Did you install gstreamer? You can find Windows installers from here: http://gstreamer.freedesktop.org/download/
Make sure to grab both the normal and -devel .msi files.
After installing those you should have gstreamer and all its dependencies in C:\gstreamer\1.0\x86
. Test and make sure it is working! You'll also have a new environment variable GSTREAMER_1_0_ROOT_X86
which points to this directory.
So, in MSYS, make sure you have GSTREAMER_1_0_ROOT_X86\bin
in your PATH
, and add GSTREAMER_1_0_ROOT_X86\lib\pkgconfig
to your PKG_CONFIG_PATH
.
Hopefully everything should now work.
Edit: It is important to install gstreamer to the default location, under C:\gstreamer
, as it seems both the runtime and development files have this path hard coded.
A quick search of the gnome bugzilla turns up at least one bug acknowledging this problem.