hi,
yep, as aymeric said, these two streaming packages ( ffmpeg and mpeg4ip ) must be installed from sources, because pidip makes use of a lot of internal code of ffmpeg and mpeg4ip, which are not installed system-wide with 'make install'.
for ffmpeg, any cvs snapshot should be ok, even ffmpeg 0.4.8. i only recommend a special version ( http://tdegoyon.free.fr/ffmpeg-cvs-2003-03-04.tar.gz ) cause it's been proven to be stable ( but it has the drawback of not supporting recently added codecs ).
for mpeg4ip, it's been tested with mpeg4ip-1.0
sevy [ who thinks that a bad chili is anyway better than polenta, especially with milk ]