I have several RTP streams coming to from the network, and since RTP can only handle one stream in each direction, I need to able to merge a couple to send back to another client (could be one that is already sending an RTP stream, or not… that part isn’t important).
My guess is that there is some algorithm for mixing audio bytes.
RTP Stream 1 ---------------------
\_____________________ (1 MUXED 2) RTP Stream Out
/
RTP Stream 2 ---------------------
There is an IETF draft for RTP stream Muxing which might help you the link is here http://www.cs.columbia.edu/~hgs/rtp/drafts/draft-tanigawa-rtp-multiplex-01.txt
In case you want to use only one stream, then perhaps send data from multiple streams as different channles this link gives an overview how Audio channels are multiplexed in WAV files. You can adopt similar strategy