For gnash you need at least:
boost
http://sourceforge.net/projects/boost/
gtkglext
http://gtkglext.sourceforge.net/
Slackbuilds available for both here:
http://slackbuilds.org/repository/
Then you can choose to use ffmpeg OR gstreamer. I usually use ffmpeg, because I don't like dealing with all the gstreamer plugins ... a PITA. A slackbuild of ffmpeg is available at slackbuilds.
Make sure to read the README in gnash directory.
I use the following config options:
Code:
./configure --enable-renderer=opengl --enable-media=ffmpeg --enable-gui=gtk
Usually it doesn't properly install the FF plugin, you can manually copy it to ~/.mozilla/plugins from somewhere in the build directory, find it, it's called 'libgnashplugin.so' (usually at './plugin/.libs/libgnashplugin.so' from the top of the source directory)