How to write a filter which creates a clip from nothing?

[wonkey_monkey]

Hi,

I'd like to write a plugin which doesn't take a video clip as input, but does create one and return it as output.

Is there a "right" way to do this? How should I declare the constructor, which normally looks something like this:

example::example(PClip _child,  IScriptEnvironment* env) :
	GenericVideoFilter(_child) {

, since there is no PClip _child?

Do I create my own VideoInfo structure to create the output clip?

Does anyone have an example of some code for a filter which does this?

Thanks,

David