end tracked events before replacing replay camera state on a scene switch

- test the replay model rebind against two configured models

frigate/api/app.py

@@ -45,7 +45,7 @@ from frigate.config.camera.updater import (
     CameraConfigUpdateEnum,
     CameraConfigUpdateTopic,
 )
-from frigate.const import REDACTED_CREDENTIAL_SENTINEL
+from frigate.const import REDACTED_CREDENTIAL_SENTINEL, REPLAY_CAMERA_PREFIX
 from frigate.ffmpeg_presets import FFMPEG_HWACCEL_VAAPI, _gpu_selector
 from frigate.genai import PROVIDERS, load_providers
 from frigate.jobs.media_sync import (
@@ -979,6 +979,17 @@ def _config_set_in_memory(request: Request, body: AppConfigSetBody) -> JSONRespo
                     status_code=400,
                 )
 
+            # an unresolvable scene would crash the threads that look up the model
+            detect_update = sections.get("detect")
+            if isinstance(detect_update, dict) and "scene" in detect_update:
+                try:
+                    config._resolve_camera_model(cam_name, detect_update["scene"])
+                except (TypeError, ValueError):
+                    return JSONResponse(
+                        content={"success": False, "message": "Invalid detect scene"},
+                        status_code=400,
+                    )
+
             for section_name, update in sections.items():
                 err = apply_section_update(camera_config, section_name, update)
                 if err is not None:
@@ -987,6 +998,11 @@ def _config_set_in_memory(request: Request, body: AppConfigSetBody) -> JSONRespo
                         status_code=400,
                     )
 
+            # the model is resolved again from the scene when the replay
+            # camera is recycled by the refresh below
+            if "detect" in sections and cam_name.startswith(REPLAY_CAMERA_PREFIX):
+                config.drop_camera_model(cam_name)
+
         # Publish ZMQ updates so processing threads pick up changes
         if body.update_topic and body.update_topic.startswith("config/cameras/"):
             _, _, camera, field = body.update_topic.split("/")

frigate/app.py

@@ -76,7 +76,7 @@ from frigate.models import (
 from frigate.notices import install_registry
 from frigate.notices.registry import NoticeRegistry
 from frigate.object_detection.base import ObjectDetectProcess
-from frigate.object_detection.util import detection_frame_size
+from frigate.object_detection.util import create_detection_input_shm
 from frigate.output.output import OutputProcess
 from frigate.ptz.autotrack import PtzAutoTracker
 from frigate.ptz.onvif import OnvifController
@@ -399,14 +399,7 @@ class FrigateApp:
             model = self.config.model_for_camera(name)
             model_cameras[model.scene].append(name)
 
-            try:
-                shm_in = UntrackedSharedMemory(
-                    name=name,
-                    create=True,
-                    size=detection_frame_size(model),
-                )
-            except FileExistsError:
-                shm_in = UntrackedSharedMemory(name=name)
+            shm_in = create_detection_input_shm(name, self.config.models)
 
             try:
                 shm_out = UntrackedSharedMemory(

frigate/camera/maintainer.py

@@ -16,7 +16,7 @@ from frigate.config.camera.updater import (
 )
 from frigate.const import REPLAY_CAMERA_PREFIX
 from frigate.models import Regions
-from frigate.object_detection.util import detection_frame_size
+from frigate.object_detection.util import create_detection_input_shm
 from frigate.util.builtin import empty_and_close_queue
 from frigate.util.image import SharedMemoryFrameManager, UntrackedSharedMemory
 from frigate.util.object import get_camera_regions_grid
@@ -127,13 +127,10 @@ class CameraMaintainer(threading.Thread):
                 max(model.width, model.height),
             )
 
