From e12b2dc68c2316f09280ef82ce9779fc9a82af00 Mon Sep 17 00:00:00 2001
From: Josh Hawkins <32435876+hawkeye217@users.noreply.github.com>
Date: Sat, 26 Oct 2024 17:27:02 -0500
Subject: [PATCH] Prevent division by zero in lpr confidence checks (#14615)

---
 frigate/embeddings/maintainer.py | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/frigate/embeddings/maintainer.py b/frigate/embeddings/maintainer.py
index 00804c63f..2084e6b7a 100644
--- a/frigate/embeddings/maintainer.py
+++ b/frigate/embeddings/maintainer.py
@@ -599,14 +599,20 @@ class EmbeddingMaintainer(threading.Thread):
             return
 
         top_plate, top_char_confidences = license_plates[0], confidences[0]
-        avg_confidence = sum(top_char_confidences) / len(top_char_confidences)
+        avg_confidence = (
+            (sum(top_char_confidences) / len(top_char_confidences))
+            if top_char_confidences
+            else 0
+        )
 
         # Check if we have a previously detected plate for this ID
         if id in self.detected_license_plates:
             prev_plate = self.detected_license_plates[id]["plate"]
             prev_char_confidences = self.detected_license_plates[id]["char_confidences"]
-            prev_avg_confidence = sum(prev_char_confidences) / len(
-                prev_char_confidences
+            prev_avg_confidence = (
+                (sum(prev_char_confidences) / len(prev_char_confidences))
+                if prev_char_confidences
+                else 0
             )
 
             # Define conditions for keeping the previous plate