from 


class BaseImageSource(QObject):
    frameReady = Signal(QPixmap)
    errorOccurred = Signal(str)

    def start(self): ...
    def stop(self): ...


class BaseControlSource(QObject):
    errorOccurred = Signal(str)
    parameterChanged = Signal(str, object)

    def set_parameter(self, name: str, value): ...
    def get_parameter(self, name: str): ...
    def list_parameters(self) -> dict: ...