Video w/ alpha channel
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- ********
- How do I create a RGBA based video with alpha channel?
- What file format should I export that as?
- Douglas0
prores4444 supports alpha.
otherwise, animation compression or tif sequence.- will need to render out of AE.Douglas
- indeed! i usually go with animation codec, since it's default :-xmcmillions
- PNG is great, too. Smaller than animation, lossless. Usually plays smoother. ProRes 4444 doesn't work with everything.Chief
- Yolo0
option in Output Module settings in AE on channels dropdown
- mcmillions0
is this for streaming/web purposes though? i could have sworn flv can handle an alpha channel if i'm not mistaken.
- ********0
no, its not web purpose and it wont play in movie player.
- ********0
First question is how to compose a sequence that has alpha.
I based the animation with black bg and when I take that out, I see nothing. Its a solid layer with black bg.
- ephix0
post screenshots
- 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...
- ********0
Thanks fyoucher1. I will try that.
- ********0
short answer is render as a png or tif sequence or as RGBA (don't forget the A) uncompressed render. Also you probably realize this but don't actually put a layer as your background. There's a little 'show alpha' button at the bottom of the preview screen if you want to make sure your comp does in fact have transparent areas.
- Hombre_Lobo0
^like he said,
an image sequence is usually the simpler, more choice, but you can export quicktime mov's with alpha channels easily enough.
just make sure the software you import the mov into supports it and interprets it correctly.
- the simpler, more choice, is that the queens english?ephix