video out of sync.

[modsoul]

i have this video encoded in xvid . every time i encode it to some other format (x264) it causes a noticeable out of sync audio. but then i tried muxing the encoded audio stream with the orignal video stream and it came out perfectly in sync. so i think the problem is not the audio encoding but rather the video. i thought maybe there is some problem with the fps of the file so i set

assumefps (25, 1, true) in the avisynth script and then encoded it but still did not help. i am at my wits end. please any help ?

[4321]

what encoder do you use? is the audio stream in vbr?

[modsoul]

oh sorry for not includiong the deatilo;ls. i encoded audio and video with megui (x264) and audio was mp3 lame..

notice that if i start the same file in Vdub it say the audio is improperly VBR encoded and will produce 0 ms skew. i have even tried ripping the entire audio stream to .wav (full processing mode) and then encoding it to 128 kbps mp3 cbr. to no effect.