import numpy as np
import cv2

*** = cv2.VideoCapture('hhh.mp4')

while(***.isOpened()):
    ret, frame = ***.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    cv2.imshow('frame',gray)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

***.release()
cv2.destroyAllWindows()