Prototyping for smart tv

So I’m trying to create an interactive prototype to get some user feedback on a connected TV app. I found an article online where someone has done a bit of a hack and using an iPad to airplay the prototype onto an Apple TV https://cdn-images-1.medium.com/max/800/1*mQkByZjCE0Z7_IKI6EBWVg.gif

I am really struggling to get the screen ratio correct, at the moment it is shrinking in the middle of the TV and not filling the whole screen. Can anyone help with this please? What dimensions should the prototype be set at?

If the iPad is not the same aspect ratio of your TV then it doesn’t matter what is displayed on the iPad, nothing will fill the TV screen.

You could also try air playing your mac’s display, with the preview window fullscreen.

Hmm but then how would you emulate the remote control touch interaction?