audio sync issue keeps increasing

[LoboNagual]

Hi everyone,

I would really appreciate your help. I am new to OBS and still trying to find my way. The first time I did a video recording, I noticed the sound sync was off and quickly found a post that spoke about the Sync Offset in the Audio Mixer Settings. I did some test videos and found the lag was about 80ms. The next time I did a recording, I found the sync was off again, ran some test videos and found the lag was about 150ms. This happened again and the lag was 300 and again yesterday and it was 650.

Can any one please tell me what setting I need to change so this stops happening?

Here is my latest log file:

https://obsproject.com/logs/BdAza9KeRaDWXcpP

Thanks in advance for all your help. Lots of love, Daniel

 

[Lawrence_SoCal]

CBR (constant bit Rate) is a typical format required by Streaming Platforms. When recording a Constant Quality format is recommended instead (ex CPQ).

Not sure if same applies in MacOS world as in Windows, where especially under-powered hardware (M1 chips are energy, not performance optimized) having mis-matched audio sampling rates is NOT a good thing

16:39:23.890: coreaudio: Device 'BlackHole 16ch' [48000 Hz] initialized​

16:39:23.890: [Loaded global audio device]: 'Desktop Audio'​

16:39:23.992: coreaudio: Device 'External Microphone' [44100 Hz] initialized​

16:39:23.993: [Loaded global audio device]: 'Mic/Aux'​

16:39:24.063: coreaudio: Device 'Shure MV7' [44100 Hz] initialized​

so getting those all to be the same might be a good start?

Typically, audio, which takes less processing gets ahead of video. The trick then is to typically delay Audio (if I'm reading the log correctly, you are delaying Video?)

• Paul Richards of PTZ Optics/StreamGeeks video I use for A/V sync https://streamgeeks.us/how-to-fix-obs-audio-and-video-sync-issue-with-a-new-tool/
• https://streamshark.io/obs-guide/audio-delay

Then there is using System Monitor to check hardware resource utilizations. Be careful of having unnecessary apps open, background tasks running etc. Other (excessive for what you are doing) system load could be impacting CPU availability leading to varying sync rates

 

[LoboNagual]

Hi Lawrence,

Thanks for the info. Sorry for my lack of experience in all this.

1) How do I change the sampling rate for the different microphones. Also, I will only ever use my Shure MV7, is there a way for me to remove the others? Would that help?

2) I am not consciously delaying video, the only delay I've manually added is the Sync Offset in the Audio Mixer Settings. If the log shows that the video is being delayed, what could be causing that and how can I fix that?

3) Going forward, I'll quit out of all my other apps when I record to see if that makes a difference.

And I'll definitely check out the StreamGeeks tool you suggested.

Thanks again.

 

[LoboNagual]

Some additional information:

1) I never added all the other microphones, the system added them automatically and I can't figure out how to remove them.

2) I wasn't able to access the tool you suggested but I found another one and just used it now.
https://squares.tv/posts/the-easiest-way-to-sync-mic-audio-in-obs

My audio Sync Offset is now up to 933ms. All the other apps were turned off. I can't figure out why it keeps increasing.

3) I just remembered that I did add a video delay filter but didn't have it on, based on a video I watched on the topic. So I just removed that completely even though it was set to zero.

 

[Lawrence_SoCal]

1) How do I change the sampling rate for the different microphones.

That is operating system specific... sorry, I don't know in Apple's walled garden what the answer is... looking it up should be easy

Also, I will only ever use my Shure MV7, is there a way for me to remove the others? Would that help?

Go to OBS Settings, and check Global Audio devices. Remove/Disable those you don't plan to use.

2) I am not consciously delaying video, the only delay I've manually added is the Sync Offset in the Audio Mixer Settings. If the log shows that the video is being delayed, what could be causing that and how can I fix that?

Sorry, appears I misread/misunderstood something in your original post?

3) Going forward, I'll quit out of all my other apps when I record to see if that makes a difference.

always a good idea

My audio Sync Offset is now up to 933ms. All the other apps were turned off. I can't figure out why it keeps increasing.

that is a lot.

3) I just remembered that I did add a video delay filter but didn't have it on, based on a video I watched on the topic. So I just removed that completely even though it was set to zero.

Good, as there is always a chance a given Filter/Effect, even when set to zero, will actually be running, impacting CPU and processing time.

