Real-world support for full range and greater color depths

[drmpeg]

Originally Posted by benwaggoner

Why? I would have thought that "non-constant" would refer to the 12-bit mode with high dynamic range luma, which has a different, steeper gamma for high values.

They're two different things. Transfer characteristics selects a gamma and matrix coefficients selects the way RGB is converted to/from YCbCr.

For the transfer characteristics (--transfer), bt2020-10 selects the normal gamma (same as BT.709) and bt2020-12 selects the steeper gamma.

For the matrix coefficients (--colormatrix), bt2020nc selects a non-constant luminance system (same as BT.709 but with different coefficients) and bt2020c selects a constant luminance system.

http://www.itu.int/rec/R-REC-BT.2020-0-201208-I/en

Ron

[drmpeg]

Here's a document that goes deep on the constant/non-constant luminance issue.

http://www.itu.int/dms_pub/itu-r/opb...2012-PDF-E.pdf

Ron

[benwaggoner]

Originally Posted by drmpeg

Here's a document that goes deep on the constant/non-constant luminance issue.

http://www.itu.int/dms_pub/itu-r/opb...2012-PDF-E.pdf

Thanks. I'll check it out.

[Lyris]

Originally Posted by mp3dom

Since the topic also mentions greater color depth, I would like to point out the Panasonic "Master Grade Video Coding". There are not a lot of infos about it, but seems that the hint is to use the bluray MVC structure to use the base view as the standard image, and the dependent view for increase the bit depth of the video. Panasonic players with MGVC support should be able to 'merge' the MVC and outputs a 2D video with up to 12bit informations. Also, this method allows to fully use the 60 Mbps of the bluray 3D specs.
Here some explanation (JP)

Wow - and this is from April! Thanks for posting that, I didn't know anything about it.

[pandy]

Originally Posted by sneaker_ger

(Plus it only outputs RGB).

Nope - you can use RGB output as YPbPr :

http://forum.doom9.org/showthread.ph...99#post1604899
http://forum.doom9.org/showthread.ph...80#post1604480

Any RGB video output can be turned to YPbPr.

[foxyshadis]

Originally Posted by drmpeg

Here's a document that goes deep on the constant/non-constant luminance issue.

http://www.itu.int/dms_pub/itu-r/opb...2012-PDF-E.pdf

Ron

Constant in this case means linear, right? Whoa, I had no idea 2020 supported that, and that actually makes 12- and 16-bit useful! Especially combined with the wider gamut. It really has everything a visual quality geek could want, I hope other color systems die in a hurry.

[LigH]

Originally Posted by mp3dom

Since the topic also mentions greater color depth, I would like to point out the Panasonic "Master Grade Video Coding". There are not a lot of infos about it...

Some details and further links in English in the avsforum

More details also in German in the bluray-disc.de lexikon

A thread in the VideoHelp forum pointed out that Studio Ghibli appears to sell some (but the thread starter may not have bought those, so, well ... at least this part of the thread is not a valid topic here).

Common Blu-ray players seem to handle the MVC stream but not the substream with additional color depth.

[Balling]

Lol, that is not that simple! First of all Y values of 16-235 can be more than 235 and should be presented, that is called Superwhite and has nothing to do with xvYCC. xvYCC may use 241-254 Cb, Cr (as 0 and 255 are reserved for synch in HDMI, but not reserved in files, of course), but that does not mean that values lower than 241 cannot be in xvYCC. For example, YCC=135,155,12 is translated into RGB=-43,184,184, that is in xvYCC. See https://www.avsforum.com/threads/xvy...ation.1170632/

[SeeMoreDigital]

Wow...

This topic was started way back in Oct 2012 and last posted in Oct 2015...

Things have moved on!

[Balling]

Originally Posted by SeeMoreDigital

Wow...

This topic was started way back in Oct 2012 and last posted in Oct 2015...

Things have moved on!

No, they did not. Apple 4K TV uses xvYCC601 even for Dolby Vision. https://www.avsforum.com/threads/202.../post-60360409

[Balling]

To convert that properly to modern BT.2020 HDR one will need to use XYZ matrixes (also in the standard). May be interesting to implement. Kodak PhotoCD imagery also used the same OETF function for encoding.