Glitchy video speeds


New Member

I'm an inexperienced user. I'm trying to use OBS to record demos of guitar amps. The issue I'm having is with glitchy video when recording.

Presonus Firestudio Project firewire audio interface
2013 MBP running OSX 10.14.6
Logitech C920 interface

I've been experiencing problems with glitchy video, so I've run two tests, one using OBS and one using Apple's Photo Booth. The video was of a pendulum metronome ticking back and forwards. The audio stream is great on both. The video stream is fine on Photo Booth, but very glitchy on the OBS video with the pendulum visibly speeding up pausing, slowing down etc. This test is repeatable.

In OBS I've only got one video source running and one image overlay. The issue happens with and without buffering on the video capture source, it happens with different cameras and it happens when recording to MKV or MP4.

I'm aware that I'm running old hardware, but it should surely still be possible to get comparable results out of OBS to the decent ones I can get out of Photo Booth with the same setup?

I'd really love to get this sorted so I can try using some of the great features on here!


New Member
Thanks dgatwood. Unfortunately even ultrafast didn't make a difference to the problem.

I've discovered that lowering the fps to 10fps stops the glitches but the video is pretty terrible at 10fps when viewing someone playing guitar.

It still doesn't make any sense to me that Photo Booth handles this perfectly well at 30fps and OBS doesn't.
The only encoder option in OBS is software x264, but could it be that Photo Booth has access to a hardware encoder that OBS doesn't? I don't know much about these things.

Edit: that seems to be what this link implies:

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