Garbage mattes do not retain alpha when saved with animation codec?

Question

Garbage mattes do not retain alpha when saved with animation codec?

Hello all,

I am exporting video with an alpha channel to be used in a flash piece. I am exporting using quicktime conversion and animation codec with millions+ colors and everything works fine until I apply a garbage matte. Am I doing anything wrong? (just making sure)

Thanks a million.

Ben

17" Powerbook, Mac OS X (10.4.3)

Posted on Sep 25, 2007 7:50 PM

Reply

Answer 1

Leigh J

Level 1

115 points

Sep 26, 2007 8:51 AM in response to MultiMedia_Reed

I'm a little confused. When are you applying the garbage matte. Before you export to the animation codec? Or are you exporting it, bringing it back in, then applying the garbage matte?

Leigh

Reply

Answer 2

James M.

Level 4

1,977 points

Sep 26, 2007 9:02 AM in response to MultiMedia_Reed

You might need to explain what you are doing step-by-step, and what you want to achieve, as your question is a little confusing.

Reply

Answer 3

Sep 26, 2007 9:50 AM in response to James M.

Fair enough - thanks for responding. I am applying a 4 point garbage mask to my clip, then a key filter, then exporting with the quicktime converter as animation codec with millions+ color to preserve the alpha. Then I take that quicktime file, encode it as flash video (On2 Vp6, with alpha channel encoded) and import it into an .fla. When the garbage matte is present, there is no alpha. When I turn off the garbage matte, everything is perfect.

What I am trying to do is confirm that there isn't anything else I should have done to make the garbage matte work in that scenario. (primarily for my sanity)

Thanks and let me know if this helps.

Reply

Answer 4

Leigh J

Level 1

115 points

Sep 26, 2007 10:00 AM in response to MultiMedia_Reed

I would check to make sure that the alpha is being preserved. I've exported with a garbage matte and have not had a problem with retaining the alpha. Try bringing the exported clip back into FinalCut just to make sure the alpha is actually there.

Reply

Answer 5

Sep 26, 2007 10:25 AM in response to Leigh J

Are you perhaps rendering the sequence before exporting? That will flatten the layers against an empty background without the alpha.

However, the key filter is probably killing your alpha. FCP's alpha handling is weirdly unconventional and we've been screaming about it for many years. Alpha that are created in one filter are often overridden or disregarded by another. It's lame.

You may need to insert a nest operation between the matte and the keyer.

bogiesan

Reply