从指定文件中切割出指定大小的子文件，我用它将一个YUV序列的每一帧分割出来，然后又将每一帧的Y、U、V单独分割出来 -from the designated cut out for the specified size paper, I use it a YUV sequence of each frame to split up, and then each will frame the Y, U, V separate separated