crc.c

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/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "config.h"
#include "common.h"
#include "bswap.h"
#include "crc.h"

#if CONFIG_HARDCODED_TABLES
static const AVCRC av_crc_table[AV_CRC_MAX][257] = {
    [AV_CRC_8_ATM] = {
        0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15, 0x38, 0x3F, 0x36, 0x31,
        0x24, 0x23, 0x2A, 0x2D, 0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
        0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D, 0xE0, 0xE7, 0xEE, 0xE9,
        0xFC, 0xFB, 0xF2, 0xF5, 0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
        0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85, 0xA8, 0xAF, 0xA6, 0xA1,
        0xB4, 0xB3, 0xBA, 0xBD, 0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
        0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA, 0xB7, 0xB0, 0xB9, 0xBE,
        0xAB, 0xAC, 0xA5, 0xA2, 0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
        0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32, 0x1F, 0x18, 0x11, 0x16,
        0x03, 0x04, 0x0D, 0x0A, 0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
        0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A, 0x89, 0x8E, 0x87, 0x80,
        0x95, 0x92, 0x9B, 0x9C, 0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
        0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC, 0xC1, 0xC6, 0xCF, 0xC8,
        0xDD, 0xDA, 0xD3, 0xD4, 0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
        0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44, 0x19, 0x1E, 0x17, 0x10,
        0x05, 0x02, 0x0B, 0x0C, 0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
        0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B, 0x76, 0x71, 0x78, 0x7F,
        0x6A, 0x6D, 0x64, 0x63, 0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
        0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13, 0xAE, 0xA9, 0xA0, 0xA7,
        0xB2, 0xB5, 0xBC, 0xBB, 0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
        0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB, 0xE6, 0xE1, 0xE8, 0xEF,
        0xFA, 0xFD, 0xF4, 0xF3, 0x01
    },
    [AV_CRC_16_ANSI] = {
        0x0000, 0x0580, 0x0F80, 0x0A00, 0x1B80, 0x1E00, 0x1400, 0x1180,
        0x3380, 0x3600, 0x3C00, 0x3980, 0x2800, 0x2D80, 0x2780, 0x2200,
        0x6380, 0x6600, 0x6C00, 0x6980, 0x7800, 0x7D80, 0x7780, 0x7200,
        0x5000, 0x5580, 0x5F80, 0x5A00, 0x4B80, 0x4E00, 0x4400, 0x4180,
        0xC380, 0xC600, 0xCC00, 0xC980, 0xD800, 0xDD80, 0xD780, 0xD200,
        0xF000, 0xF580, 0xFF80, 0xFA00, 0xEB80, 0xEE00, 0xE400, 0xE180,
        0xA000, 0xA580, 0xAF80, 0xAA00, 0xBB80, 0xBE00, 0xB400, 0xB180,
        0x9380, 0x9600, 0x9C00, 0x9980, 0x8800, 0x8D80, 0x8780, 0x8200,
        0x8381, 0x8601, 0x8C01, 0x8981, 0x9801, 0x9D81, 0x9781, 0x9201,
        0xB001, 0xB581, 0xBF81, 0xBA01, 0xAB81, 0xAE01, 0xA401, 0xA181,
        0xE001, 0xE581, 0xEF81, 0xEA01, 0xFB81, 0xFE01, 0xF401, 0xF181,
        0xD381, 0xD601, 0xDC01, 0xD981, 0xC801, 0xCD81, 0xC781, 0xC201,
        0x4001, 0x4581, 0x4F81, 0x4A01, 0x5B81, 0x5E01, 0x5401, 0x5181,
        0x7381, 0x7601, 0x7C01, 0x7981, 0x6801, 0x6D81, 0x6781, 0x6201,
        0x2381, 0x2601, 0x2C01, 0x2981, 0x3801, 0x3D81, 0x3781, 0x3201,
        0x1001, 0x1581, 0x1F81, 0x1A01, 0x0B81, 0x0E01, 0x0401, 0x0181,
        0x0383, 0x0603, 0x0C03, 0x0983, 0x1803, 0x1D83, 0x1783, 0x1203,
