Audio / Video Gradually go Out of Sync???

[thirdvalve]

Having an odd problem that I've never experienced before with OBS.

A media file that I have starts off just fine, but gradually, the video and the audio go out of sync, so that by the time it ends the two are a full 1 second or more off. The full clip is only about 30 seconds in length. This same MP4 does NOT exhibit any problem playing back with the Windows 10 Media player (or anything else). I've tried appying the "sync" offset - but that doesn't help of course, because the lag is gradual.

What could be causing this? I have not changed any settings in OBS, and I play back media content all the time. This is new.

 

[thirdvalve]

I did two things :

1. Reduced the video bit rate to 6000

2. Stopped the Adobe Update background service. (I have Premier installed).

It all plays correctly now.

I had also previously bumped up the process priority to "Highest" - but that alone did make any difference.

Odd problem. Still not sure the above steps were actually responsible for solving the problem... or if it was some other issue.

This aspect of OBS keeps me on edge sometimes.