算数编码，包括： 对文件符号进行概率统计，生成编码表； 对文件进行压缩编码； 对文件进行解压缩，比较原始数据和解压后的数据之间是否有损耗。(Arithmetic coding, including: The probability statistics of the file symbols are carried out and the coding table is generated. Compress and encode the file. The file is deco