What file format? You should be able to embed srt files in MKV files. inb4 MKV fail

For srt file the contents look something like this (toy story 3 subs)

Code:
1
00:01:08,485 --> 00:01:10,653
Soldi, soldi, soldi!

2
00:01:17,494 --> 00:01:20,204
Hai un appuntamento con la giustizia,
Bart il Guercio.

3
00:01:20,497 --> 00:01:23,207
Peccato sceriffo, sono sposato.

4
00:01:25,377 --> 00:01:26,419
Betty la Guercia!
So you see that the subtitles are numbered, and it shows a timestamp. it goes HH:MM:SS,SSS

Hope this gets you started. If you have more questions lemme know.