This needs LAV filters installed. The LAV filters installers doesn't work in proton. You need to download K-lite codec pack 1385 basic. Install by WINEPREFIX=~/.local/share/Steam/steamapps/compatdata/556140/pfx wine K-Lite_Codec_Pack_1385_Basic.exe Then go to LAV splitter settings and enable for every codec and option. Then sit back and enjoy preferably in 4k 60fps mode. Or go to the planetarium at The National Space Centre in Leicester and watch it there. Both great experiences.