        0x3003, 0x3583, 0x3F83, 0x3A03, 0x2B83, 0x2E03, 0x2403, 0x2183,
        0x6003, 0x6583, 0x6F83, 0x6A03, 0x7B83, 0x7E03, 0x7403, 0x7183,
        0x5383, 0x5603, 0x5C03, 0x5983, 0x4803, 0x4D83, 0x4783, 0x4203,
        0xC003, 0xC583, 0xCF83, 0xCA03, 0xDB83, 0xDE03, 0xD403, 0xD183,
        0xF383, 0xF603, 0xFC03, 0xF983, 0xE803, 0xED83, 0xE783, 0xE203,
        0xA383, 0xA603, 0xAC03, 0xA983, 0xB803, 0xBD83, 0xB783, 0xB203,
        0x9003, 0x9583, 0x9F83, 0x9A03, 0x8B83, 0x8E03, 0x8403, 0x8183,
        0x8002, 0x8582, 0x8F82, 0x8A02, 0x9B82, 0x9E02, 0x9402, 0x9182,
        0xB382, 0xB602, 0xBC02, 0xB982, 0xA802, 0xAD82, 0xA782, 0xA202,
        0xE382, 0xE602, 0xEC02, 0xE982, 0xF802, 0xFD82, 0xF782, 0xF202,
        0xD002, 0xD582, 0xDF82, 0xDA02, 0xCB82, 0xCE02, 0xC402, 0xC182,
        0x4382, 0x4602, 0x4C02, 0x4982, 0x5802, 0x5D82, 0x5782, 0x5202,
        0x7002, 0x7582, 0x7F82, 0x7A02, 0x6B82, 0x6E02, 0x6402, 0x6182,
        0x2002, 0x2582, 0x2F82, 0x2A02, 0x3B82, 0x3E02, 0x3402, 0x3182,
        0x1382, 0x1602, 0x1C02, 0x1982, 0x0802, 0x0D82, 0x0782, 0x0202,
        0x0001
    },
    [AV_CRC_16_CCITT] = {
        0x0000, 0x2110, 0x4220, 0x6330, 0x8440, 0xA550, 0xC660, 0xE770,
        0x0881, 0x2991, 0x4AA1, 0x6BB1, 0x8CC1, 0xADD1, 0xCEE1, 0xEFF1,
        0x3112, 0x1002, 0x7332, 0x5222, 0xB552, 0x9442, 0xF772, 0xD662,
        0x3993, 0x1883, 0x7BB3, 0x5AA3, 0xBDD3, 0x9CC3, 0xFFF3, 0xDEE3,
        0x6224, 0x4334, 0x2004, 0x0114, 0xE664, 0xC774, 0xA444, 0x8554,
        0x6AA5, 0x4BB5, 0x2885, 0x0995, 0xEEE5, 0xCFF5, 0xACC5, 0x8DD5,
        0x5336, 0x7226, 0x1116, 0x3006, 0xD776, 0xF666, 0x9556, 0xB446,
        0x5BB7, 0x7AA7, 0x1997, 0x3887, 0xDFF7, 0xFEE7, 0x9DD7, 0xBCC7,
        0xC448, 0xE558, 0x8668, 0xA778, 0x4008, 0x6118, 0x0228, 0x2338,
        0xCCC9, 0xEDD9, 0x8EE9, 0xAFF9, 0x4889, 0x6999, 0x0AA9, 0x2BB9,
        0xF55A, 0xD44A, 0xB77A, 0x966A, 0x711A, 0x500A, 0x333A, 0x122A,
        0xFDDB, 0xDCCB, 0xBFFB, 0x9EEB, 0x799B, 0x588B, 0x3BBB, 0x1AAB,
        0xA66C, 0x877C, 0xE44C, 0xC55C, 0x222C, 0x033C, 0x600C, 0x411C,
        0xAEED, 0x8FFD, 0xECCD, 0xCDDD, 0x2AAD, 0x0BBD, 0x688D, 0x499D,
        0x977E, 0xB66E, 0xD55E, 0xF44E, 0x133E, 0x322E, 0x511E, 0x700E,
        0x9FFF, 0xBEEF, 0xDDDF, 0xFCCF, 0x1BBF, 0x3AAF, 0x599F, 0x788F,
        0x8891, 0xA981, 0xCAB1, 0xEBA1, 0x0CD1, 0x2DC1, 0x4EF1, 0x6FE1,
        0x8010, 0xA100, 0xC230, 0xE320, 0x0450, 0x2540, 0x4670, 0x6760,
        0xB983, 0x9893, 0xFBA3, 0xDAB3, 0x3DC3, 0x1CD3, 0x7FE3, 0x5EF3,
        0xB102, 0x9012, 0xF322, 0xD232, 0x3542, 0x1452, 0x7762, 0x5672,
        0xEAB5, 0xCBA5, 0xA895, 0x8985, 0x6EF5, 0x4FE5, 0x2CD5, 0x0DC5,
        0xE234, 0xC324, 0xA014, 0x8104, 0x6674, 0x4764, 0x2454, 0x0544,
        0xDBA7, 0xFAB7, 0x9987, 0xB897, 0x5FE7, 0x7EF7, 0x1DC7, 0x3CD7,
        0xD326, 0xF236, 0x9106, 0xB016, 0x5766, 0x7676, 0x1546, 0x3456,
        0x4CD9, 0x6DC9, 0x0EF9, 0x2FE9, 0xC899, 0xE989, 0x8AB9, 0xABA9,
        0x4458, 0x6548, 0x0678, 0x2768, 0xC018, 0xE108, 0x8238, 0xA328,
        0x7DCB, 0x5CDB, 0x3FEB, 0x1EFB, 0xF98B, 0xD89B, 0xBBAB, 0x9ABB,
        0x754A, 0x545A, 0x376A, 0x167A, 0xF10A, 0xD01A, 0xB32A, 0x923A,
        0x2EFD, 0x0FED, 0x6CDD, 0x4DCD, 0xAABD, 0x8BAD, 0xE89D, 0xC98D,
        0x267C, 0x076C, 0x645C, 0x454C, 0xA23C, 0x832C, 0xE01C, 0xC10C,
        0x1FEF, 0x3EFF, 0x5DCF, 0x7CDF, 0x9BAF, 0xBABF, 0xD98F, 0xF89F,
