The 1K approximate safe limit for argument+result
string lengths that LeftStr, RightStr and MidStr impose
(see bug report with ID 1263366) creates an average
usable limit of approx. 512 bytes for any string script
The above figure arises from the need to succesfully
execute statements such as the following:
t = LeftStr(s, StrLen(s) - 1)
This usable limit is very low for any realtively
advanced application using strings. If you cannot
imagine such an application have a look at:
It is also very cheap to increase it; a simple increase
of the buffer size used by the functions above is
enough (if of course other design constrains do not apply).
If a large increase creates other problems, then an
increase of the buffer to 2K will be enough, since
there is a way to double it by user-replacements of
LeftStr, RightStr and MidStr (going
more than 4K is useful only if the issue in bug report
with ID 1263404 is addressed).
Please consider this feature request for the next
release of Avisynth.