HLG High Dynamic Range

**Doctor M** · **Doctor M** 2021-01-18, 06:54 PM Special user

I know there are HDR to SDR methods, but is it possible to convert between different HDR formats?

Specifically, I'd like to try converting some HLG to HDR10.

**babouin** · **babouin** 2021-01-18, 08:45 PM Special user

Using this script is the closest I got the last time I tried to convert from HDR10 to HLG: https://github.com/FranceBB/LinearTransformation/
But it's not as simple as it seems because HLG is not as good as HDR10.

**Doctor M** · **Doctor M** 2021-01-19, 08:41 AM Special user

I'm not sure what some of the abbreviations are so I'm not sure which script to go with.
I want to go from HLG to HDR10 though, so there shouldn't be too much loss (maybe?).

**TomArrow** · **TomArrow** 2021-01-21, 06:35 AM Power user

You can do it with the AVISynth plugin z_ConvertFormat function. Just enter HLG as input color transfer function and st2084 as output transfer function. Or vice versa. Naturally if you go from normal HDR to PQ and there's highlights above 1000 nits, they will get clipped.

**Doctor M** · **Doctor M** 2021-01-25, 02:06 AM Special user

Heh, started playing with this and realize I'm out of my depth on this one. I can't get the source to play via avisynth, let alone figure out proper use of z_ConvertFormat.
Directshowsource doesn't seem to work. z_CF is confusing. Should something simple like this work:
directshowsource("Source.mkv)"
z_ConvertFormat("st2084")

**TomArrow** · **TomArrow** 2021-01-25, 02:16 AM Power user

Look up the documentation, that explains how to use it: http://avisynth.nl/index.php/Avsresize#z_ConvertFormat

You need to provide 3 values for source and target color space each.

HLG High Dynamic Range

Doctor M

babouin

Doctor M

TomArrow

Doctor M

TomArrow