PythonCRC-32CRC-32MPEG-2循環(huán)冗余檢驗

1、PythonCRC-32CRC-32MPEG-2循環(huán)冗余檢驗參考：1. CRC（循環(huán)冗余校驗）在線計算2. CRC32/MPEG23. python求crc32值的法4. 關(guān)于python實現(xiàn)CRC32的應(yīng)和總結(jié)5. python crc32()函數(shù)和C+計算crc326. C# CRC32校驗 之 CRC-32/MPEG-2算法crc.pyReverts bit order of the given numberArgs:for i in range(width):if (num i) &1 != 0:reflected |= 1 (width - 1 - i)return reflecte

2、ddef make_table(width):Create static sized CRC lookup table and initialize it with 0.initializer =(0 for _ in range(256)if width =8:return array.array(B, initializer)elif width =16:return array.array(Q, initializer)else:width (int): Number of bits of the polynomialpolynomial (int): CRC polynomialdef

3、 _init_(self, width, polynomial, initial_value, final_xor_value,input_reflected , result_reflected):self.width =widthself.msb_mask =0 x01 (self.width - 1)self.reflected_table =Nonedef _call_(self, value):Compute the CRC checksum with respect to the model parameters by usingself.table =self.calculate

4、_crc_table()crc =self.initial_valuefor cur_byte in value:if self.input_reflected:cur_byte =reflect(cur_byte, 8)# Update the MSB of the CRC value with the next input bytecrc =(crc (cur_byte (self.width - 8) &self.cast_mask# This MSB byte value is the index into the lookup tablecrc =(crc 8) &self.cast

5、_mask# XOR-ing remainder from the loopup tablecrc =crc self.reflected_tableindex# Final XBORreturn crc self.final_xor_valuefor divident in range(256):cur_byte =(divident (self.width - 8) &self.cast_maskcur_byte = self.polynomialelse:cur_byte =1reflected_divident =reflect(divident, 8)cur_byte = self.

6、polynomialelse:=(8, 0 x1d, 0 xff, 0 xff, False, False)crc8_cdma2000crc8_darccrc16_ccit_zerocrc16_arccrc16_cdma2000crc16_dds_110crc16_dect_rcrc16_dect_xcrc16_dnpcrc16_acrc16_kermitcrc16_modbuscrc16_x25crc16_xmodem=(16, 0 x1021, 0 x0000, 0 x0000, False, False)crc32crc32_d=(32, 0 xa833982b, 0 xffffffff

7、, 0 xffffffff, True, True)=(32, 0 x04c11db7, 0 xffffffff, 0 x00000000, False, False)=(32, 0 x04c11db7, 0 x00000000, 0 xffffffff, False, False)=(32, 0 x814141ab, 0 x00000000, 0 x00000000, False, False)=(32, 0 x04c11db7, 0 xffffffff, 0 x00000000, True, True)=(32, 0 x000000af, 0 x00000000, 0 x00000000, False, False)assert crc16_ccit_zero(bHello world!) = 0 x39dbassert crc16_x25(bHello world!) = 0 x8edbcrc_test.pybyte_length =len(tempData)for i in range(byte_