WIP Windows DirectX 11 upgrade test thread
(2016-02-25, 17:51)Ed76 Wrote: @crawfish
the whole thing is a little confusing right now, let me explain:
you can choose between 2 options (if your tv needs limited color room (most tvs need this)):

1) output rgb limited + (disable limited color room within kodi) and all is fine. this will give you a good picture quality.

That would be the last resort. Having the card output RGB 16-235 (or YCbCr) instead of RGB 0-255 means video has to be expanded from Video Levels to PC Levels (as you noted) so it works out when the card compresses all output to the 16-235 range right before it puts the signal on the wire. This is the levels round trip that tends to introduce banding in gradients. It is because of the banding that I believe Kodi 16 is causing a levels round trip, even though my card is outputting RGB 0-255. It could also simply be setting everything below 17 to 16 and above 234 to 235, but the banding suggests otherwise.

Quote:if you want a better picture quality than 1) you have to set:

2) output full rgb (driver) + enable limited color room within kodi.

That's what I described doing in my message. I trade black/white crush on the desktop for video that calibrates the same as my standalone BD player, that doesn't sacrifice BTB/WTW, etc. This is the "passthrough" mode for video.

Quote:up to kodi 16 beta 4 afedchin used the "old method" of changing color room from full to limited. with that method kodi tries to "tell" your gpu driver to use limited color room. that worked good under dx9 (kodi15) but with dx11 (kodi16) it did not work on some gpus (e.g. ati/amd) because of driver problems. for these gpus the result was kodi sets your gui correct to limited color room but not for videos (video remains full color room).

the "new method" should work independently of drivers. with the new method the operation from full to limited color room is done within shaders.

Does changing the "Render method" make a difference for your AMD card? As I said in my message, it does not for my Nvidia card. The only thing that helped was disabling DXVA2. Again, it was fine in earlier Kodi versions. Also, to be clear, Kodi 16 is outputting limited range video for me, only values < 17 have been replaced by 16 and values > 234 by 235, plus it has introduced banding in gradients, as I described in more detail in my message. It's not the "passthrough" that I got from earlier versions of Kodi.

P.S. I believe you're using the word "room", but "range" is the customary term and the one used by Kodi. Or am I missing something?
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Messages In This Thread
New build 14/02/2015 - by afedchin - 2015-02-14, 15:16
RE: Windows DirectX 11 upgrade test thread - by crawfish - 2016-02-25, 21:09


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