音频转化大师很好用http://www.baidu.com/s?ie=gb2312&bs=%D2%F4%C6%B5%D7%AA%BB%BB%B4%F3%CA%A6%CF%C2%D4%D8&sr=&z=&wd=%D2%F4%C6%B5%D7%AA%BB%AF%B4%F3%CA%A6%CF%C2%D4%D8&ct=0&cl=3&f=8
