lerobot/common/cameras/opencv/camera_opencv.py [410:472]:
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        if self.stop_event is not None:
            self.stop_event.set()

        if self.thread is not None and self.thread.is_alive():
            self.thread.join(timeout=2.0)

        self.thread = None
        self.stop_event = None

    def async_read(self, timeout_ms: float = 200) -> np.ndarray:
        """
        Reads the latest available frame asynchronously.

        This method retrieves the most recent frame captured by the background
        read thread. It does not block waiting for the camera hardware directly,
        but may wait up to timeout_ms for the background thread to provide a frame.

        Args:
            timeout_ms (float): Maximum time in milliseconds to wait for a frame
                to become available. Defaults to 200ms (0.2 seconds).

        Returns:
            np.ndarray: The latest captured frame as a NumPy array in the format
                       (height, width, channels), processed according to configuration.

        Raises:
            DeviceNotConnectedError: If the camera is not connected.
            TimeoutError: If no frame becomes available within the specified timeout.
            RuntimeError: If an unexpected error occurs.
        """
        if not self.is_connected:
            raise DeviceNotConnectedError(f"{self} is not connected.")

        if self.thread is None or not self.thread.is_alive():
            self._start_read_thread()

        if not self.new_frame_event.wait(timeout=timeout_ms / 1000.0):
            thread_alive = self.thread is not None and self.thread.is_alive()
            raise TimeoutError(
                f"Timed out waiting for frame from camera {self} after {timeout_ms} ms. "
                f"Read thread alive: {thread_alive}."
            )

        with self.frame_lock:
            frame = self.latest_frame
            self.new_frame_event.clear()

        if frame is None:
            raise RuntimeError(f"Internal error: Event set but no frame available for {self}.")

        return frame

    def disconnect(self):
        """
        Disconnects from the camera and cleans up resources.

        Stops the background read thread (if running) and releases the OpenCV
        VideoCapture object.

        Raises:
            DeviceNotConnectedError: If the camera is already disconnected.
        """
        if not self.is_connected and self.thread is None:
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lerobot/common/cameras/realsense/camera_realsense.py [480:543]:
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        if self.stop_event is not None:
            self.stop_event.set()

        if self.thread is not None and self.thread.is_alive():
            self.thread.join(timeout=2.0)

        self.thread = None
        self.stop_event = None

    # NOTE(Steven): Missing implementation for depth for now
    def async_read(self, timeout_ms: float = 200) -> np.ndarray:
        """
        Reads the latest available frame data (color) asynchronously.

        This method retrieves the most recent color frame captured by the background
        read thread. It does not block waiting for the camera hardware directly,
        but may wait up to timeout_ms for the background thread to provide a frame.

        Args:
            timeout_ms (float): Maximum time in milliseconds to wait for a frame
                to become available. Defaults to 200ms (0.2 seconds).

        Returns:
            np.ndarray:
            The latest captured frame data (color image), processed according to configuration.

        Raises:
            DeviceNotConnectedError: If the camera is not connected.
            TimeoutError: If no frame data becomes available within the specified timeout.
            RuntimeError: If the background thread died unexpectedly or another error occurs.
        """
        if not self.is_connected:
            raise DeviceNotConnectedError(f"{self} is not connected.")

        if self.thread is None or not self.thread.is_alive():
            self._start_read_thread()

        if not self.new_frame_event.wait(timeout=timeout_ms / 1000.0):
            thread_alive = self.thread is not None and self.thread.is_alive()
            raise TimeoutError(
                f"Timed out waiting for frame from camera {self} after {timeout_ms} ms. "
                f"Read thread alive: {thread_alive}."
            )

        with self.frame_lock:
            frame = self.latest_frame
            self.new_frame_event.clear()

        if frame is None:
            raise RuntimeError(f"Internal error: Event set but no frame available for {self}.")

        return frame

    def disconnect(self):
        """
        Disconnects from the camera, stops the pipeline, and cleans up resources.

        Stops the background read thread (if running) and stops the RealSense pipeline.

        Raises:
            DeviceNotConnectedError: If the camera is already disconnected (pipeline not running).
        """

        if not self.is_connected and self.thread is None:
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