Hello,

is NDI suitable (well, more suitable than the Blackmagic Decklink cards) for IMAG? With the use of another computer that just shows the NDI video in fullscreen mode.

I am still using the old Decklink quad for inputs and outputs and have about have a second of lag on it.

What's the best way to have the least amount of delay on the output? (besides using the fullscreen, don't want any other program to plopp on the big screen or my mouse accidentally to be shown)

What's the best video card for those purposes with Vmix? Are there anyOr will there always be such a big lag because it's just a video mixer?

If you're using a small number of sources (6 or less) for the IMAG screens, and they're available as NDI signals (converted by vMix, NewTek's Connect or BirdDog), and if you can manage with straight cuts, then something that makes use of the "NDI Routing" functionality (like my NDI Router app) can act as a switcher in the NDI domain and will add no further latency to the signal path. However, there is an issue with some NDI3 sources, which was not present in NDI2, whereby the sources don't switch immediately like they used to do. I've not changed anything in my code, and I haven't got to the bottom of what causes it (from the NewTek side of things), but I look forward to seeing if NDI 3.5 is any different.

Hey Michael !

1 . correct. NDI Router by Martin Kay is a fantastic utility, despite, as he stated, since v3 it's less responsive than it used to be

2 . yes it does

Guillaume

Shoudn't be. Not tested yet for production as I now use a hardware router systematically, but NDI 3 or 3.5 (as it's the version that we're using already in vMix though it was not announced) shouldn't be different than NDI 2. I'm not talking the issue Martin Kay noted in regard to his own NDI Router software.


Correct answer is "it depends". We've been discussing this lately in Tom's FB group.
Frame counter... I did this long ago. That's why I know for sure there is much less latency on vMix inputs (they are distributed immediately after NDI conversion) than on vMix output.

My testing was as follow:
one laptop playing a clock with thousands of seconds in a web browser (javascript)
one cam shooting at the screen with hdmi out getting in vMix via a capture card
vMix Desktop Capture grabbing browser window for NDI ingest

This way I could compare (I was taking pictures at 1/1000 or doing printscreen)
- transport time up to vMix (hdmi in in preview, ndi in in PGM). there is a very slight difference
On a third computer, I had several NDI monitors fed with :
- direct NDI from laptop 1
- direct NDI from HDMI source converted by vMix
- vMix output either with NDI clock or HDMI clock
Results vary a lot. Not kept my results but I'm 100% positive HDMI input delivered by vMix is much faster than PGM.
By taking pictures I could get all 3 computers monitors all together next to each other.

Thanks JoseL but we were talking NDI output here.
Also I never use physical outputs on the capture card as it's slower and less reliable than using the HDMI out on the graphic card itself.

Guillaume

+1. Decklink or aja sdi out is a bad decision.

Direct out is the best way for performance. If need more outs use ndi.

Hdmi to sdi and sdi to hdmi non scaling converters do not add latency, or near zero.