I'm trying to get an Alpha Matte out of AE to use in FCP.
It needs to be DV PAL, lower field first. So I've set that up, then checked alpha only in the render options. I'm left with a black and white quicktime. Nice.
The problem comes when I try to set it up as an alpha matte in FCP. It's just not recognising the alpha channel at all (no checkerboards in the background when I double click the clip - just black). So when I set it up in the timeline and change the blending mode with some video underneath as the manual suggests, nothing happens.
I'm sure I followed the exact steps a while ago with success, so I'm stumped this time - I can't see how I can do anything differently. I'm definitely not leaving a solid or anything at the bottom of the stack in AE, and changing the alpha option to straight/black/white doesn't work in FCP (it defaults to non/ignore).
Are you trying to make a matte layer for export? or actually export a file with an alpha channel? If the latter, then as Rafael says that's not possible with DV. Animation is the codec to use. If the former, put a white color matte on the top layer and apply travel matte alpha to it. When you export that you will have a black and white video that can be used as as matte track for transparency.
All the best,
Class on Demand DVDs "Complete Training for FCP6," "Basic Training for FCS2" and "Final Cut Express Made Easy"
Author: "Final Cut Pro 5 Editing Essentials" and "Final Cut Express 4 Editing Workshop"
beside the other comments:
(I'm also not sure what you want)
If you want FCP to recognize the file as alpha, you need a normal layer as well. What you are doing now is making a QT that is flagged as video, not as alpha.