Half Res removes alpha on footage
by Rune Månsson
on
Jun 26, 2009 at 8:33:49 am
Hi folks
I have a problem, I'm working on a project where I use footage in the Quicktime PNG format with alpha included. But when I turn the resolution down to quicken the workflow, the alpha is dumped and the footage is dispalyed on a black background instead. I full res everything works fine, but that's not an optimal solution.
I've tried to purge all, restart Ae and restart the machine, but still no luck. Any ideas why this is? I've never had this problem before.
Re: Half Res removes alpha on footage by Roland R. Kahlenberg on Jun 26, 2009 at 11:05:13 am
It isn't clear how you have 'turned down the resolution'. Are you using proxies for this or simply lowering the comp's or layer's resolution and quality setting respectively?
Another thing to nore is that using the QT PNG isn't something most professionals use. For Alpha Channel support, such users go with either uncompressed or Animation or a CODEC that is native to their video I/O.
You will want to provide info on the resolution of the source footage and details on how you lowered the resolution of the source footage.
Cheers
RoRK
broadcastGEMs - AEPro Volume 02 (Professional Adobe After Effects Project Files - Now Available). Adobe After Effects Training in South East Asia.
Re: Half Res removes alpha on footage by Rune Månsson on Jun 26, 2009 at 11:43:02 am
hi Roland
Thanks for your quick reply. The resolution of the footage varies, since it has been cut to fit that actor inside. but they are between 400x800 to 800x800
I'm not working with proxies since the files are relatively small as they are.
The resolution I was talking about was the viewport resolution (Full/half/third/quad), when I turn it down to quicken the viewport render, the alpha is dumped. Layer quality is untouched.
I'll try to render the sequences with QT Animation, to see if that helps.
Re: Half Res removes alpha on footage by Roland R. Kahlenberg on Jun 26, 2009 at 12:19:00 pm
Heya Rune, you have quite an unusual issue here. If coverting the QT PNGs to the Animation CODEC results in the same issues then it is likely an AE issue rather than the source footage.
I can only suggest deleting prefs for a quick fingers-crossed solution that it isn't anything more serious.
But before doing that I would render out short section, with settings that allow for an Alpha - to check if it's just a preview thingy as opposed to having the issue reflect itself onto a rendered movie.
Oh DAMN! Having typed this much, I do recall having an issue with alpha-laden QT PNGs. It was a request from the Disney folks here. I ended up going either uncompressed or Animation. So, try converting/rendering the PNGs to Uncompressed.
Good Luck
RoRK
broadcastGEMs - AEPro Volume 02 (Professional Adobe After Effects Project Files - Now Available). Adobe After Effects Training in South East Asia.
