Emby Live TV supports setting up NextPVR as a TV Tuner source. Once you have NextPVR setup and ready to use it's very simply to add to Emby. You do not need to setup guide data in NextPVR as we will set this up in Emby.
Click the Live TV menu option from the web admin and you will see a screen similar to this.
Click the + sign next to TV Sources and you will get the following screen:
Select the M3U Tuner option from above and more options will appear looking similar to this:
All you have to do is type in the URL to your NextPVR machine like shown in the above picture. The above URL will work for NextPVR Version 5 if installed on the same machine as Emby. If it's running on a different computer just replace "localhost" with the IP address of that machine.
You can optionally set a specific tuner count as done above.