自己写的一个wavetotext的代码。鉴于网上大多数都不可用，或者用起来很麻烦。解决了由软件生成的wave,fmt字段16位转18位多出两位的问题,Write a wavetotext their own code. In view of the majority is not available online, or use up a lot of trouble. Solved by software-generated wave, fmt field is 16-bit transfer