libavformat-dev 4:0.6.1-2ubuntu1 (i386 binary) in ubuntu natty

 This is the demuxer library from the ffmpeg project. 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.