Matroska Encoder

Matroska like a Russian doll, is a container, able to store a variety of sub-formats.

Extension: .mkv
 

Compression Options

Being a container many encoding options are present for Matroska: H264, HVEC H265 and VP9, as well as the option to copy 1:1 (re-mux) an existing format (such as h264 in a .mp4 file) which copies the video and audio without encoding.

To learn about the options for the various encoders:  H264, H265, VP9