        0x176E, 0x367E, 0x554E, 0x745E, 0x932E, 0xB23E, 0xD10E, 0xF01E,
        0x0001
    },
    [AV_CRC_32_IEEE] = {
        0x00000000, 0xB71DC104, 0x6E3B8209, 0xD926430D, 0xDC760413, 0x6B6BC517,
        0xB24D861A, 0x0550471E, 0xB8ED0826, 0x0FF0C922, 0xD6D68A2F, 0x61CB4B2B,
        0x649B0C35, 0xD386CD31, 0x0AA08E3C, 0xBDBD4F38, 0x70DB114C, 0xC7C6D048,
        0x1EE09345, 0xA9FD5241, 0xACAD155F, 0x1BB0D45B, 0xC2969756, 0x758B5652,
        0xC836196A, 0x7F2BD86E, 0xA60D9B63, 0x11105A67, 0x14401D79, 0xA35DDC7D,
        0x7A7B9F70, 0xCD665E74, 0xE0B62398, 0x57ABE29C, 0x8E8DA191, 0x39906095,
        0x3CC0278B, 0x8BDDE68F, 0x52FBA582, 0xE5E66486, 0x585B2BBE, 0xEF46EABA,
        0x3660A9B7, 0x817D68B3, 0x842D2FAD, 0x3330EEA9, 0xEA16ADA4, 0x5D0B6CA0,
        0x906D32D4, 0x2770F3D0, 0xFE56B0DD, 0x494B71D9, 0x4C1B36C7, 0xFB06F7C3,
        0x2220B4CE, 0x953D75CA, 0x28803AF2, 0x9F9DFBF6, 0x46BBB8FB, 0xF1A679FF,
        0xF4F63EE1, 0x43EBFFE5, 0x9ACDBCE8, 0x2DD07DEC, 0x77708634, 0xC06D4730,
        0x194B043D, 0xAE56C539, 0xAB068227, 0x1C1B4323, 0xC53D002E, 0x7220C12A,
        0xCF9D8E12, 0x78804F16, 0xA1A60C1B, 0x16BBCD1F, 0x13EB8A01, 0xA4F64B05,
        0x7DD00808, 0xCACDC90C, 0x07AB9778, 0xB0B6567C, 0x69901571, 0xDE8DD475,
        0xDBDD936B, 0x6CC0526F, 0xB5E61162, 0x02FBD066, 0xBF469F5E, 0x085B5E5A,
        0xD17D1D57, 0x6660DC53, 0x63309B4D, 0xD42D5A49, 0x0D0B1944, 0xBA16D840,
        0x97C6A5AC, 0x20DB64A8, 0xF9FD27A5, 0x4EE0E6A1, 0x4BB0A1BF, 0xFCAD60BB,
        0x258B23B6, 0x9296E2B2, 0x2F2BAD8A, 0x98366C8E, 0x41102F83, 0xF60DEE87,
        0xF35DA999, 0x4440689D, 0x9D662B90, 0x2A7BEA94, 0xE71DB4E0, 0x500075E4,
        0x892636E9, 0x3E3BF7ED, 0x3B6BB0F3, 0x8C7671F7, 0x555032FA, 0xE24DF3FE,
        0x5FF0BCC6, 0xE8ED7DC2, 0x31CB3ECF, 0x86D6FFCB, 0x8386B8D5, 0x349B79D1,
        0xEDBD3ADC, 0x5AA0FBD8, 0xEEE00C69, 0x59FDCD6D, 0x80DB8E60, 0x37C64F64,
        0x3296087A, 0x858BC97E, 0x5CAD8A73, 0xEBB04B77, 0x560D044F, 0xE110C54B,
        0x38368646, 0x8F2B4742, 0x8A7B005C, 0x3D66C158, 0xE4408255, 0x535D4351,
        0x9E3B1D25, 0x2926DC21, 0xF0009F2C, 0x471D5E28, 0x424D1936, 0xF550D832,
        0x2C769B3F, 0x9B6B5A3B, 0x26D61503, 0x91CBD407, 0x48ED970A, 0xFFF0560E,
        0xFAA01110, 0x4DBDD014, 0x949B9319, 0x2386521D, 0x0E562FF1, 0xB94BEEF5,
        0x606DADF8, 0xD7706CFC, 0xD2202BE2, 0x653DEAE6, 0xBC1BA9EB, 0x0B0668EF,
        0xB6BB27D7, 0x01A6E6D3, 0xD880A5DE, 0x6F9D64DA, 0x6ACD23C4, 0xDDD0E2C0,
        0x04F6A1CD, 0xB3EB60C9, 0x7E8D3EBD, 0xC990FFB9, 0x10B6BCB4, 0xA7AB7DB0,
        0xA2FB3AAE, 0x15E6FBAA, 0xCCC0B8A7, 0x7BDD79A3, 0xC660369B, 0x717DF79F,
        0xA85BB492, 0x1F467596, 0x1A163288, 0xAD0BF38C, 0x742DB081, 0xC3307185,
        0x99908A5D, 0x2E8D4B59, 0xF7AB0854, 0x40B6C950, 0x45E68E4E, 0xF2FB4F4A,
        0x2BDD0C47, 0x9CC0CD43, 0x217D827B, 0x9660437F, 0x4F460072, 0xF85BC176,
        0xFD0B8668, 0x4A16476C, 0x93300461, 0x242DC565, 0xE94B9B11, 0x5E565A15,
        0x87701918, 0x306DD81C, 0x353D9F02, 0x82205E06, 0x5B061D0B, 0xEC1BDC0F,
        0x51A69337, 0xE6BB5233, 0x3F9D113E, 0x8880D03A, 0x8DD09724, 0x3ACD5620,
        0xE3EB152D, 0x54F6D429, 0x7926A9C5, 0xCE3B68C1, 0x171D2BCC, 0xA000EAC8,
        0xA550ADD6, 0x124D6CD2, 0xCB6B2FDF, 0x7C76EEDB, 0xC1CBA1E3, 0x76D660E7,
        0xAFF023EA, 0x18EDE2EE, 0x1DBDA5F0, 0xAAA064F4, 0x738627F9, 0xC49BE6FD,
        0x09FDB889, 0xBEE0798D, 0x67C63A80, 0xD0DBFB84, 0xD58BBC9A, 0x62967D9E,
