crc.c (6597B)
1 /* libFLAC - Free Lossless Audio Codec library 2 * Copyright (C) 2000,2001,2002,2003,2004,2005 Josh Coalson 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * - Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * - Neither the name of the Xiph.org Foundation nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR 23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include "private/crc.h" 33 34 /* CRC-8, poly = x^8 + x^2 + x^1 + x^0, init = 0 */ 35 36 FLAC__byte const FLAC__crc8_table[256] = { 37 0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15, 38 0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D, 39 0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65, 40 0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D, 41 0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5, 42 0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD, 43 0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85, 44 0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD, 45 0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2, 46 0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA, 47 0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2, 48 0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A, 49 0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32, 50 0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A, 51 0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42, 52 0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A, 53 0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C, 54 0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4, 55 0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC, 56 0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4, 57 0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C, 58 0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44, 59 0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C, 60 0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34, 61 0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B, 62 0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63, 63 0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B, 64 0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13, 65 0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB, 66 0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83, 67 0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB, 68 0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3 69 }; 70 71 /* CRC-16, poly = x^16 + x^15 + x^2 + x^0, init = 0 */ 72 73 FLAC__uint16 FLAC__crc16_table[256] = { 74 0x0000, 0x8005, 0x800f, 0x000a, 0x801b, 0x001e, 0x0014, 0x8011, 75 0x8033, 0x0036, 0x003c, 0x8039, 0x0028, 0x802d, 0x8027, 0x0022, 76 0x8063, 0x0066, 0x006c, 0x8069, 0x0078, 0x807d, 0x8077, 0x0072, 77 0x0050, 0x8055, 0x805f, 0x005a, 0x804b, 0x004e, 0x0044, 0x8041, 78 0x80c3, 0x00c6, 0x00cc, 0x80c9, 0x00d8, 0x80dd, 0x80d7, 0x00d2, 79 0x00f0, 0x80f5, 0x80ff, 0x00fa, 0x80eb, 0x00ee, 0x00e4, 0x80e1, 80 0x00a0, 0x80a5, 0x80af, 0x00aa, 0x80bb, 0x00be, 0x00b4, 0x80b1, 81 0x8093, 0x0096, 0x009c, 0x8099, 0x0088, 0x808d, 0x8087, 0x0082, 82 0x8183, 0x0186, 0x018c, 0x8189, 0x0198, 0x819d, 0x8197, 0x0192, 83 0x01b0, 0x81b5, 0x81bf, 0x01ba, 0x81ab, 0x01ae, 0x01a4, 0x81a1, 84 0x01e0, 0x81e5, 0x81ef, 0x01ea, 0x81fb, 0x01fe, 0x01f4, 0x81f1, 85 0x81d3, 0x01d6, 0x01dc, 0x81d9, 0x01c8, 0x81cd, 0x81c7, 0x01c2, 86 0x0140, 0x8145, 0x814f, 0x014a, 0x815b, 0x015e, 0x0154, 0x8151, 87 0x8173, 0x0176, 0x017c, 0x8179, 0x0168, 0x816d, 0x8167, 0x0162, 88 0x8123, 0x0126, 0x012c, 0x8129, 0x0138, 0x813d, 0x8137, 0x0132, 89 0x0110, 0x8115, 0x811f, 0x011a, 0x810b, 0x010e, 0x0104, 0x8101, 90 0x8303, 0x0306, 0x030c, 0x8309, 0x0318, 0x831d, 0x8317, 0x0312, 91 0x0330, 0x8335, 0x833f, 0x033a, 0x832b, 0x032e, 0x0324, 0x8321, 92 0x0360, 0x8365, 0x836f, 0x036a, 0x837b, 0x037e, 0x0374, 0x8371, 93 0x8353, 0x0356, 0x035c, 0x8359, 0x0348, 0x834d, 0x8347, 0x0342, 94 0x03c0, 0x83c5, 0x83cf, 0x03ca, 0x83db, 0x03de, 0x03d4, 0x83d1, 95 0x83f3, 0x03f6, 0x03fc, 0x83f9, 0x03e8, 0x83ed, 0x83e7, 0x03e2, 96 0x83a3, 0x03a6, 0x03ac, 0x83a9, 0x03b8, 0x83bd, 0x83b7, 0x03b2, 97 0x0390, 0x8395, 0x839f, 0x039a, 0x838b, 0x038e, 0x0384, 0x8381, 98 0x0280, 0x8285, 0x828f, 0x028a, 0x829b, 0x029e, 0x0294, 0x8291, 99 0x82b3, 0x02b6, 0x02bc, 0x82b9, 0x02a8, 0x82ad, 0x82a7, 0x02a2, 100 0x82e3, 0x02e6, 0x02ec, 0x82e9, 0x02f8, 0x82fd, 0x82f7, 0x02f2, 101 0x02d0, 0x82d5, 0x82df, 0x02da, 0x82cb, 0x02ce, 0x02c4, 0x82c1, 102 0x8243, 0x0246, 0x024c, 0x8249, 0x0258, 0x825d, 0x8257, 0x0252, 103 0x0270, 0x8275, 0x827f, 0x027a, 0x826b, 0x026e, 0x0264, 0x8261, 104 0x0220, 0x8225, 0x822f, 0x022a, 0x823b, 0x023e, 0x0234, 0x8231, 105 0x8213, 0x0216, 0x021c, 0x8219, 0x0208, 0x820d, 0x8207, 0x0202 106 }; 107 108 109 void FLAC__crc8_update(const FLAC__byte data, FLAC__uint8 *crc) 110 { 111 *crc = FLAC__crc8_table[*crc ^ data]; 112 } 113 114 void FLAC__crc8_update_block(const FLAC__byte *data, unsigned len, FLAC__uint8 *crc) 115 { 116 while(len--) 117 *crc = FLAC__crc8_table[*crc ^ *data++]; 118 } 119 120 FLAC__uint8 FLAC__crc8(const FLAC__byte *data, unsigned len) 121 { 122 FLAC__uint8 crc = 0; 123 124 while(len--) 125 crc = FLAC__crc8_table[crc ^ *data++]; 126 127 return crc; 128 } 129 130 void FLAC__crc16_update(const FLAC__byte data, FLAC__uint16 *crc) 131 { 132 *crc = (*crc<<8) ^ FLAC__crc16_table[(*crc>>8) ^ data]; 133 } 134 135 void FLAC__crc16_update_block(const FLAC__byte *data, unsigned len, FLAC__uint16 *crc) 136 { 137 while(len--) 138 *crc = (*crc<<8) ^ FLAC__crc16_table[(*crc>>8) ^ *data++]; 139 } 140 141 FLAC__uint16 FLAC__crc16(const FLAC__byte *data, unsigned len) 142 { 143 FLAC__uint16 crc = 0; 144 145 while(len--) 146 crc = (crc<<8) ^ FLAC__crc16_table[(crc>>8) ^ *data++]; 147 148 return crc; 149 }