rtpbin/rtxsend: Add unicast re-transmit support and support for session broadcasting using a multiudpsink
Submitted by GstBlub
rtpbin: Add rtcp-send-eos property.
This allows rtpbin to be used with a multiudpsink to broadcast to multiple endpoints. Setting this property to FALSE disables sending a EOS event to be sent to the send_rtcp_src_%u pad when a session is terminated, which would otherwise cause all further RTCP packets to be dropped.
rtprtxsend: Add a rtx_src request pad to allow sending unicast retransmits.
This allows a multiudpsink to be hooked up to rtpbin to broadcast to multiple receivers and use a rtprtxsend aux element to send lost packets only to the appropriate receiver using a dynudpsink.