NDI Recorder released on alpha channel: feedback please

The alpha release of ATVO 1.30.0.1 includes a new version of NDI, which we've called "NDI Recorder". This version is intended to replace the current NDI streaming functionality.

Note that you need the April 2020 release of Windows 10 in order to use the NDI Recorder.
More information on the new NDI Recorder can be found here: NDI Recorder.

Since NDI Recorder works very differently from the current solution, we want to leave it in the alpha channel in order to obtain testing feedback. Since the intention is to replace the old NDI functionality, the old functionality has been removed from the alpha channel builds.

Please gives us your feedback on:

• Does the new NDI Recorder work well? Think about performance, usability, system load (CPU, memory), etc.
• Do you depend on the functionality of the old NDI v1, or are you fine with replacing it with NDI Recorder?

I've only tested the NDI Recorder today for a few minutes.
Everthing worked fine instantly, and it's easy to use.
I will run it tomorrow on the Nordschleife endurance event for several hours. I'll report then about the hardware thing.

So the NDI Recorder was running yesterday for about 5 hours on our streaming computer.

In order of performance the was no difference between the classical version and this one.
I did not log CPU/Memory etc usage, but from what I've seen, there was no significant difference.
You want me to run some specific datalogger Nick? I could install that an make it run next WE?

Hardware

i7-4790 (non k)
GTX 1060
16 Gb Ram

In terms of performance do you mean performance or framerate of the NDI output?

The difference is this: in the old NDI v1, we use software rendering on the CPU to render each frame into NDI. The speed at which this happens is directly related to how many (visible) pixels must be rendered. A small widget is totally fine, but something close to a full screen widget is going to seriously hinder performance (usually down to 10-20 fps in my testing).

In the new NDI Recorder this is no longer the case; we use a different way to capture the overlay (on the GPU) which is no longer related to how many pixels need to be recorded. So this way should always easily reach 60 fps, while NDI v1 can often drop down to way below that.

Both went fine.
The overall performance of the computer was good, and i had constantly a stable NDI output of 60 fps from the NDI Recorder.

I used my normal theme for our broadcats, which was to heavy for the NDI v1

Today i made atvo run again for several hours

Atvo version 1.29.4.0 and only the NDI Recorder from 1.30.0.1

Webtiming, NDI Recorder and atvo worked without problems

I've attached you two pictures, one from the NDI recorder, an one from the task manager.

https://imgshare.io/image/BhUgP
https://imgshare.io/image/BhhR5

You can have a look on our Webtiming on:
Lowgrip.lu/webtime

Hey Nick,

Yesterday and today I had a lot of blinking while the NDI Recorder was running on our streaming PC.
Everything is fine until the NDI Recorder is running.
I don't want to blame ATVO to that problem.

I made a little video, and it looks like the network controller is on it's limit when NDI Recorder starts streaming.
Maybe you have a clue on that problem.

https://youtu.be/ol61bfzx2OM

What makes me wonder is that the NDI Recorder ran without problems for 24 hours on the 24h Nürburgring last weekend.
OBS is also set to internal sync on the NDI properties tab, not network.

I tried already to reduce the Graphics, to "minimize" CPU and GPU load.
Maybe you could look at the video, an you have some advice.
The only thing I've changed is, that I've set the bandwith used by iRacing to the max. (to make webtiming/3rd party standings working correctly)
The computer is connected via a 100 Mb/s to the router, and I'm connected via fiber (500Mb/s) to my ISP

Some specs of the computer

i7-4790
16Gb Ram
SSD
Nvidia 1060 (running iracing & atvo)
Nvidia 1050ti (OBS endcoding)

I rebootet the PC now, and gave it another try.
Now everything is working again, graphics on high...

Ethernet connection says 6-7Mb/s up, and +-500 kb/s down which is normal

Hi Christian, sorry for my late reply. I can't explain your problem. Have you seen it more often?

No problem Nick,

No this happend just once. On the follwing streams everything was fine.

Hey. Thought I'd give you some feedback, as I have an issue right now (and I don't know what is causing it).

