It will take little time for that to be accomplished. For example, you might want to import some uncompressed files into your music library as compressed files to save disk space. At this point, you need to give your files new names and select the folder to store them. You can use the Apple Music app on Mac or iTunes for Windows to convert song files between compressed and uncompressed formats.
That will allow you to browse through the computer and locate files for importing. From the menu bar, click on 'source' then 'open file' among the options appearing on the dropdown menu. When that is done, you can proceed to launch it. You can use handbrake with Mac and Windows among other supported platforms. It is an open source software program that you will get for free. Looking for a free MKV to MP4 converter? Here is Handbrake! Having been in the field of video editing for more than ten years, Handbrake is one among the equals that you can use to convert MKV to MP4 free.
How to Convert MKV to MP4 Using Handbrake