read_qrcode_live.py

import cv2

# initalize the cam
cap = cv2.VideoCapture(0)

# initialize the cv2 QRCode detector
detector = cv2.QRCodeDetector()

while True:
    _, img = cap.read()

    # detect and decode
    data, bbox, _ = detector.detectAndDecode(img)

    # check if there is a QRCode in the image
    if bbox is not None:
        # display the image with lines
        for i in range(len(bbox)):
            # draw all lines
            cv2.line(img, tuple(bbox[i][0]), tuple(bbox[(i+1) % len(bbox)][0]), color=(255, 0, 0), thickness=2)

        if data:
            print("[+] QR Code detected, data:", data)

    # display the result
    cv2.imshow("img", img)
    
    if cv2.waitKey(1) == ord("q"):
        break

cap.release()
cv2.destroyAllWindows()