Videoio Error: V4l: Can't Find Camera Device

I am using ubuntu16.04 and trying to run opencv script. when i use: video_capture = cv2.VideoCapture(-1) it gives me error VIDEOIO ERROR: V4L: can't find camera device No video wi

Solution 1:

The suggestion api55 gave in his comment

video_capture = cv2.VideoCapture(0)

is what I would try first.

Generally, you can list the available cameras with ls /dev/video* or v4l2-ctl --list-devices. Here sample output:

NZXT-U:rt-trx> v4l2-ctl --list-devices
Microsoft® LifeCamCinema(TM): (usb-0000:00:14.0-1):
    /dev/video1

Microsoft® LifeCamCinema(TM): (usb-0000:00:1a.0-1.3):
    /dev/video0

/dev/video0 corresponds to device id 0, etc.

PS: v4l2-ctl is quite useful for solving camera issues and can do much more than --list-devices. I installed it via packagev4l-utils on a 16.04 machine.

Solution 2:

Late, but to get mine working i put in terminal:

-ltrh /dev/video*

To get a list of the video devices that are plugged into my computer. Then for each one I did:

sudo chmod 777 /dev/videox

Where x was one of the video files that were listed, giving everything access to them. Probaly not the most secure solution, but it got my code working.