1 /* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007 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 #ifdef HAVE_CONFIG_H
33 # include <config.h>
34 #endif
35
36 #include "private/crc.h"
37
38 /* CRC-8, poly = x^8 + x^2 + x^1 + x^0, init = 0 */
39
40 FLAC__byte const FLAC__crc8_table[256] = {
41 0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15,
42 0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D,
43 0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
44 0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D,
45 0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5,
46 0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
47 0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85,
48 0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD,
49 0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
50 0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA,
51 0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2,
52 0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
53 0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32,
54 0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A,
55 0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
56 0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A,
57 0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C,
58 0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
59 0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC,
60 0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4,
61 0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
62 0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44,
63 0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C,
64 0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
65 0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B,
66 0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63,
67 0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
68 0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13,
69 0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB,
70 0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
71 0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB,
72 0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3
73 };
74
75 /* CRC-16, poly = x^16 + x^15 + x^2 + x^0, init = 0 */
76
77 unsigned FLAC__crc16_table[256] = {
78 0x0000, 0x8005, 0x800f, 0x000a, 0x801b, 0x001e, 0x0014, 0x8011,
79 0x8033, 0x0036, 0x003c, 0x8039, 0x0028, 0x802d, 0x8027, 0x0022,
80 0x8063, 0x0066, 0x006c, 0x8069, 0x0078, 0x807d, 0x8077, 0x0072,
81 0x0050, 0x8055, 0x805f, 0x005a, 0x804b, 0x004e, 0x0044, 0x8041,
82 0x80c3, 0x00c6, 0x00cc, 0x80c9, 0x00d8, 0x80dd, 0x80d7, 0x00d2,
83 0x00f0, 0x80f5, 0x80ff, 0x00fa, 0x80eb, 0x00ee, 0x00e4, 0x80e1,
84 0x00a0, 0x80a5, 0x80af, 0x00aa, 0x80bb, 0x00be, 0x00b4, 0x80b1,
85 0x8093, 0x0096, 0x009c, 0x8099, 0x0088, 0x808d, 0x8087, 0x0082,
86 0x8183, 0x0186, 0x018c, 0x8189, 0x0198, 0x819d, 0x8197, 0x0192,
87 0x01b0, 0x81b5, 0x81bf, 0x01ba, 0x81ab, 0x01ae, 0x01a4, 0x81a1,
88 0x01e0, 0x81e5, 0x81ef, 0x01ea, 0x81fb, 0x01fe, 0x01f4, 0x81f1,
89 0x81d3, 0x01d6, 0x01dc, 0x81d9, 0x01c8, 0x81cd, 0x81c7, 0x01c2,
90 0x0140, 0x8145, 0x814f, 0x014a, 0x815b, 0x015e, 0x0154, 0x8151,
91 0x8173, 0x0176, 0x017c, 0x8179, 0x0168, 0x816d, 0x8167, 0x0162,
92 0x8123, 0x0126, 0x012c, 0x8129, 0x0138, 0x813d, 0x8137, 0x0132,
93 0x0110, 0x8115, 0x811f, 0x011a, 0x810b, 0x010e, 0x0104, 0x8101,
94 0x8303, 0x0306, 0x030c, 0x8309, 0x0318, 0x831d, 0x8317, 0x0312,
95 0x0330, 0x8335, 0x833f, 0x033a, 0x832b, 0x032e, 0x0324, 0x8321,
96 0x0360, 0x8365, 0x836f, 0x036a, 0x837b, 0x037e, 0x0374, 0x8371,
97 0x8353, 0x0356, 0x035c, 0x8359, 0x0348, 0x834d, 0x8347, 0x0342,
98 0x03c0, 0x83c5, 0x83cf, 0x03ca, 0x83db, 0x03de, 0x03d4, 0x83d1,
99 0x83f3, 0x03f6, 0x03fc, 0x83f9, 0x03e8, 0x83ed, 0x83e7, 0x03e2,
100 0x83a3, 0x03a6, 0x03ac, 0x83a9, 0x03b8, 0x83bd, 0x83b7, 0x03b2,
101 0x0390, 0x8395, 0x839f, 0x039a, 0x838b, 0x038e, 0x0384, 0x8381,
102 0x0280, 0x8285, 0x828f, 0x028a, 0x829b, 0x029e, 0x0294, 0x8291,
103 0x82b3, 0x02b6, 0x02bc, 0x82b9, 0x02a8, 0x82ad, 0x82a7, 0x02a2,
104 0x82e3, 0x02e6, 0x02ec, 0x82e9, 0x02f8, 0x82fd, 0x82f7, 0x02f2,
105 0x02d0, 0x82d5, 0x82df, 0x02da, 0x82cb, 0x02ce, 0x02c4, 0x82c1,
106 0x8243, 0x0246, 0x024c, 0x8249, 0x0258, 0x825d, 0x8257, 0x0252,
107 0x0270, 0x8275, 0x827f, 0x027a, 0x826b, 0x026e, 0x0264, 0x8261,
108 0x0220, 0x8225, 0x822f, 0x022a, 0x823b, 0x023e, 0x0234, 0x8231,
109 0x8213, 0x0216, 0x021c, 0x8219, 0x0208, 0x820d, 0x8207, 0x0202
110 };
111
112
FLAC__crc8_update(const FLAC__byte data,FLAC__uint8 * crc)113 void FLAC__crc8_update(const FLAC__byte data, FLAC__uint8 *crc)
114 {
115 *crc = FLAC__crc8_table[*crc ^ data];
116 }
117
FLAC__crc8_update_block(const FLAC__byte * data,unsigned len,FLAC__uint8 * crc)118 void FLAC__crc8_update_block(const FLAC__byte *data, unsigned len, FLAC__uint8 *crc)
119 {
120 while(len--)
121 *crc = FLAC__crc8_table[*crc ^ *data++];
122 }
123
FLAC__crc8(const FLAC__byte * data,unsigned len)124 FLAC__uint8 FLAC__crc8(const FLAC__byte *data, unsigned len)
125 {
126 FLAC__uint8 crc = 0;
127
128 while(len--)
129 crc = FLAC__crc8_table[crc ^ *data++];
130
131 return crc;
132 }
133
FLAC__crc16(const FLAC__byte * data,unsigned len)134 unsigned FLAC__crc16(const FLAC__byte *data, unsigned len)
135 {
136 unsigned crc = 0;
137
138 while(len--)
139 crc = ((crc<<8) ^ FLAC__crc16_table[(crc>>8) ^ *data++]) & 0xffff;
140
141 return crc;
142 }
143