matroskademux does not set codec data duration to buffer for h.264 or AVC videos
I'm using GStreamer 1.20.1 on Arch Linux
gst-play-1.0 fails to display the video content of this file: opus_WITH_COVER
It displays correctly in VLC or MPV for example. It is therefore not possible to extract a thumbnail from this file using the GStreamer APIs.
Downstream report: https://gitlab.xfce.org/xfce/tumbler/-/issues/35