Long Movies (20 min; 1.5 GB compressed) in PsychoJS and Pavlovia

Has anyone tried to build a task that will work online with Pavlovia that requires a download of around 5 GB of videos (at compressed minimum; each of 3 videos is about 20 min long). The task is very simple only requiring consecutive presentation of 3 movies (randomly selected out of 38 movies) and a space bar button press response at certain points in the continuous video. If you have tried this would you mind sharing your experience. We need to test around 150 people across these 38 stimuli and would love to be able to do it faster than running participants in person and possibly get more than 150 participants. Thanks!


Hi @cory.inman,

I cannot answer your original question as I don’t have experience with that. However, I feel like you might be better off embedding your videos from another online source (e.g., YouTube). In this way, the download would not have to be completely finished before the experiment could start. Maybe that’s the better option for you.


Thank you Adrian! This is a great idea. Do you know about how precise the logging of button presses would be using the embedded video method? We are hoping for millisecond precision if possible. One other concern is how ‘private’ we can make the videos, but I think that should be possible on YouTube. Thanks again!


Hi Cory, no I’ve never used button presses while an embedded video was running. Also, I just noticed that there is one major problem with the embedding method, which is that participants are able to pause the video. If you are interested in the timing of the button presses with respect to the movie, that’s of course not too great. Maybe there is another video host than YouTube, which does not allow the pausing of videos in embedded videos…