From 8bf1c216bbe19d0005382a061f346a95a998a76f Mon Sep 17 00:00:00 2001
From: Josh Hawkins <32435876+hawkeye217@users.noreply.github.com>
Date: Thu, 20 Mar 2025 09:17:54 -0500
Subject: [PATCH] processing in maintainer

---
 frigate/embeddings/maintainer.py | 64 ++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/frigate/embeddings/maintainer.py b/frigate/embeddings/maintainer.py
index 2fa3eeb2c..e797c8d30 100644
--- a/frigate/embeddings/maintainer.py
+++ b/frigate/embeddings/maintainer.py
@@ -1,6 +1,7 @@
 """Maintain embeddings in SQLite-vec."""
 
 import base64
+import datetime
 import logging
 import os
 import threading
@@ -13,6 +14,7 @@ import numpy as np
 from peewee import DoesNotExist
 from playhouse.sqliteq import SqliteQueueDatabase
 
+from frigate.comms.detections_updater import DetectionSubscriber, DetectionTypeEnum
 from frigate.comms.embeddings_updater import EmbeddingsRequestEnum, EmbeddingsResponder
 from frigate.comms.event_metadata_updater import (
     EventMetadataPublisher,
@@ -26,6 +28,7 @@ from frigate.comms.recordings_updater import (
     RecordingsDataTypeEnum,
 )
 from frigate.config import FrigateConfig
+from frigate.config.classification import CameraTypeEnum
 from frigate.const import (
     CLIPS_DIR,
     UPDATE_EVENT_DESCRIPTION,
@@ -97,6 +100,7 @@ class EmbeddingMaintainer(threading.Thread):
         self.recordings_subscriber = RecordingsDataSubscriber(
             RecordingsDataTypeEnum.recordings_available_through
         )
+        self.detection_subscriber = DetectionSubscriber(DetectionTypeEnum.video)
         self.embeddings_responder = EmbeddingsResponder()
         self.frame_manager = SharedMemoryFrameManager()
 
@@ -162,12 +166,15 @@ class EmbeddingMaintainer(threading.Thread):
             self._process_requests()
             self._process_updates()
             self._process_recordings_updates()
+            self._process_dedicated_lpr()
+            self._expire_dedicated_lpr()
             self._process_finalized()
             self._process_event_metadata()
 
         self.event_subscriber.stop()
         self.event_end_subscriber.stop()
         self.recordings_subscriber.stop()
+        self.detection_subscriber.stop()
         self.event_metadata_publisher.stop()
         self.event_metadata_subscriber.stop()
         self.embeddings_responder.stop()
@@ -374,6 +381,27 @@ class EmbeddingMaintainer(threading.Thread):
             if event_id in self.tracked_events:
                 del self.tracked_events[event_id]
 
+    def _expire_dedicated_lpr(self) -> None:
+        """Remove plates not seen for longer than expiration timeout for dedicated lpr cameras."""
+        now = datetime.datetime.now().timestamp()
+
+        to_remove = []
+
+        for id, data in self.detected_license_plates.items():
+            last_seen = data.get("last_seen", 0)
+            if not last_seen:
+                continue
+
+            if now - last_seen > self.config.cameras[data["camera"]].lpr.expire_time:
+                to_remove.append(id)
+        for id in to_remove:
+            print(f"Expiring plate event {id}")
+            self.event_metadata_publisher.publish(
+                EventMetadataTypeEnum.manual_event_end,
+                (id, now),
+            )
+            self.detected_license_plates.pop(id)
+
     def _process_recordings_updates(self) -> None:
         """Process recordings updates."""
         while True:
@@ -406,6 +434,42 @@ class EmbeddingMaintainer(threading.Thread):
                 event_id, RegenerateDescriptionEnum(source)
             )
 
+    def _process_dedicated_lpr(self) -> None:
+        """Process event updates"""
+        (topic, data) = self.detection_subscriber.check_for_update(timeout=0.01)
+
+        if topic is None:
+            return
+
+        camera, frame_name, _, _, motion_boxes, _ = data
+
+        if not camera or not self.config.lpr.enabled or len(motion_boxes) == 0:
+            return
+
+        camera_config = self.config.cameras[camera]
+
+        if not camera_config.lpr.camera_type == CameraTypeEnum.lpr:
+            return
+
+        try:
+            yuv_frame = self.frame_manager.get(
+                frame_name, camera_config.frame_shape_yuv
+            )
+        except FileNotFoundError:
+            pass
+
+        if yuv_frame is None:
+            logger.debug(
+                "Unable to process dedicated LPR update because frame is unavailable."
+            )
+            return
+
+        for processor in self.realtime_processors:
+            if isinstance(processor, LicensePlateRealTimeProcessor):
+                processor.process_frame(camera, yuv_frame, True)
+
+        self.frame_manager.close(frame_name)
+
     def _create_thumbnail(self, yuv_frame, box, height=500) -> Optional[bytes]:
         """Return jpg thumbnail of a region of the frame."""
         frame = cv2.cvtColor(yuv_frame, cv2.COLOR_YUV2BGR_I420)