MKV is a container format for holding multiple audio, video, picture, and text data such as subtitle tracks. It is similar to other common containers like MP4 and AVI, although MKV is open in the specification. For video contents, MKV uses a .mkv filename extension, .mka for audios, and .mks for subtitles.
MPC-HC, KMPlayer VLC Media Player MKV File Player MPV
Xvid is a cross-platform video codec for compressing video files. It can compress a video file at a more than 200:1 ratio. This, in return, makes it easier and quicker to transmit video files over the internet. Also, compressed videos take up less storage space. It compresses data using the MPEG-4 standard.
Roxio Toast 18 Eltima Elmedia Player Windows Media Player (Xvid codec) Apple QuickTime Player (Xvid codec)