL
, 0x11010b5cL
,
94 0x8f659effL
, 0xf862ae69L
, 0x616bffd3L
, 0x166ccf45L
,
96 0xa00ae278L
, 0xd70dd2eeL
, 0x4e048354L
, 0x3903b3c2L
,
97 0xa7672661L
, 0xd06016f7L
, 0x4969474dL
, 0x3e6e77dbL
,
98 0xaed16a4aL
, 0xd9d65adcL
, 0x40df0b66L
, 0x37d83bf0L
,
99 0xa9bcae53L
, 0xdebb9ec5L
, 0x47b2cf7fL
, 0x30b5ffe9L
,
100 0xbdbdf21cL
, 0xcabac28aL
, 0x53b39330L
, 0x24b4a3a6L
,
101 0xbad03605L
, 0xcdd70693L
, 0x54de5729L
, 0x23d967bfL
,
102 0xb3667a2eL
, 0xc4614ab8L
, 0x5d681b02L
, 0x2a6f2b94L
,
103 0xb40bbe37L
, 0xc30c8ea1L
, 0x5a05df1bL
, 0x2d02ef8dL
107 * NAME: crc->compute()
108 * DESCRIPTION: calculate CRC-32 value (ISO 3309)
110 unsigned long id3_crc_compute(id3_byte_t
const *data
, id3_length_t length
)
112 register unsigned long crc
;
114 for (crc
= 0xffffffffL
; length
>= 8; length
-= 8) {
115 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
116 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
117 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
118 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
119 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
120 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
121 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
122 crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
126 case 7: crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
127 case 6: crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
128 case 5: crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
129 case 4: crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
130 case 3: crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
131 case 2: crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
132 case 1: crc
= crc_table
[(crc
^ *data
++) & 0xff] ^ (crc
>> 8);
136 return crc
^ 0xffffffffL
;