Posible to sync video using audio?

Discussion in 'Digital Video' started by pianoman88, Jul 3, 2017.

  1. pianoman88 macrumors regular

    Aug 20, 2010
    So I'm recording a piano player using two cameras. I walk over and start one then go back sit down and start the other. Is it possible to sync the video using the audio as a guide? How? Just purchased Final Cut Pro X.

    I'd like to transition between videos. Is this very difficult?
  2. HobeSoundDarryl macrumors 604


    Feb 8, 2004
    Hobe Sound, FL (20 miles north of Palm Beach)
    Why not start both cameras before the piano player starts, then just crop off the part before he/she starts playing? I suspect this will be the easiest way.

    Else you can detach video from audio, eyeball synchronize it, then edit your footage to show each video track when you want camera 1 or camera 2 to be the currently-visible clip.
  3. kohlson macrumors 68000

    Apr 23, 2010
    Start both cameras. Make a loud, sharp noise, like snapping your fingers, snapping a key against a counter, or some such. Then start the piano. When you view the tracks in post, just align on the very obvious spike in the waveform, where you made the noise. You may find it easier to trim the track you started first (the longer one). Also, you can do this in FCPX's multicam capabilities. A stiff learning curve, but does just this sort of thing.
  4. ImBuz macrumors 6502


    Oct 23, 2014
  5. sahnert macrumors 6502

    Oct 20, 2003
    I think I once used the auto-sync feature in Final Cut Pro X to do this. I know it works between an audio and video clip, so probably could be done with two video clips too.

    Here are the steps I used:
  6. scottrngr macrumors member

    Dec 1, 2015
    It is not difficult at all. You just make a multi-cam clip in FCP. Use one angle as the main clip, then tell the other clip to sync to audio.
  7. boch82 macrumors 6502

    Apr 14, 2008
    Just make sure both cameras are recording audio and the same frame rate and it will work perfectly. YOu only need clean audio on 1 camera, camera audio on the other will be fine for this puropose.
  8. Unami macrumors 6502a

    Jul 27, 2010
    exactly. mark all clips, right click an select "create multicam". if a camera has created multiple clips (e.g. because of the fat32 filesystem if the card), you have to give them the same camera- or angle-name or you'll end up with a track for each. you can then use that multicam-clip for switching between the angles (but keep the audio from one track). if possible, record audio externally. obviously, both clips should have the same (or multiples of each other's) framerate and somewhat useable audio (but that's not going to be hard with a piano player). and don't forget to not cross the axis (meaning, position both on the same side relative to the stage).
  9. Bart Kela Suspended

    Bart Kela

    Oct 12, 2016
    Hollywood has basically been doing what Kohlson has described for decades.

    The common device historically used for this synchronization is called a clapboard. Here are some Google Image Search results that help illustrate this device.

    Using this device serves several functions. It provides a visual indicator of the synchronization point (when the clapper and the board meet together). It also provides an audio cue, noticeable on an audio soundtrack display as a large waveform. Modern clapboards often feature an electronic tone which is even easier to spot. It also identifies the particular clip, helpful if you have multiple takes or shots on the same recording medium (like a spool of film or a digital memory card).

    In the old days of film-based cinematography, the film camera probably didn't have its own audio recording system. The audio was recorded on a different device. For instance, while the motion picture imagery might have been filmed on an ARRI motion picture camera, the audio might have been captured on a Nagra recorder.

    Devices like the clipboard have enabled synchronization.

    This technique is still valid. Even if you have an adequate camcorder for the videography, maybe the audio recording circuitry and microphone aren't up to snuff, so you decide to use an external audio recorder like a Zoom.

    There are even iPad/iPhone based clapboard apps that replace the physical clapboard.
  10. dwig macrumors 6502

    Jan 4, 2015
    Key West FL
    It was also used as a means of recording "metadata" into the shot and onto the audio recording. Film doesn't have metadata in the same sense that an electronic file has, but the film's working title, the scene number, and the take were written on the clapboard so that they were recorded on film for later identification. The clapboard person would read the title, scene, and take out loud so that it was also on the audio recording.

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