https://bugs.winehq.org/show_bug.cgi?id=48766
--- Comment #35 from Zebediah Figura z.figura12@gmail.com --- Just install the program, please; don't install native quartz or mfplat or perform any overrides.
Is libgstopenh264.so present in your GStreamer plugin path? (i.e. /usr/lib/gstreamer-1.0/ or something similar).