add suggested changes

docs/docs/configuration/detectors.md

@@ -29,6 +29,7 @@ detectors:
 When using CPU detectors, you can add one CPU detector per camera. Adding more detectors than the number of cameras should not improve performance.
 
 ## Edge-TPU Detector
+
 The EdgeTPU detector type runs a TensorFlow Lite model utilizing the Google Coral delegate for hardware acceleration. To configure an EdgeTPU detector, set the `"type"` attribute to `"edgetpu"`.
 
 The EdgeTPU device can specified using the `"device"` attribute according to the [Documentation for the TensorFlow Lite Python API](https://coral.ai/docs/edgetpu/multiple-edgetpu/#using-the-tensorflow-lite-python-api). If not set, the delegate will use the first device it finds.
@@ -93,6 +94,7 @@ detectors:
 ```
 
 ## OpenVINO Detector
+
 The OpenVINO detector type runs an OpenVINO IR model on Intel CPU, GPU and VPU hardware. To configure an OpenVINO detector, set the `"type"` attribute to `"openvino"`.
 
 The OpenVINO device plugin is specified using the `"device"` attribute according to naming conventions in the [Device Documentation](https://docs.openvino.ai/latest/openvino_docs_OV_UG_Working_with_devices.html). Other supported devices could be `AUTO`, `CPU`, `GPU`, `MYRIAD`, etc. If not specified, the default OpenVINO device will be selected by the `AUTO` plugin.
@@ -145,3 +147,38 @@ device_cgroup_rules:
 volumes:
   - /dev/bus/usb:/dev/bus/usb
 ```
+
+## Custom Detectors
+
+Custom python detector modules can be added at `/opt/frigate/frigate/detectors/plugins` in the container.
+See the below for an example implementation.
+
+```python
+from frigate.detectors.detection_api import DetectionApi
+from frigate.detectors.detector_config import BaseDetectorConfig
+from typing import Literal
+from pydantic import Extra, Field
+
+DETECTOR_KEY = "<detector_key>"
+
+# A pydantic model inheriting from `BaseDetectorConfig`
+# Must implement the `type` attribute as below
+# Can add any number of fields to be passed from 
+# configuration to the constructor of your detector.
+class CustomDetectorConfig(BaseDetectorConfig):
+    type: Literal[DETECTOR_KEY]
+    custom_field: str = Field(default="value", title="Custom field description")
+
+
+# The custom detector class must inherit from `DetectionApi`
+# and must implement the `type_key`, `__init__`, 
+# and `detect_raw` methods as below
+class CustomDetector(DetectionApi):
+    type_key = DETECTOR_KEY
+
+    def __init__(self, detector_config: CustomDetectorConfig):
+      ...
+
+    def detect_raw(self, tensor_input):
+      return <list of detections>
+```

docs/docs/configuration/index.md

@@ -76,7 +76,7 @@ detectors:
   # Required: name of the detector
   detector_name:
     # Required: type of the detector
-    # Frigate provided types include 'cpu', 'edgetpu', and 'openvino'
+    # Frigate provided types include 'cpu', 'edgetpu', and 'openvino' (default: shown below)
     # Additional detector types can also be plugged in.
     # Detectors may require additional configuration.
     # Refer to the Detectors configuration page for more information.

frigate/app.py

@@ -186,7 +186,7 @@ class FrigateApp:
             self.detection_out_events[name] = mp.Event()
 
             try:
-                size = max(
+                largest_frame = max(
                     [
                         det.model.height * det.model.width * 3
                         for (name, det) in self.config.detectors.items()
@@ -195,7 +195,7 @@ class FrigateApp:
                 shm_in = mp.shared_memory.SharedMemory(
                     name=name,
                     create=True,
-                    size=size,
+                    size=largest_frame,
                 )
             except FileExistsError:
                 shm_in = mp.shared_memory.SharedMemory(name=name)

frigate/config.py

@@ -834,7 +834,7 @@ class FrigateConfig(FrigateBaseModel):
         default_factory=ModelConfig, title="Detection model configuration."
     )
     detectors: Dict[str, DetectorConfig] = Field(
-        default=parse_obj_as(Dict[str, DetectorConfig], DEFAULT_DETECTORS),
+        default=DEFAULT_DETECTORS,
         title="Detector hardware configuration.",
     )
     logger: LoggerConfig = Field(

frigate/detectors/plugins/cpu_tfl.py

@@ -10,14 +10,16 @@ import tflite_runtime.interpreter as tflite
 
 logger = logging.getLogger(__name__)
 
+DETECTOR_KEY = "cpu"
+
 
 class CpuDetectorConfig(BaseDetectorConfig):
-    type: Literal["cpu"]
+    type: Literal[DETECTOR_KEY]
     num_threads: int = Field(default=3, title="Number of detection threads")
 
 
 class CpuTfl(DetectionApi):
-    type_key = "cpu"
+    type_key = DETECTOR_KEY
 
     def __init__(self, detector_config: CpuDetectorConfig):
         self.interpreter = tflite.Interpreter(

frigate/detectors/plugins/edgetpu_tfl.py

@@ -11,14 +11,16 @@ from tflite_runtime.interpreter import load_delegate
 
 logger = logging.getLogger(__name__)
 
+DETECTOR_KEY = "edgetpu"
+
 
 class EdgeTpuDetectorConfig(BaseDetectorConfig):
-    type: Literal["edgetpu"]
+    type: Literal[DETECTOR_KEY]
     device: str = Field(default="usb", title="Device Type")
 
 
 class EdgeTpuTfl(DetectionApi):
-    type_key = "edgetpu"
+    type_key = DETECTOR_KEY
 
     def __init__(self, detector_config: EdgeTpuDetectorConfig):
         device_config = {"device": "usb"}

frigate/detectors/plugins/openvino.py

@@ -10,14 +10,16 @@ from pydantic import Extra, Field
 
 logger = logging.getLogger(__name__)
 
+DETECTOR_KEY = "openvino"
+
 
 class OvDetectorConfig(BaseDetectorConfig):
-    type: Literal["openvino"]
+    type: Literal[DETECTOR_KEY]
     device: str = Field(default="AUTO", title="Device Type")
 
 
 class OvDetector(DetectionApi):
-    type_key = "openvino"
+    type_key = DETECTOR_KEY
 
     def __init__(self, detector_config: OvDetectorConfig):
         self.ov_core = ov.Core()