FFmpeg
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crc.c
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1 /*
2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "config.h"
22 #include "common.h"
23 #include "bswap.h"
24 #include "crc.h"
25 
26 #if CONFIG_HARDCODED_TABLES
27 static const AVCRC av_crc_table[AV_CRC_MAX][257] = {
28  [AV_CRC_8_ATM] = {
29  0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15, 0x38, 0x3F, 0x36, 0x31,
30  0x24, 0x23, 0x2A, 0x2D, 0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
31  0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D, 0xE0, 0xE7, 0xEE, 0xE9,
32  0xFC, 0xFB, 0xF2, 0xF5, 0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
33  0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85, 0xA8, 0xAF, 0xA6, 0xA1,
34  0xB4, 0xB3, 0xBA, 0xBD, 0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
35  0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA, 0xB7, 0xB0, 0xB9, 0xBE,
36  0xAB, 0xAC, 0xA5, 0xA2, 0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
37  0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32, 0x1F, 0x18, 0x11, 0x16,
38  0x03, 0x04, 0x0D, 0x0A, 0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
39  0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A, 0x89, 0x8E, 0x87, 0x80,
40  0x95, 0x92, 0x9B, 0x9C, 0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
41  0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC, 0xC1, 0xC6, 0xCF, 0xC8,
42  0xDD, 0xDA, 0xD3, 0xD4, 0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
43  0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44, 0x19, 0x1E, 0x17, 0x10,
44  0x05, 0x02, 0x0B, 0x0C, 0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
45  0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B, 0x76, 0x71, 0x78, 0x7F,
46  0x6A, 0x6D, 0x64, 0x63, 0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
47  0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13, 0xAE, 0xA9, 0xA0, 0xA7,
48  0xB2, 0xB5, 0xBC, 0xBB, 0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
49  0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB, 0xE6, 0xE1, 0xE8, 0xEF,
50  0xFA, 0xFD, 0xF4, 0xF3, 0x01
51  },
52  [AV_CRC_16_ANSI] = {
53  0x0000, 0x0580, 0x0F80, 0x0A00, 0x1B80, 0x1E00, 0x1400, 0x1180,
54  0x3380, 0x3600, 0x3C00, 0x3980, 0x2800, 0x2D80, 0x2780, 0x2200,
55  0x6380, 0x6600, 0x6C00, 0x6980, 0x7800, 0x7D80, 0x7780, 0x7200,
56  0x5000, 0x5580, 0x5F80, 0x5A00, 0x4B80, 0x4E00, 0x4400, 0x4180,
57  0xC380, 0xC600, 0xCC00, 0xC980, 0xD800, 0xDD80, 0xD780, 0xD200,
58  0xF000, 0xF580, 0xFF80, 0xFA00, 0xEB80, 0xEE00, 0xE400, 0xE180,
59  0xA000, 0xA580, 0xAF80, 0xAA00, 0xBB80, 0xBE00, 0xB400, 0xB180,
60  0x9380, 0x9600, 0x9C00, 0x9980, 0x8800, 0x8D80, 0x8780, 0x8200,
61  0x8381, 0x8601, 0x8C01, 0x8981, 0x9801, 0x9D81, 0x9781, 0x9201,
62  0xB001, 0xB581, 0xBF81, 0xBA01, 0xAB81, 0xAE01, 0xA401, 0xA181,
63  0xE001, 0xE581, 0xEF81, 0xEA01, 0xFB81, 0xFE01, 0xF401, 0xF181,
64  0xD381, 0xD601, 0xDC01, 0xD981, 0xC801, 0xCD81, 0xC781, 0xC201,
65  0x4001, 0x4581, 0x4F81, 0x4A01, 0x5B81, 0x5E01, 0x5401, 0x5181,
