I've been testing HDR10 Expert on a Samsung S95H (TV peak set to 2600, static tone mapping) with the CroqueMr RC3 build on a 780M box, and a few DV titles look wrong:
- The Shining: washed out, especially the opening aerial shots.
- Ocean's Eleven: black crush in darker scenes.
Switching to HDR10 Basic (or native Kodi) fixes both. Can anyone else reproduce this?
I had Claude Code go at it with a private build and some additional debug logging, don't know if it's on to something or not:
Expert applies the CM2.9 L2 slope/offset/power in linear nits normalised to the TV peak: T * clamp(in/T * slope + offset)^power. Because the offset is multiplied by T, a tiny trim becomes a big black-level shift at high peaks:
┌────────────────┬───────────┬─────────────────────────────────────────────┐
│ title │ L2 offset │ effect at T = 2600 │
├────────────────┼───────────┼─────────────────────────────────────────────┤
│ The Shining │ +0.0033 │ +8.6-nit black floor (washed out) │
├────────────────┼───────────┼─────────────────────────────────────────────┤
│ Ocean's Eleven │ −0.0006 │ everything below ~1.6 nits crushed to black │
└────────────────┴───────────┴─────────────────────────────────────────────┘
(Offsets are the values CB1 resolved for a 2600-nit target, offset = code/4096 − 0.5; e.g. code 2061.5 → +0.0033.)
With nothing changed except skipping the L2 trim step, both titles looked normal. With trims applied they were washed out or crushed.