Video Resolution

I just can’t figure it out! Kodi is running and fits my screen aspect ratio and size fine but when I play a movie the video is always stretched vertically to fill the screen. I actually want it to play in the letterbox format so it’s not vertically stretched and distorted. I’m running on Android 5.1.1 with Kodi 16.1. I’ve searched and see others want the black bars to go away but actually want them there to keep the screen distortion. Everything is tall and thin.