4K DLP hack for 120 fps -- [for TI 4K projectors]

Advanced display talk, display hackers, advanced game programmers, scientists, display researchers, display manufacturers, vision researchers. The masters on Blur Busters.

4K DLP hack for 120 fps -- [for TI 4K projectors]

Postby RLBURNSIDE » 19 Feb 2017, 14:07

Hi guys, I figured I should share this here since this site is all about stuff greater than 60hz:

https://www.shadertoy.com/view/lslcRr

Here's a discussion on AVS regarding my idea to get 120fps in SDR and 96hz in HDR out of these new TI 4K projectors:

http://www.avsforum.com/forum/68-digita ... st50669905

http://www.avsforum.com/forum/68-digita ... st50886217

I believe it might just work based on the fact that they pass the 1 pixel-wide 4K torture test:

Image

You can see these new chips which have 2716 x 1528 native resolution, or 4M pixels, can indeed resolve every pixel in a UHD 2160p source image (8M pixels), by using what's known as "wobulation", i.e. showing 1/2 the pixels at time A and the other half at time B, both within the same frame duration as a standard 60hz frame.

It's similar to an idea I read here on Blurbusters (to give credit where it's due) about using the 3D mode on DLPs to engage 120 fps in 2D using SBS modes. But this is far better because it increases spatio-temporal resolution in both dimensions (space and time).

I also wrote a shadertoy for that here:

https://www.shadertoy.com/view/4sfcR8.

It works on my w1070.

The core of my idea is simply to exploit the fact that the second subframe needn't be sampled at the same time as the first, or even at the same offset.

It also should achieve stereoscopic 3D using VESA LCD-shutter glasses. I will be writing media player classic shaders to show movies on it and it should work even better in games because if you can do 60 fps at UHD then you can maybe do 120 fps at 2.7K (which is exactly half the number of pixels per frame, hence the same workload). Plus if you do it for stereo 3D you can also do VR SLI and single-pass stereo to render both eyes simultenously. Then it's just a matter of compositing the 2160p framebuffer in a similar way as I did in my shadertoy here.
RLBURNSIDE
 
Posts: 104
Joined: 06 Apr 2015, 16:09

Re: 4K DLP hack for 120 fps -- [for TI 4K projectors]

Postby Chief Blur Buster » 19 Feb 2017, 14:43

Fascinating, 4K 120fps on a DLP projector!

Do these projectors have capability for BFI -- black frame insertion?

This will reduce persistence even further. Many 3D DLPs use a BFI to help accomodate shutter-switch delay in LCD shutter glasses (the amount of time for 3D glasses LCD shutter to fade open/closed between eyes). But a side effect of this BFI for 3D mode, is the reduction of persistence to approximately 1/4th as much motion blur as 60Hz DLP.

60Hz DLP -- 100% motion blur of 60Hz
120Hz DLP -- 50% motion blur of 60Hz (each frame visible for 1/120sec)
120Hz DLP + BFI -- 25% motion blur of 60Hz (each frame visible for 1/240sec)

This assumes 50%:50% BFI ratio. Sometimes the BFI ratio is adjustable (e.g. 60% picture, 40% black frame) so there is some fudge factor.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter!
User avatar
Chief Blur Buster
Site Admin
 
Posts: 3250
Joined: 05 Dec 2013, 15:44

Re: 4K DLP hack for 120 fps -- [for TI 4K projectors]

Postby Chief Blur Buster » 19 Feb 2017, 21:11

I've split the software-based black frame insertion driver/shader into a new topic:

Shaders/Drivers with software-based Black Frame Insertion

We can continue both discussion threads, they are both very useful topics with their own different spinoff benefits.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter!
User avatar
Chief Blur Buster
Site Admin
 
Posts: 3250
Joined: 05 Dec 2013, 15:44


Return to Area 51: Display Science, Research & Engineering

Who is online

Users browsing this forum: No registered users and 2 guests