How do I change sync values manually?

Sync audio with the video.

You’ll have to delay/shift the timestamps of one of the tracks. Usually this is done for the audio track, but you can do it for the video track as well.

First, watch the video that has its sync off & determine by how much it is off. For example, if you see a person slamming a door & only hearing the sound of that half a second later, your audio track is 500ms late. This means that you’d have to shift the audio timestamps by -500ms (the inverse of much it is late).

As shifting by a negative amount will lose you data (Matroska doesn’t allow negative timestamps, therefore all frames will be discarded if their timestamps are negative after the shift), you can also apply the reverse shift to the video track: making it later by 500ms vs. the unmodified audio track.

In MKVToolNix click on the track you want to modify; then scroll down the track properties pane until you find the “Delay (in ms)” input. Here simply enter the value you want to shift the modified track by (only the amount of milliseconds & optionally the sign, e.g. just 500 or -500).

Now run & check if the result looks good. If not, repeat with refined values.


Thanks a lot for your help!!! Mkvtoolnix is the reason why I started, editing and syncing.

But honestly I don’t like this metode, I’ts easy, but I think It can’t be perfectly precise.

Depending in the situation a Delay -100, -200, -250, -350 in some cases -400.

Thanks you.