This tool is used to convert Flash Video (flv) to Media Player 4 (mp4).

Flash Video is a container file format used to deliver digital video content over the Internet using Adobe Flash Player version 6 and newer. Flash Video content may also be embedded within SWF files.

MP4 is a digital multimedia container format most commonly used to store video and audio, but can also be used to store other data such as subtitles and still images.