Sorry, if I am duplicating this, I think something went wrong when I tried to post it the first time. I was thinking that my BBB would be a good DVR (cheap, low energy consumption) but I am not sure where to start. Is there software like this that will work on AVRs?

Would I be able to use one of these on a BBB?

Could I connect an external hard drive through my home network to store the shows?

I have been doing some research since I posted this and found that some people have done it with a Raspberry Pi. I would rather use a BBB as I already have one though.