I stream video MP3 files from a PC to a smart TV all the time.
Download the PLEX Media Server (for free).
Install the PLEX client on your smart TV or Roku device (or Apple TV, or Amazon Fire TV, or use a playstation) and start streaming.
The Plex Media Server will configure your video and even bring up Netflix style menus for the video files you have.
Make that MP4 not MP3 files.