libavformat-dev 6:11.4-2 (armhf binary) in ubuntu wily

 Libav is a complete, cross-platform solution to decode, encode, record,
 convert and stream audio and video.
 .
 This is the demuxer library from Libav. It supports most
 existing file formats (AVI, MPEG, OGG, Matroska, ASF...).
 .
 This package contains the header files and static libraries needed to
 compile applications or shared objects that use libavformat.