66  0x7381, 0x7601, 0x7C01, 0x7981, 0x6801, 0x6D81, 0x6781, 0x6201,
67  0x2381, 0x2601, 0x2C01, 0x2981, 0x3801, 0x3D81, 0x3781, 0x3201,
68  0x1001, 0x1581, 0x1F81, 0x1A01, 0x0B81, 0x0E01, 0x0401, 0x0181,
69  0x0383, 0x0603, 0x0C03, 0x0983, 0x1803, 0x1D83, 0x1783, 0x1203,
70  0x3003, 0x3583, 0x3F83, 0x3A03, 0x2B83, 0x2E03, 0x2403, 0x2183,
71  0x6003, 0x6583, 0x6F83, 0x6A03, 0x7B83, 0x7E03, 0x7403, 0x7183,
72  0x5383, 0x5603, 0x5C03, 0x5983, 0x4803, 0x4D83, 0x4783, 0x4203,
73  0xC003, 0xC583, 0xCF83, 0xCA03, 0xDB83, 0xDE03, 0xD403, 0xD183,
74  0xF383, 0xF603, 0xFC03, 0xF983, 0xE803, 0xED83, 0xE783, 0xE203,
75  0xA383, 0xA603, 0xAC03, 0xA983, 0xB803, 0xBD83, 0xB783, 0xB203,
76  0x9003, 0x9583, 0x9F83, 0x9A03, 0x8B83, 0x8E03, 0x8403, 0x8183,
77  0x8002, 0x8582, 0x8F82, 0x8A02, 0x9B82, 0x9E02, 0x9402, 0x9182,
78  0xB382, 0xB602, 0xBC02, 0xB982, 0xA802, 0xAD82, 0xA782, 0xA202,
79  0xE382, 0xE602, 0xEC02, 0xE982, 0xF802, 0xFD82, 0xF782, 0xF202,
80  0xD002, 0xD582, 0xDF82, 0xDA02, 0xCB82, 0xCE02, 0xC402, 0xC182,
81  0x4382, 0x4602, 0x4C02, 0x4982, 0x5802, 0x5D82, 0x5782, 0x5202,
82  0x7002, 0x7582, 0x7F82, 0x7A02, 0x6B82, 0x6E02, 0x6402, 0x6182,
83  0x2002, 0x2582, 0x2F82, 0x2A02, 0x3B82, 0x3E02, 0x3402, 0x3182,
84  0x1382, 0x1602, 0x1C02, 0x1982, 0x0802, 0x0D82, 0x0782, 0x0202,
85  0x0001
86  },
87  [AV_CRC_16_CCITT] = {
88  0x0000, 0x2110, 0x4220, 0x6330, 0x8440, 0xA550, 0xC660, 0xE770,
89  0x0881, 0x2991, 0x4AA1, 0x6BB1, 0x8CC1, 0xADD1, 0xCEE1, 0xEFF1,
90  0x3112, 0x1002, 0x7332, 0x5222, 0xB552, 0x9442, 0xF772, 0xD662,
91  0x3993, 0x1883, 0x7BB3, 0x5AA3, 0xBDD3, 0x9CC3, 0xFFF3, 0xDEE3,
92  0x6224, 0x4334, 0x2004, 0x0114, 0xE664, 0xC774, 0xA444, 0x8554,
93  0x6AA5, 0x4BB5, 0x2885, 0x0995, 0xEEE5, 0xCFF5, 0xACC5, 0x8DD5,
94  0x5336, 0x7226, 0x1116, 0x3006, 0xD776, 0xF666, 0x9556, 0xB446,
95  0x5BB7, 0x7AA7, 0x1997, 0x3887, 0xDFF7, 0xFEE7, 0x9DD7, 0xBCC7,
96  0xC448, 0xE558, 0x8668, 0xA778, 0x4008, 0x6118, 0x0228, 0x2338,
97  0xCCC9, 0xEDD9, 0x8EE9, 0xAFF9, 0x4889, 0x6999, 0x0AA9, 0x2BB9,
98  0xF55A, 0xD44A, 0xB77A, 0x966A, 0x711A, 0x500A, 0x333A, 0x122A,
99  0xFDDB, 0xDCCB, 0xBFFB, 0x9EEB, 0x799B, 0x588B, 0x3BBB, 0x1AAB,
100  0xA66C, 0x877C, 0xE44C, 0xC55C, 0x222C, 0x033C, 0x600C, 0x411C,
101  0xAEED, 0x8FFD, 0xECCD, 0xCDDD, 0x2AAD, 0x0BBD, 0x688D, 0x499D,
102  0x977E, 0xB66E, 0xD55E, 0xF44E, 0x133E, 0x322E, 0x511E, 0x700E,
103  0x9FFF, 0xBEEF, 0xDDDF, 0xFCCF, 0x1BBF, 0x3AAF, 0x599F, 0x788F,
104  0x8891, 0xA981, 0xCAB1, 0xEBA1, 0x0CD1, 0x2DC1, 0x4EF1, 0x6FE1,
105  0x8010, 0xA100, 0xC230, 0xE320, 0x0450, 0x2540, 0x4670, 0x6760,
106  0xB983, 0x9893, 0xFBA3, 0xDAB3, 0x3DC3, 0x1CD3, 0x7FE3, 0x5EF3,
107  0xB102, 0x9012, 0xF322, 0xD232, 0x3542, 0x1452, 0x7762, 0x5672,
108  0xEAB5, 0xCBA5, 0xA895, 0x8985, 0x6EF5, 0x4FE5, 0x2CD5, 0x0DC5,
109  0xE234, 0xC324, 0xA014, 0x8104, 0x6674, 0x4764, 0x2454, 0x0544,
110  0xDBA7, 0xFAB7, 0x9987, 0xB897, 0x5FE7, 0x7EF7, 0x1DC7, 0x3CD7,
111  0xD326, 0xF236, 0x9106, 0xB016, 0x5766, 0x7676, 0x1546, 0x3456,
112  0x4CD9, 0x6DC9, 0x0EF9, 0x2FE9, 0xC899, 0xE989, 0x8AB9, 0xABA9,
113  0x4458, 0x6548, 0x0678, 0x2768, 0xC018, 0xE108, 0x8238, 0xA328,
