Question / Help Probably easy: many audio dropouts from NDI source

[JackElliott]

I'm new to OBS and I probably wouldn't even be here if it wasn't for the fact that I set up remote radio broadcasts for our local community radio station (KPOV in Bend, Oregon, USA) at music festivals. Coming up pretty soon is a festival where the a/v livestream company will be giving me an a/v NDI stream of the music over a Ethernet cable, and my job is to output the stream's audio from my laptop's headphone jack.

A couple weeks ago, I did this using Newtek's NDI Studio Monitor, which connected up easily to their stream (ethernet connection) but there were frequent brief dropouts of the audio. Back home I set up NDI Test Pattern on a computer on the LAN, and also heard the brief dropouts when using Studio Monitor on two other computers. Tried a different computer for Test Pattern, same problem.

So the guy who will be feeding me another NDI stream at another festival in a few weeks said to check out OBS Studio (see, this is about OBS and not Studio Monitor).

I have it installed on a couple of laptops, and the NDI Plugin, and I'm not getting solid connections at all. Even with Source set to Audio Only, the test tone drops in and out, stops without warning, restarts, and is generally unusable for broadcasting. Audio-only usage shows less than 3% cpu. The problem gets worse, if I go to low-res video, and high-res pretty much brings the thing to its knees. This for a static test pattern. I can view 1080 video over the lan with our Roku box, there's no bottleneck there.

I know this isn't right. But here I am. It shouldn't be this hard to get a solid audio connection over a lan.

So, the setup is:

NDI source > lan > OBS Studio w/ NDI plugin > audio to headphone jack

I've tried two computers as source using NDI Test Pattern, and since I also had the issue when getting feed from the music festival a/v guy, I'm pretty confident that the source isn't a problem.

I've tried OBS Studio on two machines here and they both suffer from continual and sometimes lengthy audio dropouts.

If any one has some kind of "hey, knucklehead, push this button" thing for me to try, I'm all ears. Thanks!

 

[DEDRICK]

Is the cable you are using to test a Cat6 or Cat5e? NDI requires a Gigabit connection, if the cable you are using is only Cat 5, not 6 or 5e, you will be limited to 100Mbps

You can check your link speed in Windows Ethernet Status, this will tell you what you are connected at

 

[JackElliott]

Many thanks, Dedrick.

So, just to confirm, NDI needs a gigabit connection to send a static test pattern image and a single probably-not-very-high-bitrate test tone? I'm connected to the LAN via wireless at 144Mbps which seems pretty sufficient for this seemingly-easy task. Window Resource Monitor shows Network usage at about 8Mbps with audio-only, about 10Mbps in high-res with the static test pattern. I don't know how I could possibly be saturting a 144Mbps connection.

 

[Narcogen]

NDI does not work well at all over wireless. Slight fluctuations in performance that cause insignificant impact to bandwidth tests can easily turn into audio dropouts.

If possible, test the setup you want to use with a wired connection. If there are no dropouts, then that's likely your answer. If you still have them, then there's something else.

 

[Boildown]

Not to mention, at a festival, thousands of people are going to be trying to use wireless at the same time, and even when they aren't using the same access point, it still will interfere with the wireless signal due to the half-duplex nature of wireless. No one will notice downloading a jpg or browsing a web page, but if you want perfect transmission of audio/video, you need a wire.