HW Transcoding QSV Quality Level - Make my CPU hurt!

Plex Media Server Desktops & Laptops
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First off, BRAVO on the implementation of zero-copy!!! You guys are amazing! I cant believe how fast my little i5 is at trans-coding multiple streams concurrently, and I love seeing that GPU graph go full tilt for a few seconds then dip down as the trans-coding gets throttled back.

So for the longest time I didnt think you could set a quality level when using HW encoding but I noticed an improvement when I set quality to “Make my CPU hurt”. This didn’t make any noticeable difference to my CPU usage graphs as far as I could tell, but I noticed a lot less distortion/artifacting during high motion scenes. Can anyone confirm if this setting actually affects HW transcoding quality level with QSV? I’m wondering if my experience was random or coincidence with QSV’s stability/reproducible results.

Keep up the great work!

Server Version#: 1.18.0.1846
Intel NUC 8i5BEH (i5-8259U,16GB RAM)

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Great question!

I have been wondering about that myself, what effect, if any that option does for gpu transcode.

And is it different between intel and nvidia.

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I may have spoke too soon, it could be a fluke but I wonder if there are issues converting HEVC Main10 (10bit) to x264 - quality was pretty bad on an anime I just streamed

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I’m not sure about the setting, I have mine on auto. However I have the same issues with quality using the latest release with zero copy on Intel QS. Mine is on a j4105. Quality is EXTREMELY blocky on even 4mbit.

It seems not all content is affected, a large majority is though.

I assume they must be running incompatible files through hardware decoding.

I have rolled my server back until this is fixed as it’s that bad users are noticing it.

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Same issue, quality gets worse and worse as the anime video continues so every 5 to 10 min a need to spot and play again.

Changing the transcode quality has no effect

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Same here with regular video too - same sections of video will come out horrible, then a rewind (retranscode) and they come out… so-so, not great but not terrible either.

I’ve rolled back to 1.17.0.1709 for now which doesn’t transcode in HW as fast, but the quality difference is night and day.

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Another thought here is that this likely isn’t directly a Plex problem. They’ve enabled “zero-copy” which i suspect is an API call up to DirectX or the Intel driver and everything beyond that is on Intel. It’s possible Intel still has some kinks to work out with zero-copy and quality.

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I think this is a zero-copy issue as well. If I roll back to the version of PMS before they enabled this function it seems to work much better.

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