CasparCG into blackmagic atem without NDI possibility

Hello guys,

I am encouter one technical problem. I have an ATEM blackmagic and i want to enter CasparCG from my computer in the top layer one source of my atem for use any overlays, top layers etc … . I don’t want to use any NDI solution because we are really limited in the environement where we will be. Is it possible to use directly the output from my computer ? If not, which solution i have ?

For resume :

My computer with CasparCG → No NDI, only cable if possible → Atem

PS: sorry for my poor english :smiley:

Thank you for the help !

Your best option is to use a Decklink card to output SDI video signals to your Atem.

If you have a desktop get the Decklink Duo 2 or if you’re running from a laptop, you can use an Ultrastudio (over thunderbolt).

You configure CasparCG output the Fill (color) and Key (transparency) signals on the decklink device and connect the two SDI cables to your Atem.
Then in the Atem software you configure a DSK to use the Fill and Key sources, like so:

Hello @Nytamin !

Thank you for your answer. Which way if I have only HDMI in port on my Atem ? Can I use HDMI protocol to do this ?

Thanks !

The “best” (ie high quality) way is to still go with the SDI Decklink option, and put two SDI-to-HDMI converters between the decklink card and your Atem. That way you still get a Fill&Key signal and can overlay your graphic on top of your content.

Then there are varying levels of worse options:

You can go with two UltraStudio Monitors and use them for Fill+Key signals. This has the risk of the Key&Fill signals being unsynced, which will show up as visual artifacts (often moving black edges) when your graphic is moving.

You can also connect your Atem as an external screen to your computers’ HDMI output (remember to configure the screen to a correct resolution and frame rate!) and configure CasparCG to output a “screen consumer” to fill that screen in borderless mode. Then you can do a “green screen” or possibly a “superblack” keying setup to get the transparency. This is of course worse because you’ll get ugly edges (and/or colors) on your graphics - but it’s free, so that’s something…

Here is another thread that touches on this topic:

Ok thank you @Nytamin ! Pretty interesting !

If i can deploy a router, is it possible to use NDI for CasparCG from a desktop ? How it takes NDI into Blackmagic atem software ?

Blackmagic ATEM‘s do NOT support NDI. You need either HDMI or on the bigger models SDI.

I like to ask before assume.
Do your computer running Caspar have a second HDMI output (like most laptops)?
When you say ATEM blackmagic, can you be more specific what model (ATEM Mini, Television, Studio, Constellation)?

If you specify better your hardware, we may try to find better solutions to match your reality.
The basic answer is Computer → HDMI out → ATEM and you have one channel.

For overlays with transparent background you need to use chroma key or luma key because you have only one output. To have FILL + KEY you need 2 channels so you need to go to a more elaborated solution.

Many possibilities and many hardware options…

All my computers, that I run Caspar on, have either a Decklink card or (in case one of my laptops) an Ultrastudio (both from Blackmagic Designs). So I get, in any case, at least two SDI outputs for fill & key.

SDI is the broadcast standard for a digital video signal and is a bit older than HDMI what originates from consumer electronics.

Using a secondary desktop as output is not a good way to get a professional result, as this displays usually do not support the TV framerate and other things like interlaceing properly.

Concerning the ATEM‘s: There are the cheap ones, that only have HDMI connectors, like the mini‘s. The TV Studio has both HDMI and SDI (BNC connectors). The more advanced stuff only have SDI‘s.

As these Decklink cards only cost a few hundert bucks I don’t find it attractive to go with a little cheaper but much more fumbly solution, But of course that’s up to you to decide.

2 Likes

I totally agree, Didi! This is why I was asking him about his reality.

I usually run caspar in a NUC with Ultrastudio Mini to have Fill+Key in SDI. I used Mini Monitor when only one channel was needed. And HDMI output in a very poor/bad environment.
Caspar does much more but I never needed more than that…

I 100% support the suggestions that add a Decklink card to a computer. Just wanted to add that on computers with a Thunderbolt 3 or later connection you can also use a PCIe expansion chassis which can house one or two PCIe boards.

Several manufacturers produce such units. My i7 NUC connects to a dual-card interface made by StarTech housing a Decklink Duo-2 and a Decklink Intensity Pro. More data on the Startech site within Amazon - see here for the 1 card interface and here for the two card interface.

The expansion chassis includes a Thunderbolt loop-through so you can connect to there devices such as disk storage.

Hello guys !!

Sorry for my poor reactivity to answer you …

Actually, i have an Atem television studio pro. I have SDI and HDMI input capacity on my Atem. I have CasparCG on a windows 11 with 1 server localhosted. I want to send overlays and videos on my ATEM.
So, i have to buy a decklink card, right ?

Other question: can i send video separated from overlays on other atem entry with the same CasparCG server ? I need 2 independant flux for video and overlays. Or i have to host 2 servers (if possible on the same machine) ?

I am starting with casparCG sorry … I am a nood x)
I will receive an X32 compact Behringer too. I will try to controll it via CasparCG with OSC output.

Thanks !

You can have multiple channels on the same server. I would suggest you buy a Decklink Duo 2 card. It has 4 connectors, so that you can have one fill & key for the graphics (2 connectors) and another output for the video (1 connector). You even have a spare for another output (preview etc.) or input.

Hello @didikunz,

Thank you for your answer. I note that you recommend duo 2 to manage the key fill and also manage the video output.

If I only have one SDI output program, I also need to buy a card to capture if I want to retrieve the stream on a Vmix on another computer ?

Yes, that’s correct and the normal workflow. I would suggest to use another computer for vMix and not use the same as Caspar is running on.

Yeah ok right, thank you everyone for your responses, I have noted everything ! And I will buy the equipment that is going well.