Am I the only one still using ExMplayer?
Sure the interface is a reminder of everything that was unholy about KDE4 but it faithfully respects your /etc/mplayer.conf directives AND it has thumbnail seeking. That's one feature that I'm unwilling to part with, and I haven't found it on any other video player for *nix. If I'm wrong about that please correct me.
I've never seen anything like this.
But a little research yielding this:
and
http://exmplayer.sourceforge.net/
Both of which have it possible in preferences.