Video Analysis Program?

Hey everyone,

Anyone know if there is a program out there to analyize video, what i need to use it for is... for instance, i have a tank of fish, i can video tape it, and now i need a program to automaticly track like 20 of these fish at any instance. In other words, i need a program to track their position at any time automaticly... possibly with even up to 400 fish.

Thanks

err .... I thought the those kinda of programs arent even avalible to the public and if they were the licenses were hundreds or thousands of dollars....

oh, darn. i need it for research, cuz it's gunna take awhile to count all those stupid shrimps swimming around.