Sound issues/stuttering when sound is embedded

[Pk1982]

Hi, i`m using a blackmagic decklink duo 2 with an blackmagic audio to sdi box. Obs 26.0.2 and decklink 11.7 driver. Windows 10 update 20H2
2 sdi cameras connected to the decklink duo 2, one straigth to the card and the other via the audio to sdi box.
The XLR mic goes to the mixer and from the mixer to the audio to sdi box and into the decklink duo 2 card in my windows 10 computer.

Scene 1 is camera 1 connected with the audio to sdi box, so the sound source in obs is: Blackmagic device. Sound is perfect.

Scene 2 is camera 2 connected straight to decklink duo 2 with sdi, so sound goes via audio input capture (blackmagic decklink duo 2 (1) audio). Sound is choppy/laggy/static, almost like an 44/48khz issue, but both obs and drivers is set to 48khz.

This worked fine ages ago so i think the issue is windows 10/obs related and how they handle the "virtual" soundcard from the decklink duo 2 card.
Works fine on an mac with obs and same setup.
Tried using wirecast and sound is fine there too.
Tried bypassing the the embedder(audio to sdi), so from mixer straight to the computer`s analog line in port via minijack: works fine.
Also tried older decklink drivers, older obs versions with no luck/same issues.

Any ideas?

 

[Pk1982]

Here`s the logfile from a test.

 

[mberg81]

Hi

We have the same problem with embedded audio through SDI. are using decklink duo 2 card.
This became a problem some time ago after windows update. the sound are choppy/stuttering.
Have turned off Game DVR. using latest driver from BMD 11.7

the sound is fine in wirecast.

mberg

 

[SaintMac]

Hi, we seem to have the same issue. Embedded sound via SDI from Atem TV Studio HD to DeckLink Mini. It is choppy and distorted. Audio via USB all is ok.

 

[BVP]

I have exactly the same problem. DeckLink Duo 2, Windows 10 20H2, OBS 26, embedded sound via SDI (in my case from a Sony FS-7 camera). And the sound is very choppy and distorted. And I also have this problem since November 2020.

The problem does not occur in Ubuntu (20) and Windows 10 versions 1903 and 1909 (the two previous versions).

I already contacted Blackmagic support. They do not know anything about this problem and can't reproduce it.

Has anybody found a solution?

 

[NFSBuff]

I created an account here just to say the issue does appear to be a Windows update. We started getting stuttering audio and dropped frames too this last week after 20H2 was installed. Using a Decklink 4K SDI.

In our case, the workaround is absolutely stupid. When we click outside of our streaming application, that is, the application is no longer the focused application, all the issues go away. This coincides with all the issues people are having when gaming in 20H2. Full screen games getting absurdly low framerates, because they're the focused app. Make a game windowed, run a benchmark, click outside the window, and most times the performance hit goes away.

 

[M1cha3lMax]

DISTORTED AUDIO FROM SDI WORKAROUND
First remove the separate audio input device in OBS and right click on the Video Input and click properties.
Click the Use custom audio device to hear the distorted audio.

It should look like this. Then uncheck the Use custom audio device.

It should look like this, and the sound should become clear.

Make sure you unhide the audio meters to the right with a left click.