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
MPEG-1 is a compression and encoding system defined by MPEG (Moving Pictures Experts Group). It creates multiple frame sequences of I, B, and P, with the I frame containing all picture data. The B and P frames only store information about the changes on the last I frame. Typically, MPEG-1 uses 1.2 Mbps data rate, which is the speed rate of CD-ROM.