You could try
https://www.freemake.com/free_video_converter/
You can try for free all the way to actually creating the playable DVD, just with an obtrusive logo across the screen. You can then unlock just for a short period for a couple of quid to remove the logo.
There is an underlying problem which makes DVD authoring more awkward than it should be. Mpeg 2 was a licensed format up until last year. Every device that played or encoded Mpeg 2 was licensed and a fee paid. That put off anyone from creating free encoding software, only commercial operations ever did it.
It's free now (since last year) but pretty much obsolete, so I guess no-one has developed free software still.