The getUserMedia function lets you access (with permission) the cameras and microphones of your users. No plugins needed! What can you do once you have this media? The possibilities are endless.
getUserMedia 函数可以（在获得授权的情况下）访问用户的相机和麦克风，不需要借助插件。借助他能实现哪些功能？一切皆有可能。