Observations on the AML chipset on the 1.2.01 firmware (read issues)...

Thanks for chipping in.

With the White Clipping test, in limited range, there should be no flashing whites past 235 (reference White).

My Z1000pro tracks the whites perfect (235) when set to limited and the display is set to limited.

 

Ok - I think I figured this out... And I think you're right - I think the box is in full range - explanation to hopefully follow when I've got my head around this - if you're right - helluva good catch!!

 

This is from my TV - https://u.pcloud.link/publink/show?code=XZfIjH5ZXtIFcgv1yKQAK19FlbNxXLOiBIFV.
The smartphone camera fails to capture the last 252, 253, but they are visible, with 253 being very, very faint.

 

Tried the video, but I can't see anything - it's black.

But, as I mentioned, there should be no white bars flashing past 235 on the White Clipping test file in limited range.

 

"there should be no white bars flashing past 235 on the White Clipping test file in limited range" but they are visible on my TV!
I don't know why the file is black - I checked the link - it works and is visible.

 

Thats what this thread is about, because they shouldn't be.

 

Anyways, I'll now leave this in @Markswift2003 hands - Mark, let me know how you get on.

 

Sometimes less is more. That is the problem, they should not be visible after 235, which has already been mentioned here several times.

 

Ok - This is gonna get complicated...

So first, forget my comments a couple of pages back about ringing - my guess is that you don't see that at all - reason being is what I was saying earlier in that my Samsung does not handle HDMI range switching in YUV. So I think this is what's causing the ringing in my case.

There's a little switch in the EDID called "Quantisation Range Selectable" and it can either be on or off for both YUV and RGB.

In your case (& @blenky 's) that switch is set high for both modes. In my case, because it's a Samsung (and Samsung are the only company I know who do this) the switch is set low for YUV and high for RGB.

I just fired up a DR box and set HDMI range to 0-255 and lo and behold I get similar results to what I get on the AML box - ie black clips at ~16 and white at ~235 BUT I get the same ringing I get with the AML box which seems to be a symptom of the Samsung's inability to select full range.

If I now set the DR box to RGB (which does support selectable HDMI range on the Samsung) I get perfect results of 16 (Black Clip) & 235 (White Clip) with no ringing if HDMI range is set to 16-235 and perfect results of 0 and 255 with no ringing if HDMI range is set to 0-255.

If I now go back to the AML box and set output to RGB - remember, my Samsung only supports range switching in RGB - and run the tests, for Black Clip I see the full range - black at 0 and for White Clip I see the full range - white at 255. So the box is definitely in full range in this case and of course there is no way to change this.

Just a note here - I have a sneaky way to enable Developer Options and if you set HDMI Range to either 16-235 or 0-255 in there, the setting doesn't stick - it returns to Auto. A lot of settings are like this in Developer Settings and some just have no effect - this is why it's been disabled.

I also found something else interesting - if I have auto resolution enabled, I get ringing on the Black Clip pattern (which is 1080p) but if I leave auto resolution off, so that pattern is upscaled to 4K, I get a perfect 16 with no ringing.

My next step is to try an AML box on another TV that doesn't have the same HDMI range restrictions as the Samsung to see if I can replicate your results exactly.

@Oldpainless can you set Resolution to 4K23 and Auto Frame Rate to " Match Frame Rate Only" and see if that has any effect on your results...

 

I tried this and didn't make a difference. Using '2-APL Clipping' file I get flashing from 223 to 245

 

Ok, can you try setting HDR options like this (use the White clip and Black Clip patterns rather than the APL pattern):

https://mega.nz/folder/AaIXRSrR#9QD3Vo1yLkVggAuQXjvXiw


UI Display Mode > SDR

HDR Output Mode > Advanced

SDR Content Output Mode > SDR

HDR10 Content Output Mode > HDR10

HDR10+ Content Output Mode > HDR10+

HLG Content Output Mode > HLG

DV Content Output Mode > DV

Dolby VS10 for SDR Content > Yes

Dolby VS10 for HDR10 Content > No

Dolby VS10 for HDR10+ Content > No

Dolby VS10 for HLG Content > No

Dolby VS10 for DV Content > No

So all options on their default except Dolby Vs10 for SDR content.

 

Perhaps this bit you didn't clock?:

https://forum.zidoo.tv/index.php?th...-2-01-firmware-read-issues.99860/#post-244793

"@Markswift2003 - Hey Mark,
Re white clipping being blown - if you change SDR to use VS10 SDR, it tracks better (ie, wont go down below 235) but still not right.

The fact the whites track differently shows the issue."

 

Ok did all that.

Black clipping - flashing from 21 and up
While clipping - flashing from 230 - 232

 

Lol - Yeah, missed that - was by the pool with a beer - that might have helped with the diagnosis if I'd seen it...

 

Thought it might

 

Same, on white clipping, still goes all the way down to 253, rather than 235 reference level.

 

So I've confirmed this for myself on a Sony TV.

I get exactly the same symptoms as both @Oldpainless and @blenky :

1. Black Clip perfect at 16
2. White Clip incorrect at 255

This is only using the AML engine in SDR and I get the same behaviour on the Dune 8K too so it's possibly an issue with the SOC.

To reiterate, this is restricted to SDR using the AML engine.

With HDR10 patterns and DV patterns, black and white clip are correct.

It should be noted that in order to correctly evaluate white clip in HDR10 and DV you need the appropriate HDR10 and DV patterns for the nit level of your TV and you also need to understand how the TV processes HDR10 - ie does it use MaxCLL or MaxMDL or both - it's not as easy as just throwing a pattern as you would with SDR. You cannot evaluate clipping in HDR10 or DV using an SDR test pattern.

If you adjust Contrast in the Zidoo's Picture Parameter settings, you can fix the the white clip in AML SDR by setting to approx 54 BUT you will mess up white clip in HDR10 (it has no effect on DV) so I don't recommend doing that since you'll lose highlights in HDR10.

 

So, not to cause confusion, I assume Realtek = AML?

And that this bug effects pretty much all TV's and Projectors.

 

Doh - will change that.

 

Besides where we can find to download sights in HDR ?? If someone has a link ..... thank you in advance.