Can't save video on Raspberry PI by using python with OpenCV

Question

import cv
import cv2
cap = cv2.VideoCapture(0)
cap.set(8,100)
out = cv2.VideoWriter('/home/pi/Desktop/output.mp4',cv2.cv.CV_FOURCC('D','I','V','X'),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(10) == 27: 
            break
cv2.VideoCapture(0).release()
out.release()
cv2.destroyAllWindows()

This code worked but it never stopped and no video file had been saved. Does anyone know how to solve this? Thanks a lot.

Do the frames show up on the screen? Are the frames exactly 640x480 pixels? What happened when you pressed Escape? — w-m
– w-m, Commented Mar 6, 2014 at 17:35
@w.m Sorry i just saw the comment. Yes, the frames showed up on the screen and it was exactly 640*480. When i pressed ESC, an error occurred. It displayed that cv2.VideoWriter object has no attribute 'release' — VaFancy
– VaFancy, Commented Mar 6, 2014 at 22:19

w-m · Accepted Answer · 2014-03-06 22:39:02Z

2

Both release() calls can be removed.

cv2.VideoCapture(0).release()

would call release() on a new VideoCapture, what you meant was cap.release().

For the VideoWriter, the release method doesn't exist - you don't have to care about releasing the VideoWriter or VideoCapture in Python. They will be released when their object is destroyed at the end of your program.

answered Mar 6, 2014 at 22:39

w-m

11.3k1 gold badge46 silver badges51 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

VaFancy Over a year ago

Thank you for answering me. I tried remove this line, but a new error occurs. "object has no attribute 'destroyAllWindows'"

VaFancy Over a year ago

And when I used "DestroyWindow('frame')", it had the same problem.

VaFancy Over a year ago

My spelling mistake. But I typed the right version in my script while having this problem.

w-m Over a year ago

And you corrected it to Window_S_, too? OpenCV does have a destroyAllWindows() method, and you are correct to call it there.

VaFancy Over a year ago

Yes,"cv2.destoryAllWindows()". It won't work, and shows object has no attribute 'destoryAllWindows'. The version of python and opencv i used are 2.7.3 and 2.3.1.

|

Collectives™ on Stack Overflow

Can't save video on Raspberry PI by using python with OpenCV

1 Answer 1

8 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

8 Comments

Your Answer

Sign up or log in

Post as a guest

Related