from camera

import cv2 as cv
cap = cv.VideoCapture(0)

define the codec and create VideoWriter object

fourcc = cv.VideoWriter_fourcc(*'XVID')

out = cv.VideoWriter('output.avi', fourcc, 20.0, (640,480))
while(1):
ret, frame = cap.read()

if ret ==True:
    out.write(frame.astype('uint8'))
    cv.namedWindow('frame', cv.WINDOW_NORMAL)
    cv.imshow('frame', frame)
    if cv.waitKey(1) & 0xFF == ord('q'):
        break
else:
    break

cap.release()
out.release()
cv.destroyAllWindows()

cv2.VideoWriter_fourcc('I', '4', '2', '0'),该参数是YUV编码类型，文件名后缀为.avi

cv2.VideoWriter_fourcc('P', 'I', 'M', 'I'),该参数是MPEG-1编码类型，文件名后缀为.avi

cv2.VideoWriter_fourcc('X', 'V', 'I', 'D'),该参数是MPEG-4编码类型，文件名后缀为.avi

cv2.VideoWriter_fourcc('T', 'H', 'E', 'O'),该参数是Ogg Vorbis,文件名后缀为.ogv

cv2.VideoWriter_fourcc('F', 'L', 'V', '1'),该参数是Flash视频，文件名后缀为.flv

--------------------------------------------------关于视频不能正常写入
1---img = cv2.resize(image, (hight, wight))；在写入前需要对图片尺寸进行重新赋值
2---