YUV444P8 is YUV but not YUVA or Y-only
YUVA444P8 is YUVA but not YUV or Y-only
Y8 is Y and YUV but not YUVA
I tried to create a hierarchy (tree view) on the
Avisynthplus_color_formats page.
See also the
Clip_properties page.
HasA() exists and it's called HasAlpha.
HasU() does not exist, but you can call try {
ExtractU } catch { ...}