OBS 28.1.0 New Audio Feature

Community Open Mic Events Tech Talk - How to setup Zoom / Audio / Video
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Just thought I would share a new OBS 28.1.0 feature I discovered yesterday.

I was looking for a way to integrate my EZ Drummer 2 desktop app as an input source to OBS without going through a DAW. When I recently upgraded I had not looked at adding additional Scene Sources, so this was the first I noticed a very hand feature being Beta tested.

As you can see from the highlighted Source in the screen grab below its called
Application Audio Capture and its a bit Ronseal ! It does exactly what it says on the tin.

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When you add the source, it presents a list of active applications and you simply select the one you want. Then go to Advanced Audio setting and make sure monitoring is set to Monitor and Output, as you would do for other audio input sources,

So after spending a while messing around and recording various EZD2 samples to ensure the output was captured alongside my ASIO Input Capture source, I thought this could be handy for recording or OMs and just as easy to add a backing track via desktop media player.

To double check the process, I have just added another Application Audio Capture source and added Groove Music and slapped on a little Yesterday as proof of concept. And voila a very simple way to add a backing track.

I could never get the Media Source to play audio successfully but this seems a sure fired way to drive backing tracks into OBS while recording your audio and video.

All good fun !

:sunglasses:

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A little addendum to this, as I prepare for OM XII.

Latency !!

But only when recording in Zoom.

Not sure what is going on but further exploration is required.
Throughout the week I have been practicing and recording the song for the next Open Mic, as I described in the first post, so to recap ;

Guitar and Vocals captured on condenser mic into AI and collected in OBS as an ASIO Input Capture. Backing drum track played on EZDrummer2 with audio collected in OBS with the aforementioned Application Capture Source.

In the multiple videos I recorded over the last couple of day with OBS, everything is synchronised, yes there is an odd timing bump but that’s clearly down to me being ham fisted. But generally my playing and the drums were together.

So I decided as all was going so well, to ditch the old vanilla flavoured version of the song (no reveal for at least 24 hours) and use a drum sample labelled Rebel Rock, right up my alley !

I’d recorded a Dry Run of the vanilla original via Zoom so was not worried about the set up for the night and generally just practised with OBS during the week, messing around with a shed load of EZD2 samples. OK a little glitch earlier today with no sound in Zoom but sorted via a reboot. This evening I thought I’d do a last check and do a final Dry Run with the drums, recording the video in Zoom. And that is where the latency occurred, with the drums being out of sync with the guitar and vocals.

At the moment my suspicions is that the Application Audio Capture not being an ASIO supported source, that is where the delay is occurring. So this is lagging behind when everything is fed down the virtual cable into Zoom. A tweak of the audio sync offset in OBS may resolve the issue but I am not sure how that will effect what I am hearing in my cans or IEMs. That’s for another day.

So I will park it here for now and investigate further after tomorrow’s Open Mic.

TBC

:sunglasses:

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If you are saying that it’s because the Application Audio Capture is using the standard Windows Audio subsystems, then that is likely to be the problem.

ASIO really isn’t relevant here.

ASIO is (as I understand it) about hardware drivers for physical audio devices. ASIO deals with things like sample rate selection on the audio device, USB packetisation and buffering and latency reporting. And it then presents a simple, standard interface to audio programs.

The reason ASIO is good for low latency is, simply, because it allow you to bypass all of the Windows audio subsystem stuff and talk directly to the hardware drivers.

The Windows audio stack is designed for general audio use and is necessarily quite complex. It has to support multiple applications using a single audio device at the same time, so you have loads of buffering, routing and software mixing and sample-rate conversion going on to try to make it as simple and easy for users as possible.

All of that adds latency and, in some cases, can degrade the audio in subtle ways.

ASIO simply allows you to bypass all of that and talk directly to the audio device driver. This gives lower latency and “sample accurate” quality audio, but it means you directly have to configure issues like sample rate and buffer size. And it also means you can only use one application at a time on an interface (unless you use hacks like Jack or ASIO4ALL).

For a virtual device, you aren’t talking to a physical audio driver, so all the things that ASIO deals with are irrelevant.

The Application Audio Capture is intercepting the standard Windows audio somehow and just connecting it as an input on OBS. It’s basically the same as a Virtual Audio system like JackD or ReaRoute.

You are having to deal with the Windows audio framework still, because normal applications only know how to output to the standard audio framework, but you aren’t dealing with audio drivers.

So, yes, it’s probably something in the Windows audio subsystem that’s causing the latency.

