At least on the gstreamer1 version in Fedora 19 this include is needed. Glima
reported it as well and I think he also uses Fedora.
modules/emotion/gstreamer1/emotion_gstreamer.c:643:4: error: unknown type name
'GstNavigationCommand'
Even if other distros or gstreamer1 versions do not need this it should be safe
to add it here.
#include <glib-object.h>
#include <gst/video/gstvideosink.h>
#include <gst/video/video.h>
+#include <gst/video/navigation.h>
#include <gst/audio/audio.h>
#include <gst/tag/tag.h>