OpenCV获取Usb相机视频流

一、设备：使用相机 BMT相影720p
二、一般usb摄像头在linux下的节点都为video，此处在我的pc上摄像头设备节点为/dev/video1，
所VideoCapture传入参数为201
三、关于属性可以查找以下链接：
https://docs.opencv.org/3.2.0/d4/d15/group__videoio__flags
__base.html#gaeb8dd9c89c10a5c63c139bf7c4f5704d

#!/usr/bin/env python
# *-* coding:utf-8 *-*

import cv2

def main():
    capture = cv2.VideoCapture(201)

    #获得码率及尺寸  
    fps = capture.get(cv2.CAP_PROP_FPS)  
    size = (int(capture.get(cv2.CAP_PROP_FRAME_WIDTH)),   
            int(capture.get(cv2.CAP_PROP_FRAME_HEIGHT))) 
    fourcc = cv2.VideoWriter_fourcc(*'MJPG')
    #TypeError: 'int' object is not callable
    #fourcc = cv2.CAP_PROP_FOURCC('M', 'J', 'P', 'G')

    #指定写视频的格式, I420-avi, MJPG-mp4  
    #videoWriter = cv2.VideoWriter('oto_other.mp4', fourcc, 20.0, (640,480))
    videoWriter = cv2.VideoWriter('oto_other1.mp4', fourcc, fps, size)

    #判断是否正常开启
    print capture.isOpened()
    frameNum = 1
    while(capture.isOpened()):
        _, frame = capture.read()
        print frameNum
        frameNum += 1
        #frame = cv2.resize(frame, (960, 540))
        cv2.imshow('frame', frame)
                videoWriter.write(frame) #写视频帧

        '''
        #每10帧存储一张图片
        if frameNum%10 == 1:
            cv2.imwrite('image'+str(frameNum)+'.jpg', frame)
        '''
        if cv2.waitKey(1) == ord('q'):
            break

    capture.release()
    cv2.destroyAllWindows()

if __name__ == '__main__':
    main()

关于fourcc函数：

fourcc()
static int cv::VideoWriter::fourcc  (   char    c1,
char    c2,
char    c3,
char    c4 
)       

Concatenates 4 chars to a fourcc code.
Returns a fourcc code
This static method constructs the fourcc code of the codec to be used in
the constructor VideoWriter::VideoWriter or VideoWriter::open