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Quicktime gamma shifts

Hi there,


i've been digging for weeks now and can't find any solution to my specific problem. I'd like to have a gamma shift free quicktime prores file either 444 or 422HQ.

I'm exporting out uf Autodesks Smoke (same with Assimilates Scratch) 3 files (QT uncompressed 8bit, QT Prores 444 and a QT Prores 422HQ) The uncompressed file is slightly (but visibly) lighter than the Prores files, which are the same gamma wise. I checked it in QT Player 10 (X) and QT Player 7. If i check the color profiles on all files (CMD+i) i'm getting HD (1-1-1) profile for the ProRes files and nothing for the uncompressed file. I think this is due to the differences (uncompressed - RGB vs. Prores - YUV). So far - so good (or actually bad). If i load all three files into After Effects (10.5) and put them into one comp and check it there theres no visually difference between all three files. they are identical (as i said visually). Right now i need to master the stuff at QT Prores 444 but i can't get a gamma shift free file (or maybe i do but it looks differnt in different applications).


I'm aware that i can use colorprofiles within AFX. I tried to get an HD profile into the RGB file header using the automator script but it would look the same. When i need to get .mp4s or h.264 files from our master files i'm using Telestreams Episode which is pretty neat and gives me excellent encoding results in a fairly reasonable time. But i need to feed it with an uncompressed file in order to maintain the gamma through the pipeline. I could do the pro res there but transcoding the uncompressed file within Episode i'm getting shifts as well. This might be caused by the bit shifts - getting 8bit uncompressed in and receiving a 10bit QT file. I really need that fixed somehow. Is there anybody who could give advices or can explain where the gamma-hickup happens?


Would be great!


Best,

Severin

Mac Pro, Mac OS X (10.7.3)

Posted on Apr 18, 2012 3:02 AM

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Quicktime gamma shifts

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