YCbCr color coding

saintfrenz · 01-28-2018, 09:38 PM

Ah I see. So "HDMI Black Level" actually refers to the RGB range?
If so, how is the mapping? HDMI Black Level "Low" is RGB 16-135 Limited Range I presume?
BTW, the TV does allow switching HDMI Black Levels even when in PC mode and I can clearly tell the difference between normal/crushed colors when flipping back and forth.
Switching between PC and other modes only switches the chroma.
I should have tested further with the DL-5500 adapter. Oh well, the DL-6950 gives me 4K@60Hz so its all good.

Learnt something new. Thanks very much.

P.S. 40-43" 4K TVs look pretty sweeet as monitors

For people stumbling on to this thread later, to use the Samsung MU6300 4K TV as a monitor:

1. HDMI UHD Color: On
2. HDMI Black Level: Normal, NOT Low. Otherwise, you have color crush
3. Mode : Set to "PC" otherwise, you don't get 4:4:4 chroma
The TV only correctly sets PC mode if the refresh rate is 30/60 Hz. If its lower eg. 24Hz it does not successfully set PC mode even if set manually. At 24Hz you still get only 4:2:2 chroma.

Backlight 15, Brightness 0, Contrast 100, Sharpness 30, Color Tone "Warm2" -> these are just my preferences.

Links of relevance:

https://www.rtings.com/tv/reviews/samsung/mu6300
https://medium.com/@keredson/using-t...r-8582390bb824

AlbanRampon · 01-29-2018, 07:32 AM

Very interesting, thank you for posting your experience.

On the Plugable adapter using the DL-6950, we have added support for hardware mouse cursor in 8.4 M0. For a very smooth mouse cursor movement, I would recommend you use it as I expect you to feel the difference.
This feature relies on new hardware block in the DL-6950 so cannot be made available on DL-5xxx... Another good reason you had to upgrade to our latest ASIC.

We keep working on a few performance improvements. They are very long developments though, so it will take a while to reach a release.

Kind regards,
Alban

qp6019352 · 01-29-2018, 03:26 PM

Quote:

Originally Posted by saintfrenz

Ah I see. So "HDMI Black Level" actually refers to the RGB range?

Yes, I already told you this in my very first reply, see:

Quote:

Originally Posted by qp6019352

On Samsung TVs, the option is usually called "HDMI Black Level", which can be set to "Low" or "Normal".

Quote:

Originally Posted by qp6019352

If so, how is the mapping? HDMI Black Level "Low" is RGB 16-135 Limited Range I presume?

Yes, I think so. But as you said, you can easily see this anyway:

0-255 source on 0-255 display = all fine
0-255 source on 16-235 display = clipped black detail (i.e. details are missing) and crushed colors
16-235 source on 16-235 display = all fine
16-235 source on 0-255 display = black looks gray and everything looks washed out and bleached

Quote:

Originally Posted by qp6019352

BTW, the TV does allow switching HDMI Black Levels even when in PC mode

Okay, but anyway, you should note that:

PCs always render at 0-255 RGB internally natively. Windows always renders in 0-255. Even when you switch your graphics driver to 16-235, it will simply compress 0-255 into 16-235 instead of really rendering at 16-235. So, it's always best to output at Full Range RGB (0-255) with a PC, since that is what it is natively rendering in. So, the display should also be configured to 0-255. Also, please note that PCs always render natively in 4:4:4. RGB is always 4:4:4 (full chroma and luma resolution).

16-235 is used for video content, i.e. for Blu-ray Disc, HDTV and so on. Video content usually is YCbCr, not RGB. And YCbCr is always 16-235. Besides, most video content is 4:2:0, not 4:4:4, i.e. you only get 960x540 color (chroma) resolution on a 1080p video/movie for example.

MGoodwin · 03-16-2020, 09:25 AM

FYI this colour coding still needs to be fixed in the displaylink driver...

if you plug into a Nvidia card you can get the colour on the screen to be perfect by being able to choose correct Colour Depth, Colour Format and Dynamic range

until Displaylink allow these settings to be correctly adjusted for TV's you will never get the colour perfect.

on behalf of everyone that does not want to have a separate cable from a laptops HDMI or DP to connect to the TV, we'd love you to fix it.

01-29-2018, 07:32 AM	#2
AlbanRampon Senior Member Join Date: Sep 2015 Location: Cambridge, UK Posts: 1,678	Very interesting, thank you for posting your experience. On the Plugable adapter using the DL-6950, we have added support for hardware mouse cursor in 8.4 M0. For a very smooth mouse cursor movement, I would recommend you use it as I expect you to feel the difference. This feature relies on new hardware block in the DL-6950 so cannot be made available on DL-5xxx... Another good reason you had to upgrade to our latest ASIC. We keep working on a few performance improvements. They are very long developments though, so it will take a while to reach a release. Kind regards, Alban __________________ Alban Rampon Senior product manager, universal docking stations and accessories "DisplayLink is proud to be a Synaptics brand." Where to download the latest DisplayLink drivers How to clean up a corrupted installation How to report issues to DisplayLink for a speedy resolution

01-28-2018, 09:38 PM	#1
saintfrenz Junior Member Join Date: Jan 2018 Posts: 3	Ah I see. So "HDMI Black Level" actually refers to the RGB range? If so, how is the mapping? HDMI Black Level "Low" is RGB 16-135 Limited Range I presume? BTW, the TV does allow switching HDMI Black Levels even when in PC mode and I can clearly tell the difference between normal/crushed colors when flipping back and forth. Switching between PC and other modes only switches the chroma. I should have tested further with the DL-5500 adapter. Oh well, the DL-6950 gives me 4K@60Hz so its all good. Learnt something new. Thanks very much. P.S. 40-43" 4K TVs look pretty sweeet as monitors For people stumbling on to this thread later, to use the Samsung MU6300 4K TV as a monitor: 1. HDMI UHD Color: On 2. HDMI Black Level: Normal, NOT Low. Otherwise, you have color crush 3. Mode : Set to "PC" otherwise, you don't get 4:4:4 chroma The TV only correctly sets PC mode if the refresh rate is 30/60 Hz. If its lower eg. 24Hz it does not successfully set PC mode even if set manually. At 24Hz you still get only 4:2:2 chroma. Backlight 15, Brightness 0, Contrast 100, Sharpness 30, Color Tone "Warm2" -> these are just my preferences. Links of relevance: https://www.rtings.com/tv/reviews/samsung/mu6300 https://medium.com/@keredson/using-t...r-8582390bb824

03-16-2020, 09:25 AM	#4
MGoodwin Junior Member Join Date: Mar 2020 Posts: 1	FYI this colour coding still needs to be fixed in the displaylink driver... if you plug into a Nvidia card you can get the colour on the screen to be perfect by being able to choose correct Colour Depth, Colour Format and Dynamic range until Displaylink allow these settings to be correctly adjusted for TV's you will never get the colour perfect. on behalf of everyone that does not want to have a separate cable from a laptops HDMI or DP to connect to the TV, we'd love you to fix it.