CODEWITHSUNDEEP
pythonnumpyopencv
ZAS
ZAS

Reputation: 1

Opencv write Video is running but the saved output.avi file is 0KB

I have tried different methods but none of them works. As video is running but and file output.avi is empty.

Here is code

import cv2
vid=cv2.VideoCapture(0)
if (not vid.isOpened()):
    print 'Error'
size = (int(vid.get(3)), int(vid.get(4)))
fourcc = cv2.cv.CV_FOURCC('M','J','P','G')
newVideo=cv2.VideoWriter('output.avi',fourcc,20.0,(640,360))
while(vid.isOpened()):
    ret,frame=vid.read()
    if ret is True:
       
        frame=cv2.flip(frame,0)
    
        newVideo.write(frame)
        cv2.imshow('frame',frame)
        if cv2.waitKey(1)& 0xFF==ord('q'):
            break
    
    else:
        break
vid.release()
newVideo.release()
cv2.destroyAllWindows()

Upvotes: 0

Views: 530

Answers (2)

Ahx
Ahx

Reputation: 8005

You need to be sure that the output frame's dimension and initialized VideoWriter dimensions are the same.

cv2.resize(frame, (640, 360))

But, I'm not sure you are using python3. Since print 'Error' and fourcc = cv2.cv.CV_FOURCC('M','J','P','G') are not python3 statements.

For python2 the answer will be:

# Add true at the and of the parameter for specifying the frames are RGB.
newVideo = cv2.VideoWriter('output.avi', fourcc, 20.0, (640, 360), True) 
.
.
if ret is True:
    frame=cv2.flip(frame,0)
    
    frame = cv2.resize(frame, (640, 360))  # missing statement

    newVideo.write(frame)
    cv2.imshow('frame',frame)
    .
    .

For python3 the answer will be:

import cv2

vid = cv2.VideoCapture(0)
if not vid.isOpened():
    print('Error')

fourcc = cv2.VideoWriter_fourcc(*"MJPG")
newVideo = cv2.VideoWriter('output.avi', fourcc, 20.0, (640, 360), True)

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

        frame = cv2.resize(frame, (640, 360))

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

cv2.destroyAllWindows()
vid.release()
newVideo.release()

Upvotes: 1

Yunus Temurlenk
Yunus Temurlenk

Reputation: 4367

The problem is simple, you are reading frame but you are trying to write them in a different size.

The solution is inside of your code. You defined:

size = (int(vid.get(3)), int(vid.get(4)))

But you didn't use it as like:

newVideo=cv2.VideoWriter('output.avi',fourcc,20.0,size)

You set the sizes as manually(640,360) which is not the size of captured frames.

Upvotes: 1

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