cv2读取视频文件并展示

vc = cv2.VideoCapture("./video/1-208.mp4" )
while vc.isOpened():
    # get a frame
    ret, frame = vc.read()
    if frame is None:
        break
    # show a frame
    if ret == True:
        frame = cv2.resize(frame,(400,400))
        frame = detect(frame)
        cv2.imshow("video", frame)
        if cv2.waitKey(20) & 0xFF == ord('q'):
            break

vc.release()
cv2.destroyAllWindows()