樹莓派 python opencv 打開多個usb攝像頭

目前連接配接兩個usb攝像頭，具體程式如下，使用的是多程序的思想打開的攝像頭，若有其他方法，歡迎留言

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

import cv2
import numpy as np
import multiprocessing

def openCamera(port):
    cap = cv2.VideoCapture(port)
    cap.set(cv2.CAP_PROP_FOURCC, cv2.VideoWriter.fourcc('M', 'J', 'P', 'G'))  # 視訊流格式
    cap.set(cv2.CAP_PROP_FRAME_WIDTH, 640)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)
    width = cap.get(3)
    height = cap.get(4)
    print(width, height, cap.get(5))

    while True:
        ret, frame = cap.read()

        if not ret:
            print("get camera " + str(port) + " frame is empty")
            break

        title = "image" + str(port)
        cv2.imshow(title, frame)

        key = cv2.waitKey(10) & 0xff
        if key == ord('q'):
            break

    cap.release()
    cv2.destroyAllWindows()


if __name__ == '__main__':
    #多程序 樹莓派上偶數對應一個攝像頭
    cam1 = multiprocessing.Process(target=openCamera, args=(0,))
    cam1.start()

    cam2 = multiprocessing.Process(target=openCamera, args=(2,))
    cam2.start()
    
           

打開單個usb攝像頭程式如下

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

import cv2

if __name__ == '__main__':
    #SunplusIT Inc 攝像頭
    cap = cv2.VideoCapture(0)
    cap.set(cv2.CAP_PROP_FOURCC, cv2.VideoWriter.fourcc('M', 'J', 'P', 'G'))  # 視訊流格式
    cap.set(cv2.CAP_PROP_FRAME_WIDTH, 640)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)
    width = cap.get(3)
    height = cap.get(4)
    print(width, height, cap.get(5))

    while True:
        ret, frame = cap.read()

        if not ret:
            print("get camera frame is empty")
            break

        str = "image"
        cv2.imshow(str, frame)

        key = cv2.waitKey(10) & 0xff
        if key == ord('q'):
            break

    cap.release()
    cv2.destroyAllWindows()