Plugin Function

[Daichi]

Is it possible to write a dll that returns a value like a boolean or string to Avisynth? If so, can someone point me in the right direction.

All the examples I've seen seem to deal with video directly.

[ChiDragon]

You can return values like that to the conditional environment; TIVTC's FrameDiff::ConditionalFrameDiff is an example of that.

I believe you can also create global variables within your plugin as side effects, but that isn't really returning the value as you say.

[gzarkadas]

All plugin functions return an AVSValue. AVSValue is a union-like class that can contain either a clip or any other type supported by Avisynth (int, float, bool, string). The only trick is that for strings (ie char* in C/C++) you should use env->SaveString to store a copy of your local char buffer and supply its return value to AVSValue constructor.

For more information see the online Filter SDK (http://avisynth.org/mediawiki/Filter_SDK) and also the contents of the "avisynth.h" header file.