Gnome Videos - No valid frames decoded before end of stream for AV1

[lejeczek]

Hi guys.

I get that when viewing an AV1 file's properties in Gnome's 
Files - Gnome Video would not playback such a file.
I am asking here for I wonder if this is Gnome-specific 
issue for... other popular media players, in Fedora, play 
such file just fine.
Or, perhaps it's OBS issue when records into AV1 ?  I've 
tried both FFmpeg VAAPI and QuickSync for video encoder, 
which result in the same issue.

many thanks, L.