Internal keyer HD

Good morning,
I'm using some Decklink cards and the keyer to overlay a logo to a video signal.
Actually I'm using a Decklink Quad.
I've 3 SD inputs (PAL standard) and a HD signal (1080i50). No problem with the SD signal, but I can't use the HD signal. When I run the HD signal, the logo is shown but I can't see the original video signal.
Can the Decklink Quad be used with a HD signal as a keyer?
Thanks

No, not in HD. You can respond to the sync callback, copy an input source from one of the the other
channels to your channel being used for output. Overwrite the buffer memory with your overlay looking
at the alpha data.

DeckLink SDI 4K ($295) is the cheapest card that can do internal HD keying.

Thanks guys, as suppoused.
@Richard, unfortunatelly, I haven't a free channel, all the four are used.

I guess other "solutions" might be

A) converting the HD signal to SD before it enters the DeckLink Quad (e.g. with the Mini Converter UpDownCross: https://www.blackmagicdesign.com/produc ... /W-CONM-16 )

or

B) using the forthcoming DeckLink Quad 2 card which supposedly will support internal keying in HD. ( https://www.blackmagicdesign.com/produc ... s/W-DLK-30 )

Hi Martin,
yes, we have bought a Quad 2 card.
Thanks.