As MKV is an open and free container format that contains diverse video, audio, and subtitle components in to one file, and let you enjoy high definition videos smoothly. In order to edit the MKV files in iMovies, a simple solution for you is to convert MKV to iMovie compatible formats via a third party video converter.
To save your time, Brorsoft iMedia Converter for Mac is highly suggested here. With it, transcode and convert MKV files to Apple InterMediate Codec .mov for iMovie in fast encoding speed and excellent quality. Besides, the an all-in-one video converter can do format conversion among various popular video and audio formats, including MKV, AVI, MTS, MOV, MPG, VOB, Blu-ray/DVD discs and more.
Step 1. Launch the MKV to iMovie video converter. Go to the "File" menu, choose "Add Video" to locate the MKV videos you want to add. You can add several files to do batch conversion.
Step 2. You can choose iMovie/FCE --> Apple InterMediate Codec(AIC) (*.mov) as the output format. The output video can be imported to iMovie directly.
Tip: Furthermore, you are provided some useful edit functions cropping, trimming, adding watermark, attaching subtitles for pre-editing your video files so that you can simplify your iMovie editing.
Step 3. Click the "Convert" button to start the MKV to AIC conversion on Mac. After the conversion, click "Open" to locate the result videos and then launch iMovie, choose File > Import > Movies..., to import the converted MKV video into iMovie. Now, feel free to edit the converted MKV files in iMovie.