Subtitle sync when concatenating MKV files

I have a movie which is split in 2 DVDs (about 3.5h long). I have run the DVD rips through Handbrake and created two MKV files with subtitles. Sound, video and subtitles are in sync in each movie.

I make a full-length MKV movie with   mkvmerge -o full.mkv part1.mkv +part2.mkv

Sound and video are still in sync, there seems to be a short blackout (1sec) between the parts, but I am unsure if this is part of the original movie.

Subtitles appear approx. 1 sec. early in the second part of the full length movie.

My question is: How to get this in sync? I have tried the track append option in mkvmerge, which results in sync between sound and subtitle, but then the video is out of sync (seems to appear late).

I have tried to find info about track lenghts with mkvinfo, but without luck. I cannot remove and reapply the subtitles with tsMuxer, because tsMuxer do not recognize the subtitle track from the mkv part files (donøt know why).

Any thoughts? My idea was to shorten the sound and video track of first part with approx. 1 sec., but I can’t figure out how. Alternatively the subtitles of part 2 should be delayed.


Ooo.  That’s an interesting question; don’t have a direct answer, but I do have a partial workaround.

You can adjust the subtitle timing on the WDTV by pressing the left or right arrow (with the movie playing) until you get it where you want.  I know that’s inconvenient, but until someone else weighs in, it’ll work…

You can remux the second MKV file using mkvmerge and there is a format specific option on the subtitle track to delay it – that ought to do the trick.

I can’t remux … or I don’t know how to … as I cannot separate the subtitles with tsMuxer (don’t recognize the subtitles track). And HandBrake has an option to adjust subtitles, but it is greyed out.


Read my reply again, Kim – remux using MKVMERGE (freeware).

I didn’t know that you could remix the parts of the MKV file “in place” without demuxing first … I will go back to the documentation and have another look.


Sure, any muxing program (like tsmuxer or mkvmerge) simply takes whatever tracks you load in and creates a new file muxed to your specifications.

In this particular case you aren’t adding any new tracks – you just load the existing file back in and change the options on that one track and then remux it out again.  mkvmerge doesn’t “know” that you haven’t loaded in any other tracks (or removed tracks, for that matter) and doesn’t care.