Video w/ alpha channel
Out of context: Reply #7
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- fyoucher10
First, is your 'sequence' in a timeline like After Effects where it's a composite of objects like images, text, etc? Or is it a 3D render of some sort with a matte that you can use to create the alpha channel?
If you're in AE, and the background is transparent, just render out the comp as either an AVI, Quicktime, or FLV (if you're using it in Flash Player. For Quicktime, you can use the Animation codec or None set to 32bit (I believe they call it 'Millions of Colors +"). I think it's the same way for AVI, make sure it's uncompressed / 32 bit. There's probably a dropdown for the alpha channel where it asks if you want to use Straight or Matted which would depend on your footage.
After you do that, if you open up the video in QT Player, you probably 'will' see a black background. Just open up the info inspector (Command + I) and double check that there's an alpha channel in there...or re-import it into AE check.
Now, if you don't have any transparency in your comp and it's all just flattened rectangular imagery and you want to actually create transparency, you'd need an alpha/track matte (i.e. if you received a 3D render from someone, they'd supply this likely as a video or PNG/TIF image sequence)...or you'll need to do some good ole' rotoscoping...