Allegedly, on or about 27 July 2017, Temlakos sent:
mplayer on command-line returns, at the end: MPEG: Missing video stream!? Contact the author, it may be a bug :( The vlc program gives me sound, but no picture--so no way to navigate the menu. However, MakeMKV produces a good DVD video--sound and picture--exactly what I would expect.
Quite likely that MakeMKV uses a different set of CODEC files, than the other programs, to do the job.
You can install mplayer without a bunch of extra codecs, you may have done that.
Though I was under the impression that VLC usually installed itself with enough of everything to do the usual tasks.