Fix audio sync the clever way - Advanced MKV: TrackTimecodeScale ?

[b0eaee9e80]

I am posting this here because this subsection is supposed to handle remuxing as well, which is what I'll hopefully do.

I am working corrently with a bunch of mkv's that are muxed in a curios way, the journey so far:

Track one: -the video itself, x264 set to 25fps
Track two: -the german audio, seemingly matching in length to the video at 25fps
Track three: -the english audio, seemingly matching in length to the video at 25fps

I play it back in mpc-hc: Everything works fine, in both languages seemingly

I play it back in vlc: The german audio works fine, the english plays seemingly to slow, an increasing delay builds up

I stream it via DLNA: Some devices build up delay, some produce hick ups on the english audio

I converted both audio and video: The english audio has pieces missing, regularly.

I check back in with mpc-hc, because it played well there: I used a stopwatch, if I play the english track the video plays roughly four percent to slow.

I demuxed the file and checked the english track: It has roughly 4 percent more samples, it was created for 23,97 fps playback. The header of the mkv was lying, concerning duration in seconds as well as in samples.

If i set the video fps to 23.976fps, the english audio works fine everywhere, the german one is now to fast, so far so good. As expected.

My resumee:
mpc-hc has some built in compensation for things like that, that's neat. Good to know, good for them.
PAL framerate is stupid.

My questions:
How does one trick the mkv header? The files came that way, and it leaves me confused. I'm only a video noob to be fair, using mkv via toolnix-gui.

How do i fix this without reencoding?
I want the files to work with other players and via DLNA too, so reencoding one of the audio tracks is what I would like to avoid.
I searched through the MKV documentation and found TrackTimeCodeScale, which was developed exactly for that purpose, but i don't know how to use it.

I'd very much like your help one that one.

[ProWo]

You will probably need to re-encode.
You can solve the matter with my Smart FFmpeg GUI, in the audio section.
https://forum.videohelp.com/threads/395425-New-small-GUI-for-FFmpeg
Select the same kbits/codec/channels as source.
In the Adapt Audio section set 23.976 FPS above and 25 FPS below.
Set Lenght/Pitch according to your needs