Ps4 pro HDR questions.

[Captainkrk]

So this is my first post and some may say I should post this maybe at the Sony forums but LTT hasn't let me down yet. So here we go. 

 

I have a PS4 pro and am trying to figure out which display mode to use....2160p RGB or YUV420.  Now I know 2160p RGB can't do 4k 10bit HDR and what not due to HDMI 2.0 limitations so the PS4 will swap to YUV422...Once this happens my dennon receiver shows it outputting at 24bit color. If I swap it to YUV420 my receiver shows it outputting at 36bits.

 

I've been reading on forums everywhere that YUV420 is for the PS4 on HDMI 1.4....so it's for "less HDR" while YUV422 is newer and bettererer. And RGB is uncompressed but only 8bits where the other 2 are 10bits....I'm just confused as to why my receiver would say the older YUV420 is saying it's 36bits and the newerererer YUV422 is showing it's only 24bits. 

 

Any help on the best way to run the PS4 would be great. Thanks in advance. 

[Changis]

19 minutes ago, Captainkrk said:

-snip-

 

a quick google search gave me this forum post which should answer all your questions

 

Spoiler

Here is SIMPLE WAY OF UNDERSTANDING IT!

YUV420 for old 4K TVs (1.4) don't support 60 HZ while RGB is for newer ones. It compresses the image - and everyone knows with compression comes some loss., With the YUV-420 you also get HDR - which together fills up the 18 GIG bandwith on the high speed cable (HDMI),.

Now if you turn on RGB - which is far superior - as its UNCOMPRESSED VIDEO - the RGB alone it eats up the whole 18 GIG bandwidth and there is no more space for HDR information being sent... So what the PS4 PRO does - it runs a special mode of YUV-422 when you want HDR with RGB...

Just try it and see for yourself... Run a HDR game in RGB - during game - press the Playstation button on controller - goto video settings and you will see its acctually running in "YUV-422" and not YUV-420

You cannot just select YUV-422 from options.. This is automatic mode PS4 PRO goes into when it wants to display HDR with RGB.

So if your TV is newest one - it will support RGB - and leave it on.. When your playing HDR game - your PS4 will go into this special video mode called: YUV-422 (and not the compressed YUV-420 mode).

Hope this makes it simple enough.. So much confusion..

When 2.2 cable comes out - full RGB and HDR will be supported - and mode YUV-422 will be phased out...

RGB + HDR = would burn out the current 2.0 cable as not enough bandwidth - hence 2.2 will support FULL RGB+HDR - for now when you RUN RGB PS4 pro will do HDR on RGB in YUV-422 mode and not YUV-420 mode. So the RGB + HDR = YUV-422 which is a small improvement over the YUV-420...

The real improvement will come once 2.2 cables are out supporting more bandwirth - then we will be able to run true RGB + HDR .. Until then we have a knockoff version called YUV-422 on the PS4 PRO ...

A step below that is YUV-420 (but for all tvs made in 2015 or before) this is the mode they use. For newer TVs - 2016 models and up - you can do RGB mode - and it will have HDR in YUV-422 (special self turning on mode for PS4 PRO)

Here is difference of YUV-422 vs YUV-420:

4:2:2: (YUV-422) The two chroma components are sampled at half the sample rate of luma: the horizontal chroma resolution is halved. [because full RGB takes up whole bandwidth on the current 2.0 cable - until 2.2 cable comes out)

4:2:0: (YUV-420) The two chroma components are sampled at half the sample rate of luma both horizontally and vertically (i.e. there's one U and one V per 2x2 group of Ys).

and incase you dont know how sampling works - | SEE BELOW |

 

SO RGB + HDR = Yuv-422 (with half horizontal and improved FULL vertical resolution)
where - YUV-420 + HDR (half horizontal and half vertical resolution)
 

 

[Captainkrk]

And that is what I find confusing...why would the older YUV420 have a higher 36Bits compared to YUV422 that is only 24bits...unless I'm wrong I believe 36bit color is better than 24? Could it be my Dennon receiver not showing the right info?

[Glenwing]

1 hour ago, Captainkrk said:

And that is what I find confusing...why would the older YUV420 have a higher 36Bits compared to YUV422 that is only 24bits...unless I'm wrong I believe 36bit color is better than 24? Could it be my Dennon receiver not showing the right info?

It's just a trade, heavier subsampling, but you get higher color depth in return. Generally color depth isn't worth much IMO, I'd prefer RGB 24 bit/px over YCbCr 4:2:2 or 4:2:0 at any color depth.