[Cin] zimg 2.8

[Andrea paz]

With "$ taskset --cpu-list 1-10 ./cin" and doing various tests with
the number of cores to disable, I always get the same error.
I don't quite understand what you mean by "zscale filter setup
string". If you mean which filter parameters I have varied then the
answer is: all the ones involving colors! One after the other or in
groups the result is always the same error. For example, if I set
Primaries; Transfer and Matrix to "input" or to "unspecified" there
are no errors; any other choice of color spaces always leads to the
same error. All this is with both the X11 and X11-OpenGL driver.

My idea is that CinGG's internal ffmpeg cannot use the libzimg library
which is external instead. Could a patch be made that enables zimg and
also builds the library internally?