说明：  读取一段视频的代码，注意需要命令行的形式运行，命令行的参数要给出视频文件名，视频文件必须要avi格式，并且放到debug中。
(Read the code section of the video, pay attention to the need for the form of command-line operation, command line parameters should be given video file name, must be avi video file format, and put in debug.)