Question / Help Inconsistent sync settings

[Neil Rutland]

Spent an entire day on this and finally decided to ask for some help. Using the Blackmagic Ultrastudio Mini Recorder w/ embedded audio. When I first create the scene everything is in sync (sound and picture) with no delay settings. This is confirmed with recording and with YouTube streams. If I quit from OBS and restart it the sound is a full second behind the video requiring a large video delay. This doesn't seem stable or reliable. Is this a driver issue for the Mini Recorder?

 

[zer0c001]

@Neil Rutland
Have you tried launching OBS from the 'Terminal' app on your mac, as opposed to just clicking on the app icon? If not, give it a try by following these steps and let me know if you run into similar issues while trying to accomplish the same tasks.

1) Open Terminal application on your Mac
2) Copy and paste the below into your terminal:
Bash:
/Applications/OBS.app/Contents/MacOS/OBS; exit
3) Hit Enter
4) Leave Terminal running while using OBS

I've found launching OBS from terminal can be helpful in alleviating various audio sync issues on Macs. Let me know if this works and feel free to post the log file or explain in more detail what happened if it doesn't.

Hope that's helpful!

 

[gonuts]

@Neil Rutland
Have you tried launching OBS from the 'Terminal' app on your mac, as opposed to just clicking on the app icon? If not, give it a try by following these steps and let me know if you run into similar issues while trying to accomplish the same tasks.

Hope that's helpful!

Thanks for posting this. I've also had issues with audio sync I can't resolve with offsets, so will also give this a try.
I'm using lapel mics into a mixer, then through a camera and into an ATEM Mini via HDMI. My recordings are at least 15 frames out of sync. When I plug a mic directly into the camera and then the ATEM mini, with an offset (can't remember figure) it works fine.

 

[zer0c001]

Thanks for posting this. I've also had issues with audio sync I can't resolve with offsets, so will also give this a try.
I'm using lapel mics into a mixer, then through a camera and into an ATEM Mini via HDMI. My recordings are at least 15 frames out of sync. When I plug a mic directly into the camera and then the ATEM mini, with an offset (can't remember figure) it works fine.

No problem @gonuts Happy to help!

Re: Your Setup - If I'm understanding you correctly, you have wireless lapel mics feeding into an audio mixer and the mixer is going into the camera directly. Then the camera is connected to the ATEM mini but there's an a/v sync issue when you stream/record? Is this correct?

First thing I would do is monitor your audio directly from the camera's headphone jack to make sure that everything is in sync there first. Can you confirm this?

Second, it'd helpful to know a) what type of mixer, b) what type of camera, c) what type of cables/converters you are using in your setup.

Once I know a little more info, I can recommend an alternative approach. If the terminal launch does the trick by itself, let me know too!

 

[Neil Rutland]

Thanks for posting this. I've also had issues with audio sync I can't resolve with offsets, so will also give this a try.
I'm using lapel mics into a mixer, then through a camera and into an ATEM Mini via HDMI. My recordings are at least 15 frames out of sync. When I plug a mic directly into the camera and then the ATEM mini, with an offset (can't remember figure) it works fine.

I will definitely try this at my next opportunity. Never even occurred to me.

 

[rak500]

Thanks for posting this. I've also had issues with audio sync I can't resolve with offsets, so will also give this a try.
I'm using lapel mics into a mixer, then through a camera and into an ATEM Mini via HDMI. My recordings are at least 15 frames out of sync. When I plug a mic directly into the camera and then the ATEM mini, with an offset (can't remember figure) it works fine.

Hi Gonuts!

Make sure your cameras are set at the same resolution as the ATEM Mini's Program Resolution, or the other way round if you prefer: the ATEM Mini converts different input resolutions and this adds a small delay, while the audio is not treated/delayed accordingly. This could add a few frames, I can't recall how much exactly. There's also a frame or two of inherent delay between in and out on the ATEM Mini depending on the resolution IIRC.
The ATEM also resynchronises input signals to make sure you can do a "clean switch" which add up to a frame of delay, which doesn't help.

Also, cameras like small camcorders or hybrid still cameras tend to have a fair amount of video delay from the sensor to the HDMI, which is generally corrected in the camera. There's a fair chance the audio is delayed accordingly in the camera to palliate for that.

Have you tried to connect the audio directly in the ATEM's audio inputs?

Also, I'm not sure I understand:
Mic to mixer to Cam to ATEM = 15 frames of delay
Mic to Cam to ATEM = less delay?
If that's the case, then the mixer could be at fault, but then again, analog mixer generally don't add delay unless they have special built-in features or effect that would do so. Are you using a Digital Mixer?

Have a good one!

 

[gonuts]

Thanks f

Hi Gonuts!

Make sure your cameras are set at the same resolution as the ATEM Mini's Program Resolution, or the other way round if you prefer: the ATEM Mini converts different input resolutions and this adds a small delay, while the audio is not treated/delayed accordingly. This could add a few frames, I can't recall how much exactly. There's also a frame or two of inherent delay between in and out on the ATEM Mini depending on the resolution IIRC.
The ATEM also resynchronises input signals to make sure you can do a "clean switch" which add up to a frame of delay, which doesn't help.

