This is easier than the user-friendly methods (sorry DietPi). I have it running happily alongside Plex and RetroPie, and it wasn't painful.
If you're installing Emby on top of an existing system that you like working with, back that up. Otherwise, start by flashing your card with the most recent Raspbian image. Set that up to your liking.
You also of course need to have a drive or drives ready to keep media files on. Please don't try to do it on the Pi's SD card. My drive simply has folders named "Music," "TV Shows," and "Movies." It was alreadly organized for Plex. Make sure the drive is plugged in and mounted.
https://emby.media/linux-server.html - Choose Debian; download the Armv7 version. In other words:
wget ~/Downloads https://github.com/MediaBrowser/Emby.Releases/releases/download/4.0.2.0/emby-server-deb_4.0.2.0_armhf.deb
dpkg -i emby-server-deb_4.0.2.0_armhf.deb
For most people, who aren't using a desktop environment on the pi - figure out the pi's IP:
ifconfig | grep netmask
This should leave you with your public-facing internal IP, and your loopback IP (127.0.0.1). Ignore the loopback IP. The other will be something like 10.0.0.27 or 192.168.1.200. If it's the latter, type http://192.168.1.200:8096 into your favorite browser, on your favorite computer on your local network.
There are a few extra things to change, where we want information written to our media drive, not the SD card.
- Settings: Advanced: Cache path - set this to something like /mydrive/emby-data/cache
- Dashboard: Paths has three more locations to set. I prefer to leave these alone, but replace them with symlinks. We have logs, metadata, and transcoding-temp - the last being the one you really want to change, because of the file sizes involved. On my media drive, I create a folder called emby-data. Note that logs, metadata, and transcoding-temp are all nestled in /var/lib/emby. What I do is:
mkdir /mydrive/emby-data/emby && cd /var/lib/ && cp -R emby /mydrive/emby-data/emby && sudo mv /var/lib/emby /var/lib/emby.bak && sudo ln -s /mydrive/emby-data/emby /var/lib/emby
Follow the prompts.
From here you just set your language preferences, and tell Emby where to look for libraries.
Watch out for the "chapter thumbnails" option for TV and Movies - probably the tradeoff between its usefulness and the potential CPU load and disk space usage is not a good one.
Also pay attention to the Emby movie naming guide (https://github.com/MediaBrowser/Wiki/wiki/Movie%20naming), which might make your life a lot easier, depending on who you are.
From there, set it up to allow remote connections (or not), accept the terms of service, and back away slowly. Although it should be working now for any client you want to use.
Other things to look into - basic advanced? - are setting up the server for remote access, including setting up port forwarding properly on your router, or even DDNS for your domain name of choice. Remote access will probably work for you without any hassle in any case, but if it doesn't, probably you just need to make sure that port 8096 is open.