实现了一个AVICap窗口类的CAviCap类,它提供了基于消息接口的访问音频和视频的应用,可以控制播放过程并支持视频捕获到磁盘。-achieved a kind of window AVICap CAviCap category, It provides a message-based interface visit Audio and video applications, can control the process and support broadcast video capture