import numpy as np
import cv2 as cv
cap = cv.VideoCapture('cams/10s.mp4')
while cap.isOpened():
 ret, frame = cap.read()
 # if frame is read correctly ret is True
 if not ret:
    print("Can't receive frame (stream end?). Exiting ...")
    break
    gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
    cv.imshow('frame', gray)
    if cv.waitKey(1) == ord('q'):
        break
        cap.release()
        cv.destroyAllWindows()