Understanding Skipped Frames

Hello Jaewon,

I am posting because I am unable to pinpoint the reason for my skipped frames. I constantly have 30 skipped frames every trial that always occur during the presentation of the stimulus. I have uploaded an example entry for skippedframeinfo, confused on how columns 5-12 are more time info entries, but stimuli presentation is timestamped at 3234, and what is interesting to note is always there are 12 columns and consistently 30/31 dropped frames. I wonder if using gen instead of mov will help, as for some reason I am unable to use gen function and it fails to find my video labels, or if using scenes to set up the stimuli is better than presenting them using "Timing Script v1" method of toggling objects and tracking eye input. Is there any advice or guidance on how to find the bottleneck or issue for skipped frames to overcome it? I am also wondering if there is a way to "preload" stimuli using the first run of userloop function and whether that could help prevent skipped frames during stimuli presentation.

Thank you,

I am curious because the same stimuli presented using a conditions file have 16/17 skipped frames, however you have informed that the use of gen_condition is discontinued and that is why I have went with using userloop function instead

Hello,

Just an update, when no stimuli is being presented no skipped frames occur at all, and I have attempted to (using old conditions file method) use gen function to "respect" old framerate of videos, however no change took place for the number of skipped frames. So essentially, I am wondering if using scenes, preloading stimuli or upgrading hardware are valid options to overcome skipped frames, and since I am a beginner I would appreciate any advice on the issue. Thanks a million

You did not provide any information about your monitors and movies. Try a refresh rate of 60 Hz, instead of 120 Hz. The size of your movies (width & height) may be so large that your system cannot process them in time.

As for preloading, see the userloop example (2 movie preloading) in the task directory of your NIMH ML installation path. It has nothing to do with skipped frames though.