说明：  本文主要讲述用Directshow进行视频捕捉（捕捉静态图像）的编程思路，并提供针对摄像头编程的一个视频捕捉类CcaptureVideo和一个示例。
(This paper describes the video capture with Directshow (capture still images) of programming ideas, and to provide programming for a video camera capture class CcaptureVideo and an example.)