Ventuz Forum

Hi Guys,
I want to ask if there is some special workflow to get key and fill outputs from DeckLink Duo on SDI licence.

I've read in Manual that key and fill is using just one stream So I've configured one stream in Ventuz cofiguration as You can see on a screenshot attached. Decklink Duo is now streaming fill from first output but the second output is empty. Because I was expecting key on second Output I want to Ask You What am I missing here Any suggestions would be appreciated

Thanks for Your advice

The decklink duo is an odd card... http://www.blackmagicdesign.com/product ... specs#4041

Although it looks like a single board with two in and two out, it actually is two logical completely independent boards with one in and one out each - on the same PCB. That's how it is presented in the av configuration: you see two boards, and each board has a single input and output.

Since we only support key & fill for boards with two outputs and the duo has only one output - twice - this board will now work for external keying. Each of the two SDI chips on the board is only connected to one input and one output jack.

I will clarify this odd behavior in the documentation. The root of the problem is that the decklink / ultrastudio hardware can handle only one stream at the same time, that is input, output or internal keying. This is totally unlike an deltacast board where each input/output can be programmed independently and simultaneously. The duo / quad boards try to work around this limitation by putting multiple chips on the same board.

Now why don't we manually split key and fill and send it to two "logical" boards? Because each output stream has a buffer-queue, and if for instance the key-queue is longer than the fill-queue, key and fill won't fit together any more. If everything is on the same board, like on a decklink 4k extreme or a deltacast 22 key, the driver will treat both outputs as "coupled" and make sure they always fit together.

Thanks for Your fast reply. If i get it well that means We are not able to send synced key and fill with Decklink Duo. Let me ask You once more - Would be possible to stream synced k & fill with single SDI licence using decklink 4k extreme? We'll have shooting in few days so We need to know if 4k extreme would solve our issue. Thanks agan!

We never tested the extreme 4k, but we tested the predecessor, the "DeckLinkHD Extreme 3", which works fine. I am confident that the latest model will work just as well. Please note that when using any of the DeckLinkHD Extreme to output fill & key, the inputs can not be used. If you need SDI input at the same time, use a "Deltacast HD-e-key 22", which is the card we recommend the most.