The S3Media Stream extension itself doesn't store any personal information about viewers. Therefore, GDPR rules do not apply to the extension itself.
However, JW Player does set certain cookies you have to be aware off if you deal with EU visitors (Brazil, Japan and other nations have similar requirements):
|jwplayercaptionsstate||Controls whether subtitles are shown automatically or not on videos and audios.|
|jwplayeridstate||Checks whether statistics tracking is enabled on videos and audios via the JW Player platform.
On this site it is set to false but this may change later on.
|_ga||Session cookie from JW Player to monitor traffic levels for the video/audio player. Expires when you close the browser.|
The last cookie only counts if you have set Google Analytics in the Default settings to yes and installed a GA script in the header of your theme.
JW Player itself(aka Longtail Ad Solution Inc.)adheres to the EU-U.S. PRIVACY SHIELD FRAMEWORK. The last time I talked with them, they said that they are preparing GDPR information for customers on their blog: https://www.jwplayer.com/blog/tag/monthly-product-update/
From version 8.3 onwards, JW player shows a clientID in the right-click context menu of the player, showing the "About this video" button (among other info):
This displays the clientID and with that clientID, the viewer can request what kind of data is stored on the server of JW Player by directly applying via the JW player site. Follow the blog for more info: https://www.jwplayer.com/blog/tag/monthly-product-update/