FFmpeg
record, convert and stream audio and video
A complete, cross-platform solution to record, convert and stream audio and video.
Utility
http://ffmpeg.org/
FFplay
very simple and portable media player
FFplay is a very simple and portable media player using the FFmpeg libraries and the SDL library. It is mostly used as a testbed for the various FFmpeg APIs.
FFprobe
gathers information from multimedia streams
ffprobe gathers information from multimedia streams and prints it in human- and machine-readable fashion.