bouldersoundguy
Senior Member

Digital audio and video devices have clocks in them that they use to determine when to capture an audio sample or video frame. They're generally very precise (as in a particular clock doesn't vary over time), but they're not all perfectly accurate (as in one clock might measure a second slightly differently from another clock). So if you record audio on something like a Zoom recorder and video on a camcorder, there's going to be drift. How long it takes before the drift becomes noticeable...

Did you record the audio on a separate device? Most likely the clocks were divergent.

I could probably make that for you.