Open up GMPlayer (or another MPlayer GUI) right-click on it, go to Preferences, click on the Font tab and from the Encoding list chose Slavic/Central European Languages (ISO-8859-2) for Romanian subtitles. Use Modern Greek (ISO-8859-7) for Greek subtitles. Be sure to also pick a font that contains the specific diacritic character sets (Verdana and Arial… Read More »
You don’t have to mix your favorite fonts with the ones that came with the system. Instead, you can make a .fonts folder in your home directory and drop all your new GNOME fonts in there.