Add more matrixes?

[pinterf]

tv.601 and tv.709 is handled already.
Plugin accepts additionally bt.2020 or Rec2020.

Does it have any reason to implement the rest?
"YCbCr Matrix" can be "tv.601" "pc.601" "tv.709" "pc.709" "tv.240m" "pc.240m" "tv.fcc" "pc.fcc"

[realfinder]

xy-VSFilter has "None" too (also Aegisub has it)

[Script Info]
YCbCr Matrix: TV.601
YCbCr Matrix: TV.709
YCbCr Matrix: PC.601
YCbCr Matrix: PC.709
YCbCr Matrix: None
'YCbCr Matrix' as well as override settings in the GUI, only have an effect on YCbCr subtitle output. The video is always untouched.

TV.601 = Output BT.601 with 16-235 YCbCr level range
TV.709 = Output BT.709 with 16-235 YCbCr level range
PC.601 = Output BT.601 with 0-255 YCbCr level range
PC.709 = Output BT.709 with 0-255 YCbCr level range
None = Output BT.601 or BT.709 with 16-235 YCbCr level range based on video resolution

If 'YCbCr Matrix' is missing from a script, xy-VSFilter will use TV.601 for legacy script compatibility. It is highly recommended to leave the GUI settings at their defaults of Auto | Auto for 'YCbCr level range' | 'YCbCr matrix'. The Auto settings obey the 'YCbCr Matrix' tag (if present), else fallback to TV.601 as decribed above.

[pinterf]

So explicite "none" is doing the auto-guess?
(meanwhile pc.601, pc.709, tv.fcc, pc.fcc, tv.240m and pc.240m are implemented)

[realfinder]

yes, it's like the auto-guess that assrender was do

[pinterf]

And why is bt.2020 not mentioned for sources larger than fhd? Or is it only for 10-12 bits?

[realfinder]

I have no idea, I didn't have any UHD or HDR source, but yes I think it's only for 10-12 bits

[realfinder]

seems bt.2020 is not used yet in ssa/ass libass/libass#297

so I think it's better to be excluded from "None" auto-guess at least for now (until Aegisub added)

[pinterf]

Long discussion but with zero result. However someone has put it on request six days ago.