Stretch as Deafult Please!

[TheDreadPirate]

Oh, that looks very interesting and although I don't fully understand it, it does sound like a similar situation and that it might work. I'll save it and try and get my head around it & learn how to do what is suggested. 

Essentially, they are modifying the parameters that ffmpeg uses with videos.  Instead of calling ffmpeg directly, Jellyfin is calling this wrapper script which calls ffmpeg + some parameters to stretch the video.

As they stated, this would only happen when transcoding since ffmpeg is only used when transcoding.