Virtual video device?

[bacterium@xxxxxxx]

Hello.
Would it be possible to write a virtual video device (i.e. no hardware) 
that would take a series of frames and dump them to /dev/video as a 
video sequence which could then be viewed by another app? Has anyone 
already done this? Any hints on how I could do this? (Source code 
samples appreciated.) Ideally, it would be done without a kernel module 
(i.e. in user space). The v4l api draft isn't terribly descriptive.

Thanx,
Adrian.