Help with A/V sync

[Mr. Worm~~]

I know that is out of topic, but I have this problem:
Have two files, one avi (xvid) for video only and the movie audio (mp3)
I found two different problems:
1-Audio need initial delay to sync at the begining of the movie, solved (fixed delay)
2-A/V async increases as movie plays, so at the begining is in sync but at the end I got a few seconds async A/V
I'm using Virtualdubmod so is easy to change delay, but dont know how to fix the progresive async.
does anybody knows how to fix that, if possible?

thank you in advance

[rathunter]

you could change the framerate of the video. For example, the audio might be recorded for 30 fps, and the video encoded at 29.97 fps.

[Voldemar_u2]

Try to save mp3 in wav, with VirtualDubMod, for example, then take clear video, add audio stream in wav, then select fullprogressive mode for audio and direct stream copy for video, then select codec for audio. It may be help with progressive desinchronization.

[Voldemar_u2]

If it dosn't help,try to select option : Video->Frame Rate...->Change so video and audiourations match. The value in "No change" field,and value in "Change..." field must not be differ more then 0,00n fps.

[Mr. Worm~~]

@both
Thankyou very much for advice, will try that also...also will cut video to match A/V duration and compensate delay