Kira_Douji wrote:I didn't compress the audio because, unfortunately, I only know how to do that with the x264 encoding. If you could link me to a guide, I'll fix this, but as is, I have no idea how to mux avi files :/.
Open the video in VirtualDubMod, go to Streams->Stream List and click Save WAV...
Convert the WAV to MP3 using an external MP3 encoder, like dBPowerAMP Music Converter (look for an older version; licensing issues make them charge for the MP3 encoder now, despite the fact that it's LAME they rely on). Then click Add... in the Stream List dialog in VDubMod and open the MP3. Make sure to disable the WAV stream. Then click 'OK', make sure the video is on Direct Stream Copy and save the new file.
It is possible to encode with VDubMod if you install the LAME ACM codec (you can get that at Rarewares), in which case you wouldn't have to use Save WAV... and could just right click on the audio stream, select 'Full Processing Mode' and then go to 'Compression' and select the MP3 encoding options. Then just make sure the video is on Direct Stream Copy (if working with the XviD file) and save the new file.
One thing to note, though: VDubMod (and AVI, for that matter) doesn't like VBR, so make sure that the MP3 is Constant Bitrate.