Convert video From mp4 to mkv

A file with the .mp4 file extension is an MPEG-4 video file format. MP4s are one of the more common video file formats used for downloading and streaming videos from the internet. It’s a highly versatile and compressed video format that also can store audio, subtitles, and still images.

MKV file extension is a Matroska Video file. It's a video container much like MOV and AVI, but also supports an unlimited number of audio, picture, and subtitle tracks (like SRT or USF).