Slow Rendering?

JasonMurray wrote on 8/15/2004, 4:28 PM
Hi everyone,

I'm an Encore user, but I got the Vegas5+DVDA2 bundle at the Aussie VASST training last week, so I decided to use it for my DVD creation and burning on the weekend.

Because of the issues I've had with rendering MPA/M2V streams out of the current version of Vegas, I left it at rendering a PAL DV AVI, and allowing DVDA to convert the video as it saw fit.

The DVD contained one menu page with two options - one, a 3-4 minute music video and the other a 6 minute video with no sound. As such there was no problem fitting the video onto the disc.

Imagine my surprise when I found that DVDA wanted around 40 minutes to render the video...! By this time I was running horribly late, so I ended up just feeding the AVIs to Encore (which made short work of the conversion) and whipping up the menu in Photoshop. End result, DVD burned and I was out of the house in about 20 minutes.

Has anyone experienced similar differences in DVDA's rendering time? Is the quality noticeably better, or is something amiss?

Jason

Comments

bStro wrote on 8/15/2004, 9:45 PM
Curious. I tried to duplicate your situation, so I created a 6 minute PAL video without audio and a 4 minute PAL video with audio. Rendered them to PAL AVIs and brought them into a new PAL project in DVDA. Total render and prepare time was 25 minutes. I didn't burn a disc.

Then I went back to Vegas, brought back the AVIs, and rendered from there. Render times were as follows:

4 minute PAL - video: 5:26
4 minute PAL - audio: 0:42
6 minute PAL - video: 7:01
---------------------------------
Total: 13:09

Brought these into DVDA, and total prepare time was 1:13. (Probably would've taken less, but it had to "render" the empty audio for the 6 minute video.)

So, rendering in DVDA took almost twice as long. Which is why I pretty much never render in DVDA (other than menus). I've heard that rendering in DVDA was slower, but I didn't think it was that much slower.

Rob
JasonMurray wrote on 8/15/2004, 10:48 PM
I suppose the question then becomes - did we do anything wrong?

Or, is DVDA's output of substantially higher quality?
bStro wrote on 8/16/2004, 7:14 AM
One thing that may be of note is that I think DVDA encodes at Constant Bitrate, and the default is 8MB/s, at that. On the other hand, the DVD Architect Video Stream templates in Vegas are set for Variable Bitrate (Max of 8MBs...I forget what the Min and Average are). So, you may be right, DVDA is probably encoding at a higher (or at least, more consistent) quality.

Problem is, such a high CBR isn't always necessary, and, unlike Vegas, DVDA doesn't give you much control over the encode settings. You can lower the bitrate, but I'm pretty sure it's always going to be CBR. (Anyone? Anyone?)

Come to think, my test probably wasn't fair. Since I don't have any PAL videos around, I made a couple really quick...with static text. So VBR probably had a major speed advantage there. Whoopsie. [grin]

I dunno, does the bitrate at which something is encoded have an effect on how fast the encode actually goes?

Rob
JasonMurray wrote on 8/16/2004, 4:32 PM
CBR should take less time to encode, since it only requires one pass over the original media.

VBR should take longer as it'll require (at least) two passes. Therefore, Vegas should be taking longer if your assumption is correct.

I'm pretty sure DVDA does VBR encoding, though...

Anyone else got any thoughts on what's happening here?
bStro wrote on 8/16/2004, 6:40 PM
Hmn?

VBR doesn't require two passes unless you choose two-pass encoding. The default in Vegas is regular "one pass."

I'm pretty sure DVDA does VBR encoding, though...

Based on? :)

Rob
JasonMurray wrote on 8/16/2004, 8:42 PM
Based on the fact that I thought I saw "V" "B" and "R" in close proximity to each other during the VASST training. :)

Anyway, I didn't realise that VBR can be done in a single pass - I thought all VBR was two-or-more passes :)

And we're STILL no closer to figuring out why DVDA takes an eternity to render... :\