no way to sync audio

[macyman]

I have been encoding movies for a while...but this one!
The original .avi is already out of sync. I checked for
bad frames so at least I also got rid of the usual "VBR message..
12500 of skew will be added... constant bitrate....etc."
I extracted audio using Virtual Dub and noticed that it was a bit
shorter (about 3 seconds) than video file. So I stretched it out
using Cooledit....but the new .avi is STILL out of sync. I have been
through the guides but can't seem to fix this one.
What I am missing here?
I figured I would fix the sync after encoding...but I get the same
problems. Although audio and video lengths match (AFTER I adjust
them so they do indeed match), the movie is still out of sync.

[wolleric]

If you don't find out the error, you can still try the "brute force attack" :

1.) Open the converted video in a player (if you converted to VCD use VirtualDub), find a scene near the beginning where a door bangs, someone starts talking or something else that is easily located in both the video and audio stream. Write down the exact time (as exactly as possible) of the corresponding picture.
2.) Load the audio stream in a sound program and find the position of the "something". Again, write down the time. Now you can calculate the time difference that you have to insert to/cut off from the beginning of the audio. Do that.
3.) Re-encode the audio. This should only take a few minutes if you use tooLame. Multiplex you video stream with this new audio stream.
4.) Repeat 1 and 2 for a scene near the end of the movie. This time the difference tells you the factor that you have to strech the audio with.
Example: If the sound has a length of 1 hour/3600 sec and at the end of the movie the picture is 3.6 seconds behind the sound, the new playback rate would be 3600/(3600+3.6)=~0.999. Remember to change + into - if the picture comes after the sound.
5.) Repeat 3.

[zosten]

Yooow,

No way 2 make the sound on the right time-line ?

You must first save the sound with virtual Dub to wav
(the wav is normaly an mp3 not a wav...that's the problem...)
then open it with Soundforge and save it to pcm 44000Hz wav without changing anything (save as) !!! ...
then again open the wav in virtual dub and You shall see now it sounds the right way !
good luck ... it has takes a long time 4 me 2 finds this f@k@ng trouble!
you can do this the same way with virtual dub but the sound is very bad then !!!! :P

zosten

[macyman]

ok guys...I'll try it out and let you know
Thanks!

[2573]

In tmpgenc, in the wizard, down source range, there is a box called audio gap correct in msec, here if you put a positive numbre, the audio goes forward respect the video that msec, i you put negative , the sound goes backward, so, the thing i have made sometimes is that:

Put the original avi in tmpgenc, goes source range and choose a portion of a scene has noise you can attack to some image, a door closed, an explosion, the star of a scene chage the sound... If the scene you take is around the end of the avi, better. Then choose a cut of some seconds and try till you find the correct time.

[FROSTBITER]

This has been the bane of my experiences as well and although im getting there this info only seems to work if the audio is out of sync at the begining,which mine isn't. I'm told that the file may be corrupt so does anyone know how/if they can be repaired?

Frosty

[Barnabas]

When a file has audio in sync at the start but then drifts out of sync, it's MUCH more truoble than it's worth to attempt to correct. Even by compressing or expanding the audio, you will probably have at least part of the file be out of sync. Fixing a file that's out of sync the same thru the whole movie is easier to fix and is the only one I ever bother with.