Greenscreen alphachannel export problems/FLV

[MarkNorway]

Hey!
I have recorded a greenscreenfootage i FULL HD size... i only need an output in .flv on 200 x 200 px
I use finalcut pro7 and Motion for/primate for keying. exellent plugin. First i tried Keylight in After Effects but with a result which wasnt acceptable. i managed with no problems to export this and there after convert it to .flv

But then i foung the plugin in Motion. It will be hard for meg to go back to AE when the result is far from the one i have now. BUT.. there is a but.

When i have keyed it out in Motion i have to send it back to FCP for some colorgrading and then export it with current setting to a .mov file. This works fine (i have tested it back in FCP that the alphachannel is working fine in the exported file by place it in the timeline and put a picture back. the greenscreen so far is though exported right.

So when i then go to Adobe Media Encoder the problems start.

When i try to crop i cant get the right aspects AND size/output. Even if the aspect is right in the source pane the aspects in the output pane is wrong and when i choose "change output size" the possibillity for changing size in the low right cornoer greys out.

Can any one help?

[MarkNorway]

another screen which shows the resize possibillity greys out...

[poisondeathray]

It's greyed out because you have "change output size" selected

There should be no change in AR. It should be 1:1 square pixel for a 1920x1080 source

Just crop to where you want to, leaving a 200x200 dimension. No need to resize.

If you insist on crop + resize, it has to be proportional. e.g. crop to 100x100 => resized to 200x200 (so you increase width and height doubled each). This is because the source consists of 1:1 pixels. If you don't do this the final image will be distorted from the original AR. (e.g. if you increase the height 3x, but the width 2x only)

Why don't you export from FCP instead of AME? not sure why you're doing all these steps?

[MarkNorway]

Hey thanks for reply!!
I "insist" on resize because as yousee from the first screendump, the area i want to crop i 900x900 (aprx.) and i want the output to be 200x200. Thats why i choose "change output size". Maybe i shouldnt? The dimension on the .mov i have exported is 1920 × 1080 so its strange it changes the aspect when i want to export in 200x200 (does it every time i shift to outputpane and choose "change output size"

For me its very starnge that even is i have cropped proportionally the output size look to me that it changes the aspect, since my cropped ared i 900x900 and below this its printed that the output size will be around 1200x900.. strange... im a little newbie in this...

I didnt know i could resize, crop and export to .flv format directyly from FCP?

[poisondeathray]

Ok, sorry now I see what you're doing and I see the problem.

In AME, "change output size" definitely greys out the resize. Try "scale to fit" then 200x200 in the resize video option. If your original remaining crop box was same dimensions (width=height), the aspect ratio should come out right. I'm not a fan of AME's resizing because it uses a very soft (probably bilinear) algorithm

I would personally do everything in after effects. Easier to do everything from crop , resize ,keying. I have the primate keyer for AE. I find keylight better for most sources. If you want better scaling and algorithms, you could do part of the manipulation in avisynth (but hard to access on MAC)

I don't use MAC, so I don't know if you can do that in FCP, but I would assume you could (instead of using so many programs)

[poisondeathray]

Have a look at the quality difference:

These were done losslessly (either though .png or .bmp images). So the only thing we are comparing is the crop and resize algorithms (lanzosresize for avisynth)

crop


crop+resize

[MarkNorway]

ok primatte in AE sounds great! but now i have the primatte for motion 4... off course i can use some buck for the primatte for AE..

But back to my problems... i could try to get better keying in AE with keylight but i really have to admit that skintone and fringe of green... i couldnt get rid of it in keylight while primatte just throwed it away...

Maybe you can giv me some tips there...?

[poisondeathray]

ok primatte in AE sounds great! but now i have the primatte for motion 4... off course i can use some buck for the primatte for AE..

But back to my problems... i could try to get better keying in AE with keylight but i really have to admit that skintone and fringe of green... i couldnt get rid of it in keylight while primatte just throwed it away...

Maybe you can giv me some tips there...?

What do you mean specifically? Do you mean spill? ie. green spill from reflected light off the green screen? keylight has a spill supressor. You have to play with lots of the options to get better keys from keylight. It's harder to use, but gives better results in the end IMHO. Have a look at the manual for some of the basics.

Also, I'm far from an expert on keying ; I only know the basics - I'm pretty new to keying as well. You would find better advice on creativecow.net forums or videocopilot.net forums or even adobe forums - there are better experts at those sites.