Saved videos from Garmin Dashcam 55 have no audio in iMovie or Quicktime

I've imported video files from my new Garmin 55 onto my Macbook. They play fine in my MPV player app with audio, but if I play them in Preview, Quicktime or import them into iMovie then the audio is not there anymore.

Anyone had this issue, and do we know a fix for it?
  • I also have this issue with the Garmin 45. Seems to be an Apple codec on mp4 doesn’t support the audio. Camtasia editor, iPad (Photos and Google Photos) also doesn’t have audio. Android, VLC, Google Photos on web and Android all work fine.
  • I experienced this same problem but I was able to convert the audio stream of the mp4 files the Garmin Dashcam 55 produced, with ffmpeg. This is a bit of a workaround, but in the end, the resulting mp4 files are perfectly fine for import in Final Cut or iMovie...

    To do this, use the following terminal command(s):

    # Convert the "original_files/GRMS0001.mp4" file to a new file "converted_files/GRMS0001.mp4"
    # The command below keeps the video stream of the file and only converts the audio stream to AAC so it is playable by Quicktime (and Final Cut Pro)
    ffmpeg -i original_files/GRMS0001.mp4 -c:v copy -c:a aac converted_files/GRMS0001.mp4

    # Bonus: keep the creation time, modified time, of the original file so import dates are not messed up in Final Cut Pro
    touch -r original_files/GRMS0001.mp4 converted_files/GRMS0001.mp4

    Note: You have to have ffmpeg installed on your system. The simplest way to install ffmpeg is to install homebrew and then do a "brew install ffmpeg" in the terminal.