Limit shm frame count (#12363)

* Limited shm frame count (#12346)

* Only keep 2x detect fps frames in SHM

* Don't delete previous shm frames in output

* Catch case where images do not exist

* Ensure files are closed

* Clear out all frames when shutting down

* Correct the number of frames saved

* Simplify empty shm error handling

* Improve frame safety

* Add handler logs when frame is None

* Don't fail on cleanup

* Cleanup logging

* Update docs

* Update calculation

* Restore condition

* Fix case where thumbnail is saved without frame

* Adjust debug logs

* Calculate best shm frame count

* Fix shm count calculation

* Catch missing frame

* Formatting

* Clarify docs

* Catch none frame in autotracking

frigate/embeddings/maintainer.py

@@ -78,9 +78,11 @@ class EmbeddingMaintainer(threading.Thread):
         try:
             frame_id = f"{camera}{data['frame_time']}"
             yuv_frame = self.frame_manager.get(frame_id, camera_config.frame_shape_yuv)
-            data["thumbnail"] = self._create_thumbnail(yuv_frame, data["box"])
-            self.tracked_events[data["id"]].append(data)
-            self.frame_manager.close(frame_id)
+
+            if yuv_frame is not None:
+                data["thumbnail"] = self._create_thumbnail(yuv_frame, data["box"])
+                self.tracked_events[data["id"]].append(data)
+                self.frame_manager.close(frame_id)
         except FileNotFoundError:
             pass