Enable system level HDR->SDR conversion in IINA within Catalina

[zhy3213]

Finder previewer and Quicktime player in Catalina is able to detect HDR videos and enable a system level HDR to SDR conversion by increasing the screen's actual brightness and so give HDR content a wider dynamic range, at mean while SDR contents remain the same color.
This happens to my 15-inch MBP 2018's built-in display, not sure whether it's universal for all Macs (guessing that the models with TrueTone availability is more likely to support this feature).

Here's a video capable of triggering this conversion.
Meter Placement_HDR10.mp4.zip

Supporting this new feature in Catalina could enhance the HDR playback performance a lot for IINA, and I suppose it would not require much work.

Thanks.

[Baldhal]

This conversion also works on 2019 5K iMac (without TrueTone) and nPlayer is a pretty basic player supporting this HDR conversion for all videos (the only cons is the lack of SPDIF support...).

[dasti555]

So is this actually implemented?