There is no automation for this (pkg-config will not help with getting
the plugin paths and libraries to link against). I don't know if MXE
could possibly help with this. Like getting the plugin path would be
helpful so people won't have to hard-code the path into their build
system. Is there a variable exported that least gives build systems a
chance to get to the "lib" directory?
How about using pkg-config --variable=prefix to get the prefix of the gstreamer
installation, and then using a relative path from there to the plugin path?