实现8比特字节的RS纠错编码，可以指定极性校验字节数目，能产生的最大校验序列长度为255字节（含极性校验字节）.This is an implementation of a Reed-Solomon code with 8 bit bytes, and a configurable number of parity bytes. The maximum sequence length (codeword) that can be generated is 255 bytes, including parity bytes.