I'd be inclined to start considering some optimizing config steps, as the M1 is not a performance CPU
So, do you really need to re-scale Base Canvas down 1080p down to 720p? granted that means more to process, but less CPU to re-scale. Just which takes more/less on your system, I don't know. worth testing

 

[LoboNagual]

I just checked the time lag and it's at 100ms now. Of course, I have no idea why it dropped all of a sudden. I removed the other microphones, maybe that was the issue? Let's hope it stays there. I'll post again later with an update.

Thanks again for your time and your help.

 

[LoboNagual]

I would love to be able to figure out why the audio sync keeps changing on me. I found in another forum thread within this community someone that fixed it by making sure their camera was 30 fps to match their OBS settings. I tried this and still no better. Here are some examples of the fluctuations that I keep finding every time I open the app and test the sync offset. (all these tests were conducted with the offset set to zero):


25-Sep 3:30pm = 100ms

Decided to do a string of tests by quitting and restarting OBS repeatedly:
26-Sep 4:55pm = 200ms
26-Sep 4:58pm = 600ms
26-Sep 4:58pm = 700ms
26-Sep 5:07pm = 800ms
26-Sep 5:08pm = 867ms
26-Sep 5:10pm = 700ms
26-Sep 5:12pm = 767ms
26-Sep 5:16pm = 633ms
26-Sep 5:19pm = 733ms
26-Sep 5:25pm = 767ms
26-Sep 5:42pm = 667ms
26-Sep 6:00pm = 700ms

27-Sep 5:33pm = 900ms
27-Sep 6:10pm = 600ms

28-Sep 4:22pm = 767ms
28-Sep 4:39pm = 800ms

01-Oct 4:22pm = 800ms

03-Oct 4:35 = 700ms

 

[LoboNagual]

Is there anyone that can help me with this? I would really appreciate it.

 

[NoCal_Streamer]

Is there anyone that can help me with this? I would really appreciate it.

In my painful past experience, varying delays like this were the product of a LAN issue (assuming you are measuring at the OBS head and not after YouTube processes). There may be a loop back or other anomaly or configuration error that when in play slows down some traffic, or could be some device on the LAN that slows everything when active.

In my case, it took a month of digging to find i accidentally created the loop that made a mess. To get past it, i stripped the LAN to literally just the video source, audio source, PC with OBS and outbound stream gateway. Then i implemented QoS and a few other router protocols that protected these core traffic components. Good luck.

 

[AaronD]

Do you have a cheap USB capture card? Those have random latency themselves. So if you're using one of those for the picture and getting your sound from somewhere else, then the sync will be off by a random amount every time. No setting in OBS for that, because it's already wrong before it even gets to OBS in the first place.

 

[LoboNagual]

In my painful past experience, varying delays like this were the product of a LAN issue (assuming you are measuring at the OBS head and not after YouTube processes). There may be a loop back or other anomaly or configuration error that when in play slows down some traffic, or could be some device on the LAN that slows everything when active.

In my case, it took a month of digging to find i accidentally created the loop that made a mess. To get past it, i stripped the LAN to literally just the video source, audio source, PC with OBS and outbound stream gateway. Then i implemented QoS and a few other router protocols that protected these core traffic components. Good luck.

I'm not sure where to look for any possible LAN issues. I have a simple wifi setup with a few computers and mobile devices.

 

[LoboNagual]

Do you have a cheap USB capture card? Those have random latency themselves. So if you're using one of those for the picture and getting your sound from somewhere else, then the sync will be off by a random amount every time. No setting in OBS for that, because it's already wrong before it even gets to OBS in the first place.

I am using a 2022 MacMini (M1) and am using the hardware that came with this computer.

What I don't understand is why there's no issue with the video/audio sync with other programs like Zoom or recording video using Quicktime.

 

[Lawrence_SoCal]

As for audio/video sync - are all audio devices directly connected ((USB/thunderbolt) to computer? Same for video? if yes, LAN doesn't come into play at ALL . period. Now, a bunch of 'other' network traffic overwhelming CPU? sure that could happen, but that isn't a LAN 'probem'.

