DVD-lab audio sync issue

[phinsman]

Hello...

Well I finally got the encoding process down and now I have a small issue with DVD-lab.

The audio is always ever so slightly, about .25 seconds or less, out of sync. It's not the kind of sync issue where it gradually gets worse by the end of the video. It's a uniform, out-of-sync problem the entire video. It may be as small as .1 seconds, but it drives me nuts, because I can tell when people are talking in the video that their lips don't match what they're saying. The audio is behind the video.

I ran a test with three different encoding methods to see if the problem was there:

TMPGenc -- program stream (audio & video in one file)
TMPGenc -- elementary streams (separate)
CCE -- elementary streams

I used AVISynth scripts (simple ones) of a video capture to test the encoders. The original capture was not out of sync.

They all came out the same. Same small sync problem.

I also tried compiling with DVD-Lab two different ways: with and without the flexible multiplexer engine.

Thanks for any help.

The audio used, by the way, was MP2, 128 Kbps. Should I change the bitrate?

Dale

[phinsman]

Just a quick follow-up:

I went back and tried the same clip with 192 and 256 kbps bitrates.

Still the same problem.

Dale

[mkelley]

You ought to try AC3 audio (use BeSweet with the guides on this site). It's all I ever use with DVDLab and I've never had a sync problem (or any other problem with any other audio).

Otherwise the only other advice I can give you is your audio needs to be exactly the same for all aspects of your project -- menu background and/or any other movies need to share the same rate and audio type. There are some utilities which can "offset" your audio by a certain amount (I think BeSweet is indeed one) which also might help you.

[phinsman]

Thanks mkelley.

I am trying to do what you suggested (although I've opened another can of worms because the audio isn't coming out right...a post on another forum for that problem).

Here's a question though, is there an efficient way to do this? From what I understand, to use AC3 on DVDs, you have to:

Save WAV in VirtualDub.
Convert WAV to AC3 with BeSweet.

The problem for me is, here is my situation:

* I have 1 large captured file (27+ GB) of a football game
* I use AVISynth to make clips such as 1st_quarter, 2nd_quarter, highlight1, highlight2, etc.

If I want to have clips like this, and don't want to (actually can't due to lack of free space) re-save the AVI file into clips, I have to do this:

Use AVISynth to make clips as before. Example:
#This script is for testing
video = AviSource("Y:\dolphins_jets.avi")
audio = WavSource("M:\Video Temp\dolphins_jets.wav")
AudioDub(video,audio)
Trim(197928,199028)

Then I load the script into VirtualDub, Save WAV, and use BeSweet to convert to AC3.

If I do that for each clip, it will be a very big pain.

So that's my question...is there a better way?

Much thanks,
Dale

[mkelley]

The "better way" is to think outside the box -- your problem is not one of workflow, because you know what the best workflow is. You just don't have enough disk space.

So get more -- with 120GB of 7200 disk going for less than $100 there's no excuse not to have enough disk space. One of the worst things to do to yourself in digital video is to hurt your working abilities due to lack of disk space. You'll find LOTS of times where the extra space will come in handy, and you'll be working lots more efficiently.

I upgraded my 80GB video drive to 160GB recently and was amazed at how much more productive I was able to be -- if I had known that I would have done it a lot sooner.

[phinsman]

Oh, I agree, I have been planning to buy another hard drive for a while. But -- let's just say I'm between jobs right now and it's not a good idea to spend money on such things.

In this case, though, I don't think having more space would help me as far as efficiency. I wouldn't want to re-save the files anyway; I would be recompressing in MJPEG which I understand is a bad idea. I haven't had good luck with Huffy so I stay away from it.

Thanks for the advice though. I do plan on getting a 120-gig drive or so in the near future.

I take it there's not a more efficient way to do this AC3 encoding though? I can make a DOS batch file with besweet commands to hurry up the encoding, but I still have to save each WAV separately.

Thanks again,
Dale