Canon EOS M10 MXF and iMovie workflow
Depending on your rig's capabilities, you may get stuck in editing Canon EOS M10 MXF video clips in Apple iMovie for Mac. If that's the case, transcoding Canon EOS M10 MXF media into AIC .mov format will ensure a better playback and editing experience in iMovie. Check this article and learn how to process Canon EOS M10 MXF footage to iMovie conversion in simple steps.
"I recently updated my system on my MacBook Pro to High Sierra. However, I can no longer import Canon EOS M10 MXF files to iMovie. Before the update, I'm running Sierra with iMovie 10.1.6 and I can import MXF files into iMovie. Anyone know why the update doesn't allow this? Thanks for any help."
From what we have read, High Sierra does not have support for MXF files yet. To be able to load Canon EOS M10 MXF files into iMovie properly, you will need to convert them first. Here's a guide displaying how to encode Canon EOS M10 MXF clips to iMovie's favorite AIC .mov format.
How to encode Canon EOS M10 MXF files to AIC .mov for iMovie editing?
To transcode Canon EOS M10 MXF video to AIC for iMovie editing, do as below: Download Video Converter for Mac Video Converter (It is available for Mac, simply download the proper version depending on your computer.)
Step 1: Click "Add File" to load Canon EOS M10 MXF video files into this program. 
Step 2: Select output format for iMovie Click "Profile" to select "iMovie and Final Cut Express" > "Apple InterMediate Codec(AIC) (*.mov)" as output format. AIC .mov is iMovie's favorite editing codec, which iMovie will read and handle well.

Tips: If necessary, you can click "Settings" button to modify video and audio parameters like encoder, resolution, frame rate, bitrate, aspect ratio, sample rate, and audio channels. You can also "enable 3D Settings" to add 3D effect to your source media.

Step 3: Click "Convert" to start Canon EOS M10 MXF video to iMovie conversion. As soon as the conversion is complete, click "Open Folder" to get the generated AIC .mov files for editing in iMovie with optimum performance. Hope it helps.

Comments