对从txt文件中读取的数据做DPCM压缩.-compress the data readed from txt.

此代码为G.723.1语音压缩源代码，该代码经优化后压缩时间间缩短到原来的1/5，可用于语音数据的无线传输。 已通过测试。 -This code for G.723.1 voice compression source code, the code has been optimized to compress the time shortened to 1/5 can be used for wireless transmission of voice and data. Has been