frigate/frigate/data_processing/real_time/license_plate.py

"""Handle processing images for face detection and recognition."""

import json
import logging
from typing import Any

import numpy as np

from frigate.comms.event_metadata_updater import EventMetadataPublisher
from frigate.comms.inter_process import InterProcessRequestor
from frigate.config import FrigateConfig
from frigate.data_processing.common.license_plate.mixin import (
    LicensePlateProcessingMixin,
)
from frigate.data_processing.common.license_plate.model import (
    LicensePlateModelRunner,
)
from frigate.types import TrackedObjectUpdateTypesEnum

from ..types import DataProcessorMetrics
from .api import RealTimeProcessorApi

logger = logging.getLogger(__name__)


class LicensePlateRealTimeProcessor(LicensePlateProcessingMixin, RealTimeProcessorApi):
    def __init__(
        self,
        config: FrigateConfig,
        requestor: InterProcessRequestor,
        sub_label_publisher: EventMetadataPublisher,
        metrics: DataProcessorMetrics,
        model_runner: LicensePlateModelRunner,
        detected_license_plates: dict[str, dict[str, Any]],
    ):
        self.requestor = requestor
        self.detected_license_plates = detected_license_plates
        self.model_runner = model_runner
        self.lpr_config = config.lpr
        self.config = config
        self.sub_label_publisher = sub_label_publisher
        self.camera_current_cars: dict[str, list[str]] = {}
        super().__init__(config, metrics)

    def process_frame(
        self,
        obj_data: dict[str, Any],
        frame: np.ndarray,
        dedicated_lpr: bool | None = False,
    ):
        """Look for license plates in image."""
        self.lpr_process(obj_data, frame, dedicated_lpr)

    def handle_request(self, topic, request_data) -> dict[str, Any] | None:
        return

    def expire_object(self, object_id: str, camera: str):
        if object_id in self.detected_license_plates:
            self.detected_license_plates.pop(object_id)

            if object_id in self.camera_current_cars.get(camera, []):
                self.camera_current_cars[camera].remove(object_id)

                if len(self.camera_current_cars[camera]) == 0:
                    self.requestor.send_data(
                        "tracked_object_update",
                        json.dumps(
                            {
                                "type": TrackedObjectUpdateTypesEnum.lpr,
                                "name": None,
                                "plate": None,
                                "camera": camera,
                            }
                        ),
                    )