From 3d9b1996f9b274124879af294f4ac371d34f5118 Mon Sep 17 00:00:00 2001
From: Sergey Krashevich <svk@svk.su>
Date: Wed, 26 Apr 2023 02:26:54 +0300
Subject: [PATCH] Add MetaDetector implementation and configuration schema

---
 frigate/detectors/plugins/meta.py | 108 ++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 frigate/detectors/plugins/meta.py

diff --git a/frigate/detectors/plugins/meta.py b/frigate/detectors/plugins/meta.py
new file mode 100644
index 000000000..c2bb4dca6
--- /dev/null
+++ b/frigate/detectors/plugins/meta.py
@@ -0,0 +1,108 @@
+import logging
+import numpy as np
+import os
+from frigate.detectors.detection_api import DetectionApi
+from frigate.detectors.detector_config import BaseDetectorConfig, ModelConfig
+from frigate.util import deep_merge
+from typing import List, Tuple, Dict, Any, Literal
+from typing import Union
+from typing_extensions import Annotated
+from enum import Enum
+from pydantic import Field, parse_obj_as
+import importlib
+import pkgutil
+
+logger = logging.getLogger(__name__)
+
+DETECTOR_KEY = "meta_detector"
+
+DetectorConfig = Annotated[
+            Union[tuple(BaseDetectorConfig.__subclasses__())],
+            Field(discriminator="type"),
+        ]
+
+class MetaDetectorConfig(BaseDetectorConfig):
+    type: Literal[DETECTOR_KEY]
+    detectors: Dict[str, DetectorConfig] = Field(
+        default={"cpu": {"type": "cpu"}},
+        title="Detector hardware configuration.",
+    )
+    max_detections: int = Field(
+        default=20,
+        title="Maximum number of detections to return after merging results",
+    )
+
+
+class MetaDetector(DetectionApi):
+    type_key = DETECTOR_KEY
+
+    def __init__(self, meta_detector_config: MetaDetectorConfig):
+        self.max_detections = meta_detector_config.max_detections
+
+        self.detectors = []
+
+        for key, detector in meta_detector_config.detectors.items():
+            detector_config: DetectorConfig = parse_obj_as(DetectorConfig, detector)
+            if detector_config.model is None:
+                detector_config.model = meta_detector_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),
+                meta_detector_config.model.dict(exclude_unset=True),
+            )
+            detector_config.model = ModelConfig.parse_obj(merged_model)
+            meta_detector_config.detectors[key] = detector_config
+            self.detectors.append(self.create_detector(detector_config))
+
+        
+
+    def merge_detections(self, detections_list: List[np.ndarray]) -> np.ndarray:
+        all_detections = np.vstack(detections_list)
+        sorted_indices = np.argsort(-all_detections[:, 1])
+        return all_detections[sorted_indices[: self.max_detections]]
+
+    def detect_raw(self, tensor_input) -> np.ndarray:
+        detections_list = [
+            detector.detect_raw(tensor_input) for detector in self.detectors
+        ]
+        return self.merge_detections(detections_list)
+    
+    def create_detector(self, detector_config):
+
+        current_module_name = os.path.splitext(os.path.basename(__file__))[0]
+        modules_folder = os.path.dirname(os.path.abspath(__file__))
+        module_prefix = __package__ + "."
+
+        _included_modules = [module for module in pkgutil.iter_modules([modules_folder], module_prefix) if module.name != current_module_name]
+
+        plugin_modules = []
+
+        for _, name, _ in _included_modules:
+            try:
+                # currently openvino may fail when importing
+                # on an arm device with 64 KiB page size.
+                plugin_modules.append(importlib.import_module(name))
+            except ImportError as e:
+                logger.error(f"Error importing detector runtime: {e}")
+
+
+
+        api_types = {det.type_key: det for det in DetectionApi.__subclasses__()}
+        api = api_types.get(detector_config.type)
+        if not api:
+            raise ValueError(detector_config.type)
+        return api(detector_config)