Dynamic Management of Cameras (#18671)

* Add base class for global config updates

* Add or remove camera states

* Move camera process management to separate thread

* Move camera management fully to separate class

* Cleanup

* Stop camera processes when stop command is sent

* Start processes dynamically when needed

* Adjust

* Leave extra room in tracked object queue for two cameras

* Dynamically set extra config pieces

* Add some TODOs

* Fix type check

* Simplify config updates

* Improve typing

* Correctly handle indexed entries

* Cleanup

* Create out SHM

* Use ZMQ for signaling object detectoin is completed

* Get camera correctly created

* Cleanup for updating the cameras config

* Cleanup

* Don't enable audio if no cameras have audio transcription

* Use exact string so similar camera names don't interfere

* Add ability to update config via json body to config/set endpoint

Additionally, update the config in a single rather than multiple calls for each updated key

* fix autotracking calibration to support new config updater function

---------

Co-authored-by: Josh Hawkins <32435876+hawkeye217@users.noreply.github.com>

frigate/output/output.py

@@ -103,8 +103,10 @@ def output_frames(
 
     detection_subscriber = DetectionSubscriber(DetectionTypeEnum.video)
     config_subscriber = CameraConfigUpdateSubscriber(
+        config,
         config.cameras,
         [
+            CameraConfigUpdateEnum.add,
             CameraConfigUpdateEnum.birdseye,
             CameraConfigUpdateEnum.enabled,
             CameraConfigUpdateEnum.record,
@@ -135,7 +137,15 @@ def output_frames(
 
     while not stop_event.is_set():
         # check if there is an updated config
-        config_subscriber.check_for_updates()
+        updates = config_subscriber.check_for_updates()
+
+        if "add" in updates:
+            for camera in updates["add"]:
+                jsmpeg_cameras[camera] = JsmpegCamera(
+                    cam_config, stop_event, websocket_server
+                )
+                preview_recorders[camera] = PreviewRecorder(cam_config)
+                preview_write_times[camera] = 0
 
         (topic, data) = detection_subscriber.check_for_update(timeout=1)
         now = datetime.datetime.now().timestamp()