filter objects before triggering events

config/config.example.yml

@@ -116,6 +116,9 @@ cameras:
  # from the video stream without re-encoding. Clips are them created by using ffmpeg to merge segments
  # without re-encoding. The segements saved are unaltered from what frigate receives to avoid re-encoding.
  # They do not contain bounding boxes. 30 seconds of video is added to the start of the clip.
+ #
+ # NOTE: This will only work for camera feeds that can be copied into the mp4 container format without
+ # encoding such as h264. I do not expect this to work for mjpeg streams.
  ################
  save_clips: False
 

frigate/object_processing.py

@@ -22,6 +22,11 @@
 for key, val in LABELS.items():
  COLOR_MAP[val] = tuple(int(round(255 * c)) for c in cmap(key)[:3])
 
+def filter_false_positives(event):
+ if len(event['history']) < 2:
+ return True
+ return False
+
 class TrackedObjectProcessor(threading.Thread):
  def __init__(self, config, client, topic_prefix, tracked_objects_queue, event_queue):
  threading.Thread.__init__(self)
@@ -65,10 +70,12 @@ def run(self):
  updated_ids = list(set(current_ids).intersection(previous_ids))
 
  for id in new_ids:
- tracked_objects[id] = current_tracked_objects[id]
- # publish events to mqtt
- self.client.publish(f"{self.topic_prefix}/{camera}/events/start", json.dumps(tracked_objects[id]), retain=False)
- self.event_queue.put(('start', camera, tracked_objects[id]))
+ # only register the object here if we are sure it isnt a false positive
+ if not filter_false_positives(current_tracked_objects[id]):
+ tracked_objects[id] = current_tracked_objects[id]
+ # publish events to mqtt
+ self.client.publish(f"{self.topic_prefix}/{camera}/events/start", json.dumps(tracked_objects[id]), retain=False)
+ self.event_queue.put(('start', camera, tracked_objects[id]))
 
  for id in updated_ids:
  tracked_objects[id] = current_tracked_objects[id]
@@ -139,11 +146,10 @@ def run(self):
  ###
  # Report over MQTT
  ###
- # count objects with more than 2 entries in history by type
+ # count objects by type
  obj_counter = Counter()
  for obj in tracked_objects.values():
- if len(obj['history']) > 1:
- obj_counter[obj['label']] += 1
+ obj_counter[obj['label']] += 1
 
  # report on detected objects
  for obj_name, count in obj_counter.items():