114  0x7DCB, 0x5CDB, 0x3FEB, 0x1EFB, 0xF98B, 0xD89B, 0xBBAB, 0x9ABB,
115  0x754A, 0x545A, 0x376A, 0x167A, 0xF10A, 0xD01A, 0xB32A, 0x923A,
116  0x2EFD, 0x0FED, 0x6CDD, 0x4DCD, 0xAABD, 0x8BAD, 0xE89D, 0xC98D,
117  0x267C, 0x076C, 0x645C, 0x454C, 0xA23C, 0x832C, 0xE01C, 0xC10C,
118  0x1FEF, 0x3EFF, 0x5DCF, 0x7CDF, 0x9BAF, 0xBABF, 0xD98F, 0xF89F,
119  0x176E, 0x367E, 0x554E, 0x745E, 0x932E, 0xB23E, 0xD10E, 0xF01E,
120  0x0001
121  },
122  [AV_CRC_32_IEEE] = {
123  0x00000000, 0xB71DC104, 0x6E3B8209, 0xD926430D, 0xDC760413, 0x6B6BC517,
124  0xB24D861A, 0x0550471E, 0xB8ED0826, 0x0FF0C922, 0xD6D68A2F, 0x61CB4B2B,
125  0x649B0C35, 0xD386CD31, 0x0AA08E3C, 0xBDBD4F38, 0x70DB114C, 0xC7C6D048,
126  0x1EE09345, 0xA9FD5241, 0xACAD155F, 0x1BB0D45B, 0xC2969756, 0x758B5652,
127  0xC836196A, 0x7F2BD86E, 0xA60D9B63, 0x11105A67, 0x14401D79, 0xA35DDC7D,
128  0x7A7B9F70, 0xCD665E74, 0xE0B62398, 0x57ABE29C, 0x8E8DA191, 0x39906095,
129  0x3CC0278B, 0x8BDDE68F, 0x52FBA582, 0xE5E66486, 0x585B2BBE, 0xEF46EABA,
130  0x3660A9B7, 0x817D68B3, 0x842D2FAD, 0x3330EEA9, 0xEA16ADA4, 0x5D0B6CA0,
131  0x906D32D4, 0x2770F3D0, 0xFE56B0DD, 0x494B71D9, 0x4C1B36C7, 0xFB06F7C3,
132  0x2220B4CE, 0x953D75CA, 0x28803AF2, 0x9F9DFBF6, 0x46BBB8FB, 0xF1A679FF,
133  0xF4F63EE1, 0x43EBFFE5, 0x9ACDBCE8, 0x2DD07DEC, 0x77708634, 0xC06D4730,
134  0x194B043D, 0xAE56C539, 0xAB068227, 0x1C1B4323, 0xC53D002E, 0x7220C12A,
135  0xCF9D8E12, 0x78804F16, 0xA1A60C1B, 0x16BBCD1F, 0x13EB8A01, 0xA4F64B05,
136  0x7DD00808, 0xCACDC90C, 0x07AB9778, 0xB0B6567C, 0x69901571, 0xDE8DD475,
137  0xDBDD936B, 0x6CC0526F, 0xB5E61162, 0x02FBD066, 0xBF469F5E, 0x085B5E5A,
138  0xD17D1D57, 0x6660DC53, 0x63309B4D, 0xD42D5A49, 0x0D0B1944, 0xBA16D840,
139  0x97C6A5AC, 0x20DB64A8, 0xF9FD27A5, 0x4EE0E6A1, 0x4BB0A1BF, 0xFCAD60BB,
140  0x258B23B6, 0x9296E2B2, 0x2F2BAD8A, 0x98366C8E, 0x41102F83, 0xF60DEE87,
141  0xF35DA999, 0x4440689D, 0x9D662B90, 0x2A7BEA94, 0xE71DB4E0, 0x500075E4,
142  0x892636E9, 0x3E3BF7ED, 0x3B6BB0F3, 0x8C7671F7, 0x555032FA, 0xE24DF3FE,
143  0x5FF0BCC6, 0xE8ED7DC2, 0x31CB3ECF, 0x86D6FFCB, 0x8386B8D5, 0x349B79D1,
144  0xEDBD3ADC, 0x5AA0FBD8, 0xEEE00C69, 0x59FDCD6D, 0x80DB8E60, 0x37C64F64,
145  0x3296087A, 0x858BC97E, 0x5CAD8A73, 0xEBB04B77, 0x560D044F, 0xE110C54B,
146  0x38368646, 0x8F2B4742, 0x8A7B005C, 0x3D66C158, 0xE4408255, 0x535D4351,
147  0x9E3B1D25, 0x2926DC21, 0xF0009F2C, 0x471D5E28, 0x424D1936, 0xF550D832,
148  0x2C769B3F, 0x9B6B5A3B, 0x26D61503, 0x91CBD407, 0x48ED970A, 0xFFF0560E,
149  0xFAA01110, 0x4DBDD014, 0x949B9319, 0x2386521D, 0x0E562FF1, 0xB94BEEF5,
150  0x606DADF8, 0xD7706CFC, 0xD2202BE2, 0x653DEAE6, 0xBC1BA9EB, 0x0B0668EF,
151  0xB6BB27D7, 0x01A6E6D3, 0xD880A5DE, 0x6F9D64DA, 0x6ACD23C4, 0xDDD0E2C0,
152  0x04F6A1CD, 0xB3EB60C9, 0x7E8D3EBD, 0xC990FFB9, 0x10B6BCB4, 0xA7AB7DB0,
153  0xA2FB3AAE, 0x15E6FBAA, 0xCCC0B8A7, 0x7BDD79A3, 0xC660369B, 0x717DF79F,
154  0xA85BB492, 0x1F467596, 0x1A163288, 0xAD0BF38C, 0x742DB081, 0xC3307185,
155  0x99908A5D, 0x2E8D4B59, 0xF7AB0854, 0x40B6C950, 0x45E68E4E, 0xF2FB4F4A,
156  0x2BDD0C47, 0x9CC0CD43, 0x217D827B, 0x9660437F, 0x4F460072, 0xF85BC176,
157  0xFD0B8668, 0x4A16476C, 0x93300461, 0x242DC565, 0xE94B9B11, 0x5E565A15,
