Force RGB possible with AJA Kona LHe?
by Alan Okey
on
Sep 12, 2007 at 3:12:47 am
I'm trying to figure out how to utilize the "force RGB" setting in Color. My system is a Mac Pro with ATI X1900XT graphics and an AJA Kona LHe card connected to a Sony PVM-14L5 via analog component output. The Sony can switch between RGB and component on the same inputs, and the Kona control panel allows the analog HD output format to be switched between component and RGB. The trouble is, I can't for the life of me seem to make the force RGB feature work in Color (v1.0.1). I'm attempting to do this with a 720p project. The Kona and Sony PVM otherwise work perfectly with Color, as long as the force RGB button is not checked.
The Color manual states that playback performance may be improved by offloading the RGB>YCrCb conversion to the broadcast video card, but whenever I check the force RGB button all I get on the broadcast monitor is a green screen. I've tried different combinations of selecting RGB or component OUT on the Kona and RGB or component IN on the Sony, but no joy. Am I misunderstanding the proper use of the force RGB button, or is my hardware not capable of utilizing this feature?
Re: Force RGB possible with AJA Kona LHe? by Floh on Sep 12, 2007 at 7:54:12 am
This feature has nothing to do with RGB or YUV out from your card, but it is about the way the data is pushed from your graphics card to your video (Kona) card. Your files are stored in YUV (at least as long as you are not working in e.g. DPX format). Color converts these YUV streams into RGB to be able to work with it (btw, it bypasses the regular QuickTime conversion there, giving you a faster and more accurate conversion with your highlights intact). Then Color does its work in RGB 32bit float on your Graphics card (GPU). Now if you want to see your video on a broadcast monitor Color has to push the data back to the video (Kona) card, which is usually done in YUV, so Color has to convert from RGB to YUV again.
As far as I know only the Kona 3 cards can also accept RGB streams from the PCI bus (this is not related to the video input or output, but part of the DPX/2K support), so that Color does not have to do a RGB->YUV conversion before sending the videos back to the Kona card. So as far as I know this feature does only make sense with the Kona3 board and cannot be used with the LHe or other boards.
Re: Force RGB possible with AJA Kona LHe? by Alan Okey on Sep 12, 2007 at 9:42:10 pm
[Floh]"This feature has nothing to do with RGB or YUV out from your card, but it is about the way the data is pushed from your graphics card to your video (Kona) card."
Yes, I realize that, but if the video out card and broadcast monitor are both capable of displaying RGB signals, then there would ultimately be no need to convert back to YCrCb for preview monitoring.
[Floh]"As far as I know only the Kona 3 cards can also accept RGB streams from the PCI bus (this is not related to the video input or output, but part of the DPX/2K support), so that Color does not have to do a RGB->YUV conversion before sending the videos back to the Kona card. So as far as I know this feature does only make sense with the Kona3 board and cannot be used with the LHe or other boards."
This is the relevant fact that I was looking for. What video cards supported force RGB in Final Touch?
Re: Force RGB possible with AJA Kona LHe? by Wired One on Sep 13, 2007 at 4:01:30 am
Alan,
I am having the same problem with the Kona 3. Running Ver: 3.4 it worked fine until I updated to 4.0 on the AJA control Panel. Using FORCE RGB made my external monitors (both HD and SD) go green. I called AJA they replied with an e-mail the next day
