Ensure sub label is printable to be used

frigate/object_processing.py

@@ -29,6 +29,7 @@ from frigate.util.image import (
     calculate_region,
     draw_box_with_label,
     draw_timestamp,
+    is_label_printable,
 )
 
 logger = logging.getLogger(__name__)
@@ -509,7 +510,14 @@ class CameraState:
 
                 # draw the bounding boxes on the frame
                 box = obj["box"]
-                text = obj["label"] if not obj.get("sub_label") else obj["sub_label"][0]
+                text = (
+                    obj["label"]
+                    if (
+                        not obj.get("sub_label")
+                        or not is_label_printable(obj["sub_label"][0])
+                    )
+                    else obj["sub_label"][0]
+                )
                 draw_box_with_label(
                     frame_copy,
                     box[0],

frigate/util/image.py

@@ -4,6 +4,7 @@ import datetime
 import logging
 from abc import ABC, abstractmethod
 from multiprocessing import shared_memory
+from string import printable
 from typing import AnyStr, Optional
 
 import cv2
@@ -154,6 +155,11 @@ def draw_box_with_label(
     )
 
 
+def is_label_printable(label) -> bool:
+    """Check if label is printable."""
+    return not bool(set(label) - set(printable))
+
+
 def calculate_region(frame_shape, xmin, ymin, xmax, ymax, model_size, multiplier=2):
     # size is the longest edge and divisible by 4
     size = int((max(xmax - xmin, ymax - ymin) * multiplier) // 4 * 4)