Blur Busters Forums

Who you gonna call? The Blur Busters! For Everything Better Than 60Hz™ Skip to content

Video color space format and lag?

Everything about input lag. Tips, testing methods, mouse lag, display lag, game engine lag, whole input lag chain, VSYNC OFF vs VSYNC ON, and more! Input Lag Articles on Blur Busters.

Video color space format and lag?

Postby silikone » 14 Jun 2018, 03:59

Is it possible that the color format used to transfer a video signal can be a source of input lag? The reason I ask is that the common 4:2:0 subsampling format used for videos is more often than not stored in a planar format, which if sent over a cable serially, would not be able to deliver results to the screen instantly.
silikone
 
Posts: 31
Joined: 02 Aug 2014, 12:27

Re: Video color space format and lag?

Postby Chief Blur Buster » 15 Jun 2018, 19:00

Only if the horizontal scanrate goes up. The horizontal scanrate is the number of pixel rows per second transmitted. 67KHz means a single row of pixels is transmitted in 1/67000sec (excluding transceiver delays at both ends).

So that means switching 4:4:4 vs 4:2:2 vs 4:2:0 makes no difference in input lag.

But switching to lower chroma resolution can enable a higher refresh rate (more bandwidth available to go higher Hz).

Which does mean less lag.

Over ten years ago, my old Samsung 245BW monitor could overclock to 75Hz but it switched to 4:2:0 when it did that.

Today, monitors like the Predator X27 monitor can only do HDR at 144Hz if you go less than 4:4:4 chroma.

The refresh rate is the bigger determinant of the scanout-related input lag. (Unless HDMI 2.1's new Quick Frame Transport techniques are used -- that's essentially a Large Vertical Total -- a higher scanrate. A large VBI with a faster active-image scanout)
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter!
To support Blur Busters: Official List of Best Gaming Monitors | G-SYNC | FreeSync | Ultrawide
User avatar
Chief Blur Buster
Site Admin
 
Posts: 4863
Joined: 05 Dec 2013, 15:44


Return to Input Lag

Who is online

Users browsing this forum: No registered users and 6 guests