Problem exporting Alpha channels from AE
 

Can anyone give an example of a workflow using PHD exporting alpha channels from AE.

I have imported green screen ftg. into after effects then use keylight,

render ...then export as Cineform AVI using cineform encoder.

Other settings are RGB+alpha,Millions of colors +,premultiplied.

When I import into ppro cs4 I get footage with black matte, no alpha

got stung with that today...5 hours of rendering down the tubes

you have to click format options beside the video output options if you are using the cineform avi preset...there you will see a checkbox for enable alpha channel....which is disabled by default

I saw that but it's greyed out.Ended up just going with microsoft avi which defeats the purpose...but it was a time issue

When I make titles in AE, I've had to export from AE using Quicktime with mill of color + which does give an alpha channel. Using Prospect hd.

I''m using CS3 so if I'm using a Cineform preset and import the quick time title, it works on track two with appropriate transparancy. In order to get it to play back from the time line, I have to hit CNTL-spacebar (per Jake Sagraves).

Here's a thread about this. Check out posts 7,8, 9.

http://www.dvinfo.net/forum/cineform...-cineform.html

If you have a better way to do the alpha channel, please let me know.
John Rich

Wait! What? ProspectHD supports alpha channel???

I am using Prospect HD. But in AE when I go to render... under the output...format options ...in the cineform box my alpha channel option is grey. I can export a mov or avi with alpha fine. But when I import from ppro cs4 timeline I want to send it back as cineform...same way it came in.

Cineform avi imported to ppro timeline ,export to AE from timeline and key greenscreen using keylight...then render and export as cineform avi is my goal.

Like I said my alpha option in the cineform box is greyed out. I think that's my problem

Maybe I'm out to lunch on this, but I don't believe the CFHD codec that ships with ProspectHD had ever provided any alpha channel support.

I guess in AE, the output option under cineform controls for alpha, is greyed out for future use. Makes no sense to me. Unless the greyed out box is on my end

As the link I mentioned above, Dave Neuman says that Cineform doesn't support an alpha channel except in the high end products (not Prospect HD). That's why I have to export something out of AE that requires an alpha channel, as Quicktime. I can then reimport the quicktime clip back into premiere (CS3 in my case).

John Rich

I'm doing the same here. I did read the thread. Although I would think Prospect would be included in the "high end" versions of cineform...guess not.Thank you!

it's not greyed out on my end....
Prospect4K though...