5K videos now stuttering, never used to before

[kfumble £]

Virtual desktop used to play 5K/hevc VR videos smooth and seamlessly, for some reason all 5K video playbakc stutters now even more so when I move my head around.

Regular HD VR videos (h.264) still play perfectly fine.

On Windows 10, htc vive, have only tried rebooting PC so far to no avail

[ggodin]

This is because of a recent Windows 10 update that removed the HEVC decoder. Solution is to simply download it from here: https://www.microsoft.com/en-us/store/p/hevc-video-extension/9n4wgh0z6vhq

Other possible causes is the dynamic supersampling feature that was recently added: this can cause double supersampling so tuning it down or turning it off in Virtual Desktop will reduce the GPU usage.

[kfumble £]

I have the hevc video extension app that you linked to, and I launched it but that didn't help.
When I click to launch the extension, it opens up the Film and TV app, and from there I can open and play the same hevc 5K VR videos smoothly in its 2D video player, but the same 5K VR videos played in Virtual Desktops player are still stuttering.

I tried selecting 'Force Software decoding' in VD and the stuttering goes away, but the frame rate during playback isn't as smooth and seems slightly in slower motion.

Which exact settings in SteamVR should I select to help disable the extra supersampling?
Under Applications tab, I have Virtual desktop app resolution adjustment set to 100%.
Under Video tab, Manual override is checkmarked at -- 100%
Under Developer tab, I am unsure of which of these I should have checkmarked?
-Allow asynchronous reprojection?
-Allow interleaved projection?
-Enable Advanced Supersample Filtering?
-Enable Always-On Reprojection?

Additional notes:
Whirligig player with Direct Show Video path option also stutters, BUT when switching to 'Windows Media Foundation' video path, 5k video playback is perfectly smooth like old times!

(btw, I am on K-Lite codec Full pack to latest 14.0.7, Nvidia GTX 1080 Ti driver 388.71)
Maybe update driver issue? (latest driver was a causing my vive to turn off after a few seconds)

[ggodin]

I’m actually able to repro the stuttering with the Vive and Rift now. Going to investigate.

[ggodin]

Alright so did some investigation and it appears that the recent HEVC decoder change in Windows 10 has degraded the performance of hardware decoding for DirectX 9 implementations (that’s the type of decoding I’ve used in Virtual Desktop for the last 3 years). If you play HEVC videos in Windows Media Player (or Virtual Desktop since it uses the same tech) you’ll notice it uses far more CPU than GPU to decode the video compared to the Movies and TV app (which uses a Direct11 based implementation).

So there are 2 ways for me to solve this:

1) Tell Microsoft that they regressed performance and hope they fix it on their side (highly doubt they’ll take the time to fix this)

or

2) Change the video player in Virtual Desktop to use a DirectX 11 implementation.

I’ll likely push to get this fixed on both fronts in case either one doesn’t work out but 2) it isn’t a simple task and might take a few weeks.

[kfumble £]

Thanks for your timely responses and looking forward to a fix soon, in the meantime there isn't really much we can do is there besides 'Force Software decoding'?

[ggodin]

Yeah that’s the solution for now or you can go back to a previous version of Windows (that’s probably impossible lol). I’ll keep this thread updated with my progress.

[CheeseFromTFC]

Any update on this? Running into the same issue.

[ggodin]

I’ll have the beta up in the next few days

[ggodin]

Ok beta branch has the new video player backend. Let me know if you experience any issues. The playback should now be smooth as butter like it was before the Windows update that messed things up.

[CheeseFromTFC]

Thanks ggodin! Got it to work in DirectX 11 mode on my 1060 after installing K-Lite codec pack and selecting NVIDIA CUVID decoder in LAV settings. Sorry this feature request ended up causing you drama :) As a fellow dev, I understand your pain with these types of changes. Your work is much appreciated.

[Dwyloc]

Well for me the good news, is with dx11 mode I can play back 5k video on my 1070 and I can also use a higher level of SS for 4k video than with the dx9 mode without getting re-projection or dropped frames.

Software mode also works well for me with K-Lite codec pack installed and selecting NVIDIA CUVID decoder in LAV settings like Cheese says.

So all in all I am very happy with the current version on my Vive.

[Padarom]

Is there any way to get the beta branch on the Oculus version of Whirligig?