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traderdude123 · 12-03-2020, 04:52 PM

(12-03-2020 01:59 PM)ToastyX Wrote:
(12-03-2020 07:25 AM)traderdude123 Wrote: is there some restriction in the bandwdith per channel in the HDMI 2.1?if that is indeed the case, then i think its not possible to get YCC444/4k/100hz/12 bpc.
HDMI 2.1 has enough bandwidth. It might be a GPU or driver limitation.

Then would CRU util might help?

I really hate that LG decide to cut the bandwidth.

Now this is the only hope to get a high refresh rate with full chroma.

Please Toasty, do see if something can be done.

Thanks for all your effort.

AchillesBoi · 12-03-2020, 07:58 PM

(12-01-2020 04:22 AM)ToastyX Wrote:
(11-30-2020 09:32 PM)AchillesBoi Wrote: It seems to me that the bug here is caused by editing the EDID, maybe something CRU is doing is conflicting with the way Windows (or the GPU) reads that data?
No, it's an AMD driver bug. It's probably applying an 8-bit gamma table to 10-bit color, causing 1/4th the brightness.

Like I said earlier, this bug is also present when using 8 bit color. If I set my display to 8 bit color before applying the CRU modifications, and then I make sure it is set to 8 bit color after using CRU the bug still shows up, so I am sure it is not doing what you think it is doing.

Oh well, I was hoping for a fix but I understand if it is outside your abilities. Thank you anyways, I really appreciate it!

***ToastyX*** · 12-04-2020, 01:14 AM

(12-03-2020 07:58 PM)AchillesBoi Wrote: Like I said earlier, this bug is also present when using 8 bit color. If I set my display to 8 bit color before applying the CRU modifications, and then I make sure it is set to 8 bit color after using CRU the bug still shows up, so I am sure it is not doing what you think it is doing.

Oh well, I was hoping for a fix but I understand if it is outside your abilities. Thank you anyways, I really appreciate it!

I don't know what conditions trigger the bug because not everyone has this problem. It has to be related to incorrectly setting the gamma table somehow because I doubt it's changing the brightness of the monitor. You can try using the Windows display calibrator and just click next all the way to create a color profile with the default colors. Then maybe Windows will load the correct colors and override whatever the driver is doing.

***ToastyX*** · 12-04-2020, 01:26 AM

(12-03-2020 04:52 PM)traderdude123 Wrote: Now this is the only hope to get a high refresh rate with full chroma.

YCbCr/RGB 4:4:4 is full chroma. The bit depth is color precision. I think the TV has a 10-bpc panel, so it can't really display 12 bpc anyway.

traderdude123 · 12-04-2020, 06:18 AM

Yes, but sending a 12 bpc signal makes the images look so much more vibrant and colorful.

10 bpc looks a bit dull compared to 12 bpc.

This is the whole reason for wanting 444 @ 12 bpc. Otherwise i would not bother if there no clear difference between 10 bpc and 12 bpc.

and i have tested this thoroughly , i thought my eyes were fooling me. But there is a clear difference.

KDOG2023 · 12-04-2020, 02:12 PM

I went and did it but whenn i did the reset my screen didnt work on hdmi, the screen said not support, so i pluggeed it in with vga and my screen was red/purple? Huh

***ToastyX*** · 12-05-2020, 04:25 AM

(12-04-2020 06:18 AM)traderdude123 Wrote: Yes, but sending a 12 bpc signal makes the images look so much more vibrant and colorful.

10 bpc looks a bit dull compared to 12 bpc.

This is the whole reason for wanting 444 @ 12 bpc. Otherwise i would not bother if there no clear difference between 10 bpc and 12 bpc.

and i have tested this thoroughly , i thought my eyes were fooling me. But there is a clear difference.

Then something else is changing because the bit depth doesn't affect color vibrancy. Maybe the TV is disabling some processing when it receives a 12 bpc signal.

In the extension block, in the HDMI 2.0 data block, what is the max TMDS character rate? It needs to be at least 1190 for 3840x2160 @ 100 Hz, but I don't know if HDMI 2.1 uses that information. It's normally 600 with HDMI 2.0.

traderdude123 · 12-05-2020, 08:05 AM

(12-05-2020 04:25 AM)ToastyX Wrote:
(12-04-2020 06:18 AM)traderdude123 Wrote: Yes, but sending a 12 bpc signal makes the images look so much more vibrant and colorful.

10 bpc looks a bit dull compared to 12 bpc.

This is the whole reason for wanting 444 @ 12 bpc. Otherwise i would not bother if there no clear difference between 10 bpc and 12 bpc.

and i have tested this thoroughly , i thought my eyes were fooling me. But there is a clear difference.
Then something else is changing because the bit depth doesn't affect color vibrancy. Maybe the TV is disabling some processing when it receives a 12 bpc signal.

In the extension block, in the HDMI 2.0 data block, what is the max TMDS character rate? It needs to be at least 1190 for 3840x2160 @ 100 Hz, but I don't know if HDMI 2.1 uses that information. It's normally 600 with HDMI 2.0.

Max TMDS rate is 300 Mhz.

But doesn't HDMI 2.1 higher bandwidth use FRL signalling?

***ToastyX*** · 12-05-2020, 05:22 PM

(12-05-2020 08:05 AM)traderdude123 Wrote: Max TMDS rate is 300 Mhz.

In the HDMI 2.0 data block, not the HDMI data block.

traderdude123 · 12-05-2020, 07:17 PM

(12-05-2020 05:22 PM)ToastyX Wrote:
(12-05-2020 08:05 AM)traderdude123 Wrote: Max TMDS rate is 300 Mhz.
In the HDMI 2.0 data block, not the HDMI data block.

its 600