Re-encode Audio Stream in an AVI

First Re-encode the audio

1. Download both VirtualDub and the LAME ACM codec.
2. Uncompress and install the LAME ACM (Right click on the files and choose install).>/li>
3. Uncompress VirtualDub. Run VirtualDub.exe
4. Choose "File->Save WAV..."
5. Choose "Video->Direct Stream Copy"
6. Choose "Audio->Full processing mode"
7. Choose "Audio->WAV Audio...", Now select the WAV file you saved earlier.
8. Choose "Audio Compression...", select lameACM and the relevant bitrate. I always use a CBR audio stream. You could use GSpot to look at the original encoding of the Audio in the AVI file.
9. Finally choose "File->Save as AVI..."

Test the AVI file to make sure the audio is in sync. If the original audio was VBR you might need to resync the audio. To do this:

1. Open the new AVI file in VirtualDub
2. Choose "Video->Direct Stream Copy"
3. Choose "Audio->Interleaving". In the audio skew correction section insert the correct skew value. You'll have to approximate this to start with and then fine tune it as you go. Just "File->Save as AVI..." after each skew correction. Note that the skew corrections are relevant to the AVI file that is open in VirtualDub, not the one's you have saved.

Give it a go and let me know how you get on... I wrote this off the top of my head so if something doesn't make sense let me know...