On 2025-01-15 03:04, Simon Ser wrote: >> The BT.709 and BT.2020 OETFs are the same, the only difference >> being that the BT.2020 variant is defined with more precision >> for 10 and 12-bit per color encodings. > > Just to make sure, the spec defines this precision, correct? It's > not an AMD-specific thing? > Yes, see [1] >> Both are used as encoding functions for video content, and are >> therefore defined as OETF (opto-electronic transfer function) >> instead of as EOTF (electro-optical transfer function). > > Ah, and IIRC the OETF is not the mathematical inverse of the EOTF, > right? So it makes sense to have separate entries for EOTF and OETF > and their mathematical inverses. > Correct. EOTF and OETF are used for reciprocal purposes but they're not necessarily inverses of each other. Some curves are defined as EOTF and others as OETF. > Again, I am no HDR expert. No worries. One would think this isn't rocket science but when looking at it closely it doesn't seem too far off. Granted, I'm neither a rocket scientist nor an HDR expert, so what do I know. :D [1] https://en.wikipedia.org/wiki/Rec._2020#Transfer_characteristics Harry
