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 decompressed to compare the loss between the original data and the decompressed data.)