LarrylLix said:
Nice idea but wouldn't long HDMI cables lose the high-def effects offered with HD or even 4K coming on strong? Good HDMI cables can get very expensive.
Run multiple Cat5/6 cables to media centre areas.
HDMI can be reliably run upwards of 50 feet. That and the cables aren't necessarily all that expensive. You just need to make sure they're heavier gauge. Also note most electrical code does specify that you're "supposed to" use cabling tested and rated for in-wall installation. Lots of folks ignore this, but it's worth keeping in mind (for current safety and future resale).
It's absolutely a good plan to run multiple CAT5E cables to each location. At least 3. One for something-over-CAT5, one for Ethernet and one for another of either.
Some HDMI distribution schemes required 2 CAT5 cables, current ones usually require only one. But they might require CAT6 (little actually does).
If you only run one Ethernet cable then you'll need to add an Ethernet switch in-room. Which is pretty much going to be required when you factor all the gizmos into the equation. TV's and the receivers have Ethernet ports. Local media streamers also (FireTV, Roku, AppleTV). Sure, lots of them claim to be able to work over WiFi. Reality is that streaming a lot of media over wireless ends up being a problem, so DO NOT plan on that working (especially if there's any other nearby WiFi networks in active use).
But to your first question, the big issue is sending IR remote control signals back to the cable boxes. There are various ways to do this, typically with a powered IR receiver in-room, wired via CAT5 back to the rack and then back out again with emitters stuck on the front of the cable boxes.
If this sounds like a gerry-rigged nightmare, welcome to "automation".
There are some HDMI-over-CAT5 solutions that also include IR sending back to the sources. I've not worked with any of them.
If you want my advice? Plan on the boxes still being in the room. There are a ton of very clever ways to mount a cable box. Their IR pickups are such that even if mounted vertically behind the back of the TV you should still be able to control them due to IR "bounce" off nearby surfaces.
Meanwhile, plan on wiring each location that *might* have a TV with two RG6 coax cables and three CAT5E. That'll cover the basics. There's little need to add more coax, but a few extra CAT5 or a CAT6 would be worth considering for anything that might be more than "just a TV", like in a bedroom, guest room or the like.