OBS audio sync and drift/wandering issues.

[Braith]

Hello



If there is an email address I would be happy to enquire there.

I am having audio sync & drift issues. The sync does not stay the same between recording starts, and between closing and opening of OBS. I am a video technician. The audio drifts in MP4 recordings by a few frames at 50p. Setting "enable buffering" under the capture device reduces the drifting by about half from six frames to three altogether (one ahead, two behind, not three either way), but does not completely remove it. Separating the audio from the video device and using it as a separate audio input capture device does not work, as it delays the audio so it is behind the video, this cannot be fixed by a negative audio offset. If anyone may be able to assist or direct me elsewhere that would be appreciated. I have been testing it with a universal counting leader (like at the start of a film) for accurate testing. Originally I thought audio sync offset would be all I needed, but upon testing I discovered it is wandering/drifting/moving during a recording, not just out by a fixed amount. I have also tried several OBS versions, including the latest (a week ago or thereabouts).

I am using CRF encoding, but I tried CBR also, and have had the same issues. I have not tried anything other than MP4 h.264 though.

I have tried this on several computers. The one with the (we think) best processor seemed to drift one frame less than another computer, whether this is relevant, I do not know.

If there is a commercial help facility, for business use, please let me know, but I seem unable to find it.

Here is a log from one computer, but not the one I did most of the testing on, and only of course showing one set of parameters/settings in this log.

Thank you very much,
Braith

 

[koala]

Everything on your machine is ancient: hardware, OS and OBS, and the hardware is rather on the low end for video encoding, so it's difficult to give state of the art advice.
As far as I know, audio drifting like yours is due to losing video frames while encoding, so the video becomes shorter than the audio, so video advances faster then audio at playback time.
Your log doesn't include a recording session, so it's not possible to see how your video encoding will run.

You should be able to use the Quicksync (QSV) hardware encoder. Use it instead of x264. You need to reduce frames lost or lagged due to rendering lag and encoding lag. They need to be zero or near zero.