Mystery audio sync problem

[Xoanon]

Ive captured a 10-min film with Sonic MyDVD on my new Adaptec Videoh! PCI card. It captures in MPEG-2 (DVD-compliant). I play back the MPEG in Windows Media Player and its fine. I then bring the MPEG into VirtualDub-MPEG2 and convert it to AVI so I can edit it in Premiere. It is then I encounter problems.

The audio is slightly out of sync with the video and as the video plays further through, I have to constantly shift the audio back and forth in Premiere to get it in sync when editing. Ive tried various different codecs for the conversion from MPEG to AVI but the audio sync is still there and its only on the AVI file.

The funny this is, when I first got the card/software, I was capturing 45min episodes of TV shows to MPEG-2 then trimming in VirtualDub, converting to Huffyuv AVI, converting to M2V, creating AC3s from the audio and then burning in DVD Lab Pro. I had no audio synch issues then. Now I suddenly do!

I have more than the necessary system specs for the PCI card, so I know its not that (notwithstanding the MPEG plays fine after capturing). This is not a case of dropped frames or anything, its just the AVI wont play properly after decompression.

I cant capture in AVI format using Premiere or VirtualDub, as the former only recognises my DV card and the latter says "Cannot connect to the desired capture driver".

It seems the only thing I can do is invest in an AVI capture card, but at present I cannot afford it. I'll keep trying to sort this problem out but right now I am at a loss as to what is wrong.

Anyone out there who may be able to offer some help, please drop me a line. It will be much appreciated.

Thanks a lot.

[adyga]

Test this:
*capture some 5min or more + some more to be cut later on step 3
*demux with DGIndex (with video output m2v)
*cut the excess parts with Cuttermaran
*mux with any other tool, maybe MPEG tools in TMPGenc, or just open the m2v with Vdub and do only video processing
*add the resulting audio from step 3 in the end
check the results
I had never encountered audio sync problems with my cheap card (bt based)
regards

[DaMo]

I've had sync issues myself until I recently found out that certain soundcards (such as SB Live) require a sample rate of 48000, instead of 44.1.

(Note: Can someone pls explain why its better to set the audio rate @ 48 instead of 44.1 since I do VCD's which require 44.1).

Another tip I also tried in relation to sync was to set the video in VirtualDub as "Direct Stream copy" and to change the framerate so that the durations match and to set the audio stream to "Full processing".

I now have perfect sync in all my captures.

[Nelson37]

GAV - During previous conversions (that worked), was Premiere used? Did you save audio to WAV before converting to M2V? What did you use to encode the HuffyAvi back to MPG-2? This appears to be substantially different than your current procedure, which does not work.

Have you checked the audio synch with several different programs? Some will react differently to the same file. Do I understand correctly that the amount of desynch increases as the file plays?

If I am seeing your process correctly (not sure of this), there appears to be a major difference in procedure which is also noted in the sticky about audio synch as one of the first things to try.

Please detail changes in process as questioned above.

[Xoanon]

Hi Nelson.

This is what I am doing:

- Capture in MPEG-2 using Sonic MyDVD
- Bring MPEG-2 into VirtualDub-MPEG2 and save as Huffyuv AVI (already there are sync issues here)
- Bring AVI into Premiere to edit
- Audio sync problem has to be manually corrected every once in a while but shifting the audio track

[neomaine]

gavsalked,

Why aren't you capturing direct to avi with huffyuv? The sync should go away and you'll have more (and easier) editing options.

Sorry, just read up on the card and see that's its an MPEG1/2 capture device. I'd say you got the wrong tool for the job. If you were capturing to MPEG1/2 and going straight to VCD/DVD then you'd probably be OK. But your not. You've got some editing and touch up that you want to do first but have to go with AVI with those tools.

So, you can either get software that can handle the MPEG2, give you some basic cutting abilities and can then author. This would be preferable since there would be no re-encoding. Remember, each time you go from one lossy format to another, you WILL loose quality. If that's the case, I'd recommend something like Ulead Movie Factory or even better, TMPGenc DVD Author. Both can handle MPEG2.

Now, if you like the software you're using and want to get a little bit more into your authoring, then I'd sell the Videoh! and get an AVI capable capture device or even a basic ATI AIW card. Either can be had for under US$50...less than half the cost of that Adaptec card.

I myself am a basic MPEG2 to DVD guy and use TMPGenc Plus and Ulead MF2. Haven't gotten around to using TMPGenc DVD Author yet but from the threads it seems to take the place of both pieces of software I use.

[Xoanon]

I'm UK-based, are there any capture cards you can recommend by name? I have spent ages looking online and cant find ANYTHING about AVI capture cards, it really is unbelievable lol!

But yes, I now know I need an AVI card but the one my father saw was about £150. Are there any PCI cards I can get cheaper?

And whats an ATI car?

Thanks a lot, man.