Trinidad and Tobago Computer Society Collection of Free and Open Source Software for WINdows

Handbake is a tool for converting videos from a variety of source formats to modern video formats (MP4, MKV, WebM).

Handbrake supports presets of converted videos for video playback on many devices or for upload to video sharing websites. You can queue several video files for conversion, if you have a large number of videos to convert.

See Handbrake's documentation for more details.