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RED_SIM
@sim.red

I want to talk about a big Steam Frame problem no one seems to mention: image quality. SteamVR's streaming pipeline has a serious bug that blurs high-contrast edges. I managed to partially fix it. These are real screenshots from the headset after decoding and lens correction.

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dark 🏳️‍⚧️
@darkswordsman.com

Honestly not sure why we don't use 4:4:4 for everything nowadays. It technically uses a *little* more data, but the bulk of the compression is happening through the encoder. 4:4:4 is basically free clarity.

RED_SIM
@sim.red

I used 250% supersampling here, so it's not an effect of the small resolution. If you thought the excess blur came from the optics, now you know it starts on the PC, before compression! I'd really like someone at Valve to see this and fix it. Details below.

RED_SIM
@sim.red

As you can see, the fix doesn't remove all the blur. That's why we need 4:4:4 color sampling. In this comparison you can see that Pyrowave looks much cleaner in my vibe-coded prototype on Frame. However, it doesn't work in runtime yet. So, Valve, please... you know what to do!

RED_SIM
@sim.red

Here's the bug: SteamVR's PC VRLink shader genforencode_ps_chroma_full_stack.fxo doubles chroma derivatives that already account for 4:2:0, blurring color before HEVC. My patch averages matching 2x2 RGB pixels after sRGB conversion, then computes Cb/Cr.

RED_SIM
@sim.red

I already managed to contact a person from Valve, so I hope it will be fixed soon!