However, BDMV files are usually larger than MKV files because they contain menus, navigation information, and other additional features that are not included in MKV files. Therefore, if your goal is to create a complete backup of a Blu-ray disc, BDMV is the way to go. However, if you're looking for a more convenient way to transfer and play your Blu-ray files, you can use a BDMV converter to convert BDMV folder to MKV format.