So, I am on Alpha 1.32.2 and trying to use NDI Recorder. Only issue: the attached screen is what OBS Studio and Streamlabs OBS outputs, which pretty much sounds like some kind of scanline fail (which is odd with a digital signal, but eh, I've seen worse).

Would you have any pointer as to why I get such a result?

Are you using some kind of non-standard color format or resolution or something? It looks like probably the color format is wrong and output the wrong number of pixels per row or something.

Hi Nick, I wanna capture ATVO only by NDI and not having it on my monitor, is there any solution for me?
I have the NDI source working pretty well on OBS, but I have it also on my monitor, its annoying.

Thx

You can use the settings to move the overlay physically off your monitor screen. Note that you need to have at least 1 pixel of your overlay "window" on a monitor, otherwise NDI cannot render it anymore and you'll get a blank capture. That pixel doesnt need to have anything on it, it can be just a transparent corner.

For example with 1920x1080 on a monitor of the same size, you can move the overlay to 1919 x, 1079 y.

Has anyone experienced issues with Windows' audio while using NDI? As soon as I start streaming via NDI, it makes my audio on Windows a little crackly. As soon as I turn it off, the problem goes away. As far as I can tell, it could be an issue with the NDI plugin for OBS itself, but if that was the case maybe someone here has experienced it.

I have not noticed that, but also did not look for it specifically. Does it also happen when you don't "consume" the NDI source in OBS? E.g. just close OBS but leave NDI Recorder running?

Nick Thissen wrote:
I have not noticed that, but also did not look for it specifically. Does it also happen when you don't "consume" the NDI source in OBS? E.g. just close OBS but leave NDI Recorder running?

Yes, any time I have NDI Recorder running, OBS open or not, I get the audio clicking. It happens across all of my audio, outside of OBS and it shows up in the recordings/streams when the Recorder is running.

How much CPU is being used (in total and by NDI?)

Nick Thissen wrote:
How much CPU is being used (in total and by NDI?)

~25%, about 7% by the Recorder and 10% by OBS, the remainder is just other processing I have running at the moment. I'm not even loaded in the sim at the moment, just chilling on the desktop. It's barely noticeable, and intermittent, but there. Been searching for other fixes and nothing has worked as of yet. It's minor but definitely an annoyance that would be great to get rid of if I can find the cause!

This is on a Ryzen 5 3600X with an RTX 3080.

Kyle

That doesn't sound too bad then, I was worried you were maxing out the CPU causing sound to mess up or something.

Just curious: with the OBS plugin you can also "send" NDI frames (the opposite of what you do now). Do you get the same kind of sound issues when you do that instead of stream the ATVO graphics with our NDI Recorder? I'm just trying to check if the issue is in NDI or in the way we capture the graphics.

NDI does have the ability to send sound (perhaps this is causing it), but I am not using that at all so that should not cause any issues.

Nick Thissen wrote:
That doesn't sound too bad then, I was worried you were maxing out the CPU causing sound to mess up or something.

Just curious: with the OBS plugin you can also "send" NDI frames (the opposite of what you do now). Do you get the same kind of sound issues when you do that instead of stream the ATVO graphics with our NDI Recorder? I'm just trying to check if the issue is in NDI or in the way we capture the graphics.

NDI does have the ability to send sound (perhaps this is causing it), but I am not using that at all so that should not cause any issues.

Doesn't seem to have the issue when I send NDI frames - just with the ATVO Recorder. I'll be testing it more extensively the next few days and will get back to you if I notice any patterns or anything useful. Thanks Nick!

Edit

I have discovered that, unlike I previously thought, this issue does not seem to affect audio output past OBS, just what I'm hearing live.

Kyle

After some more testing, it does appear that the NDI recorder in ATVO affects my system audio, causing some sort of glitchiness/skipping. It can be heard in headphones listening to music being played from any source on the computer, and I am told it is affecting my microphone in Discord as well. I use a Behringer mixer with its USB audio interface - the recorder wouldn't do anything that would mess with that area of windows, would it?

Kyle

I have been trying to reproduce but I cannot hear any difference in sound quality whether I have NDI Recorder running or not.