+            create_detection_input_shm(name, self.config.models)
+
             try:
                 UntrackedSharedMemory(name=f"out-{name}", create=True, size=20 * 6 * 4)
-                UntrackedSharedMemory(
-                    name=name,
-                    create=True,
-                    size=detection_frame_size(model),
-                )
             except FileExistsError:
                 pass
 

frigate/camera/state.py

@@ -296,7 +296,8 @@ class CameraState:
         return frame_copy
 
     def finished(self, obj_id: str) -> None:
-        del self.tracked_objects[obj_id]
+        # state rebuilt after a resolution or scene change no longer has the object
+        self.tracked_objects.pop(obj_id, None)
 
     def on(self, event_type: str, callback: Callable[..., Any]) -> None:
         self.callbacks[event_type].append(callback)

frigate/object_detection/base.py

@@ -113,6 +113,23 @@ class AsyncLocalObjectDetector(BaseLocalDetector):
         return self.detect_api.receive_output()
 
 
+def map_input_frame(
+    frame_manager: SharedMemoryFrameManager, camera: str, model: ModelConfig
+) -> np.ndarray | None:
+    """Map a camera's detection input segment as this model's input tensor.
+
+    The segment is sized for the largest configured model, so it can be larger
+    than this model's input.
+    """
+    buf = frame_manager.write(camera)
+    shape = (1, model.height, model.width, 3)
+
+    if buf is None or len(buf) < model.height * model.width * 3:
+        return None
+
+    return np.ndarray(shape, dtype=np.uint8, buffer=buf)
+
+
 class DetectorRunner(FrigateProcess):
     def __init__(
         self,
@@ -154,14 +171,10 @@ class DetectorRunner(FrigateProcess):
                 connection_id = self.detection_queue.get(timeout=1)
             except queue.Empty:
                 continue
-            input_frame = frame_manager.get(
+            input_frame = map_input_frame(
+                frame_manager,
                 connection_id,
-                (
-                    1,
-                    self.detector_config.model.height,  # type: ignore[union-attr]
-                    self.detector_config.model.width,  # type: ignore[union-attr]
-                    3,
-                ),
+                self.detector_config.model,  # type: ignore[arg-type]
             )
 
             if input_frame is None:
@@ -227,14 +240,10 @@ class AsyncDetectorRunner(FrigateProcess):
                 continue
 
             assert self._frame_manager is not None
-            input_frame = self._frame_manager.get(
+            input_frame = map_input_frame(
+                self._frame_manager,
                 connection_id,
-                (
-                    1,
-                    self.detector_config.model.height,  # type: ignore[union-attr]
-                    self.detector_config.model.width,  # type: ignore[union-attr]
-                    3,
-                ),
+                self.detector_config.model,  # type: ignore[arg-type]
             )
 
             if input_frame is None:

frigate/object_detection/util.py

@@ -6,18 +6,39 @@ import threading
 from numpy import ndarray
 
 from frigate.detectors.detector_config import InputTensorEnum, ModelConfig
+from frigate.util.image import UntrackedSharedMemory
 
 
-def detection_frame_size(model: ModelConfig) -> int:
-    """Get the shared memory size a camera needs to hand frames to a model.
+def create_detection_input_shm(
+    camera: str, models: list[ModelConfig]
+) -> UntrackedSharedMemory:
+    """Create the shared memory a camera hands detection frames through.
+
+    It is sized for the largest model so a camera re-added under the same name
+    with another scene can reuse it. Detectors keep mappings of it, so it is
+    never unlinked while they run.
 
