Zero-Lag Multithreaded RTSP Frame Grabber in Python

import threading
import cv2
import time

class RTSPStreamReader:
    def __init__(self, rtsp_url):
        self.cap = cv2.VideoCapture(rtsp_url, cv2.CAP_FFMPEG)
        self.lock = threading.Lock()
        self.ret = False
        self.frame = None
        self.running = True
        self.thread = threading.Thread(target=self._update, daemon=True)
        self.thread.start()

    def _update(self):
        while self.running:
            ret, frame = self.cap.read()
            with self.lock:
                self.ret = ret
                self.frame = frame
            if not ret:
                time.sleep(0.1)

    def read(self):
        with self.lock:
            return self.ret, (self.frame.copy() if self.frame is not None else None)

    def stop(self):
        self.running = False
        self.thread.join()
        self.cap.release()