VS10 incorrect black levels when in SDR or HDR

Thought I would start a thread for tracking the progress of fixing the bug of the black levels being incorrect when VS10 is outputting in SDR or HDR modes. @mirror are there any updates on this?

 

I'm waiting for feedback from the engineers at the moment.

The issue isn't just the black floor, it's black and white clipping relative to the overall levels too.

I'll post some updated clip numbers when I had a chance to test later today - I have figures from older firmware and while I don't expect them to be different I think it best to run new tests just to be sure.

 

Thanks for all of your help with this Mark.

 

So here are the clipping levels measured with Masciola 4K HDR black and white clipping patterns:

​

So the first thing to note is that as previously discussed and observed by a lot of users, the black floor is raised for VS10 HDR and VS10 SDR rendering them unusable.

Beyond that there are a issues with black and white clip relative to that black floor.

The numbers in red are the correct values, ie what they should be.

For 10-bit video, black clip should be 64 in all cases.
Since I tested with 1000 nit test patterns, white clip for HDR (whether HDR10 or DV) should be 723 which equates to 1000 nits.
For SDR, since the HDR input is tone mapped to SDR, white clip should be 940.

(For completeness I've included 8-bit results for SDR which are correct at 16-235)

So the only 10-bit modes that have correct black/white levels are SDR.2020 and LLDV/DV

Realtek engine HDR has a correct black clip and although black will be crushed, it's only by a few clicks.
Both SDR modes, Realtek and VS10 have poor black clip and very poor white clip and VS10 has the additional problem of raised black floor.
VS10 HDR wouldn't be too bad except for the raised black floor so all luminance values are raised relative to that.

I'll say again:

The only 10-bit modes that have correct black/white levels are SDR.2020 and VS10 LLDV/DV

 

Got confirmation this morning that once the engineers have sorted out the recent instability issues they'll be looking at this problem

 

Great news, thanks for keeping on top of it.

 

Mark, how do these levels get adjusted with vs10 and compatibility off ?? does that use the lldv ??
or to use the lldv, choose that from the hdr option ??

thanks much for your time.

 

Not sure what you mean - you can't adjust the black floor unless you use the Brightness setting in which case you crush black badly and the black clip will be worse than it already is.

But LLDV output is fine - as you can see from the table above, black is correctly clipped at 64 and white is correct at 723 (1000nits) when using a 1000nit test pattern and 1000nit Dolby Block.

Bottom line - don't worry about Dolby Vision output levels - they are correct.

And yes, if you choose LLDV from the HDR options, all content is converted to LLDV.

 

and about AUTO mode, Is there something wrong ?

 

No, Auto is fine.

Except for Black/White Clip depending on the HDR mode as per the table above - but the black floor issue doesn't come into it.

 

Thanks Mark

 

THANK YOU A LOT MARK
The vs10 will be a good fonction to enhance sdr 8 bits movies in hdr tv/projectors.
It is a reason I bought the 1000 pro.

 

so hdr for sd, compatibility off, does that use the lldv ?? or something else
in selecting the vs10, for non hdr content, or hdr content,
does that use the lldv ?? with the proper levels, or does it have the raised black floor
(not referring to adjusting, just the output from the z9x per your clipping level measurements)

 

Not quite sure what you're asking - When you say "hdr for sd" do you mean "Dolby Vision Engine for SDR" or "Dolby Vision for HDR" and when you say "lldv" do you mean VS10 Engine?

 

Hi Mark, sorry I'm a little slow today. Does this mean the black/white levels for SDR content is correct when setting the HDR to Auto or Dolby Vision VS10 Engine for HDR?

I set mine to Dolby Vision VS10 Engine for HDR and Compatibility Mode OFF I get LLDV for all HDR content so that's good (if I set Compatibility Mode ON I get standard DV). Just wondering my SDR content will fall on which mode in the table with this Dolby Vision VS10 Engine for HDR setting. I'm using LG C9 TV.

EDIT: Just checked your pinned thread, so I will get Rec.709 for SDR content when I set to Auto or Dolby Vision VS10 Engine for HDR mode. So black/white level is correct then, cool!

 

Yes - just to confirm - with HDR set to either Auto or Dolby Vision VS10 Engine for HDR, 8-bit Rec.709 SDR content will output in Rec.709 and the levels are correct.

 

Awesomeness! Thanks a lot Mark!

 

"Yes - just to confirm - with HDR set to either Auto or Dolby Vision VS10 Engine for HDR, 8-bit Rec.709 SDR content will output in Rec.709 and the levels are correct."
"I set mine to Dolby Vision VS10 Engine for HDR and Compatibility Mode OFF I get LLDV for all HDR content so that's good"

that was basically my question, just I worded it poorly. last try.
Dolby Vision VS10 Engine with compatibility off, is Dolby Vision Engine for SDR and Dolby Vision Engine for hdr the levels are correct, right ?? is it better to set it to lldv for all, vs Dolby Vision Engine for SDR and auto say for hdr ?? just aiming for the output levels to be correct.
thank you for your time.

 

Gotcha!

I assume you're using a Dolby Vision display, so if that's the case the answer is yes, levels will be correct (more or less since Realtek HDR clips black very slightly). But to give a bit more explanation:

If you use the VS10 engine for any display other than a Dolby Vision display then the levels are wrong (black floor raised and clipped).

If you have a Dolby Vision display then levels will always be ok (subject to slight black clipping with Realtek HDR mentioned above) because you will either be outputting SDR and HDR from the Realtek engine (HDR Auto) or DV/LLDV (using VS10 modes)

If you output everything in LLDV, then yes, black and white clip are correct for all content and black floor is good too.

 

Excellent, thanks so very much. Yes the set is a sony 950h, lldv capable.
(sorry for the confusion, and I appreciate your patience )

thanks again for your time.