python opencv 将图片保存为视频

#!/usr/bin/env python
import cv2
from cv2 import VideoWriter,VideoWriter_fourcc,imread,resize
import os
img_root="/home/zhang/20201024/yolo"
#Edit each frame's appearing time!
fps=5
#fourcc=VideoWriter_fourcc(*"MJPG")
#videoWriter=cv2.VideoWriter("./Vid.avi",fourcc,fps,(720,720))
videoWriter = cv2.VideoWriter('yolo.avi', cv2.VideoWriter_fourcc('M','P','E','G'), fps, (720,720))
im_names=os.listdir(img_root)
#for im_name in range(len(im_names)):
for filename in os.listdir(img_root):
    #frame=cv2.imread(img_root+str(im_name)+'.jpg')
    imgname="/home/zhang/20201024/yolo/"+filename
    frame=cv2.imread(imgname)
    frame=cv2.resize(frame,(720,720))
    print imgname
    #cv2.imshow("frame", frame)
    videoWriter.write(frame)
    cv2.waitKey(1)
videoWriter.release()