5.2 DSK Based Switch to Live Configuration (v2.0)

Owned by Thomas Staiger
Last updated: Jan 28, 2019 by Georg Deisting
2 min read

The advantage of using the built-in method is, that it is possible to switch between a live signal and the playout of a movie without the need of a video router. In addition it is possible to add graphics to the live signal without the need of a second video device.

Like described above, there are two methods to achieve this and here is how the DS Keyer based setup (AJA only) has to be done.

Activating the 4K mode of an AJA device, the ability to do hardware based Up, Down and Cross conversion as well as the ability to activated the DS Keyer or to play out Fill&Key will be disabled. So make sure the UFC Mode firmware is loaded to be able to use an DSK based switch to live method.

Using the AJA DS Keyer means that the video card synchronizes to the incoming video and not to the reference signal. Therefore any reference signal attached to the "Ref In" will be ignored, so make sure that the incoming video signal is stable. In order to stabilize the signal in advance (i.e. before it is sent to the video card input) you must use a frame synchronizer. Suited frame synchronizers can be found on the → AJA Website but it is also possible to use a BMD ATEM switcher to stabilise the signal. There is no need for a frame store, in case the signal comes from a switcher and the switcher is always turned on.

Playing out ClosedCaption data

CC data is only supported using devices from AJA while using a "Without DSK" or "Disabled" Live SDI input configuration in the channel settings of just:connect. Selecting a "With DSK" based method will disable the play out of closed captions completely.

Connect a signal and select the input in the AJA control panel

Connect the live signal to any of the available video inputs and select that input in the AJA control panel Input Select.

Activate the built-in downstream keyer of the AJA device 

Configure the AJA downstream keyer according to this screenshot to activate the pass-through mode:

  • Mode: "Frame Buffer over Video In"
  • Audio Out: "Frame Buffer"

Select the right switch to live method for your channel

Open the Advanced Output Format settings of just:connect and select one of the available Without DSK-based settings.

  • With DSK, default black: Black will be played out in case nothing is playing in the timeline of the UI.
  • With DSK, default pass-through: The connected signal will be played out in case nothing is playing in the timeline of the UI.


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