

I can try it again, but what I did was compare h265 to SVT-AV1 in ffmpeg, using a couple different clips of different styles (including a video from my phone and some ripped blu-ray movies). I used “constant quality / variable bitrate settings, and ran each file with a variety of settings for both encoders. I judged the videos with a quality comparison tool ffmpeg has, and I also took subjective notes when I could tell the difference.
I found AV1 did better at very low quality (when it was firmly into the region where it was visibly different, AV1 did have better quality per bitrate).
But when trying to produce high-quality clips, AV1 was never able to produce a clip that matched the quality score of h265, even when the bitrate of the AV1 file was higher.
Jellyfin simply doesn’t work as well as Plex unfortunately.