Audio sync when ripping DVDs

[shmokes]

Is there anything worse than finishing ripping a couple of DVDs only to test them and find that the audio doesn't match the video? 


No.  There is not.   

[Samstag]

There are supposedly tools out there that will resynch the audio (as long as it's a constant offset) but I've never done it so I couldn't give you any names.  It should be a pretty quick process.

[shmokes]

It wouldn't be quite so bad if my computer wasn't three years old, but it takes a few hours to rip and encode a DVD into Divx.  From what I understand, that can be done in less than ten minutes on new machines.

[Samstag]

That was my main motivation for going for a quad-core processor this time around.  It's not a 10-minute job, but video encoding is greatly improved on a multi-processor setup.

[shmokes]

I seem to remember a Maximum PC Dream Machine article from a couple years ago (before quad-core processors even existed) and it seems like they used a two or four processor motherboard, each one filled with a dual-core processor, so they had either four or eight cores, and they used No. 1 DVD Ripper to rip and encode a feature-length DVD into a Divx file in something like 11 minutes.  It was long enough ago that I figured that off-the-shelf mainstream consumer PCs would be putting in similar numbers by now.

At any rate, my single-core 3.6 Ghz P4 can still run most things pretty well, but I'll be damned if video encoding isn't the slowest thing on earth.  So when the files end up with video and audio that don't sync up, it's just so irritating.  When I get a little time I'll try and track down some syncing software.  That would be pretty great if I could quickly get everything synced up rather than having to start the whole encoding process over again and hope that it gets it right this time.

[ahofle]

What software are you using?  Have you tried using a different codec like Xvid?  I'm not sure the problems you are describing are due to CPU limitations.  I have a P4 3.0 Ghz and haven't had those problems. 

Also, in case you didn't already know about this, http://www.videohelp.com is a great resource for tutorials on encoding, converting, etc.

[SavannahLion]

Is the sync immediately noticeable or does it "drift" as the movie play?

For the first, I don't have an answer. I haven't encountered the problem... yet.

For the second, I did encounter. There's an obscure problem relating to the quality of the crystal(?) in your audio card clock. During play back, I understand that the software uses timing "blips" or markers within the file to resync the audio to the video. Other tricks are employed such as frame doubling or skipping as well. However, encoding the audio uses the audio card clock (that's the theory anyways). If you specify the audio to be encoded at a specific rate, but the hardware audio clock is off by 0.001Hz, the markers are set for the incorrect rate and drift occurs. Some software spot the drift and modify the markers or the video accordingly, others well.... don't do so well.

This problem was annoying and obscure enough that I seriously considered finding out how just how far my $3,000 laptop could fly.

[shmokes]

Interesting.  It definitely drifts, though it's noticeable enough right off the bat.  But sometimes it's perfectly fine too.  It's weird.  I used to encode with No. 1 DVD Ripper and had the problem pretty frequently.  Sometimes I'd have to rip a disc three or four times before it came out right, but usually it worked well.  Then I switched to Intervideo DVDCopy, and that just worked and worked.  I must have ripped a couple dozen discs and now, suddenly, the problem is back, and not just on a single disc.  It's messing up all of the -- to the point that I'm back on No. 1 DVD Ripper.  Grrr.

[boykster]

With storage space so cheap there's no reason to encode anymore IMHO....just rip to ifo/vobs and playback with a program that supports them (zoomplayer / windvd / etc)

 

[jbox]

That's not overly practical yet for your average home network. Streaming a DivX file involves sending less then a quarter of the traffic for around 90% of the quality (for normal don't-see-every----smurfing----pore TVs). So no-one else can do pretty much anything else while you're watching the movie. 

As for the speed issue, there is no way a 3.6 Ghz P4 is not enough for video encoding. If it's taking (say) two or more hours I would take a good hard look at tweaking the drive channels (both DVD and HDD) before I'd blame the CPU for the bottleneck. Are either of them slaves, does windows have DMA switched on for both, are you imaging the disk first before burning, etc... 

And having sub-titles out of synch is even more annoying, because you have to watch it for a bit first to make sure (since the point is you don't know who is saying what to start with). 

[shmokes]

Well the drives are SATA, so no slave and I'm almost positive that there's no DMA on SATA drive either (or rather they basically act like DMA devices to begin with).  They're also striped together in a RAID 0 so performance should be pretty good.  I don't image the discs first.  Is the performance difference that much better that it offsets the extra time imaging the disc the hard drive first?  I gotta say, one downside to that is I've gotta babysit the thing while I'm imaging it so that I can start ripping and encoding once it's done imaging.  I can't just pop in a disc, hit go and leave.

As far as storage . . . I don't know.  I've got about 1.5 TB of storage in a consumer RAID 5 NAS box and 1 TB of it is already filled up, and that is with exclusively compressed formats.  If I was just ripping I would have far exceeded my capacity.  And I love this thing because it acts as its own Samba server, so I don't have to leave my computer on all the time wasting power in order to always have access to my media, so I'm not especially excited about outgrowing the thing any time soon. 

And, frankly, even if storage is cheap right now,  my wife is our only breadwinner for the foreseeable future and we're living in an incredibly expensive city. I am an unemployed law student taking $40,000 in student loans EVERY YEAR!  Getting a job is out of the question.  Not only would it simply be impossible -- I'm up all night most nights reading cases as it is -- but it is not allowed by the school.  It's considered a violation of the honor code and you can be expelled for it.  I've got a really powerful, fun poor-man's setup going on from all the equipment I've amassed over the past five years, but I'm where I am for the next few years.  Spending money to upgrade my home theater in any way right now would just be irresponsible.

[boykster]

You shouldn't even be watching movies then, now should you 

That's not overly practical yet for your average home network. Streaming a DivX file involves sending less then a quarter of the traffic for around 90% of the quality (for normal don't-see-every----smurfing----pore TVs). So no-one else can do pretty much anything else while you're watching the movie. 

That's simply ridiculous.  I can concurrently stream uncompressed DVDs from a single linux server to as many as 5 clients and still use the network for general usage, and that's on 10/100 gear.  I just upgraded to gigabit to every port not to increase concurrent capacity, but to increase ripping / transfer speed, pure and simple.  What are you using for a network?  Tin cans and yarn?

I guess I'd rather spend more time enjoying my digital media that funking around with it trying to get it to work and look good.

Edit: oh, and sure, compressed video might look just fine on your SD set today, but do you really want to invest all this time and effort into ripping your digital media, only to have to do it again when you upgrade to an HD set?  And I do mean WHEN, as SD sets won't be available forever and your existing gear will eventually fail. 

 

[Havok]

I don't see the problem? You've got a bunch of movies for Kung Fu theater now!

 

[clanggedin]

I use DVD Shrink (free) and I have never had audio sync problems on any of my ripped DVDs.

[ahofle]

I use DVD Shrink (free) and I have never had audio sync problems on any of my ripped DVDs.

Ditto.

[Havok]

The guy that wrote DVD Shrink now works for Nero - he stopped development on his software a while ago. You guys will not be able to copy any of the newer Sony protected DVDs...

I use DVD Fab - you have to pay for it, but it works just as good as Shrink, and can copy everything, not just older DVDs. Or, check out Slysoft's AnyDVD.

[ahofle]

You use also tools like 'RipIt4Me' that work in conjunction with DVD Shrink/DVD Decrypter for the newer encryption schemes.