OpenCv error can't open camera through video capture

Question

I was using my cam through opencv and suddenly after restarting I ran my code it shows below error:

[ WARN:0] global /io/opencv/modules/videoio/src/cap_v4l.c         


        

Answer 1

I had the same problem, Just change 0 to 1,then to -1 and back again to 0. Don't know why this worked for me.