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Compressed vs. Uncompressed Alpha
This is my first post and I’ve been having difficulty searching for the answer to this. I am currently building Render and Output modules which will be passed around for others at my place of work to use. As such I need to make sure that they are correct and I am having difficulty determining what the better alpha setting to use is: Compressed or Uncompressed.
Obviously, I know the big difference is file size, but can someone please explain what the major differences are. The majority of my output settings will be using the Avid DNxHD codecs.
I am using AE CS4. I hope I have provided enough details.
Thanks,
Roy. -
4 Replies
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You will export separate file with alpha?
if you thing export RGB+Alpha you have no options, need to be unconpressed.Alexandre Braso
http://www.pixelsrender.com.br -
That is what I thought as I am rendering one QT RGB+alpha, so I built my templates using uncompressed. So, if I understand correctly, a compressed alpha is only usable when rendering as two separate files…one fill and one matte/alpha.
Thanks for the quick response, I apprecite it!
Roy.
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Thanks for the clarifications Dave, I appreciate the help. I had responded to your earlier post but there was an error after I hit Post Direct so I guess it never made it.
Anyway, all I had basically said was the since the work being done by the editors isn’t all that intensive for the most part I wanted to keep their files in the same native codec as what they are using in the Avid. This is what lead to my original post, but I agree completely that you want the best possible quality coming out of your AE work. I just want to cut down on the transcoding time when bringing it back into the Avid. Also, the source footage sent from Avid to AE is exported “Same as Source” so using the Animation Codec (in this case) would unjustifiably bloat the file size.
Roy.
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The Avid DNx codec does support alphas, however that hasn’t always been the case. I can’t remember when it changed but in the beginning it would render out a quicktime and claim it had an alpha. In reality it did…but it was a full screen alpha.
I personally like to use straight as it can get me as close to compositing entirely in AE when using soft or gradient alpha elements. However, I am building presets for both types so that the editors can choose which suits their particular needs best.
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