How to synchronize iPhone video and microphone audio in iMovie?

Question

How to synchronize iPhone video and microphone audio in iMovie?

1. I have video footage captured with an iPhone 5s (roughly 7 minutes of piano).

2. I have audio footage captured with a third-party microphone (same 7 minutes of piano playing).

3. I bring these two pieces of footage into iMovie and line them up at the beginning of the clips.

4. When I start playing the movie, the video and audio are in sync. Towards the end of the movie, the video and audio are out of sync by roughly 0.5 - 1 second.

My question is how do I synchronize the iPhone and microphone footage in iMovie?

Is this a problem with the video captured with the iPhone?

Or is this a problem with iMovie not able to synchronize video and audio from multiple clips?

Note: I cannot use beat markers to solve this, because the piano playing does not fall on equal durations ("beats").

iPhone 5s, iOS 7.0.4

Posted on Dec 23, 2013 2:36 AM

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Answer 1

Apr 28, 2017 12:29 PM in response to Alex Reynolds

I had a similar problem with the audio and video sources switched; I had to use the iPhone for audio and a Canon 70d for the video. The problem was that the iPhone audio was using a rate of 44.1 kHz while the video was using an audio encoding rate of 48 kHz. I used the free Audacity program to re-sample the audio to 48 kHz and exported it at that rate so I could import that into iMovie and have it match up. You should be able to get the audio encoding rate from iMovie or another player and compare it to the video encoding rate.

http://www.audacityteam.org/

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