Terrible Echo with NDI setup

[CharlieA]

I'm wanting to recording some Skype webinars with OBS and every time I record them I'm getting a horrible echo, like 3 seconds after I say something you hear it bounce again. Everything sounds fine in the session, its only after the session when I check the recording its got the echo.

This is my setup:

Audio Output - That's just so I can record the audio of everyone in the Skype chat and also an audio I display on my screen (like a YouTube video)
NDI - My face and voice
Screen - Self-Explanatory

I have a feeling the Output Capture might be what's causing the feedback but I'd like some advice on how to resolve this.

 

[Lawrence_SoCal]

So you are capturing the audio directly via NDI, sending that Skype, and then capturing audio from Skype (which includes you and has normal Internet latency) as well.... yup, echo

Do you have an NDI PTZ camera, or ?? just curious, what is you audio/video feed such that you are using NDI?

Skype (Zoom, etc) filters out echo when it is source and input on audio. but you have separate channels with huge time delta, so that echo cancel doesn't apply. This isn't a use case I deal with, so hopefully someone more knowledgeable than I will comment
but until then, I suspect capturing/recording audio only from Skype would make the most sense

The challenge is if you are using OBS to feed Skype (virtual cam?), in which case you have to transfer the audio from OBS to Skype
Assuming everything you want is in the Skype scene/session, is there a reason/obstacle to not simply using Skype's record feature?
Otherwise I'm wondering how to take A/V via NDI, output that to Skype (that is what you are doing, right?) then have Skype screen in OBS as source and capture it but not the A/V from NDI?? are you adding/modifying your NDI video feed in OBS before sending to Skype? if not, why not can from camera into Skype?

Sorry if I'm confused, but seem something missing in my understanding of the use case or an odd/complex/loop OBS setup

 

[CharlieA]

So you are capturing the audio directly via NDI, sending that Skype, and then capturing audio from Skype (which includes you and has normal Internet latency) as well.... yup, echo

Do you have an NDI PTZ camera, or ?? just curious, what is you audio/video feed such that you are using NDI?

Skype (Zoom, etc) filters out echo when it is source and input on audio. but you have separate channels with huge time delta, so that echo cancel doesn't apply. This isn't a use case I deal with, so hopefully someone more knowledgeable than I will comment
but until then, I suspect capturing/recording audio only from Skype would make the most sense

The challenge is if you are using OBS to feed Skype (virtual cam?), in which case you have to transfer the audio from OBS to Skype
Assuming everything you want is in the Skype scene/session, is there a reason/obstacle to not simply using Skype's record feature?
Otherwise I'm wondering how to take A/V via NDI, output that to Skype (that is what you are doing, right?) then have Skype screen in OBS as source and capture it but not the A/V from NDI?? are you adding/modifying your NDI video feed in OBS before sending to Skype? if not, why not can from camera into Skype?

Sorry if I'm confused, but seem something missing in my understanding of the use case or an odd/complex/loop OBS setup

There's two reasons I don't want to use Skype's record feature. Firstly the quality is poor (15FPS), and you can't adjust the size of your camera window in a group chat, but you can adjust it in OBS.

Yeah, I've just tested NDI with no Audio Output and there's no echo, but the issue is how to capture the audio for people participating in the group, when they ask questions and so forth, or if I want to play a video and have the audio recorded. I can't possibly create an NDI source for each person because I don't know how many people will attend and its too much hassle to set up.

 

[CharlieA]

So you are capturing the audio directly via NDI, sending that Skype, and then capturing audio from Skype (which includes you and has normal Internet latency) as well.... yup, echo

Do you have an NDI PTZ camera, or ?? just curious, what is you audio/video feed such that you are using NDI?

Skype (Zoom, etc) filters out echo when it is source and input on audio. but you have separate channels with huge time delta, so that echo cancel doesn't apply. This isn't a use case I deal with, so hopefully someone more knowledgeable than I will comment
but until then, I suspect capturing/recording audio only from Skype would make the most sense

The challenge is if you are using OBS to feed Skype (virtual cam?), in which case you have to transfer the audio from OBS to Skype
Assuming everything you want is in the Skype scene/session, is there a reason/obstacle to not simply using Skype's record feature?
Otherwise I'm wondering how to take A/V via NDI, output that to Skype (that is what you are doing, right?) then have Skype screen in OBS as source and capture it but not the A/V from NDI?? are you adding/modifying your NDI video feed in OBS before sending to Skype? if not, why not can from camera into Skype?

Sorry if I'm confused, but seem something missing in my understanding of the use case or an odd/complex/loop OBS setup

Think I've been able to things set up to look how I want now (albeit it is a bit complicated to set up). As below:

What I've done is keep the Audio Output with Skype (so you can hear both me and the other person), and kept the NDI video and muted the audio in the mixer to get rid of the audio. Bit of an arse about face way of doing it, but it works. Only problem is the audio sounds kind of fuzzy, I suppose because its having to pass through Skype before coming into OBS. Unless you can think of a better way of doing it?