Should Linear Rec. 2100 not be gamut bound?

[facelessuser]

Linear Rec. 2100 is an alias for Linear Rec. 2020. Rec. 2020 is the base for HDR spaces Rec. 2100 PQ and HLG. It's not explicitly needed, but it is more made available for people to more easily associate a linear form of the spaces. One could use Linear Rec. 2020 with no issues.

So, the problem is that these HDR spaces have a lot more headroom. The linear form of Rec. 2100 is still bound to an SDR range. This only matters is you bother to check the gamut of the linear space or I guess serialize (the default options will attempt gamut mapping if the SDR range is exceeded).

You can't simply specify an HDR limit as it varies for PQ and HLG. You could really configure the max HDR to anything you want. It can really be defined to anything. So, the thought is maybe we just let the Linear Rec. 2100 space just be unbound so users aren't confused when it gets gamut mapped to an SDR range. We would still keep Linear Rec. 2020 bound.

The alternative is we just leave Linear Rec. 2100 defined as is. If you don't want it to be gamut mapped, just disable gamut mapping when you serialize it and don't check if the linear space is in gamut.