When I try to select a device in the guvcview video controls tab, I see a menu where there are two identical entries for each physical device. Apparently selecting the first device of a given type results in video being displayed correctly, whereas selecting the second causes guvcview to hang.
I have a Logitech webcam and a USB Microscope. It is the microscope that causes the problems - only a single instance of the webcam is in the device menu until I plug in the microscope, then both the webcam and microscope entries appear doubly.
I have googled the issue and now believe that the second entry is a virtual device giving meta data about the second (this thread gives an explanation). v4l2-ctl shows both devices:
Code:
paul@clio:~$ v4l2-ctl --list-devices
UVC Camera (046d:0994) (usb-0000:00:14.0-13):
/dev/video0
/dev/video1
Digital microscope: Digital mic (usb-0000:00:14.0-5.1.1):
/dev/video2
/dev/video3
I have two questions:
Why do I only see the menu entries doubled up after I plug in the microscope ?
Is there any way to prevent guvcview doing this annoying behaviour ?
Many thanks.