I'm no expert with VirtualDub as I ditched it long ago due to hating the thing but you have to strip the audio from each and resample it at the same bitrate.
I had this lying in a document but I think its the steps to be taken.
Using VirtualDub
1- Start VirtualDub
2- File/Open Video File/choose the movie
3- Audio/Interleaving/Set the value that you want in the "Audio Skew Correction" box
4- Video/ Set to "Direct Stream Copy".
5- Audio is set to "Direct Stream Copy" by default, so nothing to do here.
6- File/Save AVI as (give it a name)
Not sure if its correct but google has plenty of answers.
Whenever I have had this problem I use AVI Audio Decompressor. Its quick, one click and coverts to PCM then simply join the 2 AVI's together using VDub and AVI Append.
Download avi2vcd but you only require Decompress.exe![]()
Tried that, once decompressed they still didnt join, I give up![]()