# Black Magic SDI 4k **URL:** \ **Category:** FAQ\ **Created:** [October 9, 2018, 3:04pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911 "2018-10-09T15:04:38Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Dandrum](https://casparcgforum.org/user_avatar/casparcgforum.org/dandrum/32/649_2.png) [@Dandrum](https://casparcgforum.org/u/Dandrum)\ **Post date:** [October 9, 2018, 3:04pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/1 "2018-10-09T15:04:38Z")
Hi, is it possible to get Key/Fill out of a BM DeckLink SDI 4k ? On the Page it says: “You also get RS-422 deck control, internal keying and reference input for a complete solution for editing,” [https://www.blackmagicdesign.com/products/decklink/techspecs/W-DLK-11](https://www.blackmagicdesign.com/products/decklink/techspecs/W-DLK-11) My Mixer is a Black Magic Television Studio HD. Shoud it be possible to send a HD SDI Signal in 4:4:4 with internal key and only use one SDI input on the mixer instead of two ? Or if not is it possible to use two SDI outs on the DeckLink or do i need a DeckLink Duo 2 ? Greetings Dan ---
**Author:** ![didikunz](https://casparcgforum.org/user_avatar/casparcgforum.org/didikunz/32/7_2.png) [@didikunz](https://casparcgforum.org/u/didikunz)\ **Post date:** [October 9, 2018, 3:20pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/2 "2018-10-09T15:20:49Z")
> [@Dandrum](#): > > Shoud it be possible to send a HD SDI Signal in 4:4:4 with internal key and only use one SDI input on the mixer instead of two ? No, the card can only output OR input. > [@Dandrum](#): > > or do i need a DeckLink Duo 2 Yes, that is the cheapest way to get fill and key. ---
**Author:** ![mint](https://casparcgforum.org/user_avatar/casparcgforum.org/mint/32/2355_2.png) [@mint](https://casparcgforum.org/u/mint)\ **Post date:** [October 9, 2018, 4:49pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/3 "2018-10-09T16:49:16Z")
Well, technically it can output AND input at the same time. (in hd) There is however no option on the TV studio HD to add graphics that way, so you will need at least two inputs on the vision mixer or settle for not having graphics on the multiviewer and use CasparCG as your program out. ---
**Author:** ![didikunz](https://casparcgforum.org/user_avatar/casparcgforum.org/didikunz/32/7_2.png) [@didikunz](https://casparcgforum.org/u/didikunz)\ **Post date:** [October 9, 2018, 4:52pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/4 "2018-10-09T16:52:16Z")
> [@mint](#): > > …and use CasparCG as your program out I would never do that 🙂 ---
**Author:** ![mint](https://casparcgforum.org/user_avatar/casparcgforum.org/mint/32/2355_2.png) [@mint](https://casparcgforum.org/u/mint)\ **Post date:** [October 9, 2018, 5:15pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/5 "2018-10-09T17:15:08Z")
Ahh, yes, well I’ve run shows where CasparCG was the most reliable piece of equipment we had so then I am not worried about it.😁 ---
**Author:** ![didikunz](https://casparcgforum.org/user_avatar/casparcgforum.org/didikunz/32/7_2.png) [@didikunz](https://casparcgforum.org/u/didikunz)\ **Post date:** [October 9, 2018, 5:47pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/6 "2018-10-09T17:47:29Z")
…you are right, but I would not do it because of me, not because of Caspar 😉 ---
**Author:** ![Dandrum](https://casparcgforum.org/user_avatar/casparcgforum.org/dandrum/32/649_2.png) [@Dandrum](https://casparcgforum.org/u/Dandrum)\ **Post date:** [October 10, 2018, 10:51am UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/7 "2018-10-10T10:51:21Z")
OK well then i will get a Duo 2 ---
**Author:** ![jackreynolds](https://casparcgforum.org/letter_avatar_proxy/v4/letter/j/e8c25b/32.png) [@jackreynolds](https://casparcgforum.org/u/jackreynolds)\ **Post date:** [October 11, 2018, 2:46am UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/8 "2018-10-11T02:46:23Z")
It isn’t the perfect solution, however our studio would run graphics out through an SDI 4K, with a bright pink background behind all the graphics layers, and that would be chroma keyed out. It isn’t perfect, but it will do. If given the option though, take the Duo 2. ---
**Author:** ![Dandrum](https://casparcgforum.org/user_avatar/casparcgforum.org/dandrum/32/649_2.png) [@Dandrum](https://casparcgforum.org/u/Dandrum)\ **Post date:** [June 23, 2019, 11:15pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/9 "2019-06-23T23:15:08Z")
I bought a DUO 2 and its even better then i thought. Its been a while and i did some events with it and because the duo 2 have 4 channels i now can run some different configurations from ONE caspar server over the duo2. For example: 2x Fill/Key so 4 channel 2x Fill / 2x Key 1x Fill/Key and 2 Video Layers for trailers or so 1x Fill/Key 1x Video 1xSpecial Graphics and additional infos for Moderators that not shown in the live feed Im happy with the Duo2 and the performance is good. I used it with 1080p50 (germany) Greetings Dan ---
**Author:** ![stephenmontgomery](https://casparcgforum.org/letter_avatar_proxy/v4/letter/s/58956e/32.png) [@stephenmontgomery](https://casparcgforum.org/u/stephenmontgomery)\ **Post date:** [November 12, 2020, 8:28pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/10 "2020-11-12T20:28:44Z")
I always thought the DUO 2 was to be avoided as you could get sync issues with the key and fill channels not being in sync with each other. Am I remembering wrong or has that issue gone away? ---
**Author:** ![hreinnbeck](https://casparcgforum.org/user_avatar/casparcgforum.org/hreinnbeck/32/154_2.png) [@hreinnbeck](https://casparcgforum.org/u/hreinnbeck)\ **Post date:** [November 12, 2020, 8:56pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/11 "2020-11-12T20:56:07Z")
That’s wrong, when the DUO2 is correctly configured, the card itself handles the RGBA. However some might have wrongly configured CCG to output fill and key to 2 outputs on the DUO2 instead of configuring the DUO2 to gang 2 outputs together for key+fill natively from the card. ---
**Author:** ![didikunz](https://casparcgforum.org/user_avatar/casparcgforum.org/didikunz/32/7_2.png) [@didikunz](https://casparcgforum.org/u/didikunz)\ **Post date:** [November 12, 2020, 11:05pm UTC](https://casparcgforum.org/t/black-magic-sdi-4k/911/12 "2020-11-12T23:05:06Z")
> [@stephenmontgomery](#): > > I always thought the DUO 2 was to be avoided as you could get sync issues with the key and fill channels not being in sync with each other. That has been the case with the old Duo card. The Duo 2 has hardware fill & key.