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Keeping the alpha channel
Posted: Wed Feb 25, 2009 12:03 am
by soundman1024
I've got a theatre show coming up that I'm looking to use modul8 to head up the projection with. I've got some animations I'm looking to use that have been encoded in the animation codec with the alpha channel in tact. When I put these into modul8 the playback is unacceptable. I don't believe this issue is a result of a slow computer. (8x3.0ghz, 8gb, Radeon x1900)
I've gone through the help and the remedy seems to be to rendering clips in the photoJPEG codec. I opened up Compressor and rerendered them as photoJPEGs, and the playback rate is no longer an issue; however, it doesn't seem the alpha channel is still in tact. Is the photoJPEG codec compatible with the alpha channel?
If photoJPEG does not support the alpha channel, what codec does support the alpha channel and is a good friend of modul8?
Posted: Wed Feb 25, 2009 1:19 pm
by Vibber
try exporting with the PNG codec. Don't know how it compares performance wise with Animation...
Photojpg does not support alpha channel.
Posted: Wed Feb 25, 2009 3:09 pm
by sigmasix
can you tell us what's the resolution of your animation media?
Posted: Thu Feb 26, 2009 4:35 am
by soundman1024
@vibber I don't remember seeing png as an option in Compressor 3, but I'll look for it. If I find it I'll be sure to post the results here.
@sigma The content is 720x486. The animations I need the alpha channel for are smoke and fire mainly. I've tried using keyers on photojpeg copies, and it just wasn't working out so well.
Posted: Thu Feb 26, 2009 4:14 pm
by vanakaru
I just used alpha on mapping project. I was barely able to run 3 layers on my MBP 2.5ghz. The size was 1200x800. But at the show I used MacPro like yours and had no issues.
BTW I exported the animation at the 70% quality. Had no difference on how it looked, but strained CPU less considerably.
But overall using alpha in M8 is difficult at least.
Posted: Fri Feb 27, 2009 2:13 pm
by Vibber
@soundman1024: PNG is an export option in Quicktime Pro on the Mac, so I just assumed it would be available in Compressor....
Posted: Fri Feb 27, 2009 7:25 pm
by vanakaru
I do not use Compressor, but usually you get the qt codec by selecting QT in export and settings or options button, that opens all the codecs you have installed for QT.
Posted: Sat Feb 28, 2009 12:58 am
by deepvisual
there a few work arounds for poor performance with alphas.
one is make the file size 50% then scale it up in M8
another is make your clips with a solid blue background and use the lumakey (B) setting.
you'll get a slight blue halo, but no one is watching anyway.
Posted: Mon Mar 02, 2009 2:51 pm
by ilan
Someone is ALWAYS watching
