Premiere 4K source playback in HD?

I've got a new Decklink Studio 4K card that I'm trying to use in Premiere (Windows) and am running into what seems like a limitation with the Decklink software, but I'm hoping I'm just doing something wrong and this can be fixed..

Basically I have 4K source material but am only editing in HD; the output of the Decklink is running into an SDI->HDMI mini converter (also BM) feeding a consumer HD monitor. It seems like however whenever you load a clip into the source monitor in Premiere, the Decklink is trying to change the output of the card to match the format and framerate of the source clip rather than leaving it alone matching the sequence settings. Which in this case means the monitor goes black.. and then you click back on the sequence viewer and the Decklink switches back to HD (which takes several seconds as the monitor flashes and resyncs to seeing a signal it understands.)

With my other systems with AJA cards, Premiere (or the Kona driver for it, I'm not sure whose responsibility it is) just scales the source clips to HD and everything works fine.

Can the Decklink not do this in Premiere, or am I just missing the magic combination of config settings?

There should be a setting in Premiere to scale down for lower resolution BM preview.
Something like this:



It's in Preferences/Playback. When you choose BlackMagic Playback next to it there is Setup option. It should be there if I'm correct.

For the Decklink Studio 4k my choices are "No output", "Scale Down", and "Scale Up."

The problem I guess is that the source isn't an "unsupported frame size" -- in this case it's switching the output to 4K DCI. I really need it to leave the hardware alone and scale to the sequence size (HD) whether it's unsupported or not.. just like it does for the sequence its self.

Looking like I'll have to get rid of this Decklink and get a Kona..

Ups, yes your signal is detected as supported one Interesting problem.
You can solve it, but you need correct BM card- the one which does support hardware scaling. In this case you set resize in card settings and then any UHD signal is resized to HD. Only top end models support it though (still cheaper than AJA).


Decklink 4K Pro does this:

Colorspace Conversion
Hardware based real time on output.
3D Processing
Left eye/right eye dual stream capture & playback.
Ultra HD to HD Down Conversion
Built in, high quality hardware down converter outputs Ultra HD to HD or HD to SD down converted signal on SDI B. Down converted SD selectable between letterbox, anamorphic 16:9 and center cut 4:3 styles.

so you get UHD preview on 1 SDI and HD downscale on another. No idea if it will scale 4K DCI though

Other solution is some converter box which can pass 4K SDI and output scaled HD SDI/HDMI. AJA has one, probably BM also. This may be cheaper option.