I have used Pi and NAS with a 4 TB external HDD and it works pretty well. I never used Jellyfin/Plex server, just used to play locally on my TV through Kodi. If your smart TV is less than 3 years old, you don't need to worry about format support, x.265 will work.
In a simple NAS setup, the Pi is just reading the file and sending it over the network. So if you have a USB3 HDD and wired connection to the Pi (even 100 mbps is enough), your Pi will never be a bottleneck.
And unless you plan to stream content from your home over the Internet (when you're not home), I wouldn't recommend Jellyfin/Plex. Kodi is good enough. It's more customisable than the others and has a lot more options. Works well out of the box. And if you need a shared library, you can do that using MySql server on the Pi. It's a very simple setup, no technical know-how needed.
In a simple NAS setup, the Pi is just reading the file and sending it over the network. So if you have a USB3 HDD and wired connection to the Pi (even 100 mbps is enough), your Pi will never be a bottleneck.
And unless you plan to stream content from your home over the Internet (when you're not home), I wouldn't recommend Jellyfin/Plex. Kodi is good enough. It's more customisable than the others and has a lot more options. Works well out of the box. And if you need a shared library, you can do that using MySql server on the Pi. It's a very simple setup, no technical know-how needed.
I plan to run the Pi in headless mode. Is the Pi an ideal solution? Do you guys recommend Plex, Kodi, JellyFin, or some other service?