Audio synch problem with authoring

[Aspic]

Can anyone help with this audio synch problem from a total and utter newbie? I've done a search on the forums and audio synch problems seem quite common, but none that I have found directly answers my particular query. If you can think of a thread that you believe answers my query then please post a link and ignore my unobservance.

Anyway - my problem:

Summary:
An mpg with no apparent audio synch problems loses synch when authored into DVD format using a variety of DVD authoring software (Nero 6 and TMPGEnd DVD Author 1.6).

Details:
Originally I had a .avi move (DivX) that I tried converting to DVD format using DVD2SVCD using this guide http://club.cdfreaks.com/showthread.php?t=61142. The outcome of this process was a DVD format folder that when played in software PC DVD players seemed to lose audio synch more and more (I typically "burn" to HDD to check for such results and then copy the VIDEO_TS/AUDIO_TS to a DVD - saves wasting a DVD). Similar problems occured when trying Nero.

The interim DVD2SVCD .mpg seemed fine, but after some searching on the internet for anyone with similar problems and hopefully solutions I tried loading the interim .mpg into VirtualDub. This produced a series of
"Anachronistic or discontinuous timestamp found in audio stream 0 at byte position xxx" errors on loadup. Aha I thought. It appears to be find but there might be some sort of error in the original .avi. So I loaded up the original .avi into VirtualDub and was presented with the error:
"Virtualdub has detected an improper VBR audio encoding in the source avi file and will rewrite the audio header with standard CBR values during processing for better compatibility. This may introduce up to 16600of skew from the video stream. If this is unacceptable, decompress the 'entire' audio stream to an uncompressed WAV file and recompress with a constant bitrate encoder (bitrate: 121.9+or- 18.5kbps)"

Thats the problem I thought - now to find a solution. Looking around the internet some more I found this very useful post http://forum.digital-digest.com/archive/index.php/t-24731-p-1.html and followed the advice. After TMPGEncing the resulting silent .avi and .wav together I had my .mpg which VirtualDub seemed happy with and viewed on my PC with no audio synch problems at all. I tried authoring the .mpg to a DVD (again to a HDD folder first) using TMPGEnc DVD Author only to find thataudio synch problems still remained when viewing the contents of the folder in a software DVD player . I tried other authoring programmes such as Nero with the same results.

To my mind therefore:
* its not the TMPGEncoding (or whatever the posh word for it is) of the fixed .avi as the resulting mpg doesn't produce any errors in VirtualDub
* its not the DVD drive as I'm not using it yet, authoring to a HDD folder instead
* it must be something to do with the authoring but I am at a total loss as to what. As I mentioned at the top I couldn't find many other posts with theis precise problem that actually had a solution attached.

And help gratefully received - remember I'm a total newbie so please be gentle with me.

Thanks.

[harley2ride]

Before loading any file to your pc, make sure that your HD is defragged. It is also best to have a separate HD for video files (no software on it), and have it be on the opposite ide that the burner is on. Make sure that you shut down unnecessary background tasks, then reload your source file to the pc, then encode and reburn. Those are the most common things that affect sync problems. Only other thing is usually a bad source file...

[Aspic]

Thanks for the advice. I'll give it a go but I don't hold out much hope - I refreshed my PC installation a week or so ago so the HDD should be in good nick. The encoding seems to be OK, its just the authoring that is throwing up the problems, but I'll try reauthoring with minimal other process footprint.

One other thing I should mention - I've seen lots of references to similar problems been thrown up by non 48KHz audio streams. The original avi and VirtualDubModed .wav file are both 48KHz, but when I run the TPGEncoded .mpg through AVICodec or GSpot there does not seem to be any information about the audio stream, although there is sound when I play it on the PC.
AVICodec gives the following on the .mpg:
File : 3.93 GB (0.0 B), duration: 1:30:51, type: MPG, 0 audio stream(s), quality: 80 %
Video : 3.63 GB, 5700 Kbps, 25.0 fps, 720*576 (16:9), MPG2 = MPEG 2 (SVCD/DVD), Supported
The audio line is blank

GSpot claims not to support the file (which it lists as MPEG/VOB)

Is this OK or a symptom of the problem?

[Abond]

The last version of GSpot (2.52 beta1) should support mpeg analysis.
You didn't mention which sw player you are using. Another check can be done in TMPG-MPEG Tools Demultiplex tab - it should list all the streams inside mpg.

[Aspic]

I've tried WMP and VLC. I'm aware that some of these sw players correct any snch problems at playtime - are there any that don't so that I can check that its definitely not the .mpg

Thanks for the tip about the TMPEng tool. I tried it and it gives:
video_stream: MPEG-2 Video 720x576 25fps 5700kbps
audio_stream: MPEG-1 Audio Layer-2 48000Hz 384 kbps

[Abond]

Well, it seems OK for me. Lastly I can advise you to try another authoring SW. Maybe muxman - try it to see if the audio synch will improve after authoring. You must give to muxman elementary streams though.

[abc-123]

First, I want to compliment the original poster on such a wonderfully detailed first post!

Second, I think you should go back to the avi audio and re-rip it off the avi. Use a program like avi2wav to do it instead of virtualdub, since it usually does the jobs miraculously that virtualdub chokes on. Then, CHECK YOUR AUDIO TIME LENGTH and compare it to the video. Make sure it's the same.

Third, use ffmpeggui to convert the audio to mp2. Tmpgenc is notorius for not converting sound that well. Author and test again.

And please report back and tell us if this fixed it. If there's still a problem after having done this the right way, maybe others can help you further.

[Aspic]

Its solved now. I was recently looking up the guides on this site (specifically this one: https://www.videohelp.com/forum/viewtopic.php?t=249135) which basically said what you posted abc i.e. seperate the audio and video streams, use in this case TMPGEnc Express to encode the video and ffmpeggui to encode the audio stream. I did this, mixing the two together at the end with TMPGEnc Express again and authored with TMPGEnc DVD Author - and it worked - the DVD had synched audio. Looks like your post was bang on the money abc.

Abc, abond, and harley2ride - thanks a lot for all your help.