Firewire. 
Don't know very many mITX boards that have it built in.
This is the board that you would probably need. Next it to determine if you need a GPU.
Is the video rendering program you have GPU accelerated? How fast does it need to be able to render video and how complex of a video are we talking here?

Don't know very many mITX boards that have it built in.
This is the board that you would probably need. Next it to determine if you need a GPU.
Is the video rendering program you have GPU accelerated? How fast does it need to be able to render video and how complex of a video are we talking here?






