How to reduce the delay of the capture card

Hello there
On the computer using Millumin, GPU or CPU or expensive capture card, which can minimize the delay of the capture card. Currently I mainly use bmd capture card
How to optimize the system if possible

many thanks



  • Hello @Eason,

    What is your goal? How much (at maximum) should be the latency between the camera and the video projection ?
    In last beta, we added support for Bluefish444 devices, that have lower latency than Blackmagic ones.

    Best. Philippe

  • thank you for your reply
    I often take some technical projects on the conference site. I use millumin as a screen control solution. In addition to playing videos, I also collect camera or director signals (1080i50), ppt or keynote signals (1080p30 or 2160p30). The habit is to advance all signals to millumin, put all pictures and videos into millumin, then arrange all content according to customer needs, and then output to the screen device through the dp or hdmi interface (**** p60) on the graphics card. So I do n’t use e2 devices.
    My main problem is that there is a short delay between the camera image on the screen and the scene. Although few customers have pointed out this problem, I am not satisfied with it myself.
    I know there are many reasons for delays, capture cards, computer computing, screen processors, and so on. I hope to reduce the delay as much as possible. The capture card and the screen processor are more difficult to solve, but I can improve the configuration of the computer running millumin. Therefore, for the above problems, are there any good suggestions on the computer configuration, the gpu or cpu is more important Can Bluefish444 devices improve this problem? Can using Bluefish444 devices in millumin only optimize videos in ProRes format?

  • Hello @Eason,

    # Can Bluefish444 devices improve this problem ?
    We observed lower latency than Blackmagic, 1 or 2 frame better, so it should improve your your workflow.
    However, keep in mind that Bluefish444 cards are more expensive than Blackmagic ones, and requires a Thunderbolt chassis.

    # How to improve latency ?
    Using 1080p60 instead or 1080i50 or 1080p30 should make the capture faster, so improve your workflow. Even 720p60 would be better over 1080i50 or 1080p30.

    # Can using Bluefish444 devices in millumin only optimize videos in ProRes format ?
    I do ot understand the question, since Millumin only supports Bluefish444 capture cards. It has nothing to do with movies or codecs.

    Best. Philippe

  • Hello Philippe Thank you for the information

    That's right, because in our case, the video signal provided by most camera teams is 1080i50, I can't decide on them. Some teams provide p signals which is better. ppt can accept a little delay. So in order to reduce the pressure on the graphics card, I usually use p30.
    Sorry I made some mistakes myself. Bluefish444 is a capture card. I mistakenly think it is Apple Afterburner. Bluefish444 is indeed very expensive.
    When I tested in the studio, I used the 1080i50 signal input to bmd, and the 1080p60 output from the graphics card to the monitor. The delay between this is relatively small, and I can accept it. But during the show, because there will be a larger output, more video and picture material will run at the same time. There will be a lot more delay. So I think that as long as you solve the computer pressure, you can solve part of the delay. I wonder if you agree with me.
    So based on this judgment, I will think of how to improve the computer configuration reasonably. If my opinion is wrong, please correct me, it will help me.
    In addition, I also saw support for Afterbumer in the update of V3.15.g. In which areas can I actually use it? Can it help millumin perform a large number of calculations. Does it work only when the material is in ProRes format?

    Thanks again

  • Hello @Eason,

    Adding more video or using larger outputs should not affect capture delay, unless your computer (probably the graphics card) reaches its limits (so it cannnot render all frames). Display the FPS in Millumin (seee "Output" menubar), and check that it is stable.
    Also, you may have additional cables and converters for your show, so the video signal would take more time to be displayed (in comparison at your studio).

    Best. Philippe

    PS : Afterburner car only help the computer to decode ProRes movies (so it is not useful for capture)

  • Ok thank you Philippe
  • edited April 2020
    Hi Eason, in my opinion essential, once you have even one device that has 50p or 50i, you should run your setup completely in 50Hz and 50 fps.

    Either a complete 60Hz or 50Hz setup with all devices.

    No different mixture of different refresh rates.

    It is complex but helps "always" when micro-jerking should also occur.

    Citizen Caine
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