Grab+analyze stream frames and output the result to overlay

I’ll do things in whatever way is most efficient/makes it possible. I’d like to be able to stream Super Smash Bros matches, grab the character damage %s in real time and output the +/- to the overlay (showing who is in the lead by how much damage).

(Go to the link below if you aren’t familiar with what smash bros looks like).

https://www.google.ca/search?q=smash+wii+u+gameplay&safe=off&es_sm=93&source=lnms&tbm=isch&sa=X&ei=KMnYVOnNMdOcyATs_4KICA&ved=0CAkQ_AUoAg&biw=1920&bih=947#imgdii=_