Dynamically enable/disable cameras (#16894)

* config options

* metrics

* stop and restart ffmpeg processes

* dispatcher

* frontend websocket

* buttons for testing

* don't recreate log pipe

* add/remove cam from birdseye when enabling/disabling

* end all objects and send empty camera activity

* enable/disable switch in ui

* disable buttons when camera is disabled

* use enabled_in_config for some frontend checks

* tweaks

* handle settings pane with disabled cameras

* frontend tweaks

* change to debug log

* mqtt docs

* tweak

* ensure all ffmpeg processes are initially started

* clean up

* use zmq

* remove camera metrics

* remove camera metrics

* tweaks

* frontend tweaks

frigate/output/output.py

@@ -17,6 +17,7 @@ from ws4py.server.wsgirefserver import (
 )
 from ws4py.server.wsgiutils import WebSocketWSGIApplication
 
+from frigate.comms.config_updater import ConfigSubscriber
 from frigate.comms.detections_updater import DetectionSubscriber, DetectionTypeEnum
 from frigate.comms.ws import WebSocket
 from frigate.config import FrigateConfig
@@ -59,6 +60,12 @@ def output_frames(
 
     detection_subscriber = DetectionSubscriber(DetectionTypeEnum.video)
 
+    enabled_subscribers = {
+        camera: ConfigSubscriber(f"config/enabled/{camera}", True)
+        for camera in config.cameras.keys()
+        if config.cameras[camera].enabled_in_config
+    }
+
     jsmpeg_cameras: dict[str, JsmpegCamera] = {}
     birdseye: Optional[Birdseye] = None
     preview_recorders: dict[str, PreviewRecorder] = {}
@@ -80,6 +87,13 @@ def output_frames(
 
     websocket_thread.start()
 
+    def get_enabled_state(camera: str) -> bool:
+        _, config_data = enabled_subscribers[camera].check_for_update()
+        if config_data:
+            return config_data.enabled
+        # default
+        return config.cameras[camera].enabled
+
     while not stop_event.is_set():
         (topic, data) = detection_subscriber.check_for_update(timeout=1)
 
@@ -95,6 +109,9 @@ def output_frames(
             _,
         ) = data
 
+        if not get_enabled_state(camera):
+            continue
+
         frame = frame_manager.get(frame_name, config.cameras[camera].frame_shape_yuv)
 
         if frame is None:
@@ -184,6 +201,9 @@ def output_frames(
     if birdseye is not None:
         birdseye.stop()
 
+    for subscriber in enabled_subscribers.values():
+        subscriber.stop()
+
     websocket_server.manager.close_all()
     websocket_server.manager.stop()
     websocket_server.manager.join()