No x264 hw decoding on Intel Iris Plus

[bonecruizer]

I am using Jellyfin v10.10.7 on a proxmox LXC running on an Intel  Nuc.

Not the most simple setup when it comes to proper hardware accelaration, but it works - partly.

I have the video device working in the container. When I play an HEVC encoded file, I can see that the GPU is being used.
However, the x264 encoded titles do not seem to use hardware decoding. I the logs, I can see that ffmpeg does NOT use the arguments for hardware decoding. So somehow it seems that Jellyfin decides not to use hardware acceleration for these titles.

GPU is Intel Iris Plus.

In the transcoding --> playback config I have x264 hw decoding enabled.

At first I thought it had to do with the technical part of the GPU passtrough etc, but when I give a manual command to ffmpeg it will also play the x264 titles with hw acceleration.

What could be the reason that these titles are not played with hw decoding enabled?

Thanks in advance.

[nyanmisaka]

h264 includes various profiles, and the intel hardware can only decode up to High 4:2:0 8bit.

Any profile higher than this, such as High10 or High422 10bit, is not supported.

[bonecruizer]

That is an excellen suggestion, thanks!

I checked some of the files with mediainfo:

Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Chroma subsampling : 4:2:0
Bit depth : 8 bits

This would suggest that hw decoding can be used? Are there any other factors that would prevent hw decoding? My CPU is getting kind of steamy :-)