Lots of possible reasons for different performance outcome ..
- proprietary/licensed encoding schemes/protocols/libraries vs Open Source
- OBS Studio being capable of, and programmed to do, a LOT more than those other programs. Which means its needs more performance resources to pull off, and then depends on your specific settings, especially related to your hardware. It is very easy to configure OBS Studio to demand more than even the most powerful of desktop computers can execute (think $5->10K professional workstations)

What are you doing for real-time hardware resource utilization monitoring on your computer? until you are doing such, AND understand what you are viewing, trends, etc. things will appear random when they aren't.

 

[LoboNagual]

As for audio/video sync - are all audio devices directly connected ((USB/thunderbolt) to computer? Same for video? if yes, LAN doesn't come into play at ALL . period. Now, a bunch of 'other' network traffic overwhelming CPU? sure that could happen, but that isn't a LAN 'probem'.

Lots of possible reasons for different performance outcome ..
- proprietary/licensed encoding schemes/protocols/libraries vs Open Source
- OBS Studio being capable of, and programmed to do, a LOT more than those other programs. Which means its needs more performance resources to pull off, and then depends on your specific settings, especially related to your hardware. It is very easy to configure OBS Studio to demand more than even the most powerful of desktop computers can execute (think $5->10K professional workstations)

What are you doing for real-time hardware resource utilization monitoring on your computer? until you are doing such, AND understand what you are viewing, trends, etc. things will appear random when they aren't.

Yes, all devices are directly connected to my computer.

All I'm wanting to do is record a video using my external camera and microphone.

 

[LoboNagual]

Is there anyone that can help me figure out how to configure my OBS settings so that the audio sync doesn't change every time I open up the application?

 

[AaronD]

Is there anyone that can help me figure out how to configure my OBS settings so that the audio sync doesn't change every time I open up the application?

Like I said before, a different latency every time you start is not an OBS problem. No setting will fix that. OBS is getting that from one of its sources, so you need to fix the source, not OBS.

 

[Lawrence_SoCal]

If you are hoping for an easy answer, good luck. but that is wishful thinking more than anything
this stuff is complicated, and none of us know (or really want to) what all exactly is going on with your computer. So we can't give you a direct answer. it depends. And we've provided some places to start looking.
You have not indicated you have addressed some of the obvious things we've already pointed out. As such, I'm Unwatching this thread.

You are likely to get better help *if* you go back through this thread, address the issues identified (doing research on your own as required), figure out how to avoid overwhelming that low-power M1 CPU (specific you setup/needs... again none of us can tell you what you need to do), and then ask appropriate technical questions

 

[Sneaker]

Have you tried just using the audio from the webcam instead of the USB mic to see if that can record audio in sync. Getting a simple working setup would help to isolate where the issue is coming from.

Certainly setting the mic sample rate to 48khz to match your audio settings for the recording may well help or even fix the problem.

I'm not sure why the M1 is being referred to as 'low-power', it may have low power consumption, but is actually a performance CPU which outperforms previous i9 based Macs. The issue certainly isn't that the CPU is being overwhelmed ... and the CPU loading % at the bottom the screen should confirm that.

 

[LoboNagual]

Like I said before, a different latency every time you start is not an OBS problem. No setting will fix that. OBS is getting that from one of its sources, so you need to fix the source, not OBS.

Thanks Aaron, I appreciate your comment. I am sorry that I'm not a technical expert. Unlike the assumption made by Lawrence in the other response, I have spent many hours of research, on numerous occasions, trying to sort this out with no success.

I have two sources, an external camera and an external mic and have no idea how to "Fix" the sources.

It was my hope to be able to make OBS work but maybe OBS just isn't the right solution for me in the end, and I can create my videos using Quicktime or even Zoom.

 

[LoboNagual]

Have you tried just using the audio from the webcam instead of the USB mic to see if that can record audio in sync. Getting a simple working setup would help to isolate where the issue is coming from.

Certainly setting the mic sample rate to 48khz to match your audio settings for the recording may well help or even fix the problem.

I'm not sure why the M1 is being referred to as 'low-power', it may have low power consumption, but is actually a performance CPU which outperforms previous i9 based Macs. The issue certainly isn't that the CPU is being overwhelmed ... and the CPU loading % at the bottom the screen should confirm that.

Hi Sneaker, thanks for the suggestion. I'll try using the mic from the camera to see if that make a difference or not.

Where do I change the mic sample rate to 48khz? Is this within OBS or outside of OBS?

I really appreciate your help and everyone else as well.