Python: OpenCVでカメラの映像を動画ファイルとして保存する

CameraImageToMovieFile.py

import cv2

cap = cv2.VideoCapture(0)
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))

# フォーマット指定
fmt = cv2.VideoWriter_fourcc('m', 'p', '4', 'v')
writer = cv2.VideoWriter('output.mp4', fmt, 25, (width, height))

while True:
    ret, frame = cap.read()
    if ret == False:
        break
    writer.write(frame)

cap.release()
writer.release()
cv2.destroyAllWindows()