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.
Game of Thrones is an American fantasy drama television series created for HBO by showrunners David Benioff and D. B. Weiss. It is an adaptation of A Song of Ice and Fire, George R. R. Martin 's series of fantasy novels, the first of which is titled A Game of Thrones.