diff options
Diffstat (limited to 'src/libid3tag/crc.c')
-rw-r--r-- | src/libid3tag/crc.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/libid3tag/crc.c b/src/libid3tag/crc.c new file mode 100644 index 000000000..76e78ea45 --- /dev/null +++ b/src/libid3tag/crc.c @@ -0,0 +1,137 @@ +/* + * libid3tag - ID3 tag manipulation library + * Copyright (C) 2000-2003 Underbit Technologies, Inc. + * + * 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: crc.c,v 1.1 2003/08/14 03:57:13 shank Exp $ + */ + +# ifdef HAVE_CONFIG_H +# include "config.h" +# endif + +# include "global.h" + +# include "id3tag.h" +# include "crc.h" + +static +unsigned long const crc_table[256] = { + 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, + 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L, + 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, + 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, + 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, + 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, + 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, + 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L, + + 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, + 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, + 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, + 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, + 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, + 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL, + 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, + 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, + + 0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, + 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, + 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, + 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, + 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, + 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, + 0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, + 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, + + 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, + 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, + 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, + 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, + 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, + 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, + 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, + 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, + + 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, + 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, + 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, + 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, + 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, + 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L, + 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, + 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, + + 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, + 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, + 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, + 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L, + 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, + 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, + 0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, + 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, + + 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, + 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, + 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, + 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, + 0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, + 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, + 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, + 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, + + 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, + 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, + 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, + 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, + 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, + 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL, + 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, + 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL +}; + +/* + * NAME: crc->calculate() + * DESCRIPTION: compute CRC-32 value (ISO 3309) + */ +unsigned long id3_crc_calculate(id3_byte_t const *data, id3_length_t length) +{ + register unsigned long crc; + + for (crc = 0xffffffffL; length >= 8; length -= 8) { + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + } + + switch (length) { + case 7: crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + case 6: crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + case 5: crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + case 4: crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + case 3: crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + case 2: crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + case 1: crc = crc_table[(crc ^ *data++) & 0xff] ^ (crc >> 8); + case 0: break; + } + + return crc ^ 0xffffffffL; +} |