Please help - Wav file shorter than MPG - audio out of synch

[rossinator]

Hi, I trying to convert an MPG of a "24" episode I downloaded. If I play the original file, the audio stays in synch, but when I attempt to make a DVD out of it with DVD Workshop, the audio looses synch about 30 minutes into the show.

Following the advice from this forum, I used virtualdub to strip out a WAV of the audio, and I used TMPGEnc to re-encode the video using the uncompressed WAV. It was still out of synch towards the end of the show.

Important Part... One thing I noticed and found odd is the WAV file is 4 seconds shorter than the MPG. How can I fix this? How could the original video have been in synch?

Here are the details for the original MPG:

MPEG-1 Information:

Video Track
Frame Size: 352x240
fps: 29970 fps
# of frames :77285
time: 42:58
Average bitrate: 1151 kbps

Audio Track
Format: 44KHz stereo, 224 kbps layer II
# of frames: 98565
Total Size: 70404K

Thanks for your help

[rossinator]

Here are the stats on that video from VIrtualDub. Thanks in advance for your help.

[rossinator]

Anyone else have this problem? I've noticed no one's responded. Did I word my post incorrectly?

Thanks

[tluxon]

Yes, I'm having similar problems and am also interested in some of the replies.

Tim

[rwarren]

I am having the same problem. I am trying to put a DivX movie onto DVD and I cannot get it in sync, even though the original plays fine. When I strip the audio out with VirtualDub, the audio is 12 seconds shorter than the video. I tried to use CoolEdit 2000 to "stretch" the wave file to make it 12 seconds longer but it is still out of sync. I have a suspicion that bad frames are the reason it is out of sync after conversion but not out of sync on the original. My only problem now is figuring a way around it.

Richard

[rwarren]

Can anyone help?

[antoniosgubba]

I've had similar problems with the audio WAV being a slightly different length to the video file...therefore creating sync problems.
Obviously you need to make the audio the EXACT length as the video...even a difference of half a second will cause sync problems..you've tried the correct technique, ie timestretching the audio to the length of the video, BUT, this is what I found through trial and error:

Using Cooledit to timestretch the audio I found it to be a little out in the final length of audio it produced....for example I might enter a final time of, say, 1:45:28.659 and it would produce a final audio length of say 1:45:28.255 ....this is around half a second and is enough to produce sync problems as the movie progresses.

I also tried Soundforge 6 to timestretch the audio......but I found that this program only produces a final audio time to an accuracy of 0.1%....this can also mean that it produces a final time around half a second different to what you tell it to produce...again sync problems.

I solved this problem by using Goldwave....this program produces final audio to an accuracy of 0.01%...and I find it does produce audio no more than 1/25th of a second different to what you tell it to produce.....with this size of audio/video time difference sync problems are not noticable.

Think you can get Goldwave from the Tools section...if not try doing a Google search for it.

Gubba.

[rwarren]

I will give GoldWave a try. Actually, I believe I tried using it to separate the wav from the avi but the length of the audio and video were still different. However, I did not try the time stretching to make them the same length. I will give it a shot!!

[antoniosgubba]

Cool...post back if it works ok for you

[rwarren]

I believe this DivX file has VBR audio. Should that matter?

[antoniosgubba]

Nope...I've done several with VBR audio...just extract the audio to a WAV with virtualdub before timewarping with Goldwave....under Audio in virtualdub select Full processing, compression=none, conversion change to 44100 (mark the "high quality" box too)...then save as WAV.

[antoniosgubba]

By the way...unless you have a super fast PC, Goldwave takes a fair time to do the conversion (about 20 minutes on my Duron 850)...don't worry if it just seems to be hanging and doing nothing....leave it to run and it will eventually do it.

[ZippyP.]

If you're using Goldwave then there's no need to extract with Vdub. Just load up your AVI, make your adjustments to the audio, then save it out and your wav is created. Yes it handles MP3-vbr (and AC3 as well) as long as the codecs are installed.
p.s. Make sure you use Vdub first to "scan video stream for errors" and save the AVI (audio and video direct stream copy) if there was any bad frames.

[antoniosgubba]

omg I didn't know you could do that with Goldwave....thanks Zippy

Should save me a bit of time....do I still have to extract the audio and save it as a WAV and then reload that WAV into Goldwave again to timewarp it?...or can I do it all in one step, ie load the AVI...extract the audio and then timewarp it before saving the resultant WAV?

[ZippyP.]

All in one: Load the AVI, make the time adjustment, save the WAV.
No extraction necessary, Goldwave does it when you load the AVI.

[antoniosgubba]

....thanks Zippy...nice tip!...should save me at least an hour for each conversion

[ZippyP.]

My pleasure.