After mpv I've just found that VLC 3.0.11x64 (in Win7x64) with
OpenGL video output gives ~ right colors (incl. red) while playing HLG on SDR monitor.
Who can extract ps_2_0 or ps_3_0 shader from I suppose
libplacebo (license is LGPLv2.1+) to use in app SmartDVB?