NDI feed; maximum feeds/bandwidth and reliability?

Hey folks. I’m working on a potentially very large live streaming installation, with upwards of 20 cameras. I’m looking at a variety of solutions at a variety of budgets, and on the cheaper end, I’m trying to determine if it’s even possible to run 15 to 20 Mevo Start cameras in NDI mode (1080p 15Mbps), and pull all of those feeds into a software system, such as mimolive. How reliable is the NDI feed feature? Is there a hard limit on how many feeds you can ingest and mix, or is it purely determined by CPU/GPU? I’d probably spec out a high end Mac Studio for this setup. Is there any way to determine how many NDI feeds it could handle other than just trying it? (obviously it’s not exactly something that’s easy to just try without actually buying a ton of gear).

Any and all insight is appreciated, thank you!

Hi @PhotoJoseph That is a very exciting project and it would be very helpful to get a number of how many NDI|HX feeds a Mac Studio with mimoLive can handle.

In theory, it should be possible, but we haven’t tried it.

Since NDI|HX is using h.264 compression, each of the feeds will be need to be decompressed. For this, hardware decoders will be used until they are saturated, then it will fall back to software decoding which is depending on the number of CPU cores.

I know that one customer has tried 18 mimoCalls, which are also using h.264. This was on an iMac Pro Intel with 18 CPU cores (which means 36 cores in hyperthreading).

Bottom line: I don’t see any other way than to try it.

Testing how many NDI|HX streams a Mac Studio M1 Ultra can handle was on my list, but I screwed up ordering the Mac Studio and now it is scheduled for end of August…

Using that much NDI can also strain general network bandwidth.

Thank you @Oliver_Boinx — do you feel that decoding NDI|HX is on-par with decoding the mimoCaller streams? You said the customer tried 18 calls… do you know how successful it was?

Thanks for the reply!

The Mevo is only 15mbps, so 20x 15 is only 300 mbps, and should be easily managed by a gigabit switch. I’d definitely install a dedicated managed network for this. Thanks for the link @Troy.

Sorry, yes, the customer used 18 mimoCalls successfully, as far as I know.

Now that I think more about it, there is a difference as the mimoCalls are only around 3 Mbps per stream and some of them could have been encoded in VP9 instead of h.264, so the NDI results could well be different.

Got it, thanks. So ultimately… we really don’t know without testing!

It should be cheaper to install first 5 of them and than scale the processing needs up to 4x.