Change color range of the alpha channel

graphics
playout

#1

Hello,
I’m running version 2.2 on a machine with a Decklink 4K Extreme feeding a key and a fill to my ATEM. Right now the alpha channel is outputting in a limited range (16-235) which is causing some undesired effects when the ATEM combines them for DSK overlay. I belive the ATEM expects a full range (0-255) signal. Is it possible to change the way CasparCG outputs to the alpha channel? I have tried to google my problem but did not find anything of use so I decided to try here.


#2

I think I remember reading this was a bug in a version of the decklink driver.
What version of the driver are you using, and does the issue occur with the latest version?


#3

People have told me about that bug before and I tried installing the latest driver but without any change. Now that I saw your message I tried it again but made sure to completely uninstall the previous version and running a clean up before installing the latest version and that fixed it.

So for anybody that find this with the same issue. It seems that the bugged part of the driver can stay even after updating so make sure to uninstall previous version before installing the latest update.

Thanks for the help


#4

Hi

In ATEM allso check Premultiplied in DSK. Caspar normally works in Premult.

/o