Lower timeout in object processing (#17970)

On startup, the object processing pipeline would be delayed for 10ms every iteration through the loop while the end event subscriber blocked. For users with large numbers of cameras and a fair amount of detected objects, this would cause the detected objects queue length to rise and frames to be eventually dropped, leading to processing delays, incorrect frame times applied to thumbnail_data, and other seemingly unexplainable things.

frigate/const.py

@@ -129,3 +129,7 @@ AUTOTRACKING_ZOOM_EDGE_THRESHOLD = 0.05
 
 JWT_SECRET_ENV_VAR = "FRIGATE_JWT_SECRET"
 PASSWORD_HASH_ALGORITHM = "pbkdf2_sha256"
+
+# Queues
+
+FAST_QUEUE_TIMEOUT = 0.00001  # seconds

frigate/record/maintainer.py

@@ -27,6 +27,7 @@ from frigate.config import FrigateConfig, RetainModeEnum
 from frigate.const import (
     CACHE_DIR,
     CACHE_SEGMENT_FORMAT,
+    FAST_QUEUE_TIMEOUT,
     INSERT_MANY_RECORDINGS,
     MAX_SEGMENT_DURATION,
     MAX_SEGMENTS_IN_CACHE,
@@ -38,8 +39,6 @@ from frigate.util.services import get_video_properties
 
 logger = logging.getLogger(__name__)
 
-QUEUE_READ_TIMEOUT = 0.00001  # seconds
-
 
 class SegmentInfo:
     def __init__(
@@ -536,7 +535,7 @@ class RecordingMaintainer(threading.Thread):
             # empty the object recordings info queue
             while True:
                 (topic, data) = self.detection_subscriber.check_for_update(
-                    timeout=QUEUE_READ_TIMEOUT
+                    timeout=FAST_QUEUE_TIMEOUT
                 )
 
                 if not topic:

frigate/track/object_processing.py

@@ -28,7 +28,7 @@ from frigate.config import (
     RecordConfig,
     SnapshotsConfig,
 )
-from frigate.const import UPDATE_CAMERA_ACTIVITY
+from frigate.const import FAST_QUEUE_TIMEOUT, UPDATE_CAMERA_ACTIVITY
 from frigate.events.types import EventStateEnum, EventTypeEnum
 from frigate.models import Event, Timeline
 from frigate.track.tracked_object import TrackedObject
@@ -682,7 +682,9 @@ class TrackedObjectProcessor(threading.Thread):
 
             # cleanup event finished queue
             while not self.stop_event.is_set():
-                update = self.event_end_subscriber.check_for_update(timeout=0.01)
+                update = self.event_end_subscriber.check_for_update(
+                    timeout=FAST_QUEUE_TIMEOUT
+                )
 
                 if not update:
                     break