I recorded audio in voice memo, on a separate iPad (hooked up to a mic), when I try to sync the audio to the movie I recorded at the same time on the iPhone camera, it goes out of sync the further along the iMovie timeline I go. Thus I believe voice memo records at a speed other than 30FPS. Any work arounds?
Thanks!
iPhone 7 Plus, iOS 14
As a workaround, use the slider above and to the right of the timeline to fully expand out the timeline. Then control-click on the audio clip in the timeline and, in the pop up menu, select Show Speed Editor. That will reveal a slider handle in the upper right hand corner of the clip. Slide it back and forth slightly to increase or decrease the speed of the clip, until the audio syncs with the video. Sliding left increases the speed. Sliding right decreases the speed. If necessary you can split the audio clip here and there and work with the different segments.
You can also control-click on the video clip and do the same procedure. So you can work with both clips to sync things up. However, usually working with the audio clip will suffice.
-- Rich
As a workaround, use the slider above and to the right of the timeline to fully expand out the timeline. Then control-click on the audio clip in the timeline and, in the pop up menu, select Show Speed Editor. That will reveal a slider handle in the upper right hand corner of the clip. Slide it back and forth slightly to increase or decrease the speed of the clip, until the audio syncs with the video. Sliding left increases the speed. Sliding right decreases the speed. If necessary you can split the audio clip here and there and work with the different segments.
You can also control-click on the video clip and do the same procedure. So you can work with both clips to sync things up. However, usually working with the audio clip will suffice.
-- Rich
Great. Glad that the workaround did the trick.
Audio speed is measured in sample rate. A voice memo is recorded at 44.1 kHz (at least on the Mac), that is slower than an audio recorded at 48 kHz. So, with an audio editor app you can adjust the sample rate to vary the speed of the audio.
If you open the audio voice memo clip in QuickTimePlayer, and do a Window/Show Movie Inspector, you can see the sample rate and the data rate of the audio. Perhaps you can then export the video clip from iMovie using the custom Quality setting to match up the data rates. I've not tried that, but possibly it could work.
I have found that it is just easier to use the speed adjustment slider method that I suggested, as long as it renders a satisfactory result.
-- Rich
I did try Rich's method, and it did work well enough for this purpose, so thanks again!
For anyone else trying to find a solution to the same issue, please note, audio does not have a frame rate. IMovie should be able to detect the speed of the video clip and sync the audio to the video that was recorded separately, but as I found that is not always the case.
I will be trying spire audio app next time I'm recording the audio separately, as from other readings it is of better quality.
Thanks for the info Rich.
I was hoping for a more precise solution for this particular project. For instance I see that the audios speed can be adjusted by percentage. If I could find the exact speed (FPS) the audio is recorded at in voice memo then I should be able to calculate the offset. I’m yet to find that data online.
voice memo FPS versus camera video FPS
