https://bugs.winehq.org/show_bug.cgi?id=56712
--- Comment #10 from vv221 accounts.winehq.org@vv221.fr --- GStreamer might not be the culprit: I uninstalled all GStreamer plugins on the system playing the videos (even the "base" plugins), and the videos are still played successfully (both video + audio).
Is there another system that WINE could be using for media playback?