Audio drifts out of sync

[kskreider]

Windows 10 Pro
i-5 12600/32GB RAM (b-die)
EVGA 3080 ti Hybrid

I have been recording live streams and noticed that sometimes the video and audio stay in sync for a 90-minute recording and sometimes they do not. I am seeing that a file may stay in sync for approximately the first half of the video and then they begin to drift out of sync by the end of the file.

If I try multiple times I can typically get a clean recording but I do not want to keep wasting 3, 4, or 5 tries at 90 minutes each with spot-checking. I suppose I can figure out how to stretch the audio in Davinci but shouldn't this just work?

Have others seen audio and video drift out of sync?

 

[Lawrence_SoCal]

1. don't ignore pinned post in this forum about posting your OBS log so folks can check a stream/recording log for settings details

Previous troubleshooting I've read about
- mentions ensuring same audio sampling rate across audio devices (ok if not, if all else is just right, but if system gets busy, and sampling rate mis-match, then potential for drift)
- making sure CPU is not overwhelmed during recording session as that can lead to drift (amongst other undesirable effects)

 

[kskreider]

Thank you, Lawrence and I saw it but was unsure if logs were appropriate in this use case. I will have to wait and reproduce the drift since the ten webcasts that I was capturing expired this morning. I will post a log then. I was capturing the video in the 2K native formats for my monitor so 3-hour files were pretty large. Although I also tried 1080p as well as splitting the capture into two pieces to make smaller files. It may have been a read/write issue with my Samsung Pro NVME, otherwise, this task does not tax my GPU or CPU at all.

 

[Lawrence_SoCal]

A single recording session, at 1440p30? that would not, on its own, saturate a NVMe SSD. HOWEVER, if that SSD is your boot drive, and you are running other tasks, security s/w, etc.. etc... then no way for any of us to know your Disk I/O rates. Standard Hardware Resource Monitoring is key (Task Manager (Performance) and/or Resource Monitor are your friends

 

[AaronD]

Might it be related to this issue on GitHub?:

Audio Monitoring Buffer Buildup / Offsync · Issue #4531 · obsproject/obs-studio

Operating System Info Windows 10 Other OS No response OBS Studio Version 26.1.1 OBS Studio Version (Other) No response OBS Studio Log URL 2021-04-15 11-03-34.txt OBS Studio Crash Log URL No respons...

github.com

That's about the Monitor (usually headphones) output getting out of sync while the main output (stream and recording) stays good, but *maybe* there's something similar going on for you?