Burning DVDs - audio/video sync problems

[Christien]

Can anybody explain to me, in plain terms, why it is I'm having major problems burning avi files to DVD, where the audio is way out of sync with the video?

I downloaded season 11 and 12 of Top Gear and I'm trying to burn them to DVD, 2 episodes per disc. So far only one episode has burned properly so the audio and video are in sync. I can't for the life of me figure out what's different, either in the files themselves or how I'm burning them. In the one episode that I did get to work, the other episode on the disc is screwed.

I'm using Nero Vision v4.5.0.24 (part of Nero Premium 7), and the avi files are DivX. If it makes any difference, the sync is fine when played through Winamp, but off when played back through Windows Media Player, though not as bad as when burned to DVD and played back on my DVD player. That leads me to believe it's a codec issue, but AFAIK you can't change Nero's codec.

Thanks for any tips.

[spuggy]

Probably encountering a buffering issue whereby the audio is arriving too late for the video cell and getting dropped/delayed. Or the software might be generating GOP cells that aren't properly closed, or are too long. Or the video bitrate of the generated stream is too high for your DVD player (or for the media) and it's barfing. Or almost anything, really...

Does the DVD play OK on the computer itself with your software DVD player, or does it show the same sync problem? This could help isolate your problem to either the mastering process or your set top player itself...

Strangely, many cheap DVD set top players are much more resilient than their brand name counterparts, and often seem to play anything they can understand, and the published specifications can go hang. "Brand name" DVD players seem to be a lot more picky and fussy.

I pretty much think Nero - like most Windoze tools - sucks, and never use it for anything more than backing-up directories/files or maybe burning a pre-mastered ISO image.

Broken MPEG streams can be very difficult - or practically impossible - to repair. I've played with some streams that were damaged by frame-editing software (e.g. to remove commercials). Unless you really want to know what MPEG-2 I, B & P frames are and the difference between a closed and an open GOP - and then puzzle out what (possibly limited) subset of the DVD specification your DVD player will accept - I suggest you find another approach...

If you really want the show badly, one approach I've had some success with is to remove all encapsulation (e.g. the AVI container itself) by rendering the video to a raw YUV image stream (HUGE!) and the audio to a raw PCM stream and re-encode and re-multiplex it to MPEG-2 video stream with AAC/AC-3 audio (as MPEG audio is only legal for PAL DVDs, according to the specification) with software that lets you access the nuts'n'bolts of what's going on under the covers (like VBV buffer size in the multiplexed stream(s), audio offset delays etc.). If done correctly, you'll end up with an MPEG system container with blank DVD VOBU's inserted, and you can then author it into a DVD. Lot of learning, lot of work, lot of disk space, lot of CPU.

I used to do this kind of thing on Unix with mplayer/ffmpeg/avidemux/mplex/DVDauthor. There are Windoze versions of at least some of these tools, but it's a learning cliff and the NTFS 4GB file limit will bite you within about 30 seconds of rendering YUV streams, sorry. Did I mention YUV streams were very large? A YUV stream is a series of full-size DVD (720x480) image frames with no compression at all, you'll certainly want full (e.g. 24 bit) color, and it's 29.97 frames per second...

I guess the short answer is that you'd probably be a lot happier buying a hardware DVD recorder for $60, plugging the S-Video output of your graphics card into the input and playing the episode on your computer via Winamp, VLC or mplayer - whatever works for you - hitting record manually and going off to do something else for an hour.

[Christien]

Wow, thanks for such an awesomely detailed answer! You're right that it's only worth so much effort. I'd rather just burn it as a data DVD and watch them that way. The only difference is lack of a menu.

What a pain in the ass. I wish BBC would release Top Gear DVDs in region 1 format!

[spuggy]

Originally Posted by Christien

Wow, thanks for such an awesomely detailed answer!

You're welcome. I've been there, done that - that's two years of my life I want back!

Actually, it was a lot of fun. But it's easier to just buy it.

You're right that it's only worth so much effort. I'd rather just burn it as a data DVD and watch them that way. The only difference is lack of a menu.

What a pain in the ass. I wish BBC would release Top Gear DVDs in region 1 format!

Uhhhm?

Your problem is that Aunty Beeb only releases them in PAL format region-locked to Region 2 (UK/Northern Europe)?

Oh well. Y'see now, little did you know, but you actually asked the wrong question, and there's a simple answer...

See, being a furriner 'n all, I have DVD's that, perversely, I want to watch where ever I might happen to be in the world this year. Seeing as how I paid for them. How unreasonable of me, when I should obviously just buy mutliple copies, one for each market I visit, and just do without my favorite shows if some Marketing Drone decides they won't be available there. Yah, right.

Many of my favorite shows aren't ever going to get released on DVD in the US, there's just no market for things like "The Comic Strip", "Rising Damp" or "The Fall and Rise Of Reginald Perrin" here. (BTW, here's a Hot Tip you might not know: amazon.co.uk IS NOT THE SAME AS amazon.com. There is UK market-specific stuff for sale there. And they'll ship to the US perfectly happily.)

The answer, my friend, is very simple. Buy one of these puppies (I bought myself two the other week, but no other affiliation): Ebay BIN Item

This is similar to the Cyberhome CH-300 player (same hardware, better (later) firmware).

It does Progressive Scan (if you use the component outputs).

It does flawless PAL->NTSC upconversion, or vice-versa. So you can play PAL DVD's on an NTSC TV (or NTSC DVD's on a PAL TV).

You can set them to be Region 0 players (region-free) with the remote in 5 seconds (open tray, make sure no disk inserted, close tray, menu, "1", "9" "enter", up/down arrows to select desired region, "enter", you're all set). Then you can play DVD's from any region.

Oh, and they're small enough to pack, and they're multi-voltage, so they work anywhere in the world.

Now, the Cyberhome has a bad rep for some examples not lasting well. The power supply can get a bit marginal (couple of caps are prone to leak), and they will then typically fail to read DVDs reliably after the voltage dips a tad low.

That said, mine is still working fine after 3+ years of very heavy use - and I still bought a pair of the TruTechs.

The earlier Cyberhome firmware tends to drop some frames on the PAL->NTSC upconvert (fixed in the later units). Which I notice and it drives me absolutely crazy (my roommate can't see it), so I bought the TruTech to see if it did a better job - and it's completely flawless, like the later Cyberhomes were reported to be.

It's an option. It's what I did. Obviously *I* think it's the best option - YMMV.