You can play AVI files stored on your computer or mobile hard disk adopting DLNA servers on your Roku device as a Roku AVI player. In that case, Roku will able to direct stream AVI files utilizing the AVI support provided by DLNA servers, or play AVI files since DLNA servers have automatically transcoded AVI to Roku-friendly formats.
DLNA servers that are compatible with Roku Media Player: Windows Media Player/Center, Serviio, Plex, Twonky, MiniDLNA/ReadyDLNA/ReadyMedia, PlayOn. Among them all, Plex could be the most recommendable choice - Firstly, it’s popular enough that almost everyone is well acquainted; Secondly, Plex Server works really well on Roku as tested; Thirdly, building Plex on Roku is not so sophisticated.
Thus in the following, I’ll take Plex as an example to demonstrate how to configure everything for your Roku, hopefully you can easily understand how it works and get the hang of it.
Cast Plex to Roku
Step 1. Have Plex Media Server built on your computer or a storage device, make sure it has access to secure connections.
Step 2. Navigate to https://www.plex.tv/ to acquire Plex Media Server GUI for your PC. Install it and login to your Plex account, and create and manage your digital library. Now you’ve made Plex a Roku AVI files player!
Step 3. Locate and click the “Select Player” button at the upper-right side of the main interface > Cast > Connect Plex Media Server with Roku device via WLAN.
Search Plex from Streaming Channels on Roku
Step 4. Go to the channel store on your Roku device > search from “Streaming Channels” > add Plex.
Add Plex to Roku
Step 5. Logging in your account. After associating your account with the Roku device, the AVI file stored within can be played normally on Plex. Try playing AVI on Roku to see if it works.