XviD avi out of sync

[Silenceville]

Hi! I have re-encoded a xvid coded avi file in avirecomp, i have added a subtitle. But the final avi file is the audio out of sync. In the original is the audio fine. I have set the same output size as orgininal..So..can I fix it somewhere? Or a setting in avirecomp. Plz help! Is is very annoying.

[redwudz]

This usually applies to AVI to MPEG conversion, but check the file with Gspot and look for MP3 VBR audio. That might be the problem. If so, convert the audio to CBR and mux that back into the converted video.

[Silenceville]

It is VBR, so where can i demux and mux back then in XviD codec? I have the xvid codec installed on my computer. VirtualDub?

[jman98]

You can demux the AVI with VirtualDub, convert the MP3 file with something like BeSweet, and then mux it back into the AVI with VirtualDub again. To demux the audio, go to the Audio Streams tab and select your audio stream and then click on Demux. Convert that to CBR and then remux it back in with Virtual Dub by opening the original file, going to the Audio Streams tab and disabling the original audio stream and adding the new CBR stream.

I don't know why so many idiots use VBR audio with Divx/Xvid. It doesn't save as much space as they think and it just causes a lot of sync problems.

[Silenceville]

I dont get it, I´ve just done that, but the audio is still out of sync. Wtf!

[Silenceville]

You can demux the AVI with VirtualDub, convert the MP3 file with something like BeSweet, and then mux it back into the AVI with VirtualDub again. To demux the audio, go to the Audio Streams tab and select your audio stream and then click on Demux. Convert that to CBR and then remux it back in with Virtual Dub by opening the original file, going to the Audio Streams tab and disabling the original audio stream and adding the new CBR stream.

I don't know why so many idiots use VBR audio with Divx/Xvid. It doesn't save as much space as they think and it just causes a lot of sync problems.

Does it matter if i use virtualdubmod or just virtualdub?

[reman]

I have the same problem with an XVID file. (Not a big fan of XVID).

I have demuxed the audio to a PCM wav file and then combined them in TMPGenc 4 XPress and they are still out od sync. If I add the 10.22 seconds (10220ms) to the front the movie starts in sync but then slowly goes out of sync.

Any ideas?
reman

[mats.hogberg]

XviD is a video codec, and totally unrelated to any audio problems you may experience. I've come to terms with the fact that not all AVIs lend themselves to conversion into other formats or other manupilations that require reencoding. Drfing sync problems usually is a sign of a framerate conversion or bad/undecodable frames in the video.

/Mats

[Inv8r_ZIM]

Does this method using VirtualDub simply remux the A/V, or does it re-encode the video (and thereby reduce the video quality); and if so, is there an easy method for muxing a wav together with DivX/XviD without re-encoding?

[manono]

No reencoding takes place if you Direct Stream the video (Video->Direct Stream Copy). If the audio is out of synch by the same amount all the way through, none of this demuxing and reencoding is necessary. Just adjust the delay (Streams->Stream List->Right-click the audio->Interleaving->Audio Skew Correction). And if VBR MP3 audio is involved, don't use VDub for the job, but VDubMod.

As mats.hogberg says, if you have a progressive asynch (the audio gets farther and farther off as the movie goes along) then something else is at work (unless you allowed VDub to mess with it).

[jsmiddleton4]

The problem I have is when converting to a ntsc fps of 29.97 the video gets ahead of the audio. The orginal file is 23.98 Xvid encoded. I used Super and it is tolerable but not perfect. And as reported here, the longer it plays the more it gets out of synch. I had thought about chopping the original up and then reassemble the pieces but don't have the time.

Something gets out of synch when converting from teh 23.98 to the 29.97.

Jim

[mats.hogberg]

That's how things goes, when you just select a different output frame rate than input frame rate. Why change the frame rate?

/Mats

[guns1inger]

Encode it as 23.976. add 2:3 pulldown with DGpulldown (23.976 -> 29.97 option). and author. If the audio still gets out of sync it is an audio problem, and not poor video encoding at fault.

[Inv8r_ZIM]

Okay, how about this; I've got an MPG, apparently (according to GSpot) encoded with Div3, and using VBR audio. In VLC it plays fine, but I need to mix in another audio track, preferably using Vegas as it's just my editor of choice. Vegas can't deal with the audio in the video file, as usual. I saved as Wav though VirtualDub, and imported that into Vegas - it is progressivly Asynch, and way, WAY off by the end of the file. Vegas reports the length of the video as being about 4s different than the audio, and both are shorter than the file appears in VLC. I've also tried converting the audio through GoldWave, but with the same results. Even stretching both audio and video to the same length in Vegas doesn't solve the sync problem. Womble can't handle the file as an MPG (becuase of the VBR audio, but oddly enough, it plays fine if you just rename it to an AVI), and besides wants to re-encode the whole thing - time consuming, and hopefully not neccessary, as I'd rather not loose video quality. Does anyone know anything about ProjectX, or some other possible fix? Does this sound like just a badly written MPG file?

[mats.hogberg]

I've got an MPG, apparently (according to GSpot) encoded with Div3

it plays fine if you just rename it to an AVI

AFAIK, Div3 can't be in a mpg container, so in fact, I'm confident this is actually an AVI. What if you load it in VirtualDub, and save it out again using Direct Stream for both audio and video?

/Mats

[redwudz]

If it's a Divx3, it's not a MPG. When you saved the audio out as a WAV with VD, did you use the Full Processing setting? If not, that can cause problems.

There is no reason the VBR audio should be out of sync when saved as a WAV unless it was messed up before. Or the video was missing frames. A software player doesn't always choke on missing frames, so being able to play it is not a positive indicator that the file is perfect.

If the sync problem is from a bad audio offset, easy enough to fix if you know how much offset correction you need.

If it's from the audio and video lengths differing, harder to fix, but still, just match the lengths of the two files.

More likely the problem you describe comes from a corrupted video or audio file, along with VBR audio, maybe combined with a bad framerate change. It's the combination of sync problems that can make a file very difficult to fix.

[mwkurt]

Run your divx/xvid file through AVIMuxGUI. It will detect any audio offset and correct it for you automatically. Always works for me.
Maek

[mike999]

i had an issue with a downloaded avi file which played fine on my computer, but had a terrible progressive out-of-sync of audio and video on my standalone DivX player. I solved it with Avidemux2, just loaded the AVI file into it, it asked if it should build a VBR time map which I answered with "yes". I set Video and Audio options to "Copy". Then I saved the file and it played fine on my standalone player.