Sampling & analysing a TV stream in near real time

Hello All,
 
I’m working on a final year project for college & am hoping somebody can put me in the right direction.
 
I’m planning to design a consumer electronic device that would sample a TV stream (via SCART in PAL format) & analyse this to detect things such as commercial/ ad breaks in near real time.
 
I’m completely new to the video capture area but I’ve been looking at the ADV7441A chip & then possibly passing this onto a Blackfin chip for the DSP side of the application.
 
I’m unsure of
 
  • Is this application possible/ realistic
  • What the best video format for analysis would be
  • How to analyse the captured video
  • The processing power to analyse this in near real time
 
I’d appreciate any input/ suggestions as to the best method of implementing the solution.
 
Regards,
 
Leo738