求pcm文件的基音周期，用matlab编写，作图说明，用平均幅度差算法修正自相关算法来求基音周期-Find the pitch period pcm files, using matlab, plot descr iption, with the average magnitude difference algorithm for auto-correlation algorithm to find correct pitch

1.短时能量2．短时平均过零率3、短时自相关函数4.基音周期-1. The short-term energy 2. 3 short-time average zero-crossing rate, short-term autocorrelation function 4. Pitch