No ideas from anyone?

Wow, I am also suffering from the same desynchronization problem with
Vegas+DVDA. I've rendered long projects with Vegas 3.0 going into DVD Complete
and not suffered this problem. I also don't think I noticed this type of
problem a few weeks ago when I was studying Vegas. I'm really confused.

After an hour I think the video preceeds the audio by somewhere between
three-quarters of a second and a second and a quarter. After 20 minutes
of video it's pretty clear that stuff is getting out of sync. This happens
regardless of whether I render using the DVD Architect NTSC Stream
template or the standard DVD NTSC template. It also happens regardless
of whether I run AC3 or WAV as my elementary audio feeding into DVDA.

I'm back to the drawing board. I used Vegas 3.0 and DVD Complete for long
videos before and had no trouble.

Hey, are any of you guys using the Timestretch/Pitch shift on your audio?
I think I've found that the Timestretch doesn't get applied when one
renders. I don't have much Timestretch applied (rate is 100.0179%) but
it has to be applied by Vegas for things to be in sync. At render time,
Vegas isn't applying the correction. I can "Render to a New Track" and the
audio on the rendered track doesn't match (visually) the track that has the
Timestretched event.

My solution to the problem is to do the timestretch in CoolEdit and then
import the result into Vegas.

I have the same problem in DVD-A as well, posted a similiar thread in that forum and no news yet. Has Sonic Foundry encountered this before? I am wondering if it is certain types of .avi files or something that do this but since all I have is this one file, I'm not sure.

potatophysics - Can you give me a sample/walkthough of how you do the timestretch in CoolEdit and then import into vegas? You can email it to me if you want to, or post it here. Let me know what is best for you.

We've tested very long files prior to release but I'd be happy to look at this again.

What is the orginal source format?

How was the original source format captured? (what app, what card)

How was the original source format rendered, and what apps were used?

Were ANY 3rd party apps involved in the capture/render/author/burn process?

Anything else that will help us reproduce this will be helpful.

Thanks

Hey SonicEPM, here are the specs of the .avi I am using. It is some old movies some friends and I made in sixth grade that my friend encoded a long time ago, here are the specs:

- The file is a .avi, I believe he recorded it from VHS, he recorded it last yearn and will try to get a hold of him to ask.
- Kind of like the first, not 100% sure of the source, but the .avi sound is perfectly in sync
- Resoution is 352 x 240, 1 Hour 42 Min Long, MPEG-3 Audio, 29 FPS, 108kbps Data Rate, 24bit sample, DIVXMPG4 V3 compression

Thanks!

Is the sync problem only apparent in DVDA's preview, or is it also out of sync on a burned DVD played on a set-top player?

MainConcept Tech Support

I am also having similar problems, only with an MPEG source file. It may be a different problem, but I thought I would add it to the post in case it helped to isolate the problem. - I have tried quite a few things to fix, but to no avail.

The audio/video are in synch during preview. When I render the file in MPEG2 audio and video, they become increasingly out of synch up until 60 minutes into the video, then the audio drops completely. Here are the specifics on the source media:

Video: 640x480x32, 02:00:27:06, MPEG-2
Audio: 32Khz, Layer 2
FileSize: 6.92GB
From - Creative Labs Video Blaster MPEG-2 capture card, 382Kbps audio, 8MBps video

I tried rendering the audio only in the AC-3 plug-in, same result
When I tried rendering the audio only in W64 at 48K sampling, it stopped after 1 hour - don't know if it got out of synch or not
WHen I re-compressed it in DVD Architect, it took 16 hours and managed to have all of the audio, but it was out of synch

My current theory is that there is some 4GB limit somewhere stopping the audio at 1 hour and that the sampling rate being 32K rather than 48K is causing the audio to become out of synch.

Cal Irish

Re: Zurgdawg and instructions for doing the timestretch in Cool Edit
I adjust the timestretch in Vegas until everything lines up and sounds good on
preview. If your event end and event start do not coincide with the start of the
audio file and the end of the audio file move the event in and out points until
they are. If necessary, duplicate your project and with the new project move
things around so you can stretch the in and out points to be the file in and out.

