file_video_stream.py

class FileVideoStream:
    def __init__(self, path, workers=6, queue_size=128):
        # Get number of frame
        self.nb_frame = imutils.video.count_frames(path)

        # Compute number of frame per workers
        self.bias = math.ceil(self.nb_frame / workers)

        # self.stream = cv2.VideoCapture(path)
        self.streams = {}

        for i in range(1, workers):
            start = (i * self.bias) - self.bias
            stream = cv2.VideoCapture(path)
            stream.set(cv2.CAP_PROP_POS_FRAMES, start)

            self.streams[start] = {
                "stream": stream,
                "queue": Queue(maxsize=queue_size),
                "stopped": False
            }

            print(self.streams[start]["stream"])

    def start(self):
        t = {}

        # start multiple thread to read frames from the file video stream
        for key in self.streams:
            t[key] = Thread(target=self.update, args=(key, ))
            t[key].daemon = True
            t[key].start()

        return self

    def update(self, index):
        stream = self.streams[index]["stream"]
        queue = self.streams[index]["queue"]
        stopped = self.streams[index]["stopped"]

        i = index
        last_frame_index = index + self.bias

        while True:
            if stopped or i > last_frame_index:
                return

            i = i + 1

            if not queue.full():
                grabbed, frame = stream.read()
                if not grabbed:
                    self.stop(index)
                    return

                # add the frame to the queue
                queue.put(frame)

    def stop(self, index):
        # indicate that thread should stop
        self.streams[index]["stopped"] = True

    def read(self, index):
        # return next frame in the queue
        return self.streams[index]["queue"].get()

    def more(self, index):
        # Return True if there are still frames in the queue
        return self.streams[index]["queue"].qsize() > 0