158  0x87701918, 0x306DD81C, 0x353D9F02, 0x82205E06, 0x5B061D0B, 0xEC1BDC0F,
159  0x51A69337, 0xE6BB5233, 0x3F9D113E, 0x8880D03A, 0x8DD09724, 0x3ACD5620,
160  0xE3EB152D, 0x54F6D429, 0x7926A9C5, 0xCE3B68C1, 0x171D2BCC, 0xA000EAC8,
161  0xA550ADD6, 0x124D6CD2, 0xCB6B2FDF, 0x7C76EEDB, 0xC1CBA1E3, 0x76D660E7,
162  0xAFF023EA, 0x18EDE2EE, 0x1DBDA5F0, 0xAAA064F4, 0x738627F9, 0xC49BE6FD,
163  0x09FDB889, 0xBEE0798D, 0x67C63A80, 0xD0DBFB84, 0xD58BBC9A, 0x62967D9E,
164  0xBBB03E93, 0x0CADFF97, 0xB110B0AF, 0x060D71AB, 0xDF2B32A6, 0x6836F3A2,
165  0x6D66B4BC, 0xDA7B75B8, 0x035D36B5, 0xB440F7B1, 0x00000001
166  },
167  [AV_CRC_32_IEEE_LE] = {
168  0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
169  0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
170  0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2,
171  0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
172  0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
173  0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
174  0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
175  0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
176  0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
177  0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
178  0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106,
179  0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
180  0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
181  0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
182  0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950,
183  0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
184  0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
185  0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
186  0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA,
187  0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
188  0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
189  0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
190  0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84,
191  0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
192  0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
193  0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
194  0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E,
195  0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
196  0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
197  0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
198  0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28,
199  0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
200  0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
201  0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
202  0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242,
203  0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
204  0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
205  0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
206  0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
207  0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
