The current AVIWrite class uses the Video for Windows (VfW) API, the thing back from the 16 bit Windows days ^^

EDIT:
OK, since the Kega Fusion system does not work directly for Windows, maybe we can port it? After all, Linux does support shared objects, so you would have to recompile the plugins for diferent systems.

Another possibility would be to use only OpenGL shaders for pixel filtering. I don't know much about that yet, but maybe it is possible to put them in OS-independant files and compile them at runtime before usage? Even though there might not be many of them around, I'm very sure many interested people will write them once the architecture for them stands.


Another vision:
- Do not internally work with VIDEO_1x/2x/3x/4x or whatever, just use either windowed or fullscreen mode, probably fullscreen being non-exclusive to make switching faster and to keep widgets.