The VideoLAN Forums

Hello, I'm getting out of sync audio on Xvid avi files. It's happening with all of them from different locations - at first i thought maybe it was the file itself but when it's happening all the time with every file i think it must be something wrong at my end. I've tried looking on the internet for help but I'm a bit stuck. Using the latest VLC on XP.

I will confirm this for you! There are NO known problems with XviD type files and audio sync in any container.

This is generally a problem with the sound card not being able to control the video or the video not allowing control by the audio. However, other file types and or containers would also be effected.

See ReClock on the web for more information.

Thanks for the quick reply. I've just had a look for reclock, downloaded it and tried it. It doesn't seem to load with VLC + it made the playback worse with other programs - the picture became jerky as well the the audio still being out of sync. The problem i have is that that dvd plays perfect with VLC, both from the disc and from the hard drive. But with the xvid avi's the picture and sound is perfectly smooth but out of sync. The amount of sync shift seems to be variable i can't tell for sure.

Generally speaking sync problems are an encoding issue. Jerky audio and or video is the inability of the sound and or video not taking control or allowing control. New drivers most generally resolve the issue and is not limited to certain types of files.

The reference to ReClock was informational and the program itself takes some understanding and time to set up. I did get it to work with VLC after lots of trial and error. But this was not the reason for the reference.

VLC does allow for slip sync through the use of the ctrl k (audio delay up) and ctrl l (audio delay down). This is intended for small errors in the encoding process.

Ah . the slip sync definately helps. so it's a problem with the original encoding? is it possible for me to perminantly resysnc the audio within the avi file? what would be a good tool for that?

Ah . the slip sync definately helps. so it's a problem with the original encoding? is it possible for me to perminantly resysnc the audio within the avi file? what would be a good tool for that?

virtualdubmod works pretty well for doing that http://forum.doom9.org/showthread.php?t=109724
doom9 is a fantastic forum for encoding infoz

Load the file into VirtualDub, VirtualDubMod, or NanDub.
Set BOTH "Video"(VirtualDub, VirtualDubMod and NanDub) and "Audio"
(VirtualDub and NanDub - VirtualDubMOD>"Streams>"Stream list") to "Direct Stream Copy".

A) If the difference between audio and video is constant throughout the

video:

From the "Audio" dropdown menu, select "Interleaving" (For

VirtualDubMOD, rightclick on the listed audiostream and then select

"Interleaving")
Under "Audio skew correction", set an appropriate number of

milliseconds (positive or negative) in the box labelled "Delay audio track

by"
Save with a new filename


B) If the difference increases as the movie plays:

From under the "Video" dropdown menu, select "Framerate" - and

select "Change so video and audio durations match"
Save with a new filename

thanks for the info i'll give it a try

it'll probably take you a few tries to make it work, but at least virtualdubmod is fast