http://tiltforums.com/t/pinball-manufacturers-please-add-easy-hdmi-output-for-streamers/3071
http://tiltforums.com/t/twitch-livestream-setups/107
One of those threads should get you started. Don't know for sure who did the video setup at Banning, but I suspect it was the INDISC folks, who ran the tournament there.