Institute for Language Sciences Labs


Why does my audio / video stutter when I use ZEP?

Last updated on 30 October 2017 by Jan de Mooij

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If you are running an experiment and you notice certain audio or video stimuli stuttering or being played with a certain delay, then it seems as if ZEP can’t load the stimuli files fast enough. Especially for time sensitive experiments, this can be catastrophic.

If this happens it is very likely that you are running your experiment directly from the project folder. The project folder is stored in the cloud, which means that, in addition to all advantages you get there is also a downside: every time your computer needs a file from it, it downloads it in the background. Your computer will do this as fast as possible, and usually you won’t notice anything, but if a lot of people try to download files at the same time (which may occasionally happen), your computer is placed in a queue and has to wait a bit for its files, which may cause ZEP to stutter or be delayed when presenting audio or video files as stimuli.

Read more about how this data storage works in this how-to.

To solve the problem, we strongly encourage everybody to download the experiment to the specific lab computer you are working on in advance. This should be done with care, however. You can find detailed instructions for this procedure here.

If you are already running your experiment as described in the how-to linked above, there may be a problem with your media files. Drop by at the lab support room for help.