Open /usr/share/applications/mplayer.desktop change "Exec=gmplayer %U" to "Exec=gmplayer %f" That'll make it pass mplayer the local path rather than constructing a url.
Open /usr/share/ applications/ mplayer. desktop
change "Exec=gmplayer %U" to "Exec=gmplayer %f"
That'll make it pass mplayer the local path rather than constructing a url.