MKV Cinema seems to refer to a service or platform where users can download or stream movies and TV shows in MKV format, which is a popular container format for video files, known for its high quality and ability to hold multiple audio and subtitle tracks. However, the specific service you're referring to might not be widely recognized or could be a confusion with other platforms.
A PC connected to a 5.1 or 7.1 surround sound system can pass through DTS-HD Master Audio or Dolby TrueHD. MKVCinema provides these lossless audio tracks, which streaming services compress heavily. mkvcinemacom pc full
Purchase a Blu-ray disc ($10-$25) and use software like MakeMKV (free while in beta) to create your own "PC full" MKV file. This is 100% legal for personal backup in most jurisdictions. What is MKV Cinema