DeckLink Extreme HD – flicker on HD output – Mac OS X

[Chris Blair]

Define intermittent.

We use an Sony LMD series (LCD) monitor with the Decklink HD Extreme with Premiere and Vegas and progressive video just plain looks weird on these. 60i video looks fine, but any of our 24P and 30P footage shot with a Panasonic SDX-900 has an odd “stutter” even after rendering. The same footage and rendered movies look and play fine on Sony broadcast NTSC monitors when played back through the Decklink, so we’ve determined it’s something in the LMD monitor, which in my opinion are NOT very good monitors.

This happens on SD material as well as HD…so that doesn’t seem to have any affect.

We bought 2 of the LMD’s and we’re really disappointed with the quality (or lack thereof) considering their price. Perhaps it has something to do with the inherent nature of how an LCD monitor dislpays progressive footage, but compared to our old Sony broadcast monitors, it’s just plain odd looking.

Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com

[James Fuller]

‘Define intermittent’ – headache inducing. By intermittent, I mean that the image on display literally flashes on and off. The speed of flashes depends on the screen resolution/refresh rate – 720p50 flashes very fast, 1080i25 slightly less, etc.

I’d love to be able to comment on the quality of the monitor, but the image onsceen is never stable enough to see the image – except when outputting in 8bit, which is often not an option.

Here’s another aspect of the problem: if I play a clip, FCP reports dropped frames. It’s like the timing of the whole system goes crazy when the display is set to output HD at 10bit (which is surely what it is supposed to do, right?)

This got me thinking: ‘maybe it’s a problem with Mac OS or FCP’. So I tried booting to Windows Vista and running a HD project in Premier – same thing happens, so apparently no problem with the software.

I’m beginning to think that we’re going to have to go for a new capture card as the Blackmagic seems to have fallen at the first HD hurdle.

[Kristian Lam]

hi James

Is the card in the top slot of your mac pro? Is the Expansion Slot Utility set to option number 2?

regards

Kristian Lam
Blackmagic Design

[James Fuller]

FIXED!!!

I love you!

I had it in slot 2 to allow it to ‘breathe’ a bit. With the card in slot 4, if you have disks in all 4 bays of the Mac Pro, the DeckLink sits very close to the drives. It’s a while since I first installed the card, but I don’t remember instructions being so specific. Maybe this is something Blackmagic could consider revising? – although I seem to be the only one to have this problem…

Thanks for the help though!

[Kristian Lam]

Cool. Your Mac has PCIe slots with assignable lanes. In slot 2, it’s probably only running on x1 PCIe bandwidth which does not have enough bandwidth for 10- bit Uncompressed HD. You might want to just check the expansion slot utility and see if can assign more bandwidth to slot 2 if you really want to use that slot.

regards

Kristian Lam
Blackmagic Design

[Ryan Jenkins]

Hi guys,
i’m not sure if it’s the same problem but i’m have the same issue with PC and premiere pro using the BM’s Multibridge Pro. The only difference is after i render the clip the flickering stops, until i drop an effect back on the clip and then it starts again until i render it??

Cheers
Ryan.

[Kristian Lam]

Hi Ryan,

Don’t think it’s the same thing. Sounds more like a field issue to me.

What kind of format you working in?

regards

Kristian Lam
Blackmagic Design

[Ryan Jenkins]

Hi Kristian,
I seems to happen on all HD projects and even when the timeline isn’t playing.It’s like when a monitor is receiving a non sync signal, it flickers and clicks. All is normal once the clips are rendered. I mainly shoot and cut progressive.
Cheers
Ryan.