Vegas DV codec - Chroma Smoothing?

BarryGreen wrote on 12/14/2003, 4:39 PM
I was doing some up-rez tests, exporting DV files from Vegas and up-rezzing using S-Spline Pro.

Vegas (apparently?) does no sort of chroma filtering, smoothing, or interpolation on the 4:1:1 color data, so there were lots of stair-step sharp edges in the output. Other codecs, like Matrox's, offer options in how they decode -- specifically there are options for "Filtering RGB -> YUV" and "Interpolation -> RGB". Selecting those options made a HUGE difference in smoothing edges, very useful for up-rezzing or perhaps chroma keying.

You can see an example of the up-rezzed output, comparing the results from a Vegas export against the results from a Matrox export, here:
http://www.icexpo.com/dvx100/CodecCompare.JPG

Does Vegas provide for any similar control over their DV codec? If so, how? And if not, can we get those features added for the next release?

Comments

pelladon wrote on 12/14/2003, 6:45 PM
No, AFAIK, Vegas does not. I agree that it should have chroma smoothing.

Even Virtualdub provides some chroma smoothing. A simple plug-in would work though, don't need to go to a new version for that.
PeterWright wrote on 12/14/2003, 8:44 PM
Interesting - the link below is to a recent comparison between Premiere Pro, FCP, Avid DV Express, Pinnacle Liquid Edition and Vegas 4.

Vegas came out top in the Chroma keying tests.

http://www.emedialive.com/Articles/ReadArticle.aspx?ArticleID=8066
snicholshms wrote on 12/14/2003, 10:05 PM
Vegas provides a lot of control on Chroma Keying.
craftech wrote on 12/15/2003, 3:12 AM
He said Chroma Smoothing not Chroma Keying.
I add a little blur to get rid of it.

John
Spot|DSE wrote on 12/15/2003, 7:26 AM
1. Thank heaven there is no chroma, luma, or stabilization attached to the codec. There shouldn't be. I surely don't want Vegas (or any other NLE) touching my media in ANY way unless I tell it to. It's a codec, not a process.
2. There are several tools that may be used to smooth chroma, and when applied, resampling will take place, and a new file results whether it's a temp file from a pre-render or a complete file as rendered. Take your screen shots from those.
Also, when using saved preview stills, are you saving as a jpg or a png. That's a huge factor in the scaling of the image and must be taken into consideration.
If you capture something from a cam or live source, Vegas does nothing to that file in any manner, until you apply a filter, title, or other edit process.
Which is exactly how it should be.
pelladon wrote on 12/15/2003, 8:30 AM
Whoa there,

Something like chroma smoothing is really a filtering operation, not something to be integrated within the DV codec. I don't think BarryGreen meant to CHANGE the DV codec, just add a option to allow this (eg. filter plug-in).
Spot|DSE wrote on 12/15/2003, 8:54 AM
It's already there. While it's not the same name, chroma smoothing is effectively just a color blur. In fact, in FCP it's called exactly that. Deartificating, chroma blur, chroma smoothing.....it's all the same basic thing with various methods of doing it. Adam Wilt wrote a great script for doing this in FCP as well, because he felt their 'brand' of chroma smoothing wasn't good enough. As I said, this is a filter process, but the first line in the post is that the CODEC doesn't allow for this. That can get newbie's and others fairly confused very quickly.
Smooth=blur
Spot|DSE wrote on 12/15/2003, 10:51 AM
BTW, for giggles, try this plug for Vegas.
http://mikecrash.wz.cz/vegas/vegas.htm
BarryGreen wrote on 12/15/2003, 1:15 PM
Whoa, Spot -- I agree with you on all counts, of course the codec should be as transparent as possible. But in my initial post, what I was asking was: Matrox allows for the OPTION, does Vegas provide a similar option? And as far as I know, that option is integrated into the Matrox codec itself, which was why I was asking if the Vegas codec did similarly.

With that said, if you look at the picture I posted, there's obviously room for improvement in how a DV image can be rendered for still shots, computer graphics, or up-rezzing. Matrox's codec does it nicely, as does Avid's. I just would prefer to do it all within Vegas instead of having to switch programs and render out from Premiere.

So what I'm hearing is that if I were to use some sort of color blur I should be able to get comparable results, which would be great. I saw Adam Wilt's script but unfortunately it's only on FCP. Which Vegas filter would provide for blurring only chroma but not the luminance channel?

I'll also give that guy's plug-in a try and see how that works.

Thanks!
Matt_Iserman wrote on 12/15/2003, 9:15 PM
For giggles? I don't think so. That plug-in is great. I had some underlit footage, which I boosted up with the HSL plug. There was a lot of grain as a result. I applied the plug-in to which you posted a link and, wow, it looks wonderful (relatively speaking, of course).

What other gems are floating around the Internet?

Thanks for the link, Spot.
BillyBoy wrote on 12/15/2003, 9:44 PM
I tired it too. Its useful in certain situations. You may even want to try it in combination with sharpen. That on the surface may sound like a dumb idea. It isn't. The plug-in chain applies FX filters in the order they appear in the chain, so they do NOT cancel each other out. So at times using a smoother followed by a little sharpening or the other way around it better than either alone.