To add Retroarch in Kodi as an external player, locate Kodi’s installation folder.
You can just press ctrl+r and paste %appdata%, it will open your appdata/roaming folder, there Kodi should be located, inside Kodi’s folder open userdata folder.
In this folder you should create a file called playercorefactory.xml, this file contains settings that will tell Kodi that there is/are other players and how to manage them.
Inside this file you have this content:
<playercorefactory>
<players>
<player name="Retroarch" type="ExternalPlayer" audio="false" video="true">
<filename>C:\Program Files (x86)\Retroarch\retroarch.exe</filename>
<args>"{1}" /fullscreen /close</args>
<hidexbmc>false</hidexbmc>
<hideconsole>false</hideconsole>
<warpcursor>none</warpcursor>
</player>
</players>
<rules action="prepend">
<rule filename=".*4x3*" player="Retroarch"/>
</rules>
</playercorefactory>
Note, in this preset, the playercorefactory file will set Retroarch as primary player for 4x3 videos, i.e., if you create a folder that has “4x3” in its name, like “Movies - 4x3” etc., Kodi will call Retroarch to play the video, you can also just set 4x3 in the video file name itself like “Movie 4x3.mkv” that it will work either way.
It’s important to have a Retroarch specific installation, apart from the one you may use for emulation, in this case I have Retroarch under C:\Program Files (x86)\Retroarch\Retroarch.exe Also, preset your Retroarch overlays and shaders beforehand, so everything will be ready when using Kodi. I set my Retroarch a TV overlay and the Crt Geom shader, nothing else.
No core should be downloaded as the video player is baked in Retroarch.exe.
Choose x86 or x64 installation here:
http://buildbot.libretro.com/stable/
Assuming everything is in place, once in Kodi, if you try playing any video file that has “4x3”, it should load Retroarch as the default player automatically inside Kodi, still, clicking with the mouse right button in the video you want to play, you have a new option, “Play Using”:
Then you can choose whatever player you have added or the default Kodi player, in this case, as the video file or folder has “4x3” file, Retroarch becomes the default player:
There are tons of overlays already, but you can always create yourself one using your favorite TV.
Some TV border samples:
Some Shaders can simulate even bad signal transmission and will also make low quality videos look decent on modern TVs, which is not only nice but totally functional.
You can basically use any TV with any background, you can rebuild your old room with your old TV if you want.
This tutorial covered the basics on how to add Retroarch as an external player in Kodi.