sync problems after converting to MP4

[AFD-Bassist]

very recently i have downloaded a avi video. it played perfectly fine, but when i converted it to MP4, the sound got off after the first 20 minutes, and its a 3 hour video. iv tried converting with videodora,Xilisoft, and 3GP_Converter. can anyone help me solve this problem? PLEASE!

[celtic_druid]

They probably all use ffmpeg for encoding, not that it should cause sync problems. What streams are in your avi? Because if it is XviD/DivX and mp3, then you can simply remux. No need to convert.

[AFD-Bassist]

all i know is that its XviD
how do you remux?

[celtic_druid]

Check out yamb/mp4box.

[AFD-Bassist]

alright, so i extracted the video and audio, but now i cant seem to get the audio to show up because its in some un-supported format ".raw"?
how do i fix this?