# import the necessary packages

from threading import Thread

import cv2

class WebcamVideoStream:

    def __init__(self, resolution, src=0, name="WebcamVideoStream"):

        # initialize the video camera stream and read the first frame

        # from the stream

        assert isinstance(resolution, tuple) and len(resolution) == 2

        self.stream = cv2.VideoCapture(src)

        self.stream.set(3, resolution[0])

        self.stream.set(4, resolution[1])

        (self.grabbed, self.frame) = self.stream.read()

        # initialize the thread name

        self.name = name

        # initialize the variable used to indicate if the thread should

        # be stopped

        self.stopped = False

    def start(self):

        # start the thread to read frames from the video stream

        t = Thread(target=self.update, name=self.name, args=())

        t.daemon = True

        t.start()

        return self

    def update(self):

        # keep looping infinitely until the thread is stopped

        while True:

            # if the thread indicator variable is set, stop the thread

            if self.stopped:

                return

            # otherwise, read the next frame from the stream

            (self.grabbed, self.frame) = self.stream.read()

    def read(self):

        # return the frame most recently read

        return self.frame

    def stop(self):

        # indicate that the thread should be stopped

        self.stopped = True