Split subtitles to line up ends of files?

Question

I'm on a windows PC and have two files of a movie that's been split into those two pieces. I also have a subtitle file, but it's in one whole piece. Is there a way, using Subtitle Workshop(what I have now) or any other free program to split that one subtitle file into two pieces such that the subtitles end at the same time the video does, and it's cut at the beginning?

I can already split it so they start at the same point and split at the end, but is there any way to do to the opposite? I'd usually just split it at the end of the first video so that the second one should already line up correctly, but I think there's an extra intermission/credits/etc. somewhere that the subtitles don't account for, so that wouldn't work. Also, the files are .ogm's, which I have converted into .mp4's of the same length, but they're of terrible quality. VLC player can play ogm's, so I figure if I can split them like this using another format I can then apply the subtitles tot the .ogm's, right?

Anyway, all help is appreciated.

Answer 1

Don't transcode your video, there shouldn't be any need to do that. You might be able to concat the two ogm videos into a single ogm, or mkv, without transcoding, just remuxing. (e.g. with ffmpeg's concat filter, and -codec copy)

http://www.nikse.dk/SubtitleEdit has a split feature. You'll have to edit the 2nd file after splitting, since the split dialog box doesn't have anywhere to add in a gap. But it's easy to apply the same time-shift to all subs in a file, with it. I haven't actually used that editor much, I think last time I had to mess around with subs I used gaupol or ksubtile, forget which, (on GNU/Linux) to stretch the timecodes in a .srt to correct for a 25fps / 23.976fps speed difference. But anyway, I think Subtitle Edit is good, and it's cross-platform. (Runs on GNU/Linux under WINE, with mono.)

Answer 2

Is there any reason to have two separate files? From my point of view, merging both parts of the video and editing the subtitle would be the easier way. You could split the file afterwards as you like and the subtitle would still be in sync if you mux it with the video.

I would recommend mmg/mkvmerge to make a single mkv (the function is called append and requires that all streams have the same properties) then shift the times where necessary in Aegisub. It is recommended to use the graph of the audio track in Aegisub for syncing/timing.

When you are done with that you can mux the subtitle into the mkv too and check again that everything is as you like. Only after you are satisfied with this project you just created should you choose the target format, which is a completely different topic.

You could use simple tools like Handbrake or go with VLCs built in conversion functionality or ffmpeg. It should be obivous that using some random tool with unknown parameters for conversion of an almost unknown file and content is likely to turn out sub-optimal or incompatible with the target playback device. Mediainfo is another useful tool in the toolbox to read detailed meta information from media files, which I prefer along with mkvmerge, ffmpeg, and Aegisub as all of them are cross-platform and FOSS.