This allow adding rtmpsink after the flv streaming have started. Otherwise, FLV streamheader is never sent to the server, which cannot figure-out what is this stream about. It should also help in certain renegotiation figures. The sink will no longer work without an streamheader in caps, though there is no known implementation of flvdemux that does not support this. https://bugzilla.gnome.org/show_bug.cgi?id=760242
rtmpsrc/sink: These plugins require librtmp from http://rtmpdump.mplayerhq.hu/ You have to build librtmp with -fPIC to be able to use it with the GStreamer plugin: make XCFLAGS="-fPIC"