The GUI needs GTK 1.2.x or GTK 2.0 (it isn't fully GTK, but the panels are),
GTK (and the devel stuff, usually
gtk-dev) has to be installed.
You can build it by specifying --enable-gui during
./configure. Then, to turn on GUI mode, you have to
execute the gmplayer binary.
As MPlayer doesn't have a skin included, you
have to download at least one if you want to use the GUI. See Skins at the download page.
A skin should be extracted to the usual system-wide directory $PREFIX/share/mplayer/skins or to the user
specific directory $HOME/.mplayer/skins
and resides as a subdirectory there.
MPlayer by default first looks in the user specific
directory, then the system-wide directory for a subdirectory named
simply can be a link to your favourite skin) to load the skin, but
you can use the -skin
option, or the
skin=myskin config file directive to use
a different skin from the skins