directshow 为基础，封装了良好的类。用于 视频的获取和视频文件的读取，播放。 可以播放特定的时间段的视频文件。-directshow basis of a good Packaging category. Video for access and video files are read and broadcast. Can be broadcast at specific times of the video files.

实现连接摄像头，实时播放摄像头的画面，记录时间段内的视频画面。-Connect the camera screen, real-time playback of the camera, to record the time period of the video screen.