Remux several AC3 from DVD to MKV

[elmuz]

Hi everybody,
this is a strange task I have these days which make me wonder a lot.
Scenario is:
I have Schindler's List DVD with ENG(AC3/DTS)+ITA(AC3) audio tracks. It is splitted in 3 DVDs of 1 hour each.
Now I came across an HD version of the same movie with just English language on it. What I wanted to do is taking the Italian track from old DVDs and mux it with the HD file.
Apparently it's quite easy... but I think it's not so obvious... because the three tracks (coming from the three DVD) have different delays in their titleset.
One solution would be open them in an audio editor software and compare the track with the HD track... but I don't want to rencode the tracks, is it possible to avoid that?

Here's in detail what I have from DGIndexer:
- ITA_AC3_1_DELAY_0ms.ac3
- ITA_AC3_2_DELAY_-224ms.ac3
- ITA_AC3_3_DELAY_0ms.ac3

If I simply join them and mux to the HD video it will go out of synch starting from the second part, right?
Any solution?

[Baldrick]

You can try delaycut to adjust the delay and also cut it if needed. Then join lossless with the command line copy /b 1.ac3+2.ac3 +3.ac3 output.ac3

But It could also be a different frame rate/duration and you must then reconvert it.

[elmuz]

Thank you Bladrick, didn't know that software...
Yeah you're right... I think I will do this way... Once I joined them, I compare the two track (hd source and joined ac3) and see if there are any difference in terms of frame rate...
About duration... well if it is just a trimming task I will apply cut/delays before remux everything...
Really a pity not being a native english speaker