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.

从一个mpeg4视频文件中，抓取给定起始结束时间段内的图像，保存为jpeg格式，使用directshow实现

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.

一个电话计费程序，能够计算跨日通话费用的计算，并可以为一天设置三个时间段，他们的计时费用可异-A telephone billing program, is able to calculate the cost of跨日call basis, and can be set to three time a day, their cost may be different time