Go to the properties of the time stretch and write down the event length and the
stretched event length. Subtract the event length from the stretched event length
and write this new number down (call it Edith). Recall that one frame is 0.0334 seconds and do your subtraction such that Edith is in seconds.

Open up CoolEdit and open your source audio file for the event. Use Save As to
make a new copy of the source file. Go to the Time/Pitch stretch event. Hit "Time Stretch" and hit "High Precision" and hit "Choose Appropriate defaults." Set the
ratio to 100.00 and then move to the box next to it called Length and write this
number down with all it's decimals. Add Edith (in seconds) to this length number
and type the result in the length box.

Hit "Ok" and wait for CoolEdit to perform the work. When it is done, save this new audio file and go back to Vegas.

In Vegas, open your main project file and duplicate the audio track that has the
time stretched event on it. Turn of attach envelopes to events. Cut the time stretched event on the new track. Drop the Cool Edit stretched audio file into the
same place as the deleted Time Stretched event and line it up with the time stretched
event on the old track. Set the in and out points as the old time stretched event.
Use Paste Properties to copy the filters of the old time stretched event on to
the new pre-stretched event. Now you can mute the old track and you have your time stretched event.

Wasn't that fun?

Re: SonicEPM, MCTech and anyone else

I have verified that the problem I was having is caused by the fact
that Vegas doesn't properly apply the timestretch filter when it
comes to render time.

I have an hour + twenty minute long audio file. If I use Timestretch in vegas
to shorten it by 8 frames the Timestretch will not be applied at render time.

Checkout a screenshot of a demonstration of this problem,
http://www.pixelogix.com/~moored/timestretch.png
my Veg file is at
http://www.pixelogix.com/~moored/timestretch.veg

The second audio track contains the audio event which was shortened by 8 frames
using the A03 crossfade scheme. The audio event is normally 1:24:00.05 long. I
used the "Render To Track" feature to make track 1. You can see in the screen shot
that as of 1:26:05.05 the rendered track does not resemble the time stretched event.

I duplicated the original track (track 2) to make track 3 and turned off the
Timestretch. As you can see, track 1 is almost identical the track 3. It is
as if the timestretch was never applied.

This failure of the timestretch feature in Vegas generated my problem.

So, I haven't looked at this thread for a while, because I figured out how to do it. I was rendering my project as an MPEG2, WITH audio. When I render them separately as a DVDA template video and a .wav or .ac3 audio file, then combine the two in DVDA, it works fine.

Thrillcat - thanks for checking back and posting your success. Glad to hear you got it working.

I tried that as well, but it didn't work for me. I was finally able to get it in synch by using a different program to render the original MPEG2 to AVI DV format, edit in V4, and render back into MPEG2 using V4. The program was ShowBiz by ArcSoft (came for free with the DVD Burner) and it uses the GoMotion MPEG2 encoders.

I've done quite a few projects since the one where I had the synch problems and they worked just fine. Must be something about the original mpeg2 source file.

Cheers,

Cal Irish

I rendered a 1 hour long mpeg 2 file and it was out of synch by the time it completed by a significant amount. The original source material is a combination of DVC Pro and DV video tape captured through the VV utility as an AVI file. I can use the material as a DVD source without any problem as long as I choose the DVD Architect template and use either AC3 or WAV as audio. But as an mpeg-2 file all by itself it gets out of synch by at least 5 or 6 seconds by the end of the hour.

I just tried rendering a bunch of short AVI clips to MPEG-1 yesterday for a multimedia project I'm working on. The longest clip was only 12 minutes long, and the others were all around 5 or 6 minutes.

The audio/video are perfectly in sync in the original AVI file, which I simply dragged into VV4 and then used the render command (no effects or anything else).

The audio/video drift out of sync in the final mpg file very quickly, and by the end of the 12 minute file, they are at least 1 second out of sync.

I'm doing highly compressed mpeg video to stick on an enhanced audio CD, so there isn't room for full quality video. This is a project I need to wrap up as soon as possible, but this drift issue is a total show stopper!

Steve