screenshot help?

[max4260]

my apartment building has a free cable service that i watch with my VLC player. its 60 channels. what im trying to do is take a screen shot of channel 2, then 10 seconds later screenshot of channel 3 and so on till channel 60 and start over at channel 2. and to complicate things even more im trying to do this without having the application be active (being minimized).

so, if anyone could tell me if this could happen with VLC or maybe point me in the right direction that would be very cool. thanks for the help!