>> Yes and tricky part was first working out what the equivalent of 15 frames is, but whatever offset I add in OBS doesn't seem to matter, seems so variable, but maybe I just have the numbers completely wrong?!

Also, cameras like small camcorders or hybrid still cameras tend to have a fair amount of video delay from the sensor to the HDMI, which is generally corrected in the camera. There's a fair chance the audio is delayed accordingly in the camera to palliate for that.

>> I've confirmed all cameras are same resolution. 1080p. Yes they are a mix of cameras including a smaller consumer one. I did notice they are on 25fps, while OBS was 30fps, but yet to test if that's fixed the sync, would make sense it might cause some sync issue I guess.

Have you tried to connect the audio directly in the ATEM's audio inputs?

>> Yes I've looked at this. As the ATEM has 3.5mm mic inputs, I think the mixer outputs are only line level and I didn't have an attenuator or other connectors, so would just distort (or maybe I just tried the wrong outputs in the heat of the moment).
I don't have the mixer with me, but something I'd like to check again if there's a mic level output available that I can run directly to the ATEM.
This is the mixer; https://ebay.us/EXSI8c

Also, I'm not sure I understand:
Mic to mixer to Cam to ATEM = 15 frames of delay
Mic to Cam to ATEM = less delay?
If that's the case, then the mixer could be at fault, but then again, analog mixer generally don't add delay unless they have special built-in features or effect that would do so. Are you using a Digital Mixer?

>> Yes sorry hard to explain, but eliminating wireless mics to the mixer, and just running a shotgun mic directly into the main camera, (with an audio offest in OBS), actually seemed to work to keep it in sync.
See attached for the entire setup if you're interested.
I have a small 4 track somewhere, which I'm keen to test to bypass the existing mixer to see if it helps.

Hi rak500. Thanks so much for taking the time to answer. I've added my replies within the quote above after the >>.
I've attached some images too showing our setup.
When I get access to the setup (once a fortnight) I try eliminating one thing at a time to set it up.
I tried loading OBS from terminal as above, didn't work at all. Maybe I typed something wrong...
Last time I did tests and found an offset that seemed to work to sync the audio, and then recording into OBS worked. (changed 100ms at a time)
Then when we did the actual webcast though, the sync was out again, some time it was in sync, then went out of sync. (maybe related to 35fps > 30fps as above!? Yet to test)

Running out of ideas though so thanks heaps for the help.

 

[gonuts]

No problem @gonuts Happy to help!

Re: Your Setup - If I'm understanding you correctly, you have wireless lapel mics feeding into an audio mixer and the mixer is going into the camera directly. Then the camera is connected to the ATEM mini but there's an a/v sync issue when you stream/record? Is this correct?

First thing I would do is monitor your audio directly from the camera's headphone jack to make sure that everything is in sync there first. Can you confirm this?

Second, it'd helpful to know a) what type of mixer, b) what type of camera, c) what type of cables/converters you are using in your setup.

Once I know a little more info, I can recommend an alternative approach. If the terminal launch does the trick by itself, let me know too!

Hi @zer0c001 Thanks heaps for the reply. I just posted a whole lot of info above then saw this. Hopefully that info helps.

Yes the audio is just never consistently in sync once through the ATEM, and into OBS.
As above I got the audio offset in OBS to what appear to be in sync - just testing Cam2 at this point, that has the mixer audio feed.
By testing and recording in OBS, the playback file was in sync (no streaming at this point)
When we went live to broadcast, it wasn't in sync any more. Went in and out effectively...

I tried the Terminal step but it just did nothing. Was it supposed to launch OBS from there?

1) Bloody good question! I just confirmed the recordings from the Cam2 (that takes the mixer audio output), and confirmed it is all in sync, for all recordings to date!
Not sure what to make of that?! The ATEM is messing with the sync of the HDMI output from the camera?
Not sure either if that would mean the other cameras might be on a different sync? Guess that goes to what @rak500 was saying about having all cameras the same, which they are.

2) This is the mixer; https://ebay.us/EXSI8c
Mix of cameras. JVC-HM100E, Sony nx70 & some other small Sony handycam.
Wireless mics; XTUGA A400 UHF Wireless Microphone System 4CH 4 Bodypack with Headset/Lapel Mic https://ebay.us/ayckK0
Just hdmi & xlr cables otherwise - see the diagrams in my other post for more info which may show it better.

Thanks again for your help.

 

[Wally44]

I have the same problem with a much simpler configuration. I have an AmCrest IP2M-858W ip camera and simple mono audio input from our separate sound system. I find about a 1.3sec lag of the video from the audio. However, when I set it and then run OBS again, I get a different value. It keeps changing every time I run OBS and it is difficult to find a setting that works every time. It also seems to vary depending on whether I have streaming and recording on. And the lag is different between the two. I'm at a loss to consistently have a synced stream.

