Blackmagic Forum

I see this in a bunch of BMD products, and I'm wondering if there's a trick to determining which specifications are exclusive of one another.

In the exact case I'm looking at today, I see the Decklink 8K Pro says it does DCI 4Kp120 3D and it does 12b 4:4:4 rec 2020 and it does bidirectional 12g SDI connections.

If all three of those are non-exclusive, that means I can hook up 4 DCI4K cameras as two stereo pairs running at 120fps at 12 bit in RGB. For US$650. If it sounds too good to be true... there's got to be a catch, right?

So is it true? Or if not, what modes are exclusive, and is there a way I or a reseller can figure what combinations are valid using an excel sheet or some online configurator without first installing the card and just testing it?

Hi Chad,

The 8K Pro supports up to quad-link 12Gb/s (48Gb/s total). The configuration for 4K DCI 444 3D 120 fps requires an aggregate bandwidth greater than this.

You need to cross reference the SDI Compliance section on the Tech Specs page with the SMPTE Image Formats specifications (particularly ST 2082-xx).

If you have a card readily available, the SDK sample DeviceList provides the full list of supported display modes and pixel formats.

Regards
Cameron

Thanks for the response. I think 4:2:2 will be enough for this project, but if it isn't can we add a second 8K Pro and make one the left eye and one the right eye?

Hi Chad,

You can use multiple DeckLink 8K Pro cards, but you would capture as seperate input streams each with its own IDeckLinkInput/IDeckLinkInputCallback object. Normally for 3D capture, the left-eye and right-eye frames are both received in IDeckLinkInputCallback::VideoInputFrameArrived callback.

If your camera sources are locked to common reference, then you can implement Synchronized Capture feature that was added to Desktop Video in 11.0. This feature allows grouping of multiple inputs to sycnhronize the start/stop capture. This feature will allow you to align the left/right eye frames based on the captured stream times. Please refer to section 2.4.13.1 of DeckLink SDK manual for more information on Synchronized Capture.

Multiple streams of 4K DCI 444 120fps will require significant bandwidth and you will need to make careful consideration with the PC system requirements for your application. As a starting point, please refer to the following support note for guidance: https://www.blackmagicdesign.com/support/note/9568.

Regards
Cameron