can't open camera by index

Asked Sep 07 '22 at 16:52

Active Sep 07 '22 at 20:08

Viewed 1,240 times

OS: ubuntu 18.04

class VideoThread(QThread):
    change_pixmap_signal = pyqtSignal(np.ndarray)

    def __init__(self) -> None:
        super().__init__()
        self._run_flag = True

    def run(self) -> None:
        # capture from web cam
        cap = cv2.VideoCapture(0)
        while self._run_flag:
            ret, cv_img = cap.read()
            if ret:
                self.change_pixmap_signal.emit(cv_img)
        # shut down capture system
        cap.release()

I used the above code to capture images using a webcam, but I got some errors like below mentioned

i tried cap = cv2.VideoCapture(1) & cap = cv2.VideoCapture(-1) both methods also failed

Now how to resolve this issue?

[ WARN:0] global /io/opencv/modules/videoio/src/cap_v4l.cpp (887) open VIDEOIO(V4L2:/dev/video0): can't open camera by index

edited Sep 07 '22 at 20:08

Christoph Rackwitz

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asked Sep 07 '22 at 16:52

Looks like a duplicate of https://stackoverflow.com/questions/59371075/opencv-error-cant-open-camera-through-video-capture#61817613 ? – Markus Sep 07 '22 at 18:48
if you have the rep, you should flag this question as a duplicate. – Christoph Rackwitz Sep 07 '22 at 20:08
what makes you think your computer even has a camera? did you try accessing it with any other program? – Christoph Rackwitz Sep 07 '22 at 20:09
Put this in self.run() in def __init__(self) -> None: – toyota Supra Sep 08 '22 at 09:41

can't open camera by index

0 Answers0