VideoWriter outputs corrupted video file

Question

This is my code to save web_cam streaming. It is working but the problem with output video file.

import numpy as np
import cv2

cap = cv2.VideoCapture(0)

# Define the codec and create VideoWriter object
#fourcc = cv2.cv.CV_FOURCC(*'DIVX')
#out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
out = cv2.VideoWriter('output.avi', -1, 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

# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()

Answer 1

The output file is corrupted because of the wrong frame rate and frame resolution. Using this code :

out = cv2.VideoWriter('output.avi', -1, 20.0, (640,480))

We set the fps/frame rate per second 20. Which was not correct. Also, the frame width and height was wrong. I solved by getting fps, width, height from the captured web_cam profile.

cap = cv2.VideoCapture(0)  #web-cam capture

fps = cap.get(cv2.CAP_PROP_FPS)
width  = cap.get(cv2.CAP_PROP_FRAME_WIDTH)   # float
height = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)  # float
out = cv2.VideoWriter('output.avi', -1,fps, (int(width), int(height)))