I don't know if these will do exactly what you're looking for, but they might be worth giving a go (all freeware)
Subtitle Worskhop
The most complete, efficient and convenient freeware subtitle editing tool. It supports all the subtitle formats you need and has all the features you would want from a subtitle editing program.
Timing operations:
Set delay (positive or negative, time or frames).
Set duration limits (maximum duration and minimum duration).
Adjust subtitles using four possible methods: 1- first and last dialogs, 2- synchronize using two points (linear algorithm), 3- Adjust to synchronized subtitles and 4- Advanced system to synchronize subtitles using an indefinite number of points.
"Time expander/reducer" to expand/reduce the final time of certain subtitles under certain conditions.
"Automatic durations" to calculate the duration of subtitles using a simple formula.
FPS Conversion with one click.
"Extend length" to extend the length of selected subtitles to the start time of the next one.
"Shift subtitle" forward or backwards a configurable amount of time.
"Read times from file" feature, to fix a subtitle using another subtitle's times.
SubEdit Player
If you like to play movies with subtitles then this is the player for you. SubEdit Player is a very easy-to-use, versatile movie player and subtitles editor. It can handle almost all common audio/video formats (with the right codecs installed) and subtitles.
SubRip
SubRip is a program which allows you to rip DVD subtitles with their timing as a text file. Can also convert vobsub(sub and idx) to srt text subtitles(vobsub to srt / sub to srt).
MV2Player
MV2Player is freeware multimedia player for Windows, with tons of useful features... including intelligent subtitles detecting/loading
Subtitle Worskhop
The most complete, efficient and convenient freeware subtitle editing tool. It supports all the subtitle formats you need and has all the features you would want from a subtitle editing program.
Timing operations:
Set delay (positive or negative, time or frames).
Set duration limits (maximum duration and minimum duration).
Adjust subtitles using four possible methods: 1- first and last dialogs, 2- synchronize using two points (linear algorithm), 3- Adjust to synchronized subtitles and 4- Advanced system to synchronize subtitles using an indefinite number of points.
"Time expander/reducer" to expand/reduce the final time of certain subtitles under certain conditions.
"Automatic durations" to calculate the duration of subtitles using a simple formula.
FPS Conversion with one click.
"Extend length" to extend the length of selected subtitles to the start time of the next one.
"Shift subtitle" forward or backwards a configurable amount of time.
"Read times from file" feature, to fix a subtitle using another subtitle's times.
SubEdit Player
If you like to play movies with subtitles then this is the player for you. SubEdit Player is a very easy-to-use, versatile movie player and subtitles editor. It can handle almost all common audio/video formats (with the right codecs installed) and subtitles.
SubRip
SubRip is a program which allows you to rip DVD subtitles with their timing as a text file. Can also convert vobsub(sub and idx) to srt text subtitles(vobsub to srt / sub to srt).
MV2Player
MV2Player is freeware multimedia player for Windows, with tons of useful features... including intelligent subtitles detecting/loading
