Robot sounds from Skype NDI via the BirdDog Mini

If you watched my livestream today, you will have seen that our Skype experiment went horribly wrong and we didn’t notice!

Jump to 50:52 for an example: https://youtu.be/yaiY9tyGCj4?t=3042

The audio is completely messed up, not even remotely intelligible. It sounds like screechy robots.

First of all, sorry, I should have been keeping a better eye on the chat! Second, I’m trying to track this down and not having much luck.

So far I’ve updated the firmware to the latest and that didn’t solve it. I’ve also verified that the audio sounds like this coming out of the headphone jack of the BirdDog itself, so the problem has nothing to do with going out over HDMI. There aren’t that many options inside of the BirdDog device, so I’m at a loss as to what else I can change.

I tried Skype NDI into OBS and that worked fine, so the problem is definitely within the BirdDog Mini. I’ve opened a support ticket with BirdDog so we’ll see what they say!

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There have been reports of audio clicks bringing NDI into VMix this week too. Nothing like what you had, but could it be something Skype did?

PhotoJoseph had the thought that it might be a sampling rate mismatch, like if the audio from the BirdDog was coming in at 96kHz but the ATEM is expecting 44.1. That’d make some sense, except there are no settings to control it on either device, but also the audio from the headphone jack on the BirdDog sounded like robots. So I guess it’s more like a mismatch between Skype and the BirdDog.

Update: BirdDog support got back to me with a theory that Skype’s NDI is fixed at 24khz, and they confirmed that the BirdDog isn’t doing any sort of format conversion or scaling, it’s just converting the NDI feed to HDMI, so it would be outputting audio at the same sampling rate as the NDI source. The ATEM Mini expects 48khz audio which explains why it wouldn’t work.

However the audio jack on the BirdDog also isn’t decoding the audio right, likely because the BirdDog’s DAC converter also expecfts 48khz and it’s getting the 24khz from Skype.

So it’s looking more and more like this just won’t be possible with the BirdDog device.

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So you need a decoder that up samples the audio. Does such a thing even exist?

I think it’s called a computer :wink:

A computer? :man_facepalming: Like the BirdDog device’s likely singleboard computer? lol Thanks Aaron. You made me laugh.

Hey folks. I was just chatting with Aaron at another place and he asked me to chime in here. So I’ve been testing the Magewell NDI to HDMI converter. I only got it a few days ago but found initially that it did not work with Skype and at least one other source (Titler Live) even though the NDI Monitor handled those sources fine. I contacted Magewell and within two days they got me a beta firmware and it fixed both issues. One tip: With the Skype NDI source, at least if you have the Magewell connected to an ATEM Mini Pro, you have to tell the Magewell to remap the audio to 48 Khz. If you don’t do that you get no audio. This is easy to do in their web admin. I’ve only had the Magewell for a few days but so far all good and I’m impressed with the support responsiveness.

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This is great to hear! It’s amazing that the Magewell has the option to remap the audio, since BirdDog support said that wasn’t something their (more expensive) device did, and it’s not even on their roadmap. I’m going to have to give the Magewell device a try!

That’s interesting BirdDog weren’t even interested in addressing this. One of the reasons I went with the Magewell despite the price was that I thought the performance might actually be better. I was reading a post on the Magewell blog showing their performance testing compared to software and another hardware decoder (forum software won’t let me include the link here) and they don’t say what the other competitive product is that they were testing against but I wonder if it was the BirdDog Mini.

Thanks for sharing this @adriancho. It is definitely useful information.

How hot would you say the Magwell unit gets?

I can stick a probe on it tomorrow but so far it’s just warm when I hold the case in my hand while it’s running. Certainly no concerns about the termperature so far. I’ll run it hard for a while and see how it affects the temperature.

So basically the unit doesn’t even get hot. It’s barely warm on the outside. A nice handy thing is that the web UI reports the internal temperature and updates it constantly. If I use the NDI Signal Generator to cycle between the pattern stills and let this run for like an hour the temperature averages around 55 degree C with an average of about 40% CPU and 35% memory usage. If I drop the resolution to 1080p it’s more like about 20% CPU and low 50s for the temperature. This is also the same if I have it rendering a constant 1080p 30fps changing camera feed. When the unit is idly and not rendering any NDI source the CPU usage is near 0% and the temperature is around 50 degrees C.

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So Magewell support got back to me and explained that the reason the Pro Convert NDI to HDMI didn’t work with Skype and Titler Live when I first got it is apparently due to differences in the NDI version between the apps and in their firmware. In fact they had tested with Skype previously and it worked. This is a little scary because it means that if you get a Skype update it’s possible it might this integration.

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I just got the Magewell device and sure enough just a black screen from Skype. I do hear audio (sort of), it’s still garbled, but more of the sound is making it through this time. I’m contacting support and will see what they say! So far I already like the Magewell a lot more than the BirdDog though.

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Hello @aaronpk

Any follow up on that topic ? Does the mage well or the bird dog now works out of the box ? Did you try with MS Teams as well ?

Thank you very much