python opencv剪切视频成多张图片

import cv2
# 将视频文件按照每秒一张图进行抓取图片
file = '123.mp4'
# path = file[:file.index('.')]
 
vc = cv2.VideoCapture(file)  # 读入视频文件
f = 1
i = 1
if vc.isOpened():  # 判断是否正常打开
    rval, frame = vc.read()
else:
    rval = False
 
timeF = 25  # 视频帧计数间隔频率
 
while rval:  # 循环读取视频帧
    rval, frame = vc.read()
    if f % timeF == 0:  # 每隔timeF帧进行存储操作
        cv2.imwrite('imgs\\' + str(i) + '.jpg', frame)  # 存储为图像
        i = i + 1
        print("i："+str(i)+',frame:'+str(f))
    f = f + 1
    cv2.waitKey(1)
vc.release()