Implement Support for "Hermite EETF" as per "BT.2390-4".

[sobotka]

To round out the functions of HDR support, the final piece seems to be the EETF for dynamic range compression as given on pages 20-21 of https://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-BT.2390-4-2018-PDF-E.pdf

[KelSolaar]

Coincidentally, I just came across this on DisplayCAL: https://sourceforge.net/p/dispcalgui/code/HEAD/tree/trunk/DisplayCAL/colormath.py#l2920

[ValZapod]

https://code.videolan.org/videolan/libplacebo/-/commit/f793fc0480f and in mpv https://github.com/mpv-player/mpv/commit/c9f6c458ea54f595127684a3bcd94f578ec42b1f but not perfect. https://github.com/mpv-player/mpv/issues/7984

[KevinJW]

Just to note the doc is now at rev 8 https://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-BT.2390-8-2020-PDF-E.pdf

[ValZapod]

AMD already implemented it for Linux Freesync HDR. https://patchwork.freedesktop.org/patch/255949/ and fixit https://patchwork.freedesktop.org/patch/396160/

[ubitux]

Just to note the doc is now at rev 8 https://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-BT.2390-8-2020-PDF-E.pdf

Starting rev 9 (now at rev 10), it appears the Hermite EETF was removed. Any idea why?

[ValZapod]

Any idea why?

ITU concentrated on BT.2446a https://github.com/haasn/libplacebo/blob/12a5cd574e965196e38f3fe80083bae39b5c8c70/src/tone_mapping.c#L298

[ubitux]

Any idea why?

ITU concentrated on BT.2446a https://github.com/haasn/libplacebo/blob/12a5cd574e965196e38f3fe80083bae39b5c8c70/src/tone_mapping.c#L298

Mmh so apparently it has been moved to Annex 5 of Report BT.2408-4.