使用 python 和 opencv 保存视频时出错

Question

This is the code to save video from the web cam

import numpy  
import cv2 
cap = cv2.VideoCapture(0)

# Define the codec and create VideoWriter object 
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)
        # write the flipped frame
        out.write(frame)
        cv2.imshow('frame',frame)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    else:
        break

cap.release() 
out.release() 
cv2.destroyAllWindows()

When I Run It In python it gives the following error

> raceback (most recent call last):    File
> "C:\Users\Prakash\Desktop\Image Proccessing\c.py", line 6, in <module>
> fourcc = cv2.VideoWriter_fourcc(*'XVID')  AttributeError: 'module'
> object has no attribute 'VideoWriter_fourcc'

Please help me solve this error

Answer 1

Python / OpenCV 2.4.9 doesn't support cv2.VideoWriter_fourcc, which is version 3.x. If you're using 2.4.x:

replace fourcc = cv2.VideoWriter_fourcc(*'XVID')

with fourcc = cv2.cv.CV_FOURCC(*'XVID')

Good example here How to Record Video Using OpenCV and Python Reproduced for reference:

#!/usr/bin/env python 
import cv2

if __name__ == "__main__":
    # find the webcam
    capture = cv2.VideoCapture(0)

    # video recorder
    fourcc = cv2.cv.CV_FOURCC(*'XVID')  # cv2.VideoWriter_fourcc() does not exist
    videoOut = cv2.VideoWriter("output.avi", fourcc, 20.0, (640, 480))

    # record video
    while (capture.isOpened()):
        ret, frame = capture.read()
        if ret:
            videoOut.write(frame)
            cv2.imshow('Video Stream', frame)

        else:
            break

        # Tiny Pause
        key = cv2.waitKey(1)

    capture.release()
    videoOut.release()
    cv2.destroyAllWindows()

Answer 2

Maybe the question is answered long ago.

Here is a workaround solution if you met this problem in whatever version.

Refer to "opencv doc": https//github.com/opencv/opencv/search?q=CV_FOURCC&unscoped_q=CV_FOURCC

#define CV_FOURCC_MACRO(c1, c2, c3, c4) \
(((c1) & 255) + (((c2) & 255) << 8) + (((c3) & 255) << 16) + (((c4) & 255) << 24))

So simply define

def fourcc(a,b,c,d):
    return return ((ord(a) & 255) + ((ord(b) & 255) << 8) + ((ord(c) & 255) << 16) + ((ord(d) & 255) << 24))