High Quality Content by WIKIPEDIA articles! Libav is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of Libav are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the avconv command line program for transcoding multimedia files. The Libav source code is published under the GNU Lesser General Public License 2.1+.