捕获arm开发板上中心威等厂家usb摄像头图像，可用来测试linux驱动安装是否正确-capture arm Development Center, and other board manufacturers usb camera images, Linux can be used to test whether the correct driver installation

v4l2在linux视频采集底层驱动，完全实现在linux下usb摄像头的视频采集，希望大家多多提意见！-v4l2 video capture underlying driver in linux, fully realized under linux usb camera video capture, I hope you do so!