GH #900: Compute display lag

Previously the BehaviorOphysLimsApi did not compute
monitor delay, but added a default value of 0.351.
This updates the default to 0.215, which is the
average of monitor delay for a large number of recent
datasets.

Additionally use the OphysTimeAligner methods to
compute the display lag, which is used in the
OphysTimeSync job to produce corrected timestamps
in the LIMS pipeline.

allensdk/internal/api/behavior_ophys_api.py

@@ -10,6 +10,7 @@
 from allensdk.internal.api.ophys_lims_api import OphysLimsApi
 from allensdk.brain_observatory.behavior.sync import (
     get_sync_data, get_stimulus_rebase_function, frame_time_offset)
+from allensdk.internal.brain_observatory.time_sync import OphysTimeAligner
 from allensdk.brain_observatory.behavior.stimulus_processing import get_stimulus_presentations, get_stimulus_templates, get_stimulus_metadata
 from allensdk.brain_observatory.behavior.metadata_processing import get_task_parameters
 from allensdk.brain_observatory.behavior.running_processing import get_running_df
@@ -38,8 +39,10 @@ def get_sync_data(self):
 
     @memoize
     def get_stimulus_timestamps(self):
-        monitor_delay = .0351
-        return self.get_sync_data()['stimulus_times_no_delay'] + monitor_delay
+        sync_path = self.get_sync_file()
+        timestamps, _, _ = (OphysTimeAligner(sync_file=sync_path)
+                            .corrected_stim_timestamps)
+        return timestamps
 
     @memoize
     def get_ophys_timestamps(self):

allensdk/internal/brain_observatory/time_sync.py

@@ -15,7 +15,7 @@
 REG_PHOTODIODE_MAX = 2.1 # seconds
 PHOTODIODE_ANOMALY_THRESHOLD = 0.5 # seconds
 LONG_STIM_THRESHOLD = 0.2 # seconds
-ASSUMED_DELAY = 0.0351 # seconds
+ASSUMED_DELAY = 0.0215 # seconds
 MAX_MONITOR_DELAY = 0.07 # seconds
 
 VERSION_1_KEYS = {