Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Advanced display talk, display hackers, advanced game programmers, scientists, display researchers, display manufacturers, vision researchers & Advanced Display Articles on Blur Busters. The masters on Blur Busters.
User avatar
Chief Blur Buster
Site Admin
Posts: 11647
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by Chief Blur Buster » 12 Jul 2021, 17:01

Yes, that's a quite reasonable algorithm -- instantaneous strobe phase accuracy is not as critical as flicker prevention algorithms.

You can slew phase "after the fact", so free floating strobe phase that slowly flywheels around to "catch up" with the frame rate, is a very adequate flicker-prevention strategy for strobed VRR.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

elexor
Posts: 169
Joined: 07 Jan 2020, 04:53

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by elexor » 14 Jul 2021, 08:28

Chief Blur Buster wrote:
12 Jul 2021, 17:01
You can slew phase "after the fact", so free floating strobe phase that slowly flywheels around to "catch up" with the frame rate, is a very adequate flicker-prevention strategy for strobed VRR.
If i freewheel really fast it will just bang up against my reference signal re-introducing the jitter i just filtered out. What I want is a way to slow down freewheeling as it gets closer to the reference signal. I can't seem to get my head around how to do that every attempt so far has failed. any ideas? or is it not possible?

often you will have a scene change or camera change that will throw it far out of phase. just want it to return close enough then slow freewheeling can take over again.

edit: figured it out for the most part.

Code: Select all

  if (leftSlewLocked && rightSlewLocked) {leftSlew = -(phaseDiff * 0.01); rightSlew = ( (frameTime - phaseDiff) * 0.01 ); leftSlewLocked = false; rightSlewLocked = false;}
  if (phaseDiff > (frameTime / 2) && slewLock == false) {slewPhase = rightSlew; slewLock = true; rightSlewLocked = true;}
  if (phaseDiff < (frameTime / 2) && slewLock == true) {slewPhase = leftSlew; slewLock = false; leftSlewLocked = true;}
pretty crappy code but it works. requires phase much quicker after camera cuts in cemu mariokart 8 without introducing jitter.
can even adapt to the super erratic retroarch vrr frametimes.
not sure why retroarch frametime consistency sucks when the content is fixed framerate predominantly. did they just not care because it's hidden by sample and hold?

User avatar
Chief Blur Buster
Site Admin
Posts: 11647
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by Chief Blur Buster » 17 Jul 2021, 17:23

It's pretty neat to see DIY strobed VRR outperforming manufacturer strobed VRR. This is better than first-generation ASUS ELMB-SYNC.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

elexor
Posts: 169
Joined: 07 Jan 2020, 04:53

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by elexor » 18 Jul 2021, 09:19

Chief Blur Buster wrote:
17 Jul 2021, 17:23
It's pretty neat to see DIY strobed VRR outperforming manufacturer strobed VRR. This is better than first-generation ASUS ELMB-SYNC.
Biggest hurdles are stuff out of my control like nvidia lfc and some games just have the most horrible vrr fracepacing i don't think you can do much with them. some games have excellent frame pacing with their internal limiters.

i once seen 60hz with frametimes like this :shock: |-|-|---|-|-|---|-|-|---

pretty sure my ref signal is showing vbp because crosstalk is lowest right before it.

Also wanted to ask you if a pll is better suited to dejittering and phase locking vbp. I still struggle with heavier filters causing too much group delay.

elexor
Posts: 169
Joined: 07 Jan 2020, 04:53

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by elexor » 25 Jul 2021, 09:37

So I have been trying out an AMD videocard and boy their LFC is so much better it actually respects the freesync range and only kicks in when below the minimum range. it also returns to the correct refresh rate fast. is much better behaved in general.

edit: would also like to mention this is with vrr via hdmi. since this amd card does not have displayport.

liquidshadowfox
Posts: 143
Joined: 05 Nov 2020, 14:03

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by liquidshadowfox » 30 Jul 2021, 04:18

Could something like this be applied to the recently release Asus XG27AQM? I made a forum post about it and I am relatively happy with the elmb sync performance BUT there's no option to increase or decrease the strobe length despite it being mentioned in the manual. Currently as it stands there's a small artifact where the lines surrounding a rendered object are slightly doubled in motion which causes the outlines to make objects look softer than what they appear. If there's a way for me to improve the VRR strobing I'd like to know more. Also how did you do this hack? were you able to manipulate everything from usb? or did you have to take the monitor apart and attach to a specific port?

elexor
Posts: 169
Joined: 07 Jan 2020, 04:53

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by elexor » 01 Aug 2021, 22:53

liquidshadowfox wrote:
30 Jul 2021, 04:18
Could something like this be applied to the recently release Asus XG27AQM? I made a forum post about it and I am relatively happy with the elmb sync performance BUT there's no option to increase or decrease the strobe length despite it being mentioned in the manual. Currently as it stands there's a small artifact where the lines surrounding a rendered object are slightly doubled in motion which causes the outlines to make objects look softer than what they appear. If there's a way for me to improve the VRR strobing I'd like to know more. Also how did you do this hack? were you able to manipulate everything from usb? or did you have to take the monitor apart and attach to a specific port?
It may be possible to do this kind of hack on other monitors.

This is a work in progress hardware hack not possible without a microcontroller, soldering and voiding warranties. single strobed vrr is complicated and has many roadblocks. If I get it working well enough for most content I will do a writeup about how it's all done. but for now it's very much in an experimental stage.

Not much you can do to make elmbsync perform better they lock overdrive and don't single strobe vrr due to flicker concerns.

liquidshadowfox
Posts: 143
Joined: 05 Nov 2020, 14:03

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by liquidshadowfox » 02 Aug 2021, 00:09

I am able to change the overdrive with the service menu to great effect. My post on this monitor can be found here: viewtopic.php?f=2&t=8826&sid=02e8fa7c74 ... 1656f1e737

I put up a lot of documentation and pictures on the motion clarity as best as I could. Thanks for the update. Really excited to see the write up even if it's experimental.

elexor
Posts: 169
Joined: 07 Jan 2020, 04:53

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by elexor » 02 Aug 2021, 02:21

liquidshadowfox wrote:
02 Aug 2021, 00:09
I am able to change the overdrive with the service menu to great effect. My post on this monitor can be found here:
Nice unfortunately the VG279QM has no such option in the service menu.

elexor
Posts: 169
Joined: 07 Jan 2020, 04:53

Re: Hacked ASUS VG279QM modified to single-strobe 60 fps capped VRR for emulators

Post by elexor » 02 Aug 2021, 05:09

Chief Blur Buster wrote:
17 Jul 2021, 17:23
phpBB [video]


Controlling the 6 OD modes with my teensy sending DDC commands directly to the monitors hdmi port. just cycling through them.
eyeballing it it seems like 200ms is the limit to how fast it can switch.

Post Reply