I am playing music from various sources, listening on relatively good headphones. I tried to listen for any difference between having NDI Recorder in "recording" mode (click Start NDI, turns orange) or in "standby" mode (stop NDI). I also tried having the NDI Recorder window itself open or closed. I can't notice any changes at all.

It's possible I just don't hear it, or it may be heavily system dependent. Can you try if it matters whether you use different sound cards for example? Onboard soundcard vs separate one if you have it?

Kyle H. wrote:
After some more testing, it does appear that the NDI recorder in ATVO affects my system audio, causing some sort of glitchiness/skipping. It can be heard in headphones listening to music being played from any source on the computer, and I am told it is affecting my microphone in Discord as well. I use a Behringer mixer with its USB audio interface - the recorder wouldn't do anything that would mess with that area of windows, would it?

Kyle

I have also tested it, but no issues for me as well. I am also running a comparable setup (two soundcards, Yamaha MG12XU mixer and some additional audio equipment) and I am really wondering what might be the issue here. If I would take a wild guess here, I'd probably check the sample rate of your soundcards. But like I said, it is a wild guess...don't expect it to necessarily solve anything here :(

Kevin Neitola wrote:
Kyle H. wrote:
After some more testing, it does appear that the NDI recorder in ATVO affects my system audio, causing some sort of glitchiness/skipping. It can be heard in headphones listening to music being played from any source on the computer, and I am told it is affecting my microphone in Discord as well. I use a Behringer mixer with its USB audio interface - the recorder wouldn't do anything that would mess with that area of windows, would it?

Kyle

I have also tested it, but no issues for me as well. I am also running a comparable setup (two soundcards, Yamaha MG12XU mixer and some additional audio equipment) and I am really wondering what might be the issue here. If I would take a wild guess here, I'd probably check the sample rate of your soundcards. But like I said, it is a wild guess...don't expect it to necessarily solve anything here :(

Thanks guys - let me play around with some device settings tonight, if it's just a me problem, it narrows it down to my audio setup & configuration. Thanks for investigating!

Kyle

I found the issue! I hadn't noticed this before, but my mixer was set to 48 kHz while Windows was set to 44.1 kHz. Changing the sampling rate in the mixer solved it. No idea why this wasn't an issue anywhere else, or why the recorder triggered something that made me notice it, but it's working perfectly now!

Side Note: Is it possible to turn off the yellow border windows adds around the NDI capture?

Kyle

The yellow border is a Windows function and can't be turned off afaik.

Thanks Zack, noted. No big deal.

I unfortunately have to retract my statement from earlier - it still isn't working right with my USB audio interface/mixer. Normal headphones doesn't seem to create the issue, so it's something in my mixer, but the NDI recorder definitely triggers it.

It runs okay at first and gets worse over time, and then stays. Very weird. Just recording my experiences here in case someone else runs into it, but I'll keep digging.

The only two things I can imagine are:

1. NDI Recorder is using enough CPU to mess with audio drivers/encoding/whatever.
2. NDI is sending audio frames by mistake. Very unlikely because I am not using that part of the NDI framework at all.

Can you try for a moment the old "NDI v1" functionality? Simply don't use the NDI Recorder window, but go into the ATVO settings and check "Enable ATVO Overlay as NDI source", then restart ATVO. Do you also have audio issues with this case?

Nick Thissen wrote:
The only two things I can imagine are:

1. NDI Recorder is using enough CPU to mess with audio drivers/encoding/whatever.
2. NDI is sending audio frames by mistake. Very unlikely because I am not using that part of the NDI framework at all.

Can you try for a moment the old "NDI v1" functionality? Simply don't use the NDI Recorder window, but go into the ATVO settings and check "Enable ATVO Overlay as NDI source", then restart ATVO. Do you also have audio issues with this case?

I do not have issues with NDI v1, other than the poor general performance from this method. No issues with audio. Just to confirm, I turned off NDI v1 and went back to the NDI recorder and the issue persists.

Kyle

Hello, I upgrade my computer and I do a new installation of ATVO. I decide to try it with the last NDI to stream with OBS, I can get the picture at the good place but ATVO is figged and send one picture and nothing change. I try 2 times and after I activated the OLD version to check. With this old version all is OK !