[mombasa123]

Gotham v13. Just downloaded it today. Please don't get me wrong - there is a significant improvement in black level compared to Frodo (and that seems to be regardless of the new limited range setting). Just that Grayscale is banded.

To be clear I have tried the following settings which both give correct black levels but have Grayscale banding :

XBMC (limited) -> Intel HD Input (full) -> Intel HD Output (full) -> Samsung (full)
XBMC (limited) -> Intel HD Input (limited) -> Intel HD Output (full) -> Samsung (full)
XBMC (full) -> Intel HD Input (full) -> Intel HD Output (full) -> Samsung (full)

The above with Intel HD Output (limited) clips black 17 and 18

Setting the Samsung to (low/limited) crushes the blacks when Intel HD Output is (full).

Fyi, MPC-HC/MadVR and VLC render black levels and Grayscale correctly with Intel HD Output (full) -> Samsung (full). GOM player has Grayscale banding like XBMC.

Cheers. I may go and sit in a corner and have a litte cry

[un1versal]

Im not sure if the intel driver would behave diffrently but the correct is

XBMC (limited) -> DRIVER (full) -> Samsung (Limited) <- that it.

Or there is some extra processing being done somewhere else.

see
Something like that in intel drivers bit.

[mombasa123]

Thanks for this. I can't tell easily from your screenshot but do you see banding lines every inch or so? I think i can towards the 'black' side of the pic.

Note that the Intel HD driver has both an Input Range setting (as per your pic) and an Quantization (RGB Output) setting.

The Quantization (RGB Output) switch doesn't show up for Samsung TV as the EDID flag in the firmware is incorrect. Workaround is to set a registry setting 'EnableRGBFullRange' to 1. I guess on Linix that would be a config setting somewhere.

Anyways I reset the Output setting to Limited (as guessing that's what your driver defaults to) and did as per your post above so that I now have :

XBMC (limited) -> DRIVER Input (full) -> DRIVER Output/Quantization (limited)-> Samsung (Limited)

Bad black crush gone, black 17 crushed, 18 barely visible. Grayscale banded.

Black Levels better (but banding still) with :
XBMC (limited/full) -> DRIVER Input (full) -> DRIVER Output/Quantization (full)-> Samsung (full)

I will post some pics when I get home tonight. Sorry not trying to be a pain and really appreciate your repsonses - be sooo good to get it working

One more thing, I am on the latest Intel HD 2500 driver version 15.33.18.64.3496.

[mombasa123]

PS : The Intel HD Output setting post :
http://www.avsforum.com/t/1477460/theory...t_23789526

And this whole thread has some incredibly useful info :
http://www.avsforum.com/t/1477460/theory...full-0-255

[un1versal]

That screenshot is a how to config your intel driver, not a screenshot of my system, Mine is properly configured and wroks just fine, btw Im on Linux.

[mombasa123]

Ok so I have been experimenting and think I know what's going on.

To recap, I get the best results with :

XBMC (full) -> Intel HD Input (full) -> Intel HD Output (full) -> Samsung (full)

But no matter what I do, cannot eliminate the grayscale banding completely.

I then started playing around with other renderers. MPC-HC/MadVR & VLC are perfect with Grayscale. I then tried out my Raspberry Pi running Raspbmc. Perfect (kinda sucks when it's a fraction of the price of supposedly superior PC hardware).

Next, I started playing around with VLC settings. Found a 'Use YUC->RGB Hardware Conversion' option. Unticked that so it used software. Whoa - banding exactly the same as XBMC.

So, look like problem is due to XBMC/Windows combo - perhap XBMC not using GPU conversion?

Guess this belongs on an XBMC Windows forum somewhere.

Thanks a lot for your help. Any further expertise would be greatly appreciated.

Cheers.

[fritsch]

Better with: https://github.com/xbmc/xbmc/pull/4573

[mombasa123]

ooh thx!!

Will give it a spin when it's in a build.

Hoping it fixes 0-255 range as well.

Cheers.

[mombasa123]

Ok just deployed the April 19th nightly and sadly still see the same issue (grayscale banding).

Also, I have been comparing black levels with Raspbmc and MPC-HC/MadVR. XBMC Windows black levels not as good. On the AVS Black Clipping test it doesn't show level 17 and 18 is significantly less visibile then the aforementioned.

Fyi, I have selected DXVA hardware acceleration on both MPC-HC and XBMC.

[nickr]

What got number is your build?

[mombasa123]

What got number is your build?

Not sure how to find out what the Git build number is but i installed XBMCSetup-20140418-3a77615-Gotham.exe

From the datestamp maybe it doesnt contain the above fix? Probably the same with the Beta 4 release.

I am going to try the OpenElec & Ubuntu versions when I get a chance. It does look like the Windows version has display issues

[jmarshall]

The above build has fixes for DXVA-HD. If you get 'correct' colours with plain DXVA or Software or Pixel shaders with or without the 16-235 switch on or off (i.e. LOTS for you to test) then come back to us.

Please post in the thread in the windows forum so that windows users see it:

http://forum.xbmc.org/showthread.php?tid=184998&page=4

[mombasa123]

Ok will do. Lots to test as you say

There goes my Easter w/e ........

EDIT : Plain DXVA with hw decoding/acceleration is perfect. No banding. Can't tell about black levels right now as its very sunny (HK) so ambient light levels are high. Software and Pixe Shaders have banding.

Will post on Windows Forum as well.

[hanzoh]

Hello,

I have been messing with the correct settings for over a year now and have mostly given up several months ago.

I'm currently on OpenELEC 4.0.2 and using an Intel Core i3-3225 which has the 4000 GPU.
My TV is a Sharp LE635 which has no setting for Full/Limited, but it could be that it enables full when using a specific HDMI port (#2 says PC) or a mode (there is a PC one next to GAME, MOVIE etc).
My AVR is a Denon 1612 which has no video processing, but I read that it lets all HDMI video signals pass through untouched, EXCEPT full range RGB which only works with DVI.

So now I have the option to set the Intel driver to Full or Limited via xrandr and the 16-235 setting in Gotham.

I assume that my TV and AVR only accept and are able to correctly process limited color ranges.
Which combination is now the correct one?
There are some blog posts about the new Intel Linux driver since kernel 3.9 which handles YCbCr badly or not all, is that still true in 3.14 (which OpenELEC uses)?

[lmyllari]

I assume that my TV and AVR only accept and are able to correctly process limited color ranges.
Which combination is now the correct one?

Try with xbmc set to full range (do not enable the 16-235 option) and the default xrandr setting (or set "Broadcast RGB" to "Limited 16:235" manually). This will give you limited range output, with infoframes that tell the TV it is a limited range signal.

If you still get grey blacks, try another HDMI input.