Blackmagic Forum

Hi folks,

I'm a new user of the Decklink 8K Pro, and I'm struggling with the lack of a dedicated manual!

I have a few questions, but i'll start with the most basic:

Strangely, i can't find anywhere a diagram listing the numbers for the physical connectors (which are referred to by number in the "Desktop Video Setup" app).

Please take a look at the attached picture, could anyone tell me if this is the correct numbering?

And to move on to the second step:

The problem is that i really don't understand how the input / output routing works on the DeckLink 8K Pro.

I'm completely new to the world of pro video, so what might be blindingly obvious to video guys is unfortunately not yet apparent to me.

Please take a look at the video below.

First things first, the 4 dots / buttons at the bottom of the setup window represent video channels, not connectors, right?

Can all 4 channels be piped down one cable at the same time?

Secondly, in the video, in the first setup ("SDI 1 in, SDI 2 out"), we can see the output of my Sony A7 camera present (1080p50)

But when i switch to ("SDI 1 in or out"), we see no signal present.

I don't understand! Why does the signal disappear?

With the set-up that works ("SDI 1 in, SDI 2 out"), is it doing this?:

"On connector 1, take channel 1 from the video signal and send it into the computer. And from the channels that come into the card from the computer, take channel 1 and send it out through connector 2"?

If so, why doesn't "SDI 1 in or out" show any signal?

And what does it even mean with "or"? What happens if there is both channel 1 is present on input AND the card receives channel 1 from the computer, then what happens? Or is SDI bi-directional down one cable??!!

I must say it's kinda weird there is no dedicated manual or even any video tutorial explaining this stuff. I guess this is a pro card so the thinking is "Anyone buying this card must surely be a video pro with prior experience of SDI capture cards so of course they're gonna know all these basics already".

The four dots are your four connectors. You can't send all the channels on one connector, though I believe on that card if you're using a quad-link SDI format, an individual channel will have a crude quarter resolution preview, based on the way quad link assembles an image. The connector mapping works like this:

1-4 in or out: Quad-link mode, half-duplex channel in or out
1-2 in/3-4 out: Dual-link mode, full duplex channel in and out
1 in/2 out: Two full duplex channels in and out
1 in or out: Four half duplex channels in or out

You can determine the correct numbering by setting it to the last option, and connecting a source. I think it's 1-3-2-4.

Thanks Jack,

After experimenting with it i worked out that my above picture (card with connectors) is correct, and the assignment is:

Connector 1 = SDI-1
Connector 2 = SDI-3
Connector 3 = SDI-2
Connector 4 = SDI-4

To me that seems incredibly unintuitive and confusing to do it like that, but what the hey, perhaps there's a reason.

I don't yet really understand it, but at least with the "1 in or out: Four half duplex channels in or out" setting i can do what i need to do for now.

It's so the loop outs are next to the inputs, and if you're running full duplex channels, the numbers go up in single increments. If you think this is confusing, try the 8-port Quad 2 card

OK!

But to not have it mentioned anywhere in any docs , i think i must have wasted an entire day with this, simply because i couldn't imagine that they would connect the physical connectors to the SDI numbers in that way, so nothing was making sense to me.......

C'mon BlackMagic, ok, so you don't want to write a instruction manual for each product, than at least give each product a quick start guide where you mention these sort of gotchas and vital information........

And for the manual you do provide, don't merge every language under the sun into one freakin 800 page PDF, that's also incredibly lazy and annoying.........

Urrrgggh, i still can't get the card to do what i want it to do, i thought i had it sussed out, but i guess i was mistaken.

When i have my Sony camera plugged in to connector 1, and have it set to "SDI 1 in , SDI 2 Out", then i see input as "1080p50".

But if i change connector 1 to "SDI 1 in or out", i see no signal.

Can anyone think what the explanation for this might be?

And in fact i really don't understand what "SDI 1 in , SDI 2 Out" means!!!!
Is it saying that if you use this connector (#1) as an output, it will output SDI 2? Why on earth would it do that?

Or is it a routing thing? So, what comes in on SDI 1 will be passed out (looped) to SDI 2 out?

Ok, so i just worked out the most crazy, stoopidest thing:

When in "SDI 1 in or out" mode, you will only see a signal present at "VIDEO INPUT" in the Desktop Video Setup app, if your software (Unreal Engine in my case) is actually set to receive from this input.

So the DeckLink 8K Pro will only show video input if your software is receiving it???? REALLY?

Check out this video, you can see that the DeckLink only shows a video input when i perform an action in my application. When i drag an asset from my content browser into the main window at 0:17, you see it switch.

Is this normal behaviour for a video capture card?