It's very frustrating that some functions don't accept pseