How to sync audio with video in mkvtoolnix

[tiger]

hi,

i have a video whose duration is :

01:47:23

i have a separate dub audio file whose duration is:
01:47:22

how to sync in mkvtool nix,
what delay i should add in the tool in dub audio track?
+1000 ms
or
-1000 ms

or any other trick?

i got a movie with dub audio, i extracted dub audio only with mkvtoolnix, its .mka audio
movie i got with dub audio have worse video quality,
and movie i have with good video quality with no dub.

so i want my video file, and dub from other video, and want to sync them.

[cholla]

Remove the audio track you do not want.
Add the good audio track to the good video in mkvtoolnix.
Load the finished video into VLC media player.
Use the keyboard hot keys in VLC: k & j.
These set the audio delay inside VLC.
When you get the audio synced in VLC then use that for then setting in mkvtoolnix.
Mux a new video this time with the corrected delay setting.

[jagabo]

The audio and video in an A/V file don't need to start at the same time, end at the same time, or be the same length. So there's no way of knowing what the initial offset should be without watching/listening to the tracks. Even if you match the tracks at the start they may no longer be synchronized by the end.

[cholla]

jagabo is correct for the start/end/length time not causing a sync problem.
Same with a variable out of sync problem/ For me those are hard to fix.

Read & follow the instructions in this post if mkvtoolnix with the delay setting detected with VLC does not work.
I've fixed a couple of video sync problems using this formula.
https://forum.videohelp.com/threads/404700-ffmpeg-aresample-async-1-not-working-on-com...ne#post2648552

[tiger]

i fixed the issue

i extracted dub with pazeera extract (instead mkvtoolnix),
added dub in mkvtoolnix and in that dub audio track i added delay +1000