 

[genesse]

I have a similar issue. I'm using a Roland VR-4HD switcher into OBS. I have 3 cameras going into the switcher, and the output of an audio mixing board going into the switcher as well. The switcher video and audio output is what goes into OBS. I've adjusted the sync offset and it looks good on one camera but not the other 2. All cameras are set on 30fps. Anything else I should check?

 

[Wally44]

I think this video on YouTube can help with multiple cameras in OBS: https://www.youtube.com/watch?v=92bSB0Pk4_w
However, I think the problem with the AmCrest camera by itself is a variable time in the delay. Why I don't now. Perhaps it is the RTSP protocol.

 

[rak500]

Hi @zer0c001 Thanks heaps for the reply. I just posted a whole lot of info above then saw this. Hopefully that info helps.

Yes the audio is just never consistently in sync once through the ATEM, and into OBS.
As above I got the audio offset in OBS to what appear to be in sync - just testing Cam2 at this point, that has the mixer audio feed.
By testing and recording in OBS, the playback file was in sync (no streaming at this point)
When we went live to broadcast, it wasn't in sync any more. Went in and out effectively...

I tried the Terminal step but it just did nothing. Was it supposed to launch OBS from there?

1) Bloody good question! I just confirmed the recordings from the Cam2 (that takes the mixer audio output), and confirmed it is all in sync, for all recordings to date!
Not sure what to make of that?! The ATEM is messing with the sync of the HDMI output from the camera?
Not sure either if that would mean the other cameras might be on a different sync? Guess that goes to what @rak500 was saying about having all cameras the same, which they are.

2) This is the mixer; https://ebay.us/EXSI8c
Mix of cameras. JVC-HM100E, Sony nx70 & some other small Sony handycam.
Wireless mics; XTUGA A400 UHF Wireless Microphone System 4CH 4 Bodypack with Headset/Lapel Mic https://ebay.us/ayckK0
Just hdmi & xlr cables otherwise - see the diagrams in my other post for more info which may show it better.

Thanks again for your help.

Hi Gonuts,
The latest ATEM Software version has a firmware update for the ATEM Mini and Mini Pro that allow for up to 8 frames of dealy on the Analog audio inputs. This could help if you use a mixer or if you take the audio that you previously fed to the camera and feed it directly to the ATEM. I've had some issues when using the "Custom Audio Source" in the Video Deevice menu to get both audio and video from the same source and am now using two separate devices in OBS for Audio and Video as the latest updates is giving me odd problems. Sometimes audio or video will fail and I need to stop/start the capture, but I get more stable results by seperating the A and V.
Cheers!

 

[RafiSofer]

Hey folks -
I'm having a similar issue where I can synch OBS and my incoming audio - but the synch is never consistent - it invariably falls out of synch. I'm using an older mac mini - (and an avid mbox as an audio front end - it's a USB interface). I'm thinking the issue is with the older processor on the mac mini... I'm using 30fps, I have an ATEM Mini capture device - but I have other capture devices too - and I just can't seem to get things to stay locked.

thanks in advance.

 

[lorenzowolff]

I have the same exact setup and issues as RafiSofer, anyone found a solution? Audio is consistent to begin with, then delay gets longer as I stream.

 

[pastorcope]

Similar issue here. Brand new MacBook Air (2020), two camera setup (Canon XA40s) into the ATEM mini pro. Several test recordings in OBS until I sync the audio up perfectly. Come back the next day, and things are no longer in sync. Also have seen the sync change within a specific recording.

I have tried plugging wireless mic receivers directly into the Mic inputs on the ATEM mini pro, I've tried doing audio through the camera, and I've tried running a channel from a mixing board into the ATEM mini pro as well. All experience inconsistent delay issues (the mixing board adds the problem of a buzz I can't get rid of).

Any help is appreciated!

 

[motibodo]

Also seeing this drifting audio sync issue. Help!?

 

[stevemanncamera]

Hi all, I've spent a couple days messing around with output, sync and async settings. I thought I had it fixed but the audio delay was inconsistent - 15, 7, 5, 3 seconds. I tried different bitrate, resolution and framerate settings on ethernet, wifi and hotspot connections and no luck. Then I happened to notice that not all of my laptop's USB ports were 3.0 - I had just assumed they were as it's a new system. I had the camlink plugged into a 2.0 jack. Once I moved it over onto the 3.0 jack, I had no sync issues, regardless of output setting.

Sometimes the solution is simple. Hope this helps others!

 

[Auction caster]

I have the same problem with a much simpler configuration. I have an AmCrest IP2M-858W ip camera and simple mono audio input from our separate sound system. I find about a 1.3sec lag of the video from the audio. However, when I set it and then run OBS again, I get a different value. It keeps changing every time I run OBS and it is difficult to find a setting that works every time. It also seems to vary depending on whether I have streaming and recording on. And the lag is different between the two. I'm at a loss to consistently have a synced stream.

I'm in a similar boat, and would love a reliable process to ensure my audio video synch is correct from the get go. Every week it changes , when no other variables have been introduced. Anyone got a process they can reccommend ?