Decklink Duo 2 Output Problems

I am having problems when outputting Millumin 4.12c thru a Decklink Duo 2 in an OWC Helios TB3-PCIe box.

Using a M1 Mac Mini, I have set up a canvas that is 3840x1080, outputting to the Duo2.

I am seeing tearing within the displays.

A vertical line scrolling across the screen tears within the screen. This happens with ProRes and HAP files.

The Activity Monitor shows no stress on the machine.

I have duplicated this with a M1 Max full spec MacBook Pro as well.

However, when I output from Mitti via the Duo2, I am not seeing this tearing. Everything plays back very smoothly. So I believe that this is not a hardware problem.

Is this a known problem? Do I have settings incorrect somewhere in Millumin?

Thanks for any help.


  • Hello @JBdevice,

    A few questions :

    • What mode did you choose on your Decklink Duo 2 ? 1080p60 ?
    • What is your version of macOS ? 11.6 ?
    • Could you compare with Millumin 4.12.c running via Rosetta ?
    • Could you compare with Millumin 3.18.o ?

    Thank you for your answers.

    Best. Philippe

  • MacOS version on both the MacMini and the MacBookPro = 12.1 Monterey.

    Decklink Duo2 Mode - 1080p60. I also tried 1080p59.94 with no visible difference.

    I am traveling over the next couple of days, but will test out 4.12c via Rosetta once I get home.

    I did try Millumin 3.18 ( downloaded last night)- I saw much smoother playout on the Duo2 via 3.18 but while HAP Q played back well, ProRes could not get to 60fps. Though both codecs did seem to play back smoothly.

    I will update this post when I am able to get back to the Thunderbolt enclosure and Duo2 card.

  • edited December 2021

    Systems tested

    M1 Mac mini and M1 MAX 16"

    Desktop Video 12.2.2 and 12.2.1

    Blackmagic UltraStudio 4K Mini

    Decklink 8K Pro in an OWC Helios TB3-PCIe box

    I tested 3.18.o and it worked fine 1080p@60 with a single output.

    4.12.c does not work with Blackmagic UltraStudio 4K Mini or Decklink 8K Pro in an OWC Helios TB3-PCIe box. 1080P@59.94 or 60. Rosetta doesn't not help.

    I downloaded this file from youtube

  • Hello @hphase,

    What do you mean by "does not work" ? You cannot output at all with your Decklink 8K Pro ? Thank you.

    I guess there is an issue between our Blackmagic implementation using Metal (the technology replacing OpenGL on macOS) and M1 machines. We will investigate this.

    Best. Philippe

  • it's tearing with any BM product. "does not work" meaning not a usable device.

  • Hello @hphase,

    Thank you for the info. So from what I understand, you have the exact same issue as JBdevice, right ?

    If you have an Intel machine : do you have the same issue on such a machine ?

    Best. Philippe

    • Could you compare with Millumin 4.12.c running via Rosetta ?

    I just tested 4.12c set to run via Rosetta.

    I am seeing the same behavior under Rosetta.

  • Hi,

    I confirm the trouble with the V4 and the black magic Desktop

    I have a macbook pro 16" M1 max 10 core 32 GPU 32 RAM

    A decklink 8kpro from black magic into a sonnet echo express iii

    With the same project open with different set-up:

    with V3.18o : no glitch on the 4 outup set up as 1920/1080 50i

    with V4.12c : a few glitch but less when opened with Rosetta.

  • Hello @JBdevice, @hphase and @Germain,

    We released the update 4.12.d with a fix. Sorry for the inconvenience.

    Do you have a question ?

    Best. Philippe

  • Thanks for the support Philippe,

    I'll test that tonight or tomorrow and give you my feedback.

  • Hi,

    looks fine with my configuration, new M1 max + Decklink 8k into a sonnet echo iii (up to what I can test for the moment at home , 1080 60p)

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