        0xBBB03E93, 0x0CADFF97, 0xB110B0AF, 0x060D71AB, 0xDF2B32A6, 0x6836F3A2,
        0x6D66B4BC, 0xDA7B75B8, 0x035D36B5, 0xB440F7B1, 0x00000001
    },
    [AV_CRC_32_IEEE_LE] = {
        0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
        0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
        0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2,
        0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
        0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
        0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
        0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
        0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
        0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
        0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
        0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106,
        0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
        0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
        0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
        0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950,
        0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
        0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
        0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
        0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA,
        0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
        0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
        0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
        0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84,
        0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
        0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
        0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
        0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E,
        0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
        0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
        0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
        0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28,
        0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
        0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
        0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
        0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242,
        0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
        0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
        0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
        0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
        0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
        0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
        0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
        0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D, 0x00000001
    },
};
#else
#if CONFIG_SMALL
#define CRC_TABLE_SIZE 257
#else
#define CRC_TABLE_SIZE 1024
#endif
static struct {
    uint8_t  le;
    uint8_t  bits;
    uint32_t poly;
} av_crc_table_params[AV_CRC_MAX] = {
    [AV_CRC_8_ATM]      = { 0,  8,       0x07 },
    [AV_CRC_16_ANSI]    = { 0, 16,     0x8005 },
    [AV_CRC_16_CCITT]   = { 0, 16,     0x1021 },
    [AV_CRC_32_IEEE]    = { 0, 32, 0x04C11DB7 },
    [AV_CRC_32_IEEE_LE] = { 1, 32, 0xEDB88320 },
};
static AVCRC av_crc_table[AV_CRC_MAX][CRC_TABLE_SIZE];
#endif

