OpenCv can't open camera by index

Question

OS

Ubuntu 20.04

OPENCV Version

4.4.0

Language

Python 3.8.5

Code and prob description:

I am trying to learn and play with OPENCV, but I am encountering a weird problem. I can not use web cam with opencv. Web cam is working with Cheese Application. I have tried multiple solutions from this answer, but none work.

I inspected code line by line, and got that error is on cv2.VideoCapture(index)

In [1]: import cv2

In [2]: cv2.VideoCapture(0)
[ WARN:0] global /tmp/pip-req-build-a3np7pha/opencv/modules/videoio/src/cap_v4l.cpp (893) open VIDEOIO(V4L2:/dev/video0): can't open camera by index
Out[2]: <VideoCapture 0x7f1773353550>

In [3]: cv2.VideoCapture(-1)
[ WARN:0] global /tmp/pip-req-build-a3np7pha/opencv/modules/videoio/src/cap_v4l.cpp (893) open VIDEOIO(V4L2:/dev/video0): can't open camera by index
Out[3]: <VideoCapture 0x7f1773304990>

In [4]: cv2.VideoCapture(1)
[ WARN:0] global /tmp/pip-req-build-a3np7pha/opencv/modules/videoio/src/cap_v4l.cpp (893) open VIDEOIO(V4L2:/dev/video1): can't open camera by index
Out[4]: <VideoCapture 0x7f17733048b0>

First connect your usb camera, test it with windows app camera if it work that's ok. Then try open it with opencv.. if don't work it: `cv2.VideoCapture(0)` try it `cv2.VideoCapture(1)` — Freddy Daniel, Mar 22 '21 at 22:55
@FreddyDaniel I have a built-in webcam, that is already working. — Ahmad Anis, Mar 23 '21 at 05:53
What I remember is that you have to close all the windows by Opencv correctly first. i.e cv2.destroyallwindows and then this might work. Any other application must not be using webcam at that tine. Restarting might help; — Ahmad Anis, Apr 21 '22 at 18:25

OpenCv can't open camera by index

OS

OPENCV Version

Language

Code and prob description:

0 Answers0