import numpy as np 
import cv2

cap = cv2.VideoCapture(0)

#Codec here that differes from format to format and OS to OS.

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:
        raise error('Video cannot be read')
        break

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