use OpenCV to read stream from web_video_server

[khoatran94]

Hi, can OpenCV read the video stream?. I got a bug that is: 'can't find starting number (in the name of file): http://192.168.0.19:8080/stream_viewer?topic=/cv_camera/image_raw in function 'icvExtractPattern' ' when using cv2.VideoCapture(). I thought opencv accepts video stream as stated in their docs, and I am using OpenCV 4.1.2