tronic307 wrote: ↑Wed Feb 08, 2023 3:01 am
That's very generous, how cool. I'd love to test a build, thanks! I wouldn't need OG mode 3 back if we could get regular HLG brighter, it might have potential. It's almost there.
I'd say if people were having difficulty with 10000 nits we could try 4000 nits for the high figure. I wonder if a higher MaxFALL like 520-550 nits would do anything to brighten the mid-tones because I've had to lower the gamma to 1.8 to try to match SDR at a gamma of 2.4. I re-calibrated my TV so that BT.1886 correlates to the 2.4 gamma setting instead of 2.2 so I could lower the gamma further, but it works for me.
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I'll set it up shortly and let you know!
The thing with the metadata is that it does not actually control the brightness of the picture. It is a suggestion to the TV, and TVs don't really use it very much. Setting it to 10000 caused problems because 10000 is a valid value used in film production, whereas 1000 is the common metadata value. Changing MaxFALL around makes no difference to the picture, I pretty much just set it to 400 since it was the suggestion.
TVs will make their own choices using the metadata only as a hint. For example, although it's set to 1000 nits, my TV cannot display more than 800. Yet, I do not have any clipping. This is all because the HDR landscape is kind of a mess and there's still a standards war going on (Dolby Vision v. HDR10). TVs just do what seems to look right and what is compatible with the most common format.
Making HLG brighter isn't really possible with our setup. The only way to get an overall brighter image is to mess with the brightness/contrast controls in the INI, but you risk raising black levels if you do that. That being said, I will give you a test build so you can see what it does for you.
For DCI P3, I generally recommend only lowering saturation slightly, 0.90.95. Contrast can also be played with to get closer to SDR, but I also think it looks fine on its own despite the color differences. DCI P3 has more brightness potential than HLG thanks to the increased contrast and gamma. I have some sub-1 gamma filters floating around as well that can be tried.
KennyL wrote: ↑Wed Feb 08, 2023 5:17 am
Hey Natrox, I think options got removed and shuffled around too hastily. BT2020 option was barely being tested and worked on. Test size for making that decision was way way too low. I read through your discussion about it in discord awhile back where it felt like you got pushed over by Kitrinx and Sentient6 if I remember correctly. Making that kind of decision in a chatroom amongst just couple of people is a terrible idea. To be fair, I also feel HDR got publicly released too soon. BT2020 could've used some more baking time in fork to see if it's actually bad or not. I'm not asking you to bring it back but please don't get forced into cutting more options especially in a chatroom where barely anyone get to chime in at the time of discussion.
You may be right, I was also not a huge fan of removing it, but then again I did find out from a lot of people that DCI P3 just performed better.
There isn't much work that can be done other than setting the right matrices. The actual HDR options we have are fairly limited.
For one, the CSC matrix is 3x4, which does not allow for full color manipulation (we'd need 4x4, the hardware isn't capable).
Other HDR functionality is unavailable. We'd need HDMI 2.0, but the chip is limited to 1.4 (I believe, could be 1.3).
HDR is already not an officially supported feature in the HDMI spec we have to use, so we did what we could.
BT2020 was never really going to look any better. The content (old games) simply do not have the color range to nicely map to this colorspace on the vast majority of TVs. The only way to improve it would be to add color LUTs to the FPGA, which is not going to happen since FPGA fabric is limited.
KennyL wrote: ↑Wed Feb 08, 2023 7:52 am
There is hdmi range mismatch happening on releases after HLG is moved to hdr=1. When hdmi_limited is set to 1 (limited) and my LG C2 hdmi range is set to Auto or Limited, black and white are crushed/clipped leading to off color. Setting hdmi range on tv to Full gives proper image, which is incorrect behavior.
I tried MiSTer_unstable_20230104_1602a0 build which has HLG at hdr=3 and hdmi range behave properly. Setting Mister limited/TV limited and Mister full/TV full give proper black and white levels.
That's strange, I will have to look into it. Might be a small bug related to packing the CSC data.
I'll investigate this, thank you for letting me know.