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a png export/import question

Posted: Tue Jul 10, 2007 9:51 pm
by moorsel
I export my animation as a png sequence. When I import this sequence in vegas, vegas asks for the properties of the media

- field order (none, upper field first, lower field first)
- pixal aspect ratio (defaults at 1)
- alpha channel (undefined, none, straight, premultiplied, premultplied (dirty)

I don't know what to enter for the first. I think I have to select the default of 1 for the pixel ratio. I am not sure what to choose for the alpha channel either (when rendering I used the default for the premultiply option, I gues this is somehow realated to this option in Vegas).

Any help is welcome, thanx in advance,

Gr,
Frank

Posted: Tue Jul 10, 2007 10:03 pm
by heyvern
Have you tried the default options? How does it look when you do this?

Fields refers to video interlacing. The default is probably okay.

Aspect ratio refers to certain video formats that don't have "square" pixels. Once again the default is probably okay... unless the Vegas project is set for something else.

The alpha channels... try them all out and see which works best. ;)
(Sorry, that is such a cop out)

Anyway, this is all guessing. Best to just try it and see.

-vern

Posted: Tue Jul 10, 2007 10:12 pm
by moorsel
Thanx for the answers, indeed the defaults seem to work best for me (at least for now). I tried to understand why. I think I can understand most of it. The premultiply stuff is still something hard to understand. I kept the defaut although I thought AS renders out premultilplied stuff (that is unless you instruct as not to do so by clicking the option).

Gr,
Frank

Posted: Wed Jul 11, 2007 4:01 am
by heyvern
I've found that "premultiply" and all those funky alpha channel options depend on the program importing the files.

There may be something I don't "get" about that aspect of the alpha, but I've had several different programs require different settings to get the same results.

It confuses me too. ;)

-vern