     Args:
-        model: The model the camera runs on
+        camera: Name of the camera
+        models: Every configured model
 
     Returns:
-        Size in bytes of one model input frame
+        The camera's detection input segment
     """
-    return model.height * model.width * 3
+    size = max(model.height * model.width * 3 for model in models)
+
+    try:
+        return UntrackedSharedMemory(name=camera, create=True, size=size)
+    except FileExistsError:
+        shm = UntrackedSharedMemory(name=camera)
+
+    if shm.size >= size:
+        return shm
+
+    # left by an earlier run with smaller models, so no detector maps it yet
+    shm.close()
+    shm.unlink()
+    return UntrackedSharedMemory(name=camera, create=True, size=size)
 
 
 class RequestStore:

frigate/test/http_api/test_http_app.py

@@ -98,6 +98,46 @@ class TestHttpApp(BaseTestHttp):
             assert response.status_code == 200
             assert app.frigate_config.cameras["front_door"].objects.track == ["person"]
 
+    @patch("frigate.detectors.detector_config.load_labels")
+    def test_config_set_in_memory_rebinds_replay_model_on_scene_change(
+        self, mock_labels
+    ):
+        mock_labels.return_value = {}
+        replay = "_replay_front_door"
+        self.minimal_config["models"] = [
+            {"devices": ["cpu"]},
+            {"scene": "thermal", "devices": ["openvino:CPU"], "width": 300},
+        ]
+        self.minimal_config["cameras"][replay] = self.minimal_config["cameras"].pop(
+            "front_door"
+        )
+        app = super().create_app()
+        app.config_publisher = Mock()
+        assert app.frigate_config.model_for_camera(replay).scene == "default"
+
+        with AuthTestClient(app) as client:
+            response = client.put(
+                "/config/set",
+                json={
+                    "requires_restart": 0,
+                    "skip_save": True,
+                    "update_topic": f"config/cameras/{replay}/detect",
+                    "config_data": {
+                        "cameras": {replay: {"detect": {"scene": "thermal"}}}
+                    },
+                },
+            )
+
+        assert response.status_code == 200
+        assert app.frigate_config.cameras[replay].detect.scene == "thermal"
+        assert app.frigate_config.model_for_camera(replay).scene == "thermal"
+        topics = [
+            call.args[0].update_type.name
+            for call in app.config_publisher.publish_update.call_args_list
+        ]
+        assert topics[0] == "detect"
+        assert topics[-1] == "refresh"
+
     ####################################################################################################################
     ###################################  Credential redaction sentinel  ################################################
     ####################################################################################################################

frigate/track/object_processing.py

@@ -91,6 +91,7 @@ class TrackedObjectProcessor(threading.Thread):
                 CameraConfigUpdateEnum.enabled,
                 CameraConfigUpdateEnum.motion,
                 CameraConfigUpdateEnum.objects,
+                CameraConfigUpdateEnum.refresh,
                 CameraConfigUpdateEnum.remove,
                 CameraConfigUpdateEnum.timestamp_style,
                 CameraConfigUpdateEnum.zones,
@@ -784,6 +785,21 @@ class TrackedObjectProcessor(threading.Thread):
 
                 self.requestor.send_data(UPDATE_CAMERA_ACTIVITY, self.camera_activity)
 
+            # a replay camera recycled onto another scene's model needs new state
+            for camera in updated_topics.get("refresh", []):
+                camera_state = self.camera_states.get(camera)
+
+                if (
+                    camera_state is None
+                    or camera_state.model is self.config.model_for_camera(camera)
+                ):
+                    continue
+
+                self.force_end_all_events(camera, camera_state)
+                camera_state.shutdown()
+                self.frame_manager.close_camera(camera)
+                self.create_camera_state(camera)
+
             # manage camera disabled state
             for camera, config in self.config.cameras.items():
                 if not config.enabled_in_config:

web/src/components/config-form/section-configs/detect.ts

@@ -240,14 +240,14 @@ const detect: SectionConfigOverrides = {
   },
   replay: {
     restartRequired: [],
-    fieldOrder: ["width", "height", "fps"],
+    fieldOrder: ["scene", "width", "height", "fps"],
     fieldGroups: {
       resolution: ["width", "height", "fps"],
     },
     hiddenFields: [
       "enabled",
       "enabled_in_config",
-      "scene",
+      hideSceneWithoutChoice,
       "min_initialized",
       "max_disappeared",
       "annotation_offset",