Libav is a set of cross-platform libraries and tools that are used to deal with multimedia files, streams and protocols, it was originally forked from the ffmpeg project. Libav includes many sub-tools like:

1. Avplay: a video & audio player.
2. Avconv: a multimedia converter plus a video & audio recorder from different sources.
3. Avprobe: a tool that connects to the multimedia file stream and returns many useful information and statistics about it.
4. Libavfilter: a filtering API for different Libav tools.