VOBs, AC3s, etc.

newUzer wrote on 5/9/2005, 9:01 PM
Will Vegas 5 accept a VOB clip containing an AC3 audio stream? I ask because I didn't think it did, so I've gotten into the habit of demuxing, using HeadAC3he to convert from AC3 to a WAV, and then recombining the streams on the timeline. I sometimes need to nudge the streams to get them in sync, but it seems to work. Also, I've always assumed when one renders using the DVD NTSC template, one gets an MPEG2 stream and an AC3 stream, but now I've begun to wonder. Do I have it right?

Comments

bStro wrote on 5/9/2005, 9:09 PM
Will Vegas 5 accept a VOB clip containing an AC3 audio stream?

It will accept it, but you wouldn't be able to use the audio. So you've been doing the right thing. Well, except that I'm guessing you're putting an MPEG2 file onto the timeline? Your work would go much faster (and you may have less sync issues) if you convert the video to AVI. Vegas = not so good editing MPEG.

I've always assumed when one renders using the DVD NTSC template, one gets an MPEG2 stream and an AC3 stream, but now I've begun to wonder. Do I have it right?

Nope. The DVD NTSC template creates an MPEG2 file with MPEG audio included. (Which is odd, now that I think of it, since most NTSC DVD players don't like MPEG audio.) The DVD Architect NTSC template, on the other hand, creates an MPEG2 stream only. When using the DVD Architect template, you should then render out your audio to an AC3 file.

Rob
ScottW wrote on 5/9/2005, 9:15 PM
Rob, the DVD NTSC template *does not* include mpeg audio by default - you have to explicitly modify the template settings to get audio. The template is for an elementary stream which cannot contain video and audio multiplexed together.

The difference between the two templates is that one is elementary, the other is a program stream (without audio).

--Scott
bStro wrote on 5/9/2005, 9:30 PM
With all due respect, Scott, please check things out before you correct someone. ;-)

I just opened a project in Vegas, did a Render As, and chose DVD NTSC for the template, and this is the description I get:

Audio: 224 Kbps, 48,000 Hz, Layer 2

When I click Custom and look at the Audio tab (I have not altered anything), "Include Audio" is already checked.

I believe you're thinking of the DVD NTSC video stream template, which in a fresh installation is two items down from the DVD NTSC template. Here's the description for that:

Audio: None

Rob
newUzer wrote on 5/9/2005, 9:30 PM
Hmmm. So, to get from the VOB to AVI one would most likely use...? And then one renders the project to MPEG2 and AC3 streams, which are then (multiplexed first?) authored by what? I can't afford upgrading to Vegas 6 +DVD, so I was thinking of an authoring-only tool in the sub-$100 regime - like DVD Author 1.5/1.6 with AC3 plug-in - or maybe neoDVD with AC3 plug-in (haven'theard anyone say anything about this app) - or even DVD-Lab, but that's my limit. Do I have the multiplexing part right or does the authoring app handle this?
bStro wrote on 5/9/2005, 9:41 PM
So, to get from the VOB to AVI one would most likely use...?

DVD2AVI, VirtualDUB-MPEG2, FlaskMPEG, maybe TMPGEnc(?)...

Do I have the multiplexing part right or does the authoring app handle this?

Depends on the authoring app. I assumed you were using DVDA already (whoops), which is happier if they video and audio are already separate. I think most apps would be fine with the audio and video being separated, but you should decide your workflow after you figure out what your authoring app is going to be. Or maybe your preferred workflow will influence your authoring app decision.

Rob
B_JM wrote on 5/10/2005, 6:53 AM
all the better authoring apps need the audio and video separate - they need to be anyway so the app can multiplex the streams to vobs ..

ScottW wrote on 5/10/2005, 6:57 AM
I sit corrected. Thanks for clearing that up.
johnmeyer wrote on 5/10/2005, 8:29 AM
VOB files

Straight path for reauthoring

Extracting Video from a DVD image
bStro wrote on 5/10/2005, 8:34 AM
You've got a macro for that post, don't you, John? ;-)

Rob
johnmeyer wrote on 5/10/2005, 8:42 AM
You've got a macro for that post, don't you, John? ;-)

Pretty close ...

Are you as sick of reading it as I am of posting it?? Man, I wish Sony would add a "FAQ sticky." I've helped with the FAQ at VASST, and have submitted some to Ed's site (jetdv), but ... oh well.

Now let's see, where is the button for "how do I create slow motion?" ...