You add the .idx file as the subtitle file. The .idx file itself points to the associated .sub file, so you don't have to tell ffmpegX about the .sub file. Note: this only works for encodings with the 'DVD mpeg2enc' preset and 'Decode with mplayer' activated.
Tonight is the night- Game of Thrones, season 6, premieres on HBO. The show begins at 8 p.m. CST, and will last for one hour.
Those who want to watch the Game of Thrones Season 5 premiere can tune in Sunday at 9 p.m. While HBO Now will be a $15 stand-alone service, for now viewers who want to watch the Game of Thrones Season 5 premiere will be able to watch it live online for free.