render quality

barrybass wrote on 4/20/2004, 4:55 PM

I have a piece of uncompressed .avi video that I'm rendering from Vegas 4.0. After rendering in NTSC DV .avi format, I compare the original and the rendered video and the rendered has suffered quality loss in the rendering process. I've talked to tech support and they don't have an answer. Anybody have any ideas?

Comments

Rain Mooder wrote on 4/20/2004, 5:04 PM

Avoid rendering to DV format or using any compression at all.
As long as you keep it uncompressed there won't be any problems.

You may have trouble figuring out how to explort your video to
any media like tape or DVD because all of those forms involve
some form of compression.

rmack350 wrote on 4/20/2004, 5:21 PM

Rendering from uncompressed to DV always involves a loss in quality because DV is compressed and is only a 4:1:1 sample. Uncompressed is a 4:4:4 sample.

But maybe you're seeing something more drastic than that?

Rob Mack

barrybass wrote on 4/20/2004, 5:42 PM

I've tried every format, including completely uncompressed .avi and I'm still getting fuzzier edges on my text and a general loss of quality from the original. I don't understand how rendering from uncompressed .avi to uncompressed .avi is causing any quality loss at all.

barrybass wrote on 4/20/2004, 5:43 PM

Actually, I've tried rendering as uncompressed .avi and it also suffers quality loss such as fuzzy edges on my text, etc. It's an obvious quality degeneration when compared to the original. Any further ideas?

rmack350 wrote on 4/20/2004, 5:49 PM

Yeah. Uncompressed to uncompressed should be a straight copy exept for effects.

Rob

rmack350 wrote on 4/20/2004, 5:56 PM

How are you viewing the result?

If on an external monitor, set the internal preview to "Full"- not "Auto"

If the internal preview window is at half size or less and set to auto then the image sent to the external monitor is also at half size and then scaled up. It looks bad no matter what you do. Internal preview needs to be set to full when using the external preview.

Does that help?

Rob

kentwolf wrote on 4/20/2004, 6:24 PM

>>...If on an external monitor, set the internal preview to "Full"- not "Auto"

Man, that one got me on stills!!!

I felt really dumb once I realized that the quality setting also affected external monitor quality too.

rmack350 wrote on 4/20/2004, 6:35 PM

Yep. It still gets me and I know to look for it!

Rob

db wrote on 4/20/2004, 7:25 PM

you should not see any difference between the Vegas generated text and the uncompressed clip ..
now if you have your project properties set up using a DV template then when you "render as" you should NOT be using the uncompressed template .. you should render as -choose the dv template then go into CUSTOM -Video - now go to video format and choose UNCOMPRESSED from the pull down window ..
if you have the project set up as 640x480 then do use the "render as" uncompressed template ...

NOW as R mack has stated when you view the results you need to have the V preview window set to FULL (preview,good,best).. to really see/test it use BEST FULL ... also you want to view it on the scopes ...
for your test- render out a few seconds of SMPTE color bars so you have more to compare on the scopes ( waveform and vectorscope) ..compare the uncompressed rendered Bar clip to the generated bars along with your text .. a weakness in DV25 is TEXT especially text with color ...