cv2_python_capture.py

import cv2
import time
import multiprocessing
import os

start_time = time.time()

# Used when trying to thread
def process_thread(ports):
    for i in ports:
        init_webcam(i)

# Slow, but used to count cameras. Works, but takes as long as taking pictures.
def count_cameras():
    for i in range(10):
        temp_camera = cv2.VideoCapture(i-1)
        retval, temp_frame = temp_camera.read()
        del(temp_camera)
        if temp_frame==None:
            del(temp_frame)
            return i-1 #MacbookPro counts embedded webcam twice

# Create the camera object and try to catch errors, but failed at catching exceptions
def init_webcam(port):
    try:
        cam = cv2.VideoCapture(int(port))
        dir(cam)
        # vars(cam)
        # print(cam)

        # exit()
        file = "images/" + str(start_time) + "-" + str(port) + ".png"
        take_picture(cam, file)
    except:
        print('No camera found on port %s' % str(port))

# Take the camera options, take a picture, then release the camera
def take_picture(cam, file):
    retval, camera_capture = cam.read()
    if camera_capture is not False: # Valid camera
        if cam.isOpened() == 1:
            # Needed for my camera, but maybe not for the others
            # retval, camera_capture = cam.read()

            cv2.imwrite(file, camera_capture)
            cam.release()
            # del (cam)
        # else: # Let's loop and let it try again
        #     time.sleep(1)
        #     take_picture(cam, file)

def show_webcam(mirror=False):
    if not os.path.exists('images'):
        os.makedirs('images')

    # portsA = []
    # portsB = []
    for i in range(0, 30):
        init_webcam(str(i))
        # if i % 2 == 0:
        #     portsA.append(str(i))
        # else:
        #     portsB.append(str(i))

        # Start thread 1
        # process_thread(portsA)

        # Start thread 2
        # a = multiprocessing.Process(target=process_thread, args=(portsA,))
        # a.start()
        #
        # time.sleep(1)
        # b = multiprocessing.Process(target=process_thread, args=(portsB,))
        # b.start()


        #
        #
        #
        # for i in portsA:
        #     # init_webcam(str(i))
        #
        #     jobs.append(j)
        # for j in jobs:
        #     j.start()


def main():
    show_webcam(mirror=True)
    print("--- %s seconds ---" % (time.time() - start_time))


if __name__ == '__main__':
    main()