Matthew Kerswill
The following line appeared in the change log for Virtual Desktop 1.30.3/1.30.4:
  • Reduced video compression artefacts with 10-bit codecs
Since then, I've noticed the opposite: inconsistent and frequently terrible image quality. Daily, I find instances of HEVC 10-bit yielding worse image quality than regular HEVC.
This is frustrating because HEVC 10-bit previously provided better image quality than regular HEVC 100% of the time. Now, I'd estimate that HEVC 10-bit provides better image quality 80% of the time whilst providing horrible image quality 20% of the time. I still use HEVC 10-bit but now find myself frequently switching codecs depending on the characteristics of the virtual environment, whereas previously HEVC 10-bit was always the best choice.
The problem is that the encoder makes certain surfaces appear like they've turned into jelly. In these areas, I observe extremely aggressive blocky compression and the little detail that remains wobbles as if attached to my subtle head movements.
The surfaces that are affected by this problem typically have one of these characteristics:
  • Subtly textured or flat shaded.
  • Dimly lit.
  • Monochromatic (lacking significant hue variation).
I request an option to toggle the specific encoding setting that was changed for 10-bit codecs in VD 1.30.3/1.30.4.
Examples
I have an RTX 2070 and I'm using Virtual Desktop's 'Medium' quality setting. I don't know if this problem will manifest on all graphics cards but, assuming that it does, I have prepared a series of example scenarios to demonstrate the problem. (Note that this problem cannot be captured by screenshots or videos - it must be seen in the headset.) I have 4 scenarios from VRChat and 1 from Half-Life: Alyx and screenshots are provided for clarity.
'The Wall - Security Sector' by DarkGrey
https://vrchat.com/home/world/wrld_4641e61e-ef6f-4a9c-a1d6-a0806b114928
  • As soon as you spawn, you will be surrounded by concrete walls that have turned to jelly.
'The Grand Fjord' by Qyr
https://vrchat.com/home/world/wrld_61021c2e-c69c-41b3-a000-6426ef5cdb05
  • Walk to the portal and use it to travel to the main area.
  • The dirt ground has turned to jelly.
'Megaton (Fallout 3)' by ControVR
https://vrchat.com/home/world/wrld_b7323160-3652-4a8a-97f5-7ca92319baf7
  • After spawning, turn right and approach the nearby door.
  • The door is jelly and, if you get close, the compression blockiness is diabolical.
'Marshmallow Peak' by Okabintaro
https://vrchat.com/home/world/wrld_58e7347e-cfcd-4f34-8169-5ba4b7047aa7
  • Toast and eat 10 marshmallows to unlock an easter egg that allows you to extinguish the campfire.
  • Observe the grey rocks that have turned to jelly.
Half-Life: Alyx main menu
  • Launch Half-Life: Alyx and turn around.
  • Many areas of the more dimly-lit rubble shift around with your small head motions.
  • Interestingly, I noticed that having your holographic hands in view seems to stabilize the picture so be sure to move your hands out of your view to see the problem.
  • Also interesting is that reducing the bitrate to 50Mbps seems to improve the image quality and reduce the jelly appearance.