VS10 incorrect black levels when in SDR or HDR

Thanks Oliver,
(less work for Mark )

 

Hi there, sorry to be a complete noob here but is the issue described in this thread the same issue a Youtuber reported (Spare Change) in his review of the z9x where it shows the black levels looking greyish when taking a screen grab compared to the same movie scene on his Panasonic Ultra HD player?

I was so close to pulling the trigger on the unit until I saw the before/after shot compared to the Ultra HD player. It's not subtle. I'm really hoping there will be a fix for this as I want to experience the content at least on par with the disc player.

 

No, absolutely not. This player has image quality on a par with, if not better than any UHD BluRay player. Under normal circumstances the luminance levels and clipping are spot on.

This problem is very specific to users of either SDR only TVs, and to a certain extent, HDR only TVs only when using the VS10 engine and then only in specific circumstances dependent on EDID and the TV's performance in relation to HDMI levels.

I haven't seen said YouTuber's "review" but from what you say I'd be very confident in saying he hasn't the slightest clue of what he's talking about.

*edit*

Yeah - just watched that review.

I was right.

 

I notice that using Dolby Vision VS10 for HDR resulted in lost contrast and raised black. I was using RGB range 16-235. I changed it to Auto and now the PQ looks much better with improved contrast and the black level looks correct. I up my Epson PJ gamma from 0 to 1 and now the shadow details looks good without crushed or light blacks. I suspect we have to use 0-255 RGB range to get the correct level for Dolby VS10 engine. @Markswift2003, do you know the status for this issue and if Zidoo knows that 0-255 have to used with VS10 engine?

 

Can this be done on the zidoo to

 

Let's hope so

 

Sorry - I missed this message the first time around!!

So yes, there is a workaround of sorts by setting HDMI range to 0-255 for affected displays but that's not the whole story (unaffected displays should have HDMI Range set to "Auto").

I had conversations with Zidoo a long time ago about hard coding the HDMI range to 0-255 for VS10 SDR/HDR however it was decided not to do this in case it affected displays that do not exhibit this problem.

Also VS10 SDR and VS10 HDR exhibit different levels (VS10 SDR is much worse) in affected displays, so simply expanding the HDMI range, although lowering the black floor on the signal also affects clipping so it's not the true solution.

I have EDIDs for the Epson 5040 and the 6040 and neither of these projectors are affected by this problem - what model is yours?

 

Zappiti would have found the solution for the 'blacks' with the VS10 ........... I give you the link of the French forum which the manufacturer talks about:
https://www.homecinema-fr.com/forum...gnature-rtd1619dr-dv-hdr10-t30116764-405.html

 

Thanks @Markswift2003.
I'm using the Epson 5040 projector, and HDMI range at Auto definitely looks correct in terms of black level in comparison to 16-245.

 

Great - so the 5040 can handle selectable HDMI Ranges and so doesn't suffer from this black level problem and yes, setting HDMI Range to Auto is correct when using VS10 for HDR/SDR with your projector.

 

Dune also: https://www.avsforum.com/threads/dune-hd-pro-vision-4k-solo.3180599/page-68#post-61095689

 

WAIT AND WE WILL SEE...
Dune was very good in big words in the past.
I hope they have manage to do it.

 

I've just done a black and white clipping and HDMI levels comparison between Zidoo and Dune in all HDR modes.

All the numbers are EXACTLY the same for both boxes so we'll be able to compare after the update...

Note that this was done on a Samsung TV with non-selectable HDMI range which has the black level issue in VS10 SDR/HDR.

The test patterns used are from R.Masciolla and are 1000nit HDR, so white should clip at 724 in HDR and 940 in SDR. In all cases, black should clip at 64.

 

Hello,

First Zappiti (Linux + Android), now Dune HD (Linux + Android )... We'll see if Zidoo also gives good news in the coming weeks about a possible fix...

See you soon

 

Let's hope so - I've been banging on about this for long enough!!

 

Hello Mark,

Yes it's true and maybe it will be possible for the Zidoo engineers to do it now...

In any case I hope for them because otherwise their box will have one or more gaps compared to their direct competitors

 

If I don’t see conclusions form Mark tests I don’t believe anything especially from dune….

 

I know this thread has been inactive for quite a while, but I don't see any conclusions (unless they are in a different thread)

 

Covered in different threads, but yes, all fixed now and has been for a while.

 

Hi @Markswift2003,

This thread made my head spin.

I know that you said that it has been fixed but I was wondering you had a chance to compare it to Dune's FW to confirm that both devices are now fixed and behave the same way.

This is partially in relation to our previous discussion in other threads about DMDReview channel recommending setting Dune / Zidoo / Zapp to Full HDMI range and display to Limited...

the video is from 2023 and they claim the problems needing it to be set this way still persist. Argh.

In my case I use Auto for HDR setting as my JVC does not support DV. Am I right that in that case I have no use for VS10 engine as it send DV formatted signal to JVC?

When you said it is now all fixed do you mean that there is no white and black levels clipping beyond the limitations of Realtek native small black level problem.

Am I right that when I leave HDR set to Auto and as my JVC does not work with DV that would mean that it is Realtek HDR engine that is in use for HDR content? If so what happens to black and white levels

Would VS10 engine be possible in my case and beneficial in any way? Does this engine only encapsulates HDR into DV container or does it do some PQ manipulation like tone mapping etc.?

Also across this thread you suggested that some displays would benefit form setting media player to Full while display to auto or limited and you were able to judge it by looking at EDID. My JVC is x7900. What would you need from me to help me decipher it all if you would be willing to look at it.

Thanks