A 28.63636 MHz fundamental frequency crystal is needed to clock the ADV7180 or ADV7182.
This crystal needs a tolerance of +/- 50 ppm over the temperature range of operation.
For analog devices evaluation boards a Golledge MA01377 crystal is used. ( see attached datasheet).
Notes on using an oscillator to clock the ADV7180 instead of a crystal:
http://ez.analog.com/thread/19637
Notes on using an oscillator to clock the ADV7182 instead of a crysta: