[Soli]

Using madVR with HDR-to-SDR conversion then output to a Non-HDR display with 3DLUT may be the other way. That way is perhaps correct on theory but unpractical. No chance for millions of non-hdr display users to do a calibration or obtain a 3DLUT.
Furthermore, madVR drops frames as hell unless you got powerful latest hardware like Kabylake or expensive vga cards.
So, atm your program is my only way to enjoy hdr on non-hdr displays.

Couldn't be further from the truth. You can make your own generic 3Dlut without even any hardware meters in about a minute. I have included a few later in this post.

And you can't really use madVR drops frames as an argument. If you don't have hardware GPU support for HEVC, then 4K HEVC is going to be really taxing for most of us (in your words: millions) that don't have the latest CPU anyways. It just so happens that *you* have a cpu that is just about powerful enough to software decode the raw frames from a 4K hevc source, but will stutter with madVR in enabled, but it is very unusual to use a beefy desktop 4 core i5/i7 with Kodi. Going on forward, all CPUs will support HEVC decoding in hardware, and madVR will then cause negligable overhead.

Can someone tell me what the situation is on Kodi in regard's to playback of HDR content on an SDR system? My personal example is that I have a few files with HDR content and my desktop software players and Kodi in Windows all play these back looking 'pale' since my displays are all SDR. I have an HDR TV but it's not REALLY HDR, it can really just process HDR signals for it's SDR panel, and my Windows powered Kodi HTPCs have graphics hardware in them that is incapable of HDR transmission. So I'm wondering if Kodi will have any means of converting HDR Rec2020 content to SDR Rec709 or sRGB for a proper 'look' on an SDR system.

You can try one of these generic 3Dluts.
https://mega.nz/#!5uQAEC5Y!_sfHlVBKsNs1t...j7zqEFFCKE

Gamma of rec.709 [email protected], Blacklevel is 0.15nits (which is typical of a "really good" IPS-LCD @ max brightness, or normal TN panel). The right one will depend on how bright your monitor can go. Since the transfer function of HDR is absolute we also need to set a brightness target when converting to SDR. Sometimes you might want to target a higher brightness target than what you actual display is as this will better preserve the transfer function at normal levels and not be so in-you-face. So even though your display is at brightness 300nits, you might want to experiment with 500-600 and even 700 targets. It depends on how you like it. There is room for subjective preferences since you don't really get anything near the "real" HDR effect until you at least hit 700-800nits.

To load a 3DLUT, you need to use Kodi Linux, or Kodi Windows DS with madVR, or MPC-HC with madVR. I reckon using a 3DLUT looks a little better than the conversion madVR does using GPU shaders. (it seems it also that madVR doesn't take into account the blacklevel) 3DLut for Kodi Windows mainline might work if you're using nightly, haven't tried.