Merging mp4 files and preserving subtitles

Question

I'm in the process of digitizing my entire movie collection. For the most part, it's pretty smooth. I'm using Handbrake to put everything in mp4 format, and it's getting moved to my Plex server.

The only issue I've run into so far is when movies span multiple discs. I figure, once I'm digitizing, I should merge the two so I get a seamless viewing. The problem is, the only way I have to cleanly merge the files is a video editor (I happen to be using VSDC Free Video Editor, but I'm not married to it). The problem is that I lose subtitles. I've only had to do this once and I accepted the loss, but I'm going to hit it again later (think LoTR extended versions) and I don't want to lose them there.

Is there a way (preferably free, of course, but I'm open to all suggestions) to merge them without losing the subtitles? Or perhaps even a good way to add them back in after the fact?

Thanks!

Answer 1

I do that all the time.

You can use

• https://github.com/mifi/lossless-cut (Open source)

• SolveigMM Video Splitter (Paid)

Both can merge files and keep the tracks by default. Takes seconds/minutes depending on your system.

The only video editor (in my experience) where I could edit the video/merge and still keep the subtitles was Power Director (paid).

The problem with it is that it requires you to do extra steps in a certain order, plus it only supports SRT and might change the font/color or any other formatting.

So if you don't actually need a video editor, the other options should do the trick.

Answer 2

You may consider to use either

1. Subtitle stream of mp4, e.g. https://gist.github.com/xer-rex/913db0dcef06c0304acd1fcb3712cd04 or
2. Burn-in subtitle in video of mp4, e.g. https://gist.github.com/xer-rex/bc80b5fbd23d1b91bb4737439816d773