The objective of this project is the development of a small board, which can be used to insert teletext data into a composite video signal. The project was started after an e-mail was forwarded to our mailing list, asking for advice regarding a teletext modem for a research project. A quick investigation revealed this project by Alistair Buxton https://github.com/ali1234/avr-teletext which inserts teletext data using a ATMEGA168 and a LM1881.
Running Buxton's design on a breadboard was easy. We are using it as our starting point now. See here:
Our code has a github repository on https://github.com/phoyd/avr-teletext and a wiki https://github.com/phoyd/avr-teletext/wiki.