int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size)
{
    unsigned i, j;
    uint32_t c;

    if (bits < 8 || bits > 32 || poly >= (1LL << bits))
        return -1;
    if (ctx_size != sizeof(AVCRC) * 257 && ctx_size != sizeof(AVCRC) * 1024)
        return -1;

    for (i = 0; i < 256; i++) {
        if (le) {
            for (c = i, j = 0; j < 8; j++)
                c = (c >> 1) ^ (poly & (-(c & 1)));
            ctx[i] = c;
        } else {
            for (c = i << 24, j = 0; j < 8; j++)
                c = (c << 1) ^ ((poly << (32 - bits)) & (((int32_t) c) >> 31));
            ctx[i] = av_bswap32(c);
        }
    }
    ctx[256] = 1;
#if !CONFIG_SMALL
    if (ctx_size >= sizeof(AVCRC) * 1024)
        for (i = 0; i < 256; i++)
            for (j = 0; j < 3; j++)
                ctx[256 *(j + 1) + i] =
                    (ctx[256 * j + i] >> 8) ^ ctx[ctx[256 * j + i] & 0xFF];
#endif

    return 0;
}

const AVCRC *av_crc_get_table(AVCRCId crc_id)
{
#if !CONFIG_HARDCODED_TABLES
    if (!av_crc_table[crc_id][FF_ARRAY_ELEMS(av_crc_table[crc_id]) - 1])
        if (av_crc_init(av_crc_table[crc_id],
                        av_crc_table_params[crc_id].le,
                        av_crc_table_params[crc_id].bits,
                        av_crc_table_params[crc_id].poly,
                        sizeof(av_crc_table[crc_id])) < 0)
            return NULL;
#endif
    return av_crc_table[crc_id];
}

uint32_t av_crc(const AVCRC *ctx, uint32_t crc,
                const uint8_t *buffer, size_t length)
{
    const uint8_t *end = buffer + length;

#if !CONFIG_SMALL
    if (!ctx[256]) {
        while (((intptr_t) buffer & 3) && buffer < end)
            crc = ctx[((uint8_t) crc) ^ *buffer++] ^ (crc >> 8);

        while (buffer < end - 3) {
            crc ^= av_le2ne32(*(const uint32_t *) buffer); buffer += 4;
            crc = ctx[3 * 256 + ( crc        & 0xFF)] ^
                  ctx[2 * 256 + ((crc >> 8 ) & 0xFF)] ^
                  ctx[1 * 256 + ((crc >> 16) & 0xFF)] ^
                  ctx[0 * 256 + ((crc >> 24)       )];
        }
    }
#endif
    while (buffer < end)
        crc = ctx[((uint8_t) crc) ^ *buffer++] ^ (crc >> 8);

    return crc;
}

#ifdef TEST
int main(void)
{
    uint8_t buf[1999];
    int i;
    int p[4][3] = { { AV_CRC_32_IEEE_LE, 0xEDB88320, 0x3D5CDD04 },
                    { AV_CRC_32_IEEE   , 0x04C11DB7, 0xC0F5BAE0 },
                    { AV_CRC_16_ANSI   , 0x8005    , 0x1FBB     },
                    { AV_CRC_8_ATM     , 0x07      , 0xE3       }
    };
    const AVCRC *ctx;

    for (i = 0; i < sizeof(buf); i++)
        buf[i] = i + i * i;

    for (i = 0; i < 4; i++) {
        ctx = av_crc_get_table(p[i][0]);
        printf("crc %08X = %X\n", p[i][1], av_crc(ctx, 0, buf, sizeof(buf)));
    }
    return 0;
}
#endif