Disable loopback while running application

[TheSashmo]

When I run an instance of Ultragrid on decklink port 0, I get a loopback on port 1, until I run another instance of Ultragrid to use port 1. This might be a decklink issue, but I have never seen that on any other non Ultragrid application. Is there an option I am missing, or is that a feature?

[MartinPulec]

You mean the passthrough mode? This is AFAIK toggled on by default for DeckLinks. On the contrary, UltraGrid disables it in recent development versions by default.

I am not completely sure from your description about the actual setup, however. Which device it is? Playback or capture? It may be also something else, like A/B playback of device profile setting for models supporting that (eg. 8K Pro). However I am not aware that there is some special non-default setting in UltraGrid in this direction.

[TheSashmo]

Quite straight forward.

Device #1 is setup to send to device #2. On device #1 the output port is showing the same as the input port. i.e. decklink port 0 has a loop through of port 1.

I have not seen any option in the decklink to disable this.

[MartinPulec]

Which version? As I wrote, development version of UltraGrid now toggles the passthrough off by default. It is option -t decklink:nopassthrough, but as it is default, it is pointless to use it as such. However you can use -t decklink:passthrough (enable) or -t decklink:passthrough=keep (device defaults).

[TheSashmo]

I'm using an older version so I will have to check. Thanks Martin.

[MartinPulec]

I see, well, only the default (== to disable) has changed recently, the option itself has been there already some time ago, so it is possible that -t decklink:nopassthrough would do the job in the end.