Fix Bad Resize For Camera Snapshot (#6797)

* Catch cases where incorrect size is requested

* Set a default if calculated height is incorrect

frigate/http.py

@@ -1118,6 +1118,15 @@ def latest_frame(camera_name):
         height = int(request.args.get("h", str(frame.shape[0])))
         width = int(height * frame.shape[1] / frame.shape[0])
 
+        if not frame:
+            return "Unable to get valid frame from {}".format(camera_name), 500
+
+        if height < 1 or width < 1:
+            return (
+                "Invalid height / width requested :: {} / {}".format(height, width),
+                400,
+            )
+
         frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
 
         ret, jpg = cv2.imencode(