Question / Help Colors (YUV full/partial and 601/709

Videophile

Videophile

Elgato
Hi All,

I was wondering what the best setting is in terms of color?

I noticed on my capture card, if I use the full color range, and set OBS MP to full and 709, the colors are bright but have a haze to them.

If I set it to partial and 601, they are very dark, almost too dark.

Would anyone from OBS (Maybe @Jim) be able to explain what Full and the color values mean?

thanks,
 
L

Lain

Forum Admin
Lain
Forum Moderator
Developer
Defaults are generally recommended if recording to prevent decoding issues (709/partial). If streaming, you should be able to use any of them. I prefer 709/full range.
 
Saturn2888

Saturn2888

Member
In the AMD drivers I know there's a place where you can set the output color mode. I bet if in there you set it to 4:4:4 RGB Full, then using 709/full will look better. Haven't messed with it too much myself, but my guess is your color settings need to match your video source's color settings.
 
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denilsonsa

denilsonsa

New Member
As described in http://referencehometheater.com/2014/commentary/rgb-full-vs-limited/ , posted by Jack0r, "full" and "partial" define which numbers are considered black and white. In partial mode, the range is from 16 to 235. In full mode, the entire 8-bit range is used, from 0 to 255.

Which one should you use? Well, you should try for yourself. Add this overlay to your video http://denilson.sa.nom.br/overscan16x9.svg and do a test streaming or a test recording. Then check if the black/gray/white squares look exactly like they do in the preview. In my Twitch streaming test, using NV12 format and 709 color space, I had to use the "partial" range to get the desired results.

Note: I've written that overlay by myself, and even shared it on reddit. Read the SVG source-code for more information.
 
K

keybounce

Member
Consider this a question from someone that knows nothing about SVG: How do I read the source code? I.e.: If I hit ctrl-U, what am I looking at?

Equally: I see in your source code that you are displaying an 0f0f0f next to a 101010. That should be 15 and 16, right? Why then does digital color meter show those as 37 and 38?

Also: My background is white. I don't see a white circle and ellipse. I see what looks like an explicit grey background, but I still am looking at a white background.
... Oh, wait -- that grey is commented out?

EDIT: Whoops, I did not see that this is in the windows section. I'm on Mac, 10.9.5.
 
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denilsonsa

denilsonsa

New Member
You may open that SVG in your browser, and also open it at OBS (as an overlay). Then, just record a short video or do a short stream.

If the settings are correct, then all squares should look different, and should have the expected values. What's more, the look of the video should be the same as in the browser. If the settings are wrong, the three leftmost and the three rightmost squares will blend together; and/or the left-most won't be black and the right-most won't be white.

In my case, while I was trying out different settings, I noticed that the colors in OBS (after streaming, or after recording to the disk) were wrong. Then I just changed the setting to get the correct colors.

keybounce said:
I see in your source code that you are displaying an 0f0f0f next to a 101010. That should be 15 and 16, right? Why then does digital color meter show those as 37 and 38?
Click to expand...

You didn't mention where you made this reading. Was it in the OBS itself? Was it on a recorded video? Or during a stream? You also didn't compare it with a rendering within the browser.

If the output is 37/38 while we expected 15/16, that probably means the full range (0-255) is being compressed to a partial range (16-235). Or maybe there is some gamma correction happening. Or something else.

I don't have a Mac, I have no idea how the color correction or color calibration works in that system.

Bottomline: if your output video looks like your input (i.e. the reference), then probably OBS is configured correctly.
 
K

keybounce

Member
I'm looking at it in Firefox. No stream or recording.

The Mac has a tendency to try to do color calibration on everything.
 
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