Hi team!
I used Builder to create an experiment that I am running in Pavlovia, where on each trial I present a 3 second .mp4 clip and participants rate the clip using a slider component. There are 500 movie files that together are 95 mb. This doesn’t seem like a lot to me.
On my own laptop (Win 11, Psychopy 2025.2.4Beta), when using Chrome or Edge, the experiment has bizarre display issues when I load more than half the files (e.g.,the slider disappears and I’m left with just the slider labels in a strange font, polygons in general do not load). This seems to be related to the number of files rather than size; half the files are about 800 kb each, the other half are less 100 kb, and I seem to have issues as soon as the number of trials exceeds ~300 regardless of size.
On Firefox, I have no issues, but a colleague piloted on their machine using Firefox and had some other problems (audio cutting halfway and video frame staying onscreen with the scale when it shouldn’t). I’m currently verifying whether it is just an issue with their device but I have my doubts.
Anyway, do you have any advice? It seems that Psychopy/Pavlovia have major issues presenting .mp4 files to the point where I may need to move to a new platform. I’ve been troubleshooting for a week at this point (as it took me a while to realise that the issues were specific to my stimuli and browser choice). Just mentioning this to give you a sense of how problematic this has been for me!
Thank you!
: the experiment seems to be working on Firefox on 3 other machines. I need to verify that the experiment runs the whole way through, at which point I will update this thread and we can close it. Any advice/insight into whether my experience is common is still very much welcome though. Thanks.