add cpu fallback detector

frigate/config.py

@@ -1287,44 +1287,59 @@ class FrigateConfig(FrigateBaseModel):
         config.model.check_and_load_plus_model(plus_api)
 
         for key, detector in config.detectors.items():
-            detector_config: DetectorConfig = parse_obj_as(DetectorConfig, detector)
-            if detector_config.model is None:
-                detector_config.model = config.model
-            else:
-                model = detector_config.model
-                schema = ModelConfig.schema()["properties"]
-                if (
-                    model.width != schema["width"]["default"]
-                    or model.height != schema["height"]["default"]
-                    or model.labelmap_path is not None
-                    or model.labelmap is not {}
-                    or model.input_tensor != schema["input_tensor"]["default"]
-                    or model.input_pixel_format
-                    != schema["input_pixel_format"]["default"]
-                ):
-                    logger.warning(
-                        "Customizing more than a detector model path is unsupported."
-                    )
-            merged_model = deep_merge(
-                detector_config.model.dict(exclude_unset=True),
-                config.model.dict(exclude_unset=True),
+            config.detectors[key] = self.generate_detector_config(
+                config, detector, plus_api
             )
 
-            if "path" not in merged_model:
-                if detector_config.type == "cpu":
-                    merged_model["path"] = "/cpu_model.tflite"
-                elif detector_config.type == "edgetpu":
-                    merged_model["path"] = "/edgetpu_model.tflite"
-
-            detector_config.model = ModelConfig.parse_obj(merged_model)
-            detector_config.model.check_and_load_plus_model(
-                plus_api, detector_config.type
-            )
-            detector_config.model.compute_model_hash()
-            config.detectors[key] = detector_config
-
         return config
 
+    def generate_detector_config(self, config: FrigateConfig, detector, plus_api):
+        detector_config: DetectorConfig = parse_obj_as(DetectorConfig, detector)
+        if detector_config.model is None:
+            detector_config.model = config.model
+        else:
+            model = detector_config.model
+            schema = ModelConfig.schema()["properties"]
+            if (
+                model.width != schema["width"]["default"]
+                or model.height != schema["height"]["default"]
+                or model.labelmap_path is not None
+                or model.labelmap is not {}
+                or model.input_tensor != schema["input_tensor"]["default"]
+                or model.input_pixel_format
+                != schema["input_pixel_format"]["default"]
+            ):
+                logger.warning(
+                    "Customizing more than a detector model path is unsupported."
+                )
+        merged_model = deep_merge(
+            detector_config.model.dict(exclude_unset=True),
+            config.model.dict(exclude_unset=True),
+        )
+
+        if "path" not in merged_model:
+            if detector_config.type == "cpu":
+                merged_model["path"] = "/cpu_model.tflite"
+            elif detector_config.type == "edgetpu":
+                merged_model["path"] = "/edgetpu_model.tflite"
+
+        detector_config.model = ModelConfig.parse_obj(merged_model)
+        detector_config.model.check_and_load_plus_model(
+            plus_api, detector_config.type
+        )
+        detector_config.model.compute_model_hash()
+
+        if detector_config.type != "cpu":
+            fallback_config = config.copy(deep=True)
+            fallback_config.model = ModelConfig()
+            detector_config.fallback_config = self.generate_detector_config(
+                fallback_config,
+                parse_obj_as(DetectorConfig, DEFAULT_DETECTORS["cpu"]),
+                plus_api,
+            )
+
+        return detector_config
+
     @validator("cameras")
     def ensure_zones_and_cameras_have_different_names(cls, v: Dict[str, CameraConfig]):
         zones = [zone for camera in v.values() for zone in camera.zones.keys()]

frigate/object_detection.py

@@ -81,6 +81,7 @@ def run_detector(
     out_events: dict[str, mp.Event],
     avg_speed,
     start,
+    using_fallback_detector,
     detector_config,
 ):
     threading.current_thread().name = f"detector:{name}"
@@ -99,7 +100,14 @@ def run_detector(
     signal.signal(signal.SIGINT, receiveSignal)
 
     frame_manager = SharedMemoryFrameManager()
-    object_detector = LocalObjectDetector(detector_config=detector_config)
+    try:
+        object_detector = LocalObjectDetector(detector_config=detector_config)
+    except Exception as ex:
+        logger.error(f"Got exception when initializing detector: {ex}, falling back to CPU detector")
+
+        object_detector = LocalObjectDetector(detector_config=detector_config.fallback_config)
+        using_fallback_detector.value = 1
+        
 
     outputs = {}
     for name in out_events.keys():
@@ -146,6 +154,7 @@ class ObjectDetectProcess:
         self.detection_queue = detection_queue
         self.avg_inference_speed = mp.Value("d", 0.01)
         self.detection_start = mp.Value("d", 0.0)
+        self.using_fallback_detector = mp.Value("i", 0)
         self.detect_process = None
         self.detector_config = detector_config
         self.start_or_restart()
@@ -176,6 +185,7 @@ class ObjectDetectProcess:
                 self.out_events,
                 self.avg_inference_speed,
                 self.detection_start,
+                self.using_fallback_detector,
                 self.detector_config,
             ),
         )

frigate/stats.py

@@ -284,6 +284,7 @@ def stats_snapshot(
             # issue https://github.com/python/typeshed/issues/8799
             # from mypy 0.981 onwards
             "pid": pid,
+            "using_fallback_detector": bool(detector.using_fallback_detector.value),
         }
     stats["detection_fps"] = round(total_detection_fps, 2)
 

web/src/routes/System.jsx

@@ -232,7 +232,7 @@ export default function System() {
           <div data-testid="detectors" className="grid grid-cols-1 3xl:grid-cols-3 md:grid-cols-2 gap-4">
             {detectorNames.map((detector) => (
               <div key={detector} className="dark:bg-gray-800 shadow-md hover:shadow-lg rounded-lg transition-shadow">
-                <div className="text-lg flex justify-between p-4">{detector}</div>
+                <div className="text-lg flex justify-between p-4" style={{ color: detectors[detector]['using_fallback_detector'] ? "red" : null}}>{detector}{detectors[detector]['using_fallback_detector'] ? " - CPU FALLBACK MODE" : ""}</div>
                 <div className="p-2">
                   <Table className="w-full">
                     <Thead>