208  0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
209  0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
210  0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D, 0x00000001
211  },
212 };
213 #else
214 #if CONFIG_SMALL
215 #define CRC_TABLE_SIZE 257
216 #else
217 #define CRC_TABLE_SIZE 1024
218 #endif
219 static struct {
222  uint32_t poly;
224  [AV_CRC_8_ATM] = { 0, 8, 0x07 },
225  [AV_CRC_16_ANSI] = { 0, 16, 0x8005 },
226  [AV_CRC_16_CCITT] = { 0, 16, 0x1021 },
227  [AV_CRC_32_IEEE] = { 0, 32, 0x04C11DB7 },
228  [AV_CRC_32_IEEE_LE] = { 1, 32, 0xEDB88320 },
229 };
231 #endif
232 
233 int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size)
234 {
235  unsigned i, j;
236  uint32_t c;
237 
238  if (bits < 8 || bits > 32 || poly >= (1LL << bits))
239  return -1;
240  if (ctx_size != sizeof(AVCRC) * 257 && ctx_size != sizeof(AVCRC) * 1024)
241  return -1;
242 
243  for (i = 0; i < 256; i++) {
244  if (le) {
245  for (c = i, j = 0; j < 8; j++)
246  c = (c >> 1) ^ (poly & (-(c & 1)));
247  ctx[i] = c;
248  } else {
249  for (c = i << 24, j = 0; j < 8; j++)
250  c = (c << 1) ^ ((poly << (32 - bits)) & (((int32_t) c) >> 31));
251  ctx[i] = av_bswap32(c);
252  }
253  }
254  ctx[256] = 1;
255 #if !CONFIG_SMALL
256  if (ctx_size >= sizeof(AVCRC) * 1024)
257  for (i = 0; i < 256; i++)
258  for (j = 0; j < 3; j++)
259  ctx[256 *(j + 1) + i] =
260  (ctx[256 * j + i] >> 8) ^ ctx[ctx[256 * j + i] & 0xFF];
261 #endif
262 
263  return 0;
264 }
265 
267 {
268 #if !CONFIG_HARDCODED_TABLES
269  if (!av_crc_table[crc_id][FF_ARRAY_ELEMS(av_crc_table[crc_id]) - 1])
270  if (av_crc_init(av_crc_table[crc_id],
271  av_crc_table_params[crc_id].le,
272  av_crc_table_params[crc_id].bits,
273  av_crc_table_params[crc_id].poly,
274  sizeof(av_crc_table[crc_id])) < 0)
275  return NULL;
276 #endif
277  return av_crc_table[crc_id];
278 }
279 
280 uint32_t av_crc(const AVCRC *ctx, uint32_t crc,
281  const uint8_t *buffer, size_t length)
282 {
283  const uint8_t *end = buffer + length;
284 
285 #if !CONFIG_SMALL
286  if (!ctx[256]) {
287  while (((intptr_t) buffer & 3) && buffer < end)
288  crc = ctx[((uint8_t) crc) ^ *buffer++] ^ (crc >> 8);
289 
290  while (buffer < end - 3) {
291  crc ^= av_le2ne32(*(const uint32_t *) buffer); buffer += 4;
292  crc = ctx[3 * 256 + ( crc & 0xFF)] ^
293  ctx[2 * 256 + ((crc >> 8 ) & 0xFF)] ^
294  ctx[1 * 256 + ((crc >> 16) & 0xFF)] ^
295  ctx[0 * 256 + ((crc >> 24) )];
296  }
297  }
298 #endif
299  while (buffer < end)
300  crc = ctx[((uint8_t) crc) ^ *buffer++] ^ (crc >> 8);
301 
302  return crc;
303 }
304 
305 #ifdef TEST
306 int main(void)
307 {
308  uint8_t buf[1999];
309  int i;
310  int p[4][3] = { { AV_CRC_32_IEEE_LE, 0xEDB88320, 0x3D5CDD04 },
311  { AV_CRC_32_IEEE , 0x04C11DB7, 0xC0F5BAE0 },
312  { AV_CRC_16_ANSI , 0x8005 , 0x1FBB },
313  { AV_CRC_8_ATM , 0x07 , 0xE3 }
314  };
315  const AVCRC *ctx;
316 
317  for (i = 0; i < sizeof(buf); i++)
318  buf[i] = i + i * i;
319 
320  for (i = 0; i < 4; i++) {
321  ctx = av_crc_get_table(p[i][0]);
322  printf("crc %08X = %X\n", p[i][1], av_crc(ctx, 0, buf, sizeof(buf)));
323  }
324  return 0;
325 }
326 #endif