<VideoWriter object> = cv2.VideoWriter(filename, fourcc, fps, frameSize)
使用 cv2.VideoWriter_fourcc()来确定视频编码格式
fourcc = cv2.VideoWriter_fourcc('X', 'V', 'I', 'D') <br>output = cv2.VideoWriter("output.avi", fourcc, 20, (640, 480))
fourcc = cv2.VideoWriter_fourcc(*'XVID') <br>output = cv2.VideoWriter("output.avi", fourcc, 20, (640, 480))
