Opencv将视频作为output.avi从视频文件而不是从网络摄像头写入

Question

我试图写一个视频从视频文件它不工作，但当我使用网络摄像头代码它的工作 有两个文件，一个是file.py，另一个是web.py 这是我的文件.py

import numpy as np
import cv2

cap = cv2.VideoCapture('People - 6387.mp4')

fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640,480))

while(cap.isOpened()):
    ret, frame = cap.read()
    if ret==True:
        frame = cv2.flip(frame,0)


        out.write(frame)

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

out.release()

cv2.destroyAllWindows()

这是我的网络摄像头。这是正常工作和编写视频

import numpy as np
import cv2

cap = cv2.VideoCapture(0)

fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640,480))

while(cap.isOpened()):
    ret, frame = cap.read()
    if ret==True:
        frame = cv2.flip(frame,0)


        out.write(frame)

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

out.release()

cv2.destroyAllWindows()`