Audio Sync Problems - Irregular delay

[ChubbsMcBeef]

Hey everyone, this problem has been really bugging me for a while now and can't seem to work out how to fix it.

The .avi files I have start off about 1 or 2 seconds behind the video and as the files progress, the delay gradually decreases. (no delay towards the end). I've had no trouble playing the files previously as the codecs/players or whatever I used seemed to compensate for the difference automatically.

I've installed/uninstalled about 4 different codec packs with no luck. Any kind of 'dubbing' program - VirtualDub, AVInfo etc. doesn't work either as both the audio/video tracks are the same length, but are not displaced at an even rate.

I'm really stuck on this and have run out of ideas to try. Any help or advice I could get would be greatly appreciated.

Cheers.

[LT. Columbo]

you can try this with virtualdubmod.

change the file to an .AVI with .WAV audio


From under the "Video" dropdown menu, select "Framerate" - and select "Change so video and audio durations match"
Save with a new filename

[ChubbsMcBeef]

It's telling me that both tracks are exactly 23.976 fps anyway, so there's no change to the audio stream.

[LT. Columbo]

so you haven't tried it?

[ChubbsMcBeef]

I think I've worked it out now. The original audio track had a variable bit rate, so I recompressed the stream at 160kbps CBR. Seems to all be syncing nicely.
Bit of a pain in the arse though seeing as all the avi's with this problem are already burned onto DVD.

[LT. Columbo]

"The original audio track had a variable bit rate"

the original should still have perfect audio synch though.

i use tmpgenc plus to encode avi's with VBR audio and don't have to change anything...it converts it to CBR during the encoding (as i select it)

glad you got it working

[Clandestino]

I have a similar problem...

I have 2 movies downloaded from internet that has the same problem, the audio starts synchronized but progressively it starts to be desynchronized through the end of the movie.

One movie has variable bitrate and virtualdub says me that it is not very compatible. It says he will rewrite the header or that I can rewrite it.

Both movies has video longer or shorter than audio (I tried adjust Frame Rate auto to match, but didn't work).

Well, I tried lot of things but the desync problem remains, what can I do?

Thanks in advance!

NOTE: None of the above worked for me.