XMP-HDR Context

[blue-j]

I believe I have some helpful information on the context of the XMP-HDR metadata listed at https://exiftool.org/TagNames/XMP.html#hdr

These appear to have first been specified in the AV1-ISOBMFF spec (6th edition).

I have also tracked it down to ISO/IEC 23008-2:2020, "Information technology — High efficiency coding and media delivery in heterogeneous environments — Part 2: High efficiency video coding."  For once, this is actually a free standard for download! : )  Search for section D.3.40

These are also from the Content Color Volume supplemental enhancement information in ISO/IEC 23000-22:2020 Amd 1 ("Multi-image application format (MIAF) — Amendment 1: Reference software and conformance for multi-image application format)" and AVIF 1.1.0.

The work:
https://github.com/AOMediaCodec/av1-avif/issues/79

So, this does not appear to be an Adobe namespace (nor strictly about HDR, I believe, though about this I am less sure).  Not sure how to present it.  Both videos and image sequences use it.  Oh, I hasten to add that I first found this in a JXL image example from Adobe's sample Gain Map imagery.

Thanks for listening.  This is my only support group of people who understand this crazy fetish.  : p

- J

[blue-j]

I decided to call it ISOBMFF since that's its origin, albeit if the file is a HEIF or AVIF, i would reference those specs?  I welcome thoughts, rants, angry rebuttals.  - J