SDP Superimposition Grouping framework
Tencent
Tencent
This document defines semantics that allow for signaling a new SDP group "S" for superimposed media in an SDP session. The "S" attribute can be used by the application to relate all the superimposed media streams enabling them to be added as an overlay on top of any media stream. The superimposition grouping semantics is required, if the media data is separate and transported via different sessions.