Home | History | Annotate | Download | only in libFLAC
      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 #if 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 
    113 void FLAC__crc8_update(const FLAC__byte data, FLAC__uint8 *crc)
    114 {
    115 	*crc = FLAC__crc8_table[*crc ^ data];
    116 }
    117 
    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 
    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 
    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