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Black Frame Flashes on Export with Alphas
So it looks like this has been asked numerous times, with no answers. That said, it hasn’t been asked for awhile so maybe there’s a solution now.
I’ve keyed out green screen on about 200 clips, and on export there are random black flash frames that show up. They sometimes appear when re rendering, and sometimes they don’t (more often than not they still do). This has effected about 80 % of the files at this point and was looking for some reason it’s happening and how to fix it.
Footage was shot HD, and dropped onto drive at 1920 x 1080 Apple Pro Res HQ. I went through and pulled takes, and exported through compressor. Exported clips out as 1920 x 1080 Animation (alphas were turned on during export, but we’ve experimented with having them correctly turned off on export to no avail). At this point they were pulled into AF, keyed and exported back out at 1280 x 720 Animations with pre multiplied alphas.
I’ve got a decent handle on this stuff, and the person helping with it is very knowledgeable, and both of us are left scratching our heads.
Does anyone has suggestions….or solutions would be even better! Thanks!
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3 Replies
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Dave is right- also, why export from AE with alpha? AE is a compositing program and you should do the compositing in there where you have a lot more control and then export the final piece without need for alpha.
Tudor “Ted” Jelescu
Senior VFX Artist
Bucharest, Romania
http://www.ennstudio.ro -
Dave, thanks for editing your original response.
Back to the question at hand, from the delivered source files they were Pro Res HD. That’s what it says when I did what you asked. They were shot on a EX-3 4:2:2 1080p, and again from the production company “Pro Res HD codec”
I’ll try checking the things you suggested. Yes, I didn’t need to export the original files out of FC with Alpha’s since there wasn’t any, but I do need to keep the alpha channels from AF.
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The original files were exported out from FC as Animation codec after clip selection. Those were pulled into AF for keying. After keying they were re-exported as animation, and resized form 1920 x 1080 to 1280 x 720 with an pre multipled alpha channel.
I’m working on these clips as well as an outsourced guy that is working off of a PC with AF. Since he’s helping Key, he’s getting only Animation codec files
The source files are not xd cam, and are Pro Res HQ.
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