Here is an example of a project driving a realtime camera with Beaglebone black.

http://www.erlang-factory.com/static/upload/media/1394631509...

There is a video for the presentation as well.

https://www.youtube.com/watch?v=OBGqVmzuDQg&list=UUKrD_GYN3i...

The trick is Bealgebone black has 2 co-processors PRUs and they can be used for realtime work:

http://beagleboard.org/pru

http://elinux.org/Ti_AM33XX_PRUSSv2

It is a programmable 200-MHz, 32-bit processor with single-cycle I/O so it can be used to toggling GPIO pins.