#==== openCV 3.0 (C )
#include <opencv2/opencv.hpp>
cvNamedWindow("openCV Video Capture Window",CV_WINDOW_AUTOSIZE) ;
frame = cvDecodeImage(&cvmat, 1) ;
cvShowImage("openCV Video Capture Window", frame) ;
#==== openCV 4.0 (C++)
#include <opencv2/highgui.hpp>
namedWindow("openCV Video Capture Window",WINDOW_AUTOSIZE) ;
frame = cvDecodeImage(&cvmat, 1) ;
cvShowImage("openCV Video Capture Window", frame) ;