Full screen Syphon / NDI Processing Q's


Wondering if someone might be able to shed some light on this for me…

In a situation where I have to use NDI for a gig to get to another PC that runs the visual setup.

However part of the show runs in Processing - no probs getting it to send via NDI to VDMX (there are some compression artefacts which I guess I’ll have to live with and is more on the NDI end)

Anyway, when I run my Processing sketch it runs full screen, then NDI picks it up, and VDMX displays from there.

My question is more around, if VDMX is then displaying fullscreen over the top of the fullscreen P5 sketch, are both those windows consuming GPU power? Or is the GPU only really being hogged by whats displayed to the output?

I’m probably going to end up with two NDI feeds - one from Processing, and the other from VDMX for the part of the show that exists there.

But I thought if by routing the p5 sketch into VDMX I could kill two birds with one stone. Dont really want my system to take more of a hit than it needs too though. The compression is kind’ve a bummer too (only running at 720).

Any ideas on what might be an optimal setup in a situation like this?

Like it would be cool if the p5 sketch could run without displaying to the main screen, and just go straight to syphon…

Realised I was getting a bit mixed up here focusing too much on NDI. I’ve routed the P5 sketch into VDMX via straight Syphon, not NDI as I was stupidly doing. Looks great now. From there I guess it’s up to the Gigabit Ethernet lords as to where things go from here…


Sounds like you’ve figured this out on your own, but for anyone who stumbles into this in the future, here is a useful thread,

tl;dr – use Syphon whenever possible, it passes image textures directly between apps on the GPU which is going to be the most efficient and highest quality transfer.

When using NDI, there is an option to use the RGB mode that is higher quality, but uses more CPU time / more bandwidth.

In general it is best if only one of your apps is going fullscreen for output – some apps (such as VDMX) can be configured to render only to offscreen buffers for when you are only going to be outputting to Syphon or NDI. Not all apps will let you do this though, depending on how they work, they may require some level of drawing to screen in order for render upkeep…
(eg in the case of VDMX you can go into fullscreen mode and disable all of the displays)

Awesome thanks David!

I see there is the NDI plugin. So, I would activate full screen, but disable displays when sending? Think I better go buy an Ethernet dongle and cable and do some testing… :)

Ah, one last Q

Sounds like the venue PC can run Spout into Resolume. Are you aware of anyway to send Syphon to Spout?

Spout is basically the Windows version of Syphon
(or Syphon is the Mac version of Spout depending on your vantage point…)
So they never exist on the same computer.
The both only work for sending video between apps on the same machine – If you need to send video between machines, NDI is your best bet.

Yes, that I understand.

Just appears we have a very finnicky in house PC system to deal with. Apparently the NDI source in Resolume isn’t happy, but Spout is, and apparently it had been done before like that. Syphon - > NDI _ NDI -> Spout -> Resolume.

Anyhow, I think i’ll report back on how it all goes. Hard to do much else from here, at least the output side on my end is sorted. Been a cool learning curve finding out about NDI though :slight_smile:

Gotcha – maybe give this a try?

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i did spot that page in my googling, noticed its discontinued. but then found a reddit page where someone was using the wayback machine to access a download. so i’ve got a copy of that now, and TCP Syphon… I believe you can send between the two. Will have to wait see till I have a Windows machine to try it on. Cheers David!