Alpha Channel Video Issue with Flash at DVinfo.net

Ken Barnett · September 13th, 2007, 01:54 PM

I have a stock video that I know has the alpha channel included however when I import to flash it still shows the black background. I have tried importing the .mov directly (with the conversion to FLV on the fly) and tried going to the flash video encoder to convert .mov to .flv. Of course I'm using the On2 codec with "encode alpha channel" checked every time.

You can see the video here: http://www.forkcreative.com/videos/tree.mov

Thanks for any help you can provide. If you are able to get it to work can you please email the FLA file my way, if you can your awesome!

info AT forkcreative.com

Bill Davis · September 13th, 2007, 07:56 PM

So what's SUPPOSED to be in the background?

Looks to me that the alpha knockout is doing just fine, but you haven't put anything in the background layer to show through. (To do an alpha channel composite you need TWO layers of video, a foreground and a background.)

Do you have a backgound layer and if so what does it look like?

My workflow for stuff like this is to composite any needed background and forground plates in an NLE like Final Cut Pro, then do a quicktime export of the COMPOSITED signal, so that Flash can then batch process the result for the web.

YMMV.

Ken Barnett · September 14th, 2007, 02:52 PM

Well, the whole point of alpha channel video in flash is that the background is other parts of your flash file so that was my purpose. I was expecting the video to import into flash with no black background (or other color for that matter) so the rest of my flash file would show through. Does that help?

Giroud Francois · September 14th, 2007, 03:02 PM

usually , if there is something transparent in the video, you have to specify it in the flash encoder. The only presence of the alpha is not enough if you do not say it must be transparent.

Ken Barnett · September 14th, 2007, 04:26 PM

When I convert the video form .mov to .flv I'm using the On2 vp6 codec and I check the "encode alpha channel" select box. Anything else I should be doing?

Ken Barnett · September 18th, 2007, 12:22 AM

No one has any help for me here? It would be appreciated.

September 13th, 2007, 01:54 PM	#1
Ken Barnett New Boot Join Date: Jul 2007 Location: Valencia, Ca. Posts: 5	Alpha Channel Video Issue with Flash I have a stock video that I know has the alpha channel included however when I import to flash it still shows the black background. I have tried importing the .mov directly (with the conversion to FLV on the fly) and tried going to the flash video encoder to convert .mov to .flv. Of course I'm using the On2 codec with "encode alpha channel" checked every time. You can see the video here: http://www.forkcreative.com/videos/tree.mov Thanks for any help you can provide. If you are able to get it to work can you please email the FLA file my way, if you can your awesome! info AT forkcreative.com

September 14th, 2007, 02:52 PM	#3
Ken Barnett New Boot Join Date: Jul 2007 Location: Valencia, Ca. Posts: 5	Alpha in flash Well, the whole point of alpha channel video in flash is that the background is other parts of your flash file so that was my purpose. I was expecting the video to import into flash with no black background (or other color for that matter) so the rest of my flash file would show through. Does that help?

September 14th, 2007, 04:26 PM	#5
Ken Barnett New Boot Join Date: Jul 2007 Location: Valencia, Ca. Posts: 5	specifying it in the encoder When I convert the video form .mov to .flv I'm using the On2 vp6 codec and I check the "encode alpha channel" select box. Anything else I should be doing?

September 13th, 2007, 07:56 PM	#2
Bill Davis Trustee Join Date: Jan 2004 Location: Scottsdale, AZ 85260 Posts: 1,538	So what's SUPPOSED to be in the background? Looks to me that the alpha knockout is doing just fine, but you haven't put anything in the background layer to show through. (To do an alpha channel composite you need TWO layers of video, a foreground and a background.) Do you have a backgound layer and if so what does it look like? My workflow for stuff like this is to composite any needed background and forground plates in an NLE like Final Cut Pro, then do a quicktime export of the COMPOSITED signal, so that Flash can then batch process the result for the web. YMMV.

September 14th, 2007, 03:02 PM	#4
Giroud Francois Inner Circle Join Date: Feb 2004 Location: switzerland Posts: 2,133	usually , if there is something transparent in the video, you have to specify it in the flash encoder. The only presence of the alpha is not enough if you do not say it must be transparent.

September 18th, 2007, 12:22 AM	#6
Ken Barnett New Boot Join Date: Jul 2007 Location: Valencia, Ca. Posts: 5	No one has any help for me here? It would be appreciated.