Downloaded mp4 has lip sync error

[Estam]

Hi all, I've googled this problem and many posts are many years old so I thought I would ask here.I have mp4 file with sound off by approx 2 seconds. I am going to convert this to an avi file (have an old dvd player) is there a program that will allow me to re-sync this while converting or is it best to re-sync first then convert. Can you please suggest a program to re-sync. Many thanks for any help...

[hech54]

You already have the right tool.... AviDemux.

[hello_hello]

It doesn't matter so much when you adjust the audio sync, so it might depend on the program you're using for converting.
Even after converting the MP4 to AVI though, you can open the AVI with a program such as VirtualDub and adjust the audio delay (from the Audio/Interleaving menu). Then resave it as a new AVI after selecting "Video/Direct Stream Copy" from the top menu. That way, VirtualDub will just copy the video and not try to re-encode it (the audio uses Direct Stream Copy by default).