python opencv取视频设备-采集视频帧;读取视频帧``` import cv2 cv2.namedWindow

import cv2

cv2.namedWindow('video', cv2.WINDOW_NORMAL)
# 设置窗口大小
cv2.resizeWindow('video', 640, 480)
# 获取视频设备-采集视频帧
# cap = cv2.VideoCapture(1)
# 读取视频帧
cap = cv2.VideoCapture('D:\Download\download\xxxxx.mp4')

# 退出与显示逻辑
print(ord('q'))
while True:
    # 从摄像头获取视频帧
    ret,frame = cap.read()
    # 显示视频帧在窗口
    cv2.imshow('video',frame)
    key = cv2.waitKey(22)
    # key = cv2.waitKey(1)

    if key & 0xFF == ord('q'):
        break
    # elif key & 0xFF == ord('s'):
        # cv2.destroyAllWindows()
        # cv2.imwrite('C:\Users\shaog\Pictures\12333333.jpeg', img)
    else:
        print(key)

cap.release()
cv2.destroyAllWindows()