NDI delay to BirdDog Flex

[carville...@gmail.com]

Hello,

I'm playing around with the Qlab NDI output option. I am getting a 13.6 second delay between pressing Go and image on stage. This happens when no image is up. If I go from one image to another it has no lag.

The projector is connected to a BirdDog Flex 4K Out. 

The computer is a Mac Pro (2013) running 12.6

Qlab 5.0.6

BirdDog is 4.5.152-LTS

Network is closed. Has not had an issue with NDI video on other devices (and that device from other devices)

There is no lag when using NDI Video Monitor on a laptop on the network.

There is no lag when using the Birddog Flex 4K In from a Thunderbolt to HDMI adaptor from the same computer.

So I believe it is something that is happening on the Birddog end. Does anyone have any experience as to what settings might need to be adjusted?

Birddog does have some network options (TCP, UDP, Multi & M-TCP) I've tried them and not seen success.

Thank you, Gregg

[Siobhán Dougall]

Hi Gregg,

I don’t have any experience with the BirdDog, but from your description it sounds like this has to do with the fact that (by default) QLab stops outputting NDI frames when no cues are active. This is in some ways a carryover from the way it treats native display output, where it’s sometimes important to be able to release the screens for the OS’s use. (This has been a topic of a fair amount of internal discussion recently, and yours is a very useful data point to add to it; I don’t think we’ve encountered devices that are this sensitive to the difference.)

For now, one workaround you could use is to enable “keep rendering between cues” in the stage editor. With this checked, once QLab starts running a cue, it will continue actively rendering black even after that cue finishes, and will only stop producing a signal if you panic the workspace.

You’d then probably want to add a cue to run first up to get the signal going—a simple black PNG with a short duration set ought to do it.

Cheers,

Siobhán

--

Siobhán Dougall (she/her)

Software developer, Figure 53

sio...@figure53.com

https://qlab.app/

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[Siobhán Dougall]

Actually, I stand corrected—I now see that we’ve had another report of someone encountering similar problems with a BirdDog. So I would say it’s a systematic issue and we’ll need to keep considering ways to address it.

Cheers,

Siobhán

--

Siobhán Dougall (she/her)

Software developer, Figure 53

sio...@figure53.com

https://qlab.app/

[carville...@gmail.com]

Thank you Siobhan. 

I did change the rendering setting and that takes care of the internal problem between cues. The delay at the first cue remains. As you mentioned I could set up an initial cue to get it going. I get a little nervous about a work around like this because I don't fully understand the mechanics behind it and am left wondering if there will be something that causes it to not work during a show. (I can tell the op not to use the panic during a show, but that doesn't mean they will remember)

For now I can use the HDMI to a converter and that works great. 

So far Qlab 5 has been great to work with, I appreciate the network possibilities and look forward to exploring them more. Hopefully the NDI issue will resolve itself. I have a different type of NDI converter I can borrow, so I will give that a shot and see if it is any different.

Thank you,

Gregg

[Kinetic Screen]

Hi Gregg, I had this exact issue with the Flex recently, and it does seem to be that it is extremely sluggish about resuming its HDMI output when the NDI signal resumes. Which is super lame, as they really should have an option to 'retain output' even if the NDI stream doesn't contain any video.

It does mean that you will have an issue when initiating a panic. My solution was to create a cue that was just a black frame, set to 'bottom' layer, and set it to have a hotkey of the ~ key, which is the one below the ESC key. So if I needed to panic, I would also immediately press ~ under it, retaining the NDI output.

[carville...@gmail.com]

FWIW - I had some time to play around with this and using the same computer and setup with Isadora - no lag to the Flex when changing scenes or starting from nothing and going into a scene. 

Gregg

On Friday, October 28, 2022 at 12:13:03 PM UTC-4 Siobhán Dougall wrote: