Hallo cyrille!
in fact, this function is available in the 10.6 version of the header file. ubuntu curently use 10.5 did you manually compile gstreamer 10.6? mixing 10.6 header with 10.5 deb package look like a bad idea.
Hm ... yes I compiled it last summer and I was thinking that I deinstalled it, but it seems that the self compiled binary is still installed ...
ubuntu 8.04 does have gstreamer 10.6 maybee i should wait until i upgrade to 8.04.
OK, if ubuntu 8.04 includes it this would be much easier !
LG Georg