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SOLVED: Alpha channel in Premiere not working on keyed footage (it 100% has alpha!)
Hi again
I’m really on a streak with these hiccups.. Ok, so, I keyed some footage in AE and exported to DNxHD with Millions of colors +, RGB+Alpha and uncompressed alpha under codec settings. Everything should be superduper transparent, and when imported back into AE it is indeed transparent. But when I import in to Premiere Pro CS6 the transparent area is simply black. No transparency at all (yes, I tried putting material under). But it indeed is there, Premiere even recognize it when I highlight my clips – it says “Movie, 1920 x 1080 (1.0), Alpha” which I was told was a sign that Premiere indeed recognizes it. Righ clicking the footage > Modify footage > Interpret Footage and “Ignore Alpha channel” is indeed unchecked. I just don’t get it.. When I “Replace with AE Composition” in my timeline it again shows up with transparency just fine in AE.. What am I doing wrong? What little button do I need to press to show the transparency as there’s is in AE under the preview window?? It’s driving me insane!
Thanks in advance
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6 Replies
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Hi Alexander,
It should indeed work. Out of curiosity, have you tried another codec instead? Just for troubleshooting.
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Hi Dennis
Now I have and thanks, I guess you were right. I tried the “Lossless Alpha” codec and I do indeed now have transparency as I want it in Premiere. So the problem is appearently how Premiere interprets the alpha channel of the DNxHD codec. The thing is, DNxHD+alpha files are already HUGE (15 GB for 3,5 min) but the Lossless Alpha seems more than twice the size(!) That’s simply too much for a project with as many clips as I have..
Does anyone know a workaround for Premiere to acknowledge the alpha channel of the DNxHD or do you have any other recommendations as to what codec to use with an alpha channel while still maintaining a good image quality within reasonable disc usage?
Messing around in After Effects and Premiere Pro
Specs for whenever I forget to include it in my oh so many forum questions:
Windows 7 Ultimate 64-bit
CPU: Intel i7-4770K @ 3,5GHz
RAM: 16 GB G.Skill 2133MHz
GPU: GeForce GTX 760
Motherboard: ASUS Z87-Pro
Seagate 1 TB -
Okay, I fixed it! Thanks to Dennis I could deduce it was simply how Premiere handled the DNxHD codec and appearently it’s just a bug they haven’t fixed yet in CS6. I don’t know how it is in CC.
If anyone else finds this thread with the same problem the fix is fortunately rather simple:
Open:
C:\Users\{USER}\AppData\Roaming\Adobe\Common
and locate the file
MediaCoreQTCodecRulesCS6.xml
open this with any text program, I just used Wordpad. You need to locate four lines concerning the DNxHD codec, all starting with “QTCodec codec=’AVdn'”. Two of them (the 2nd and 4th) ends with “decodefourcc=’2vuy'”. You need to change both lines with ‘2vuy’ to ‘argb’. Save and you should have no problem reading the alpha of the DNxHD in Premiere.Messing around in After Effects and Premiere Pro
Specs for whenever I forget to include it in my oh so many forum questions:
Windows 7 Ultimate 64-bit
CPU: Intel i7-4770K @ 3,5GHz
RAM: 16 GB G.Skill 2133MHz
GPU: GeForce GTX 760
Motherboard: ASUS Z87-Pro
Seagate 1 TB -
I pinged engineering and they replied that we don’t support alpha channels on DNx material at the moment.
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Oh, so you’re emplyed at Adobe? Still an issue in CC?
And I don’t know why, but my last post got cut off before my solution was finished. I had a special symbol in my post that appearently cut off the remaining text, but it’s updated now and it does work now in Premiere! I wonder if it has any consequences because if the fix is that simple, I don’t get why Adobe hasn’t implemented it by themselves yet.———–
Messing around in After Effects and Premiere ProSpecs for whenever I forget to include it in my oh so many forum questions:
Windows 7 Ultimate 64-bit
CPU: Intel i7-4770K @ 3,5GHz
RAM: 16 GB G.Skill 2133MHz
GPU: GeForce GTX 760
Motherboard: ASUS Z87-Pro
Seagate 1 TB -
Hi Alexander,
Yes, I’m employed at Adobe and sometimes assume that most people already know that – sorry.
Glad to hear that its working for you. What I heard was that we do support compressed DNX and uncompressed alpha. Bottom line, if it’s working for you, great!
Dennis – Adobe guy
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