I would look at whether it is possible, within your setup, to monitor at the output of OBS after all the mixing has been done. The potential problems then, of course, is you could end up with a substantial delay between what you play and what you hear.

The other thing is whether it’s possible to tweak the application settings in any way. For instance, can the application sample rate be configured? If the sample rates mismatch between applications, this can result in sample rate conversation being done, which could add latency.

I’m not that familiar with the way this all works on Windows, so I’m not sure I can offer much else in terms of advice.

I also wonder whether something like Jack would work better.

Cheers,

Keith

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Yes that’s correct and your full explanation underpins my understanding of the difference between “normal” Windows audio routing and ASIO. In layman’s term the former goes round the houses the latter is more point to point.

And that’s what confuses me here, as I would expect the latency to also show up in the OBS audio, as the drums/EZD2 would be taking the longer route. But that is not the case. The latency only shows when I record the OBS output (video and audio) in Zoom. OBS is in sync.

Like I say more investigation required but will do that with a simple 4 beat snare or kick sample and play single notes over it. Confirm OBS is synced, confirm latency in Zoom and see what impact any adjustment make.

All post OM !

Cheers and thanks for your usual in depth replies.

Toby
:sunglasses:

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Oh I see. That implies the latency is being introduced somehow in OBS. That is odd.

Cheers,

Keith

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Exactly.

What I plan to do apart what I mentioned above, is to create a “standard” non ASIO Audio Input Capture for the AI (vox n gtr), so both captures are running thru Windows Audio. Then see what happens in Zoom

All a bit bizarre.

:confused:

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Out of interest, does it stay in sync if you record in OBS rather than streaming?

Cheers,

Keith

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Yes the Dry Run recordings were all videos recorded just in OBS and all seemed ok. It was only after I streamed the output to Zoom and recorded a video there that the latency became apparent.

Now back tracking and setting up EZD in Reaper and may use that tonight if I don’t have to spend too much time faffying around. But I’ll play around with just OBS and Zoom tomorrow. Otherwise I can see me going down a troubleshooting rabbit hole and not being ready for the show !

Take care.

:sunglasses:

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Good luck with everything.

Unfortunately, it’s a bit too early for me, and it’s already been a busy weekend, so I won’t catch the show live this time.

Cheers,

Keith

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Cheers Keith, yeah crazy o’clock for you again.

:sunglasses:

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Just caught up on this one, Toby.

As is your way, you continue to push the boundaries and discover more ways to use the tools. As for me, I haven’t upgraded my OBS to v28 after I recall seeing it caused some folk some hassles.

On your issue, did you try recording from OBS while you were also streaming to Zoom? As you described it, it made no sense to me. If all is in sync in OBS then how can audio get out of sync on the mixed output? So I am wondering if somehow starting a meeting and recording in Zoom may be causing some extra latency going into OBS and maybe you weren’t aware of that?

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Watch this space David, its a bit odd :confused:

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It could be. Zoom, in my experience, is a resource hog.

If on a laptop, it may be worth checking the laptop performance settings and turning them up fully.

Cheers,

Keith

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Running it on the PC Keith but will have a play around this afternoon and see what gives.
Maybe my timing just sucks :rofl:

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Justin is having issues with audio-video sync going OBS to Zoom for the live shows too.
I know he wants a fix.
He tried tweaking these settings yesterday but couldn’t get it right.
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I could not get Zoom to pickup the OBS audio at all yesterday and my pc is running like a dog this morning. I’ve never had to change the sync offset but I recall @DavidP quoted some settings, not sure if that was obs to Zoom or relating to Reaper. On mobile so will take a look later.

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I did adjust the sync on an input before, about 50ms. Now I can’t recall if it was on the audio or the video. Not at my PC to check. I also recall @adi_mrok talking about sync offset.

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Richard

Is Justin using the virtual cable set up to send audio from OBS to Zoom, or is he sending the audio direct to Zoom ? Can you confirm that the audio is ahead of the video and not the other way around ? I can’t recall which way the latency was manifesting on last nights Blues Club and it wasn’t too bad IMHO but better if it can be synced…especially by the 9th :scream:

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@TheMadman_tobyjenner not sure - need to ask :slight_smile:

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I played with offset once and it just was way too difficult to nail exact ms of how much delay there was. Eventually gave up and like posted in Stefan’s post using Rearoute filter on obs mic that is not in use (muted in windows settings in built mic on my laptop) did the trick.