求基音周期，用C语音编写，处理pcm文件，用自相关算法求基音周期。-Find the pitch period, with the C language preparation, processing pcm file, auto-correlation algorithm for pitch.

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