OH NO - Another audio-out-of-sync-Question

[sdreeper]

Hi to all,
yes - here's another one (couldnt find something like this in the forum).

This is what i do:
After capturing tv from my ati radeon aiw 7500 i edit the captured File with vdub and then frameserve it to tmpgenc.
I make vcd or svcd.

And this is the problem:
The source mpeg is in sync.
The resulting mpeg is out of sync. The beginning is in sync and the further it goes, the bigger the asynchronity gets.

Can someone tell me whats going on here?

 

[ChickenMan]

Unless you capture both sound and video at exactly 23.976 or 25.000 or 29.97 fps, then converting to S/VCD will through the audio sync out like you describe. Capturing at 24, 25 or 30 is NOT close enough as when you convert to S/VCD, it doesnt drop a few frames to convert a 24 to 23.976, it just stretches it slightly, but not the audio, hence no syncronization.

I have posted a tutorial on how to fix the out-of-sync problem mpeg in the Tutorial section.

 

[sdreeper]

Thanks so far, i'll give it a try.
But i wonder whats causing this behavior.
it happens with every captureprogram i've tried.
and i'm capturing with 25fps.
maybe it's the soundcard (sblive player)?

 

[ChickenMan]

I've done a bit of capturing from VHS tape at 25fps and using a SoundBlaster Live Value card. I never had a problem but others did with same sound card. I assume its the drivers, suggest getting the latest drivers for it, some were released not so long ago.

 

[sdreeper]

...the latest drivers -- i'm using them
But anyway - i've tried what you advice in your sync tutorial and it worked great. Thanks for that.
Only thing you need in addition to the mentioned tools is a good stopwatch-tool.
I recommend "XNote" . You can get it at h--p://www.xnotestopwatch.com/

 

[sdreeper]

I did a few tests and found out, that vdub is responsible for the asynchronity: It can be seen (and heard) when previewing in vdub.

When I use tmpgenc to cut the commercials and make (s)vcd then there is no asynchronity.

Are there any settings in vdub to change this?
(The mpeg-source is mpeg1/iframe-only)

 

[ChickenMan]

In VD, in Audio/Interleaving... there is an option to "Delay the Audio Track", enter the number of ms needed to offset it.

 

[sdreeper]

but don't this delay the whole track?
if so, then there would be sync at the end but async at beginning.

 

[ChickenMan]

Yes your right, sorry needed to read your first post again !

Not aware of any VD setings that can fix that type of A/V sync problem. Why use VD anyway, why not just use TMPGEnc as you have done to edit out the bits you dont want and then convert to (S)VCD with TMPGenc directly.

 

[sdreeper]

i preferred vdub because the of the much smoother navigation inside the file. But from now on this has to be history