Re: OpenCV on 6.9 can't open camera

On Mon, Aug 09, 2021 at 11:56:36AM -0600, Jeff Ross wrote:
>
> Hi,
>
> I'm porting a python3 program I wrote for capturing jpegs from a USB based
> webcam, using OpenCV for capture and post-processing.?? I was running this
> on a RaspberryPi 3B+ under linux but I'm sick of battling crappy hardware
> and linux so I bought a Mini PC stick and installed 6.9.?? (dmesg follows)
>
> OpenCV (installed from the package) doesn't seem to be able to open the
> camera. The camera (in this case for testing a Logitech C910) can be
> accessed no problem with ffplay, fswebcam and video(1).?? I also opened the
> kern sysctls for both audio and video and chowned /dev/video to my user.
>
> jross@aurora-cam:/home/jross $ fswebcam?? -d v4l2:/dev/video0 -F3 --save
> test2.jpg
> --- Opening v4l2:/dev/video0...
> /dev/video0 opened.
> No input was specified, using the first.
> Adjusting resolution from 384x288 to 432x240.
> --- Capturing 3 frames...
> Captured 3 frames in 0.06 seconds. (46 fps)
> --- Processing captured image...
> Writing JPEG image to 'test2.jpg'.
>
> OpenCV not so much though:
>
> jross@aurora-cam:/home/jross $ cat open_test.py
> import cv2 as cv
> import subprocess
>
> cap = cv.VideoCapture(0, cv.CAP_V4L2)
> print(cap)
> if not cap.isOpened():
> ?????? print("Open Failed!")
> elif cap.isOpened():
> ?????? print("Open Succeeded!")
>
> height = cap.get(cv.CAP_PROP_FRAME_HEIGHT)
> width = cap.get(cv.CAP_PROP_FRAME_WIDTH)
> exposure = cap.get(cv.CAP_PROP_AUTO_EXPOSURE)
>
> print(height,width,exposure)
> frame = []
> try:
> ?????? ret, temp_frame = cap.read()
> ?????? print(ret)
> except Exception as e:
> ?????? print(e)
> ?????? #kill anything else using the camera
> ?????? pid = subprocess.check_output("fuser -k
> /dev/video0",stderr=subprocess.STDOUT, shell=True)[:-1].decode('utf-8')
> ?????? print("Exception caught! %s" % (e))
> frame.append(temp_frame)
> print(frame)
>
> jross@aurora-cam:/home/jross $ python3 open_test.py
> <VideoCapture 0x6ead5ca5570>
> Open Failed!
> 0.0 0.0 0.0
> False
> [None]
>
> I'd appreciate anyone's thoughts on fixing this!

Hi, I encountered the same problem. Just committed a fix:
https://marc.info/?l=openbsd-ports-cvs&m=162857744213080&w=2

> Jeff Ross

Kevin