Xvid audio sync issues

paull2k · Jun 13, 2003

Hey, I got a few problems with a movie I downloaded.
ChickenMan, if you read this, I tried your Tutorial to fixing audio synchronization, however, the demo version of the program Womble MPEG-VCR doesn't let you save, the most recent version is 3.14, I'm unable to locate a crack for it, not requesting a crack or a full version or anything like that, just simply stating that since you can't really save the MPEG file it's now basically useless. Anyway, in the video I downloaded, the audio is out of sync by a few seconds, and the audio comes before the video. One more thing too, the video is 25fps, why I don't know, I just wish people would learn to encode videos to a decent framerate. Do you have any suggestions for how to fix the Audio Sync issue? Any help will be appreciated. Thanks.

celtic_druid · Jun 13, 2003

25fps is a decent framerate it is PAL.

So the original AVI (assuming it is an AVI) is out of sync? If so then it could be due to bframes and poor encoding.

What format is the audio? XviD is a video codec and has nothing to do with audio.

There is no reason why you have to convert and then correct the delay.

When converting you could just frameserve with AVISynth and use the DelayAudio() command.

If using TMPGEnc for encoding you could also just adjust the AV delay with that.

You could also encode the audio seperatly with BeSweet or HeadAC3e (especially if it is AC3) and just correct the delay there.

Alternatively you could resave the AVI with VirtualDub/VDubMod correcting the delay there.

ChickenMan · Jun 13, 2003

As you have been told, at 25 fps thats PAL and is more decent than 23.976 or 29.97 obscure frame rates.

I assume the Xvid plays in sync but when converted its out of sync. Unfortunately thats a common problem. As for mpeg2vcr, you can always purchase it

Another solution if all it needs is an offset, then use bbMPEG. (actually avi2mpeg2) Run, hit Star Encoding button, then Settings. Open VS is for the *.mpv or *.m2v file. Open AS1 is for the *.mpa audio file. Open PS is the output file name. Go to Program Stream Settings tab and double click on the VCD or SVCD at the top depending what you encoded to. Then in the Startup Delay for Audio 1 at the bottom, change the ms offset to fix the audio sync problem. Then hit OK and then Start. Soon you will have a new mpg file to check the sync. If still out, just repeat with a slightly different offset number.

paull2k · Jun 13, 2003

ChickenMan,
Sorry if this sounds a bit dumb, but what exactly is the offset you mention for the audio? Do I change the Audio 1 or Audio 2, or the Pack?

edit: By the way, the original video was out of sync to begin with, not after I encoded it.

ChickenMan · Jun 14, 2003

Just change the Audio1 box ONLY. You need to delay the audio so increase the number in ms by the amount you feel it out.

celtic_druid · Jun 14, 2003

If you are not sure the value you might find it easier just to test with AVISynth rather than multiplexing mpg after mpg trying to get the value right.

paull2k · Jun 15, 2003

I would test it out with AVISynth, but I don't have the first clue as to how to use AVISynth. Maybe you could explain that to me.

celtic_druid · Jun 15, 2003

It's all in the docs, but basically as I said use the delayaudio() command (you can look it up in the previously mentioned docs).

You will also need to use avisource() to load your AVI (assuming you still have it).

If you don't have the AVI then you could frameserve the mpg.

Basically just try out different values for audiodelay() (edit file, save, play), then when you get it right do what ChickenMan suggested.