Some video players like VLC would have the option of
rendering subtitles from an external file (.srt or .sub) on videos
during playback. However, many embedded players, such
as Xbox 360, may not have that kind of options. In such kind
of case we may need to embed the subtitles in the video
track, so we can burn videos with .srt or .sub files to DVD for
DVD Player on Mac.
After extracting the tracks or having the video and subtitle
files separated already (such as .avi and .srt file ), you can
recombine them into an AVI container with subtitles
embedded by using ffmpegX as following.
More detail about : How to Burn Videos and Subtitle Files (
SRT, Sub)to DVD on Mac ?