Golden chetah is a bit like trainer road but free open source software. The UI is a bit crap, but if you have a supported trainer (kurk kinetic/tacx flow/tacx sartori and a few others) you get virtual power. All you need is an ant+ speed cadence sensor and dongle.
I find that it gives you enough to focus on. I think you can view vids via the software too, although I haven’t tried it.
There is another free one (virtual trainer?) but it on,y works on 64 bit windows or mac.