Only import tensorflow-lite when used as a detector

frigate/detectors/detector_utils.py

@@ -3,11 +3,6 @@ import os
 
 import numpy as np
 
-try:
-    from tflite_runtime.interpreter import Interpreter, load_delegate
-except ModuleNotFoundError:
-    from tensorflow.lite.python.interpreter import Interpreter, load_delegate
-
 
 logger = logging.getLogger(__name__)
 
@@ -50,6 +45,11 @@ def tflite_detect_raw(self, tensor_input):
 def tflite_load_delegate_interpreter(
     delegate_library: str, detector_config, device_config
 ):
+    try:
+        from tflite_runtime.interpreter import Interpreter, load_delegate
+    except ModuleNotFoundError:
+        from tensorflow.lite.python.interpreter import Interpreter, load_delegate
+
     try:
         logger.info("Attempting to load NPU")
         tf_delegate = load_delegate(delegate_library, device_config)

frigate/detectors/plugins/cpu_tfl.py

@@ -9,11 +9,6 @@ from frigate.log import redirect_output_to_logger
 
 from ..detector_utils import tflite_detect_raw, tflite_init
 
-try:
-    from tflite_runtime.interpreter import Interpreter
-except ModuleNotFoundError:
-    from tensorflow.lite.python.interpreter import Interpreter
-
 
 logger = logging.getLogger(__name__)
 
@@ -30,6 +25,12 @@ class CpuTfl(DetectionApi):
 
     @redirect_output_to_logger(logger, logging.DEBUG)
     def __init__(self, detector_config: CpuDetectorConfig):
+        # Import TensorFlow Lite only when this detector is actually used
+        try:
+            from tflite_runtime.interpreter import Interpreter
+        except ModuleNotFoundError:
+            from tensorflow.lite.python.interpreter import Interpreter
+
         interpreter = Interpreter(
             model_path=detector_config.model.path,
             num_threads=detector_config.num_threads or 3,

frigate/detectors/plugins/edgetpu_tfl.py

@@ -8,12 +8,6 @@ from typing_extensions import Literal
 from frigate.detectors.detection_api import DetectionApi
 from frigate.detectors.detector_config import BaseDetectorConfig
 
-try:
-    from tflite_runtime.interpreter import Interpreter, load_delegate
-except ModuleNotFoundError:
-    from tensorflow.lite.python.interpreter import Interpreter, load_delegate
-
-
 logger = logging.getLogger(__name__)
 
 DETECTOR_KEY = "edgetpu"
@@ -28,6 +22,12 @@ class EdgeTpuTfl(DetectionApi):
     type_key = DETECTOR_KEY
 
     def __init__(self, detector_config: EdgeTpuDetectorConfig):
+        # Import TensorFlow Lite only when this detector is actually used
+        try:
+            from tflite_runtime.interpreter import Interpreter, load_delegate
+        except ModuleNotFoundError:
+            from tensorflow.lite.python.interpreter import Interpreter, load_delegate
+
         device_config = {}
         if detector_config.device is not None:
             device_config = {"device": detector_config.device}