Question about DSK?

I want to use DSK for showing graphics ( lower thirds, logo of the current show, time and ticker ), but when i want to key, it always keys or the white or the black color, so i cant use graphics where is some of the black or white color ( i need both). Is there some kind solution for this? What to use as key, luminance, linear, chroma? Or there is some other thing to know that i dont know?

Thank you

I am assuming you are talking about an ATEM switcher. You didn't mention the product.

DSK does not have a chroma option available. A Luma key will use the luminance level of the source to cut the keyhole. Luminance is essentially black or white. If your graphic uses both black and white, luma keying is not a good choice. You want linear keying . . .

The best option is to create graphics with an Alpha Channel, import them into the switcher's media player, select the media player as the sources for the keyer. You need to select BOTH the "Media Player Key (Alpha channel) and the Media Player Fill (graphic) in the DSK settings.

Alpha channels are easy to do in Photoshop. The ATEM manual, while incredibly lacking information in some areas, has a pretty good section that explain keying from pages 80 - 97, if you don't understand the differences in the types.

Often lower thirds are done via an upstream key instead of a downstream key. Upstream keys have more flexibility, such as chroma (green screen) support. Downstream keys typically are only luminance keys. A luma key works by making anything that's black transparent. The trick is to make the part of your image that you still want to be black, "almost black", ie. 1 step brighter than black. Otherwise use an upstream key in chroma key mode.

For professional use, I would use a Character Genarator with separate key and fill signals. (Maybe the free CasparCG PC-software, develloped from swedish television SVT) or graphics with alpha channel in media pool.

Result: Wonderful lower thirds with real good keying.

Great answers. This is the first place where i get any answer . I have 2 video switchers, one is ATEM and the other is sony mfs 2000, i use ATEM for outdoor recording show's, but i use sony mfs 2000 as main switcher for my tv station. I need to setup dsk for sony, because for atem i dont need graphics.

Now, i have two softwares for CG, one is CG 100, other TitleBox, i use alpha always, but i just cant get right settings.

Will help if i take a photo of my switcher, panel and settings ?

In order to use Alpha keying correctly you need 2 outputs from the computer running your CG software. 1 signal fill and 1 signal key (alpha channel). The switcher are then using the black and white key signal to show the fill signal the way you wanted. You must use linear key and combine the 2 inputs in the switcher.

Do you have 2 signals from you're computer?

Hakan

Also, just to let you know, there is an app plugin for photoshop, where you can output your graphics directly from photoshop using a good video card that will simultaneously output the alpha/key and the fill. I think one of the decklink cards is capable of that.

Whether or not it is a ATEM or a Sony or a Panasonic or Grass Valley or Ross (or most other brands) switcher, if it is a decent quality one, there will be a way of keying with an Alpha Channel. You need two outputs from your source, and figure out how to set that up on your particular switcher.

[Gary Adams]

Your description of the key implies a complex image probably changing constantly. If the actual cutout or key signal doesn't change, a single still black and white image could be made to cut a constant hole to be filled with the changing graphics. This key signal could be a still in the store, while the graphics would come from a motion input. However, this only works if the key is the same all the time and does not contain a gradient or shape to coincide with the image. This could easily be handled with either the upstream or downstream keyer.

Regards, Gary

If you are using the Photoshop plugin with a computer connected with USB to the mixer you don´t need any decklink card since you can upload the graphics directly to the switchers media stores.

hakan

Thank you all for answers. I had only one output from cg connected, thats the reason why i havent right key. Man who did cabling, did it wrong. Now i need to fix that. Thank you all for telling me that i need 2 output, fill and key source. When i fix i hope it will work.

Hatl, there are two plugins, but maybe the plugin I am talking about came from Matrox. There is the BMD file based plugin to send the file to the internal media player, but we also have a plugin that we can use live as a video input with a video converter/card.