Actually, it seems the WinUAE author don't believe me as I never got any reply from him.
It's sad, because I am myself a software engineer and I now what I am talking about.
This problem is NOT caused by a bad codec configuration at all!
It's caused by a mis-synchronisation of the audio and video rendered by the emulator!
Here is a work around that should work, but I never tryed it myself :
1. In WinUAE, under the "Sound" tab, set the audio frequency to 47900.
2. Save your video in AVI, with audio saved as uncompressed PCM at 47900 khz (very important!).
3. Demux the audio to a WAV file.
4. Open the WAV file in Cool Edit Pro and adjust the sample rate to 48000 ("Edit" -> "Adjust Sample Rate").
5. Save the WAV and remux it with the AVI file.
To mux and demux I suggest you to use VirtualDub.
You should do some test, maybe 47900 is not 100% accurate, it's maybe 47899 or 47901 ?
It's tricky to get the exact value, I have to do some deeper tests.
Let me know if it solved your problem.
