GoPro video out of sync with audio from different source at the same event.

As Tom said if you create a sync clip then play that from the Event Browser, which avoids the variable of timeline rate conforming. Afterward if the drift is gone or significantly reduced that implies a timeline rate conforming issue.

Alternatively you could try creating a new custom project: File>New>Project>Use Custom Settings, and explicitly select 59.94 fps, then add the audio and GoPro clip. That would avoid rate conforming. If the drift is still present, it is more likely imprecision in the camera or recorder quartz oscillator.

It's always good to double-check the media's video frame rate. You can play the clip in Quicktime and do CMD+I, then spin down the disclosure arrow under "video details".

Note: An audio-only clip does not have a meaningful frame rate -- it exists as samples not frames. That said, there might be a few cases where a recorder stuffs a frame rate into the audio metadata, with the intent of providing info to downstream post production people. Even if that exists it should not affect NLE sync behavior.

Badmacblues wrote:

...

So it looks like the problem is the 44.1 to the 48, correct?

I don’t understand why it works in iMovie & not in FCPX.

iMovie presumes the user may not understand what audio sampling rate is and tries to automate things for the user, whereas FCP presumes the user is a bit more experienced and knows about such things...

;-)

It is unlikely the problem involves 44.1 Khz vs 48 Khz audio. It can be caused by timebase drift between the Tascam and GoPro. The internal camera/recorder timebase is often driven by an inexpensive quartz oscillator which can drift, just like different quartz wrist watches can drift.

Normally you don't see that on shorter takes, but the frequency stability of the oscillators exist on a bell curve. In a group of recording devices, if one has full plus drift and another has full minus drift, this can amount to 100 milliseconds per hour, easily enough to be apparent on a longer program such as a concert.

Higher-end cameras and audio recorders often have temperature-compensated oscillators so do not drift as much.

You can try retiming the audio very slightly in FCP. That can be tedious since you sync A/V on the start, then jump to (say) 70% down the timeline and examine the sync. If it's off, retime the audio and try again.

I don't know why iMovie would not exhibit that -- assuming you tested the exact same clips from the same devices.

As Tom implied another possible cause is rate conforming between the video clip frame rate vs the timeline frame rate. However if you only have one camera that is less likely. That said certain combinations of clip vs timeline frame rate may result in an automatic retiming operation to conform the two frame rates. Other frame rate combinations such as 24.0 to 29.97 fps use 3:2 pulldown or another algorithm so do not require retiming.

I believe there are some 3rd-party audio sync utilities that can do continuous sync drift correction but I have not used them in a long time.

What’s the audio sample rate of the GoPro? What audio sample rate is the Tascam recording? Are you using the sync clip function to sync the GoPro to the Tascam? Why are you going into Logic?

Are you using the sync clip function to sync the GoPro footage with the audio?

Try using the sync clip function. Using a project adds a third bátale matching the project specs.