RESOLVED: NDI In from iPhone stutters

Bugs
1

Hi!
I’m trying to build a very simple NDI Network where I get the Stream from the NDI HX Camera App on my iPhone. When I test the stream in the official Studio Monitor App or OBS everything runs smooth, but in Touchdesigner I have an annoying stutter where it seems like it’s dropping a frame every other second. When I use the stream from iPhone to OBS to Touchdesigner over NDI there’s no problem. So somehow OBS does something to the stream that makes it work better in TD. If I take the stream from the Studio Monitor App the problem remains. I already asked in the facebook help group but nothing helped.
Checked my firewall settings, as well as changing the fps in TD but to no avail.
Any ideas?

My specs:
Lenovo Legion 7i
RTX 2070 Super Maxq
Windows 10
Latest TD non-commercial build

2

Hello @MHrad,

I notice that you have a laptop with Max-Q, using a Monitor DAT, make sure TD is running on the dedicated GPU.

Additionally, NDI HX support is in TD experimental, only - I believe - when you toggle Hardware Decode, which would imply that your process runs on the dedicated GPU (the RTX 2070).

You could possibly toggle Low Bandwidth as well since you are on Wifi.

Cheers,
Michel

3

Thanks @JetXS for the fast response!

It is indeed running on the RTX 2070S and turning Hardware Decode on did not solve the problem. Same thing happens on low Bandwidth. I also tried running it on a Desktop PC with a RTX 2070 and with a different iPhone but the problem persisted.

4

Are you running TD v40k experimental release ? As that is the only branch with NDI HX support AFAIK.

5

Yep I tried it with the newest experimental release.

6

Do you see the same problem in Official build 2020.27390? Trying to narrow down the possibilities of what introduces it and experimental uses a different version of NDI.

7

Yep, still there unfortunately.

8

We’ve updated NDI SDK multiple times since 2020 and the NDI app hjas also changed greatly, so I retested this today with 2022.33910 and its runs great. If you experience new issues please post them here.

9

< exactly the same problem I get when sending or receiving NDI between TD and any other programs.
about every seconds, there’s a very small stutter in the stream, like a frame drop. Only in TD perform chop, it shows no frames were dropped.

So I guess the NDI encoding/decoding happens in some background thread? What can be stalling it? And how can we debug it or collect useful runtime information to share here?

11

Sorry for the delay in responding. If you send a frame number embed in your image and record that on the receiving side, does it show it’s dropping a frame, or how many?
Do you see the same issue if TD is the receiver?