Flussonic Media Server documentation


Decklink SDI

Flussonic Media Server can:

Flussonic also works with Blackmagic Decklink Quad 2 cards, which have 8 ports.

Capturing video from Decklink SDI or HDMI cards

You will need to install Blackmagic drivers, update the card and then configure the stream as follows:

stream sdi {
  url decklink://0 enc="vb=1024k preset=superfast tune=zerolatency ab=32k";

Flussonic Media Server will take the first device (0) and use its autoconfiguration feature to capture video (the search for active resolution).

Some Decklink models do not support automatic search for active resolution, and for those models you'll need to specify it manually by using the options mode and vinput. For example, if you have Intensity Pro with connected HDMI source of 720p at 50 fps, you should configure the stream as follows:

stream sdi {
  url decklink://0 mode=hp50 vinput=3 external=true enc="vb=3096k ab=64k";


  • mode - the mode of the incoming stream
  • vinput - video interface
    • 1 - Composite
    • 2 - Component
    • 3 - HDMI
    • 4 - SDI
    • 5 - Optical SDI
    • 6 - SVideo
  • ainput - audio interface
    • 0 - Analog
    • 1 - Embedded
    • 2 - AESEBU
  • external - starts capturing in an external process
    • true
    • false - default
  • vpts - the synchronization mode for video
    • 2 - by audio
    • 3 - according to the reference signal
  • apts - the synchronization mode for audio
    • 1 - by video
    • 3 - according to the reference signal

Capturing from Decklink Quad 2

If you use Blackmagic Decklink Quad 2 cards, use the duplex=full|half option to to tell Flussonic whether your card uses 4 or 8 SDI ports.

Set full if the card uses 4 ports, and set half if the card uses all 8 ports. Set this option for devices 0, 1, 2, 3.

The following configuration allows Flussonic to use 8 ports at capturing:

stream test {
  url decklink://0 duplex=half;

Important. Make sure that all the streams that are captured via Decklink Quad 2 have the duplex option specified.

Deinterlacing of progressive streams

Flussonic can deinterlace progressive streams to eliminate artifacts. For that, use the CUDA yadif deinterlace method:

stream test {
  url decklink://1 enc="vb=4000k hw=nvenc preset=slow fps=50 deinterlace=yadif ab=128k" vinput=4;

Output to Decklink SDI or Decklink HDMI cards

Flussonic Media Server not only captures but also passes video to a Decklink SDI or HDMI card.

Set the parameter push decklink://:

stream test {
  url udp://;
  push decklink://0 size=720x576 fps=50 volume=0.01 deinterlace=true;

Flussonic decodes a stream and passes it to the specified Decklink device or slot on the card itself (for example, 0). If necessary, you can use deinterlace=true to eliminate interlacing. The maximum volume (volume) is 1.0.