Excessively long render/export times in AE
 

I'm keying a 15-second 1080i HD source clip in After Effects CS4. Effects applied to the clip are three color keys, one Keylight and a garbage matte.

This is a fifteen-second clip - and it is taking over 2 hours to render out to any file type I select (flash, Quicktime, AVI, etc). I have a quad-core 2.4Ghz machine with 4GB RAM.

That is about 20 seconds of render time per frame! Premiere CS3 can render the same size video with several effects applied in less than a minute or two.

Any ideas? This is the trial version of the software - getting ready to purchase this week, but trying to work out the bugs.

No one else experiences this? I can apply the same effects (aside from Keylight) to the exact same clips in Premiere CS3 and render it out in less than 5 minutes! Granted, the After Effects Keylight result is far better than Premiere's, but should it take 26 times longer to render that one Keylight effect????

OpenGL is disabled in AE.

OK, I've isolated the problem to the HD import format. AE doesn't like Quicktime files. I've tried exporting from Premiere in H.264 and PNG formats. Can't get AE to import HDV files at all (m2ts or mpegs).

I just tried an SD keying project using a DV AVI file, and it ran smoothly. The program crashed on rendering, however.

I haven't seen where others are having such a hard time with this, but I sure am. The output from AE looks great, but it's like pulling teeth to get the program to do it.

Keylight is a hog. My only suggetion, and oneI make for a variety of similar problems, is to precompose the clip such that the keylight effect is processed all by itself-- running the other effects either before of after. This will leave as much RAM as possible free for KL to use.
I've never had a problem with QT files coming in, but I usually have to render out uncompressed avi to avoid crashes due to compressor quirks.

Yes, this is what I do too. I import MP4 files from a Sony EX1 and key them with Keylight all the time with no problems. On occation, for a looong clip, I will use AE to do a quick import then render to change the MP4 to an Uncompressed AVI. But normally I just work with the original MP4 Quicktime file.
Anyway, I pre-render out a keyed full-rez uncompressed RGB+ALPHA AVI in one pre-comp, go do something else on another computer while it renders. When it's done, I then import that AVI into the main working comp then add/with the effects and layer under the keyed/ALPHA'ed AVI.
You could also output a PNG sequence (full-rez uncompressed RGB+ALPHA), if you need to stop and start for long renders and import it in as a PNG sequence.

I should note I work on a Dual Quad Xeon with 16GB of memory at work.

Thanks for the tips! I'm shuttling clips back and forth between Premiere and After Effects using PNG file sequences, which gets me to a workable render time. Still pretty long - an hour per minute of footage, but I can live with that for now since all of the projects I'm currently working on are less than 2 minutes long.