Source code for wpilib.cameraserver

from typing import Optional

import hal
import subprocess
import threading

import logging

logger = logging.getLogger("wpilib.cs")

__all__ = ["CameraServer"]

[docs]class CameraServer: """ Provides a way to launch an out of process cscore-based camera service instance, for streaming or for image processing. .. note:: This does not correspond directly to the wpilib CameraServer object; that can be found as :class:`cscore.CameraServer`. However, you should not use cscore directly from your robot code, see the documentation for details """ _alive = False _launched = False
[docs] @classmethod def is_alive(cls) -> bool: """:returns: True if the CameraServer is still alive""" return cls._alive
[docs] @classmethod def launch(cls, vision_py: Optional[str] = None) -> None: """ Launches the CameraServer process in autocapture mode or using a user-specified python script :param vision_py: If specified, this is the relative path to a filename with a function in it Example usage:: wpilib.CameraServer.launch("") .. warning:: You must have robotpy-cscore installed, or this function will fail without returning an error (you will see an error in the console). """ if cls._launched: return cls._launched = True from ._wpilib import RobotBase if RobotBase.isSimulation():"Would launch CameraServer with vision_py=%s", vision_py) cls._alive = True else:"Launching CameraServer process") # Launch the cscore launcher in a separate process import sys args = [sys.executable, "-m", "cscore"] # TODO: Get accurate reporting data from the other cscore process. For # now, just differentiate between users with a custom py file and those # who do not. cscore handle values indicate type with bits 24-30 if vision_py: if not vision_py.startswith("/"): vision_py = "/home/lvuser/py/" + vision_py args.append(vision_py), 0x51) else:, 0x52) # We open a pipe to it so that when this process exits, it dies proc = subprocess.Popen( args, close_fds=True, stdin=subprocess.PIPE, cwd="/home/lvuser/py" ) th = threading.Thread(target=cls._monitor_child, args=(proc,)) th.daemon = True th.start()
@classmethod def _monitor_child(cls, proc: subprocess.Popen) -> None: proc.wait() logger.warning("CameraServer process exited with exitcode %s", proc.returncode) cls._alive = False