Situation:
- I have a live videocamera recording a live event
- The output is being sent to a DVD recorder (S-Video)

Goal:
- I'd like to play an "intro clip (e.g. title)" or "end-clip", and have it also recorded on the DVD (e.g. cross-fade)

Idea:
- Plug the videocam into a notebook (which has S-Video output) via Firewire
- Prerecord the end-clip and/or intro clip(s)
- Use "some software" that will overlay my intro clip/text on top of the firewire stream, and play them real-time (out the S-Video on the notebook)

My question:

What Software does this? I'm considering Adobe's Visual Communicator (previously from Serious Magic)... is there anything else that can easily accomplish this? Perhaps a different approach even?