cv2 playing video from frames code example

Example 1: how to read video in opencv python

import numpy as np
import cv2
cap = cv2.VideoCapture('videos/wa.avi')
while(cap.isOpened()):
  ret, frame = cap.read()
  gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  cv2.imshow('frame',gray)
  if cv2.waitKey(1) & 0xFF == ord('q'):
    break

cap.release()
cv2.destroyAllWindows()

Example 2: read live video from usb opencv python

import cv2
cap = cv2.VideoCapture()
# The device number might be 0 or 1 depending on the device and the webcam
cap.open(0, cv2.CAP_DSHOW)
while(True):
    ret, frame = cap.read()
    cv2.imshow('frame', frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows()