MP4 no sound in iMovie 10.1.8 on High Sierra

There’s no sound after imported MP4 video clips into iMovie 10.1.8 on High Sierra? Actually, the same issue has been reported while importing MTS video into iMovie 10.1.8 after updated to macOS High Sierra. This is probably a system issue or an audio codec issue. Here we explain a solution to solve MP4 audio lost issue while loading into iMovie 10.1.8.
MP4 no audio in imovie on high sierra
MP4 video clips have no sound in iMovie 10.1.8 on High Sierra
“I have several MP4 videos downloaded from Facebook. They played fine without any sound issues using preview and also in QuickTime Player, but once imported to the latest iMovie 10.1.8, the MP4 clips lose sound in the middle. I’ve googled a lot for a solution, but without any luck. I’m running iMovie 10.1.8 on macOS High Sierra 10.13.1 on MacBook Pro with Retina display. Any suggestions on this?”

Try restarting your computer and opening iMovie while holding down the Option and Command keys, and then selecting to delete preferences in the box that appears.

If the above does not solve it, there may be something about the audio codec in your video clips that iMovie doesn’t like. iMovie likes MOV with Apple InterMediate Video Codec and AAC audio codec. Open your MP4 clips in HD Video Converter for Mac and it will help you export AIC/AAC .mov files for editing in iMovie smoothly.

How to encode MP4 clips to AIC .mov for solving audio lost issue in iMovie 10.1.8 on High Sierra?

Software requirement
HD Converter for Mac
mp4 to imovie converter for high sierra

Follow these steps:
1. Install and run HD Converter for Mac as an MP4 to iMovie Converter on High Sierra. The main interface appears as below:
MP4 no sound in iMovie 10.1.8 on High Sierra

2. Click on ‘Add File’ to add your mp4 files into this program.

3. From the “Profile” menu, choose ‘Apple InterMediateCodec (AIC) (*.mov) as output format from ‘iMovie and Final Cut Express’ column.
iMovie won’t import AVCHD MTS correctly on High Sierra
Important: If you’ve loaded a number of video clips to do batch conversion, please do remember ticking off ‘Apply to All’ option before you start.

4. (Optional) Click ‘Settings’ button and go to ‘Profile Settings’ window to custom video and audio settings if necessary.

5. When ready, click ‘Convert’ to start transcoding MP4 files to AIC – the best suited editing format for use within Apple iMovie.

6. When the conversion process is complete, click ‘Open Folder’ button to get the generated AIC QuickTime files and open them in iMovie for further editing with optimum performance.

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