近期有需要，从视频里面提取图片，以前用软件搞的，但是现在视频太大了软件不能够一下全部将视频图片转换（因为电脑的内存不够），因此就想到使用程序读取一帧，保存一帧，然后清空，再循环-Recent need,　a video picture is extracted and used software make, but now the video is too big software is not able to all the pictures and video conversion (because the computer s memory is not enough, so he thought of using a program to read a frame, save a frame and empty, recycling