Audio Sync Issues with FCP

So, over the last two days, I had two friends run into the same problem while editing DSLR footage in FCP. The problem was that even though the sequence settings matched up with the footage from the DSLR,the audio that was recorded separately was mysteriously drifting out of sync. This is a very frustrating problem that I personally lost quite a few hours over. I tried literally everything I could think of. I thought it was the recorder I was using, my sequence settings, etc. I literally checked everything that logically would make sense. To no avail. That’s because the solution defies logic. For some inane reason unknown to mankind FCP ships with a weird “quirk”. Even though when editing DSLR footage there is no “capture” happening, the Capture Settings have to match your footage/sequence settings or you can get Audio that drifts out of sync, Hope that saves you some headaches and helps you get back to editing.

What I am referring to here is that the frame rate in your Capture Settings, not Log and Transfer, needs to match the frame rate of your footage and your Sequence Settings.


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11 replies
  1. Mark Dobson
    Mark Dobson says:

    Yeah, I’ve encountered this situation recently.

    We recorded a poetry awards ceremony using a Canon 7D with the audio recorded on a Tascam DR 100 recording Wav 24bit 48k.

    As usual I used pluraleyes to sync the clips afterwards.

    I got round the problem by splitting the clips into smaller clips where the drift was not so apparent. I wonder if the problem was caused by the audio bit rate.

    The time taken to carry out post audio syncing is not to underestimated and this experience finally convinced me to buy a xf305 to record interviews with.

  2. David Mudre
    David Mudre says:

    The reason you are experiencing drift issues is because your external audio recording is not sample accurate to your video stream. If there were a way to send a clocking signal out of the camera to an external recording device, then your audio would not have any issues. I have tried every possible means to get a usable clocking signal (that would be something not hindering in the field, like a huge rack-mounted 20 year old video-sync box I tried to use) but have so far not found a viable solution. That is the issue with having prosumer equipment that does not have professional features like a wordclock output, we have to find work-arounds. As it stands, breaking the audio into smaller pieces is the best solution I’ve found as described by a post above.

  3. Daniel Bean
    Daniel Bean says:

    That’s good to know I have to look at the capture framerate settting. My question is, what if you are working with a project that has footage that was captured at various framerates? I have a project where not only is the footage different framerates, but I have a few different sequences that are different framerates (because some are going to be for the web, and some for DVD, etc). And you guessed it, I have the audio drift problem. What do you recommend in this scenario?

  4. Ron Dawson
    Ron Dawson says:

    I experienced a similar out of sync issue last year that took a couple of weeks of posting on numerous forums for an answer. Finally, as usual, someone on CreativeCow figured it out. What was weired that the clip would drift out of sync with ITSELF! (i.e. audio at the end of the clip when viewed in FCP was out of sync). However, viewing the same clip in the Finder revealed that original clip was NOT out of sync. So I knew something was happening in FCP.

    I had recorded footage at 24p. We all know 24p is really 23.98. That’s what it says in FCP when you select 24p setting. BUT WAIT. 24p is REALLY 23.976, NOT 23.98. FCP just rounds up the number. So, I had footage transcoded in Media Streamclip where I physically typed in 23.98. When that footage was brought into FCP, audio drifted because even though FCP says 23.98, it really is 23.976. It can’t “handle” 23.98.

    My original source footage is 23.976. I in essence over-rode that by typing 23.98 in Media Streamclip. To solve the problem, I just leave the fps field blank in Media Streamclip. That way media will always be transcoded at the original fps rate.

    FCP will “freak out” if you import clips that don’t fit one of the ACTUAL frame rates: 23.976, 29.97, etc.

    I hope this helps. Thanks for a great pre-emptive article Jon.

  5. David McCreath
    David McCreath says:

    Hey, there. I sure hope you folks monitor comments on old posts. I’m very new at FCP, still using 7 for various reasons, and I’ve been looking for an answer to this drift for a couple of months now.

    When I look for Capture Settings, the closest thing I can find is File > Log and Capture … which gives me a few tabs, one called Capture Settings. However, I don’t see anything specific in there about setting a frame rate. There is a dropdown list with items like “DVCPRO HD – 1080i50 48 kHz”, but changing that appears to no effect.

    The Sequence Setting panel shows an “Editing Timebase” of 23.98, which seems like the number I should be aiming for with the Capture Settings, but I’m not sure.

    Am I looking in the right place and not seeing it, or am I looking in the wrong place? Any pointers would be deeply appreciated.


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