ChyronHego Live

Has anyone used CasparCG with a ChyronHego Live?

I am having difficulty with the pre-multiplied fill, so white at 80% alpha shows as 80% white (grey) 80% alpha.

I think it isn't possible to remove alpha from the flash or html producers, - does anyone know how to adjust the Live mixer to account for it?

Settings are limited, see picture.
ChyronHego Live Settings
IMG_20161124_114400.jpg (167.3 KiB) Viewed 2208 times

Re: ChyronHego Live

You should activate the MATE option in your mixer and select the KEY source. As I understand your image, the current mode is ChromaKeying which is wrong if you work with KEY/FILL from ccg.

What is you ccg config?

mcdikki - Wir teilen Begeisterung

Re: ChyronHego Live

How is CasparCG connected to your mixer ?

Normally, for key and fill two physical connections are needed. One for the key signal (Black / White Signal, gray is a semitransparency) and one for the fill. Normal SDI or HDMI Connections don't transport alpha (key) together with the fill. Maybe NDI can (I don't know).....

So when key and fill are the same signals, the luminance of your fill signal will be missinterpreted as key.

A 80% gray will be shown as 80% semitransparency and also gray - a semitransparency gray. Every color will be shown semitransparency; the more darker the color - the more transparency.....).

Re: ChyronHego Live

Hi mcdikki & Thos

This is the Key and Fill menu, not chroma key.
I am using a 4k Extreme card with separate key and fill output fed to two inputs on the mixer.
The source button in the picture allows you to choose the key channel, which I have done.

The documentation on these settings is non-existent but the upper and lower threshold affect the cut off for the key. RGB and alpha also seem to affect the key, but not sure.

If I have a 100% white with 80% alpha keyed over a solid white, should I expect the screen to be solid white, or to be grey?
Transparent white over white
IMG_20161124_131252.jpg (191.66 KiB) Viewed 2192 times

Re: ChyronHego Live

silid wrote:If I have a 100% white with 80% alpha keyed over a solid white, should I expect the screen to be solid white, or to be grey?
Than it should be white and you should not notice any difference. When you key over a picture instead of white you should be able to see it like throug milk.

Are you sure, that the system is aware of the alpha input and not only does a luminace key? What is the MATE checkbox doing? And probably you can choose the input for the alpha with that SOURCE button...
Didi Kunz
CasparCG Client-Programmer, Template Maker & Live CG-Operator
Media Support, CH-5722 Gränichen, Switzerland
Problems? Guide to posting Bug reports & Feature requests

Re: ChyronHego Live

Usually, you'll have to check the MATE box and select the key source. If not, the color set by the RGB faders are used as key signal.
At least this is how a few vision mixers I used have been working.

mcdikki - Wir teilen Begeisterung

Re: ChyronHego Live

Thanks for all your help.

The matte checkbox displays the key, rather than the keyed fill (source has already been selected).

The other faders all affect the key input (For example, if you are using a fill as key you can specify to use the luminance of the red as they). (Keys not using a video source are set in a different menu).

I have created a table of bars with white at differing alpha levels and then using a scope to accurately set the key levels, using these methods.

I ended up with alpha at 100%, lower margin around 30.0 and Upper margin around 6.0.

It is still darker when laid over pure white, but will probably do for my purposes.

Re: ChyronHego Live

It's a good idea not to check the mixer settings without some prepared test which makes hard for mixer to "fake" proper keying. All mixers have modes where they use only Key Source instead of Key Source/Fill combination. Attached is my own version, feel free to use it anyway you see feet.

If you adjust the mixer settings with only the graphics you use in the event, it may have only elements which are easy to deduce only from Key Source channel, and you can see the problem when it is too late. The card attached has transparent areas in white, black and RGB colors, explicit transparency percentages and large non transparent areas. I usually put it over the colors bars, check on the instruments if color levels match, then put it over live camera to check the transparencies. You can take one glance and be positive your mixer is properly set.

Imgur link
CardHD.png (160.76 KiB) Viewed 2134 times

Re: ChyronHego Live

Thanks Itod

I have attached the interesting parts below.

When keyed against white the white bar goes grey.
When keyed against black the black bar goes grey in the middle.
Keyed against black
SNAPSHOT_BLACK.png (8.38 KiB) Viewed 2102 times
Keyed against white
SNAPSHOT_WHITE.png (8.47 KiB) Viewed 2102 times

Re: ChyronHego Live

When checking the mixer keying settings it's essential that you provide a way to check your Key Source/Fill signals before they reach the mixer. If you don't have a router in your production setup then bring another SDI monitor with you and check the signals temporally connected to that monitor directly after the CCG server computer. This way you'll find out if the source of the problem is in your computer settings or in your mixer settings.