这是一个Linux下的USB摄像头捕捉程序，是一个调用v4l2 （Video for Linux 2）非常好的例子。英文介绍为：This is a driver for the USB video bridge USBVision from Zoran/Nogatech, a USB-only cable used in many \"webcam\" devices. It supports streaming and capture of color or monochrome video