Some USB webcams come with capture buttons. Does anyone know if these buttons are hardware triggers or does the OS issue the capture command when the capture event is detected (thus a huge delay)? I've tried pressing the button, but I don't get a response in Ubuntu. Does pressing the button trigger a 'software capture' somehow?
You may need to get software for the camera that allows for the utilization of the button. If there is none, you could also try to make a macro or something that will start a capture when the button is pressed. (Such as AutoHotKey, though that's for keyboard macros. AutoKey for Ubuntu: https://code.google.com/archive/p/autokey/downloads)
It's also possible that the camera was made for Windows and not Ubuntu. This would mean that if, when the button is pressed, the camera searches for the Windows Camera program, it can't find it, so nothing happens.
Hope this helps!