And the capture button on the USB camera(or webcam), press the button must be treated with opencv-python that is captured.
AMCap (window 7) the capture button, the software was working well, guvcview (ubuntu) software was working well in the capture button.
However, the signals do not know how to handle the capture button on the opencv-python.
Let me know how you want to handle the signal. (in window 7/8)