Preview quality affecting render quality?

Gior wrote on 6/19/2011, 6:59 AM
Dear all,

I use Vegas Movie Studio HD Platinum 11.
Today I rendered a short clip (30 sec), based on standard DV material, using the Blue-Ray template 1920x1080 50i (sony avc). I wanted to evaluate the feasibility to "upscale" a DV-based movie approx 1 hour long, getting an idea of the time required with my PC.
In the template window there is the possibility to select the quality of the preview shown in the main Project window. I selected "draft" thinking to drive the CPU effort mostly in the rendering, thus shortening the required time.
The result was a movie full of artifacts, a lot worse than the one I would get with a "traditional" DVD quality.
I eventually selected "good - full" for the preview quality in the template and I repeated the process, keeping the same parameters as before.
This time I got a very good result as expected. So in this very moment I am rendering the whole movie in this way (it will take approx 6 hours).
While I am waiting, here is my doubt: is really preview quality affecting render quality? This seems strange to me, maybe I made some other mistake.
Can you please let me know your idea?
Gianpaolo

Comments

Steve Grisetti wrote on 6/19/2011, 10:07 AM
Preview quality has nothing to do with your output. It is, as you'd expect, just the quality of view in the Preview window. The advantage of setting is low is that your computer puts less power into creating a nice preview and more into actually processing the video. But how it looks in the Preview window has nothing to do with how the actual video will output. (Preview quality DOES affect the quality of a still frame snapshot from a video -- but that's an entirely different subject.)

Upscaling video from DV to hi-def is probably not a good idea. You're essentially telling the computer to create pixels -- four times as many pixels as the original video. So it's not going to make a hi-def video. It's just going to make a bigger, fuzzier video. And it's going to take many times render it.

In fact, most disc players have very nice upscaling software built into them. This will make your DVD video look almost as good as high-def.

But, if you give it a bad-looking high-def video, you're just side-stepping this feature so, for all of your time and effort, it's going to look worse than if you'd have just left it at standard-def video and let the disc player do the upscaling.
Gior wrote on 6/20/2011, 2:00 PM
Thanks Steve, I understand and agree with what you say.
I tried that solution because I was not so happy with the "normal" DVD template (PAL, 16:9), that uses main-concept encoder.
I only modified the bitrate, setting it constant at 9 Mbps.
The result was a mpeg-2 file which seems to me a bit "poor" (too many artifacts during motion) and (in one case) with fuzzy pixels spoiling the image. Too poor considering the bitrate.
So I was in doubt between upscaling (which actually makes no sense) and keeping a mpeg-2 file I don't feel happy with...
So I ask again for suggestions, this time for mpeg2 encoding...
Thanks
GP
PS: the result of the encoding with AVC is however good, better than the mpeg2 file, but it required hours and for sure I will not repeat the experience!
Steve Grisetti wrote on 6/20/2011, 2:11 PM
You're not still trying to make hi-def video out of standard-definition video, are you, Gior?

That's the part I was most concerned about. There's just no successful way to do this.
Gior wrote on 6/20/2011, 11:25 PM
No, Steve, I'm not trying that. I'm aware of what you say.
I was not satisfied with the MPEG2 result and I tried that other way just as a workaround.
The actual point is that - to me - the file encoded in mpeg-2 is not so good as I expected (some spoiled images and too many artifacts near moving objects/people).
Since I encoded at constant bitrate of 9 Mbps, I expected something more (compared to other experiences).
On the other hand, I'm new to Vegas 11 (which I like a lot), and so I would like to now if there is some specific in the settings of the DVD template I have to do, based on others experience.
Thanks again
Gior