GStreamer can dump media graphs in Graphviz .dot format, in a location pointed by GST_DEBUG_DUMP_DOT_DIR env-var:
$ export GST_DEBUG_DUMP_DOT_DIR=/tmp
Now run gst-launch in the console, it will automatically create .dot files in /tmp, one per state transition:
$ gst-launch playbin2 uri=file:///test.mp4 ^C
Now we we can convert the .dot files to to PNG images:
$ cd /tmp $ for i in *.dot; do dot -Tpng -O $i; done
There's a ton of useful info in the media graphs, make sure to check them out!
All credits go to GStreamer team's online docs: http://docs.gstreamer.com/display/GstSDK/Basic+tutorial+11%3A+Debugging+tools