Avisynth+

[StainlessS]

PVideoFrame is a so called Safe Pointer (with auto self delete type stuff), and keeps a count of number of references to itself,
if more than a single reference, then is no longer writeable. summick like that.

EDIT: And frame not actually deleted until reference count goes to zero (ie nobody else is using it).

EDIT:

I checked the actual value of PVideoFrame

Also, CPP can do some clever stuff, it probably massages some results that you may get from it, Operators can be overridden to do something a little different,
but the main prob is the reference count not being 1, ie not writable.

[pinterf]

Originally Posted by real.finder

it's same I got, my system use dot (Iraq)

btw, what avs you use and what dither.dll?

Tried two different x64 dither.dll versions, both (CPP 2.5 version from 2015 and a CPP 2.6 version from 2017) are giving me the same results (and similar to the same pic you have posted here).