camera.py 文件源码

def _set_annotate_background(self, value):
        self._check_camera_open()
        if value is True:
            warnings.warn(
                PiCameraDeprecated(
                    'Setting PiCamera.annotate_background to True is '
                    'deprecated; use PiCamera.color.Color("black") instead'))
            value = Color('black')
        elif value is False:
            warnings.warn(
                PiCameraDeprecated(
                    'Setting PiCamera.annotate_background to False is '
                    'deprecated; use None instead'))
            value = None
        elif value is None:
            pass
        elif not isinstance(value, Color):
            raise PiCameraValueError(
                'annotate_background must be a Color or None')
        elif not self._annotate_v3 and value.rgb_bytes != (0, 0, 0):
            warnings.warn(
                PiCameraFallback(
                    "Firmware does not support setting a custom background "
                    "annotation color; using black instead"))
        mp = self._get_annotate_settings()
        if self._annotate_v3:
            if value is None:
                mp.enable_text_background = False
            else:
                mp.enable_text_background = True
                mp.custom_background_color = True
                (
                    mp.custom_background_Y,
                    mp.custom_background_U,
                    mp.custom_background_V,
                    ) = value.yuv_bytes
        else:
            if value is None:
                mp.black_text_background = False
            else:
                mp.black_text_background = True
        mmal_check(
            mmal.mmal_port_parameter_set(self._camera[0].control, mp.hdr),
            prefix="Failed to set annotation background")