How do I keep audio and video in sync when using Nero?

I’ve been trying for ages to solve this problem, and would appreciate any advice.

I fairly regularly use Nero 6 to create DVDs, from AVI files, that can be played in a stand-alone DVD player. The problem is that for some of the AVI files, the audio is out of sync with the video when the DVD is played on the stand-alone player. The original AVI file plays fine on the PC.

Now, I have done quite a lot of research on this, and am fairly sure that the problem is due to some AVI’s using variable bit rate MP3 sound. This would explain why on some of my DVDs the sync is fine - presumably it’s only fine for those AVI’s that use constant bit rate sound.

I would like to continue to use Nero (more precisely NeroVision) to create DVDs, but I can’t seem to get it to behave correctly. I thought I had it fixed when I came across a step-by-step guide on the web that explains how to use VirtualDub to extract the sound out of an AVI to a WAV file, and then add it back to the AVI in uncompressed form. The steps that I used are directly from here (it’s a google cache, towards the buttom of the page).

I was convinced that taking those steps would work, and although I was hoping to find a solution that didn’t involve any additional software (in additin to Nero), I was prepared to give it a try. Unfortunately, the sync was no better. Most other web sites seem to suggest either very similar steps (although possibly using different software to VirtualDub), or to not use Nero at all. In fact, I’ve tried using WinAVI to see if that was any better (it was suggested on quite a few forum threads when people were asking similar questions), but it didn’t help. I’d prefer to use Nero anyway, due to its menu creating abilities.

Does anyone have any ideas why my DVDs would be out of sync other than the use of VBR audio? If that is actually the reason (and I still believe it is), anyone see anything wrong with the 18-step process in my link above? I’ve been trying to get this to work for days, so I’d be really grateful.

Thanks in advance,
Just

I’ve used Nerovision and had a lot of issues with sync problems. It always seemed to boil down to one of these:

  1. Any file with a frame rate of 23.95 will wind up out of sync. Solution: Use Nero Movie Maker to decompress the file to raw AVI format with a frame rate of 29.95 (NTSC standard). Obviously this requires a TON of hard drive space for very long movies.

  2. The file is corrupted. Sometimes there’s a “glitch” where the picture freezes up or pixelates mometarily. Everything after the glitch will be out of sync. Solution: Same as above, or use TMPGENC to re-encode the file.

  3. Just about everything captured directly with my ATI All-In-Wonder card. Unfortunately I never did find a solution for that one. :smack:

I’ve never run into a problem where the sound was clearly the issue.

This is my first stop, every time. Nerovision’s encoder blows chunks.

TMPGEnc is a much better solution for the encoding step. Then just use Nero for what it does well – burning the media, and maybe making some menus.

I should probably mention that for some files the audio sync will still be a problem if you just do a straight encode with TMPGEnc-- with these files, you can just render a small section and keep adjusting the “audio gap correct” setting in the “Source Range” window.

It doesn’t take long to become adept at making this adjustment.

Thanks for the replies…

Hmmm… this sounds interesting (and promising). What’s so special about 23.95? I just checked the framerate of a couple of the videos that I’ve had sync problems with, and they both have framerates of 23.976. Close enough? If so, I’ll try converting them to a raw AVI. (Are you sure Nero Movie Maker is the name of the program you use? I don’t think that came with my Nero install, and googling for it doesn’t reveal any info on it.)

I hate to hijack but… how long does Nero take to burn and convert an .avi file to a DVD (let’s say 1.5 hours worth of avi video)?

I’ve been using DVD Santa which takes about 4 hours to convert the date and then it has to be manually prompted to burn the DVD which then takes another 1.5 hours or so.

I think he does mean 23.976, which is the framerate of NTSC Film. I’m pretty sure your problem is that you haven’t timestretched the audio. You’ll need an audio editor for this, or just get the freeware BeSweet (along with the BeSweetGUI) to go straight from your old WAV to your new MP2 file for use on the DVD. About halfway down the page of this guide is a nice screenshot that shows you what settings will be needed. Just be sure to leave the “Downconvert Sample Rate” box unchecked (listed as #5 in that screenshot), since you’ll be using 48KHz audio on your DVD.

Also, ditto what Larry Mudd said. For the best possible results, you’re going to want to use TMPGenc or CCE Basic as your MPEG-2 encoder. YMMV, though, since the impressive array of options on these programs could be intimidating to a beginner.

Thanks for this, but it seems the suggestions keep getting more and more complicated. Why would the audio need to be stretched? In fact, I’m pretty sure I’ve had sync problems with NTSC DivX videos that I’ve burnt still in NTSC, so the audio shouldn’t need any stretching, should it?

That seems far too long to me. I have a relatively old machine (Athlon XP 1700), and it takes under an hour to do about 40-45 minutes of video (encoding and burning). 1.5 hours would probably take 1.5 - 2 hours. And that’s using Nero - I’ve found WinAVI to be much quicker (nearly half the time for the encoding part!). Nero also doesn’t need to be prompted to burn the DVD either.

There’s more than one way to get a synch problem. I just proposed the solution that seemed most likely to be applicable to your case. This same process is also used on commercial PAL DVDs that come from film source.

Cite:

If you’re getting things done that fast, then your encoder is likely doing a single-pass CBR encode. If you just want the quickest solution and don’t care at all about video quality, then you’ll do fine with Nero. Otherwise, I’d recommend using a better program that employs multipass VBR, and letting your videos encode while you’re away from the computer (or doing something non-CPU-intensive, like goofing around on the web).

Okay, so the audio needs to be sped up by 4% if I’m converting from NTSC to PAL. That makes sense, although I would have thought Nero would do this for you (why doesn’t it?).

But more importantly, what if I’m taking a (23.976 fps) NTSC AVI and burning it to an NTSC DVD? Then I wouldn’t need to touch the audio, would I? And yet I’m pretty sure I’ve had sync problems when doing exactly that. Sorry to draw this thread out for so long… on the weekend I’ll try reburning one of the AVI’s I’ve had problems with in NTSC format, just to make sure that the sync problems are still there (although hopefully I’m wrong and they won’t be).

And now I’ve just read on the web that NTSC isn’t 23.976 fps at all - it’s actually 29.97 fps. PAL is 25 fps. I think the 4% thing fits in when converting between film (24 fps) and PAL, not NTSC and PAL. How this explains my sync problem I really don’t know.

Just to clarify, from here:

What made it confusing was that other websites rounded the 23.976 to 24. So it seems the AVI’s that are causing me problems are in NTSC Film format (no, they’re not Hollywood movies, in case you’re wondering). So maybe the problem is that Nero tries to convert them to 29.97 fps if I choose NTSC? Or would it leave it at 23.976? Maybe I need to stretch the audio by 4% if I choose PAL (23.976 + 4% = 25 roughly), and 25% if I choose NTSC (23.976 + 25% = 29.97)? There’s no option in Nero to leave it in NTSC Film (unsurprisingly).