I red that you need to install the MythTV on an another computer that serve as a serer and stream your TV on the network to go on the addon. The raspberry Pi addon seem to not work on my slice ( http://janbar.github.io/pvr.mythtv/download/index.html).
So far, It’s the best way, witout using a Windows computer to stream the TV signal through my EasyCap USB analog receiver. I will update this post as soon I make progress to build a fonctionnal DVR on the slice with a raspberry Pi TV server.
Source code compiling tutorial ( https://www.mythtv.org/wiki/Build_from_Source )
Note : MythWeb seem to surf on the web as a plugin for MythTV .