Fixed build for older ffmpeg (e.g. Ubuntu 10.4 ;-)).
Fixed build for older ffmpeg (e.g. Ubuntu 10.4 ;-)).

svn path=/trunk/libavg/; revision=5104

th3infinity/libavg,scotty007/libavg,th3infinity/libavg,yyd01245/libavg,hoodie/libavg,hoodie/libavg,yyd01245/libavg,scotty007/libavg,yyd01245/libavg,libavg/libavg,th3infinity/libavg,yyd01245/libavg,hoodie/libavg,hoodie/libavg,libavg/libavg,scotty007/libavg,scotty007/libavg,th3infinity/libavg,libavg/libavg,libavg/libavg