Vapoursynth HDR to SDR not working as expected

[Selur]

Since you didn't read the sticky and provide essential information like a debug output or what OS you are on I tried to reproduce this using a file from https://4kmedia.org/lg-new-york-hdr-uhd-4k-demo/.
I can confirm that for some reason "Filtering->Vapoursynth->Color->HDR to SDR" "HDR10ToSDR" and "ToneMap" do not seem to work as they should.
'HDR10 to SDR (DG)' and 'ToneMap (Placebo)' seem to work fine.
(later is not available in the version you use and former is Windows only)


Using https://4kmedia.org/lg-colors-of-journey-demo/ as sample, HDR10ToSDR and ToneMap seem to work fine.
HDR10ToSDR(Hable):

HDR10ToSDR(Simple):

ToneMap(Hable):

ToneMap(Möbius):

ToneMap(Reinhard):


-> I'll try to figure out why those two filters do not work as they should on some source, this evening after work.

Cu Selur