USB Webcam does not work in the newer version: 4.7.0.72

[gunarakulangunaretnam]

USB Webcam does not work in the newer version: 4.7.0.72

I wrote a simple script to read frames from a webcam, it works fine with laptop-attached webcams. When I try to use with the USB-based webcam (not-branded webcam), it returns the following error.

[ WARN:[email protected]] global cap_msmf.cpp:1759 CvCapture_MSMF::grabFrame videoio(MSMF): can't grab frame. Error: -2147024809

My Code:

import cv2


cap = cv2.VideoCapture(2)

while True:

    
    ret, frame = cap.read()
    

    if ret:

        cv2.imshow('Input', frame)
    else:
        print("dsd")

    c = cv2.waitKey(1)
    if c == 27:
        break

When I install the older version of OpenCV-python: 4.5.5.62, it works fine, I think the issue is with the newer release.

Please take a consideration on it.

[asmorkalov]

could you run the same code with old and new OpenCV versions with debug options and collect logs. To enable debug logging you need to set the following environment variables OPENCV_LOG_LEVEL=DEBUG, OPENCV_VIDEOIO_DEBUG=1

[harshkasat]

I'm also getting this error with the USB webcam. Does anyone have a solution regarding this?

[asmorkalov]

Please try the previous recommendation to give us information for debugging.

[asmorkalov]

Please try the previous recommendation to give us information for debugging.

[Maculapse]

Hi! I can confirm the same problem with 4.8.x version using usb cam. Had to downgrade to 4.5 to get it working, as mentioned by the author.

[asmorkalov]

@Maculapse could you run the same code with old and new OpenCV versions with debug options and collect logs. To enable debug logging you need to set the following environment variables OPENCV_LOG_LEVEL=DEBUG, OPENCV_VIDEOIO_DEBUG=1

[ArptPlank]

我也是4.8版本也遇到这个问题，自己的电脑上没问题，在客户的电脑上死活不行