Do you have a subtitles .SRT file not synchronized with the video?
Recently I recovered an old program that I wrote and I made it better. Now it supports milliseconds and negative numbers: add_seconds_to_srt.pl
> perl add_seconds_to_srt.pl
usage: add_seconds_to_srt.pl SECONDS[,MILLISEC] <INPUTFILE >OUTPUTFILE
> perl add_seconds_to_srt.pl -17,995
00:00:18,994 --> 00:00:24,594
00:00:00,999 --> 00:00:06,599
>
Enjoy it!
