DVD Render Workflow Questions

[Mike Prendergast]

I’m trying to get the best possible quality for dvd and blu-ray production from my project and wonder if anyone can offer some advice on my questions.

Here is a list of my questions and they are explained with details below:
Why is DVDA compressing the video and audio?
Should I do something different in the DVD Render Workflow?
Should the Pixel Aspect Ratio for the DVD render be 1.212 or 1.0?

Vegas Pro 11 Project Info: 1920x1080 59.94p for video files and project settings. The project is 1 hr 4 min.

DVD Render Workflow

1) Render HD master from Vegas project timeline (1920x1080 30p, lagarith avi file)

2) Resize HD master (1920x1080) to SD master (720x405, 30p lagarith avi) in VirtualDub using Lanczos3 algorithm.

3) Compress SD master to MPEG-2. Start Vegas project and match properties to output file in step 2.
Render with DVD widescreen 16:9 NTSC template.
a) Change to 720x480 in project settings
b) Render as DVD widescreen 16:9 NTSC template (.mpg)
c) PAR = 1.0
d) render quality = best

4) Create audio render of SD Master
Dolby Digital AC-3 Studio
Audio: 192 Kbps, 48,000 Hz, Stereo, Automatic Gain Control off.
Use this setting for stereo DVD soundtracks.
Audio: 192 Kbps, 48,000 Hz, 24 Bit, Stereo, AC3


When I use the DVD workflow above, DVD Architect Pro 6 gives the following messages:

"The video on track 2 will be compressed.
The audio on track 1 of 'myvideo' will be compressed.
The end action of 'myvideo' uses the most recent menu command before a menu is reached. It will link to the top menu or stop if no menus.
The remote button action of 'myvideo' uses the most recent menu command before a menu is reached. It will link to the top menu or stop if no menus."

Why is DVDA compressing the video and audio? I thought the purpose of creating an MPEG-2 render (step 3 below) was to compress and properly format the video for DVD creation. I’m I missing something in the workflow steps?

The video output file from step 3 is .mpg. The audio output from DVD step 4 is .ac3

For step 3c the vegas render template has the PAR = 16:9 (1.212). Should this remain at this setting? I changed it to Square (1.0).

<see dvd_PAR1.png>

DVDA settings
after making vegas render from dvd template .mpg DVDA gives warning that video is non-compliant for dvd standard.

<see DVDA message.png>

[Juris Lielpeteris]

http://download.sonymediasoftware.co...manual_enu.pdf
Pages 193-197

[Gerald Webb]

You are messed up with your PAR Mike.
1080p out of vegas,
Down res in V dub to square pixel version of your PAR of your final mpeg,
So, 1.212 x 720 = 872.64. You will need to tweak this a little to accommodate any pillar/letter boxing that occurs, eg For PAL we change from 720 to 704.
Then drop your 872 x 480 avi into a new NTSC DVD vegas project (DVD Architect widescreen template, dont change PAR) and compress to m2v .

[Mike Prendergast]

Gerald, Thanks for the reply. I'm a little confused. For this step of mine:

2) Resize HD master (1920x1080) to SD master (720x405, 30p lagarith avi) in VirtualDub using Lanczos3 algorithm.

Are you saying I should do this:

2) Resize HD master (1920x1080) to SD master (872x480, 30p lagarith avi) in VirtualDub using Lanczos3 algorithm.

[Gerald Webb]

Thats it Mike.
Then drop that into your ntsc dvd Vegas project.

[Mike Prendergast]

OK thanks.

[Juris Lielpeteris]

SD master (872x480, 30p lagarith avi) in VirtualDub using Lanczos3 algorithm)

And it will be resized in Vegas once again...
You must resize according to DVD Standarts 720(704)x480@30i, 720(704)x480@24p or 720(704)x576@25i

[Gerald Webb]

Fair enough Juris,
but,
Its not resizing in Vegas when converting to m2v, just doing a pixel aspect conversion from square to non square.
I always like to stay in square pixels right through to the final compression. IMO ( and others) It just maintains more quality through the process. Andrew Kramer from Video Copilot mentions this in a few tutorials.
As always, YMMV. If you cant notice the difference, dont do it. Just resize in Vegas (its quite good anyway).
Why would you want to make your nice Progressive footage interlaced? If the DVD player cant display true Progressive footage it will add its own interlacing anyway. I cant imagine why you would add it in yourself. Is there a reason why you would?

[Mike Prendergast]

Originally Posted by Juris Lielpeteris

And it will be resized in Vegas once again...
You must resize according to DVD Standarts 720(704)x480@30i, 720(704)x480@24p or 720(704)x576@25i

Juris, Can you help me understand this?

What should i resize to in VirtualDub? 720x480 or 704x480?
Is it better to stay progressive and go to 24p? Or use 30i
For 24p and 30i, when is that change made in VirtualDub or in Vegas during the MPEG render?

[Juris Lielpeteris]

I'm from PAL-land and use only 25i.
Diference betveen 704 and 720 is in the aspect ratio - 704 contains only active part of a scan line, 720 must contain place for the blanking impulses. I don't know correct pixel aspect ratio for NTSC DVD. In PAL it is 1.4545 for 704x576 and 1,4568 for 720x576.
In result, 704x576 have frame aspect ratio exactly 16:9, 720x576 is small wider. When playing DVD on a consumer player, picture must look exactly the same.

[Chris Hewitt]

I've been using the standard default DVDArch widescreen Pal DVD template in Vegas 11 for 720P/50 footage but changing 'deinterlacing' to 'None'. The default bitrate settings are giving me rendered files that quickly fill up a single-layer DVD, about 90 minutes max.and I find that I'm having to split to two discs per wedding.
I'm ending up with a total of about 6gb for the disc on average.
I don't want to use dual layer discs as they are a lot more expensive and I need to keep my costs down.

I'm wondering what bitrate people are using when not using the default settings, mainly for max and average bitrate settings.

[Mike Kujbida]

Originally Posted by Chris Hewitt

I'm wondering what bitrate people are using when not using the default settings, mainly for max and average bitrate settings.

Chris, I never use the default settings. If my program is 70 min. or less, I use a custom CBR of 8,000,000
Anything longer and I use Mark's bitrate calculator to determine a custom VBR setting. I always render these using 2 pass mode.
You can download it at http://www.johncline.com/bitcalc110.zip
I change the Safety margin to 5% (default is 1%) and click the "1 kilobit = 1000 bits" options found by pressing "Settings" on the main screen.

To answer your question, for a 90 min. DVD I would use custom VBR settings as follows:
7,904,000 / 6,320,000 / 3,792,000
This assumes a default AC3 setting of 192 kb/s (the Vegas default) and a very basic menu.

[Peter Riding]

I don't want to use dual layer discs as they are a lot more expensive and I need to keep my costs down

Chris, I've been using these Verbatim dual layer discs for ages without any problems:

http://www.amazon.co.uk/gp/product/B...?ie=UTF8&psc=1

At just £20 for 25 they are very affordable whilst also being a reliable brand. It stops me having to mess around with bit rate calculators or lowish variable bit rates.

I always do my PAL DVDs at a constant bit rate of 8,000. I do a separate AC3 audio file (makes a big file size saving) and bring them together in DVD Architect Pro.

I've just rendered a DVD which is 89 minutes long. Its total size is 5.39gb (5,788,552,852 as reported in Windows properties), so plenty of space for shows up to a little over 2 hours.

I'm not sure going via Virtual Dub etc is really necessary any more as recent editions of Vegas have made a good job of downsampling (I'm using AVCHD 1920x1080 progressive files).

Pete