Question / Help Sound sync offset changes randomly

[ramires.cabral]

Hi everyone.
I'm new to Obs / recording / streaming world.
My problem is the sync offset between my camera and my mic changes often. Start one recording with, let's say, 500ms then in the next recording I need to increase to 900ms. Same with streaming.
I read in this forum some tips, like check if audio device is 48KHs, which is. Audio in OBS is also set to 48KHs.
What else could I try? I saw something about device timestamp but can't remember.

My setup is like so:
A Sony A6000 connected to card capture;
A Behringer Uphoria as sound interface;
Windows 10.
Pretty simples.

My log file is included as well.

Thanks in advance for any help.

 

[Narcogen]

OBS is increasing audio buffering as required because it is either having trouble communicating with the device, or because the buffer is emptying, which would lead to stutters. So you're trying to correct consistently for a problem that is not occurring in a consistent manner.

Audio buffering can be caused by system performance problems or by other issues, but it is usually external to OBS.

11:25:41.113: [DShow Device: 'Sony A6000'] settings updated:
11:25:41.113: video device: IT9910 Capture Filter (HD)
11:25:41.113: video path: \\?\usb#vid_048d&pid_0281#6&96b9906&0&2#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\{99104000-a330-11e1-a380-991068640000}
11:25:41.113: resolution: 720x480
11:25:41.113: fps: 59.94 (interval: 166833)
11:25:41.113: format: H264
11:25:41.113: using video device audio: yes
11:25:41.113: sample rate: 48000
11:25:41.113: channels: 2
11:25:41.113: audio type: Capture
11:25:51.846: adding 42 milliseconds of audio buffering, total audio buffering is now 42 milliseconds
11:26:21.949: adding 170 milliseconds of audio buffering, total audio buffering is now 213 milliseconds

 

[ramires.cabral]

@Narcogen Thanks for your quick reply. Can you enlight a bit about "Audio buffering can be caused by system performance problems or by other issues"? I watched cpu and memory usage and seemed pretty low. What else could cause buffering? A bad or old driver perhaps? Poor usb quality cable?

Thanks again!

 

[Narcogen]

Lots of issues. CPU overload, driver problems, possibly cable problems (I guess?), different applications fighting over a driver in exclusivity mode.

 

[Kevin Monahan]

I was seeing similar sounding issues--do multiple tests without changing OBS settings but sync would shift by 10+ frames. I did discover that my camera was set to 24fps with OBS set to 30fps. I got repeatable results after the camera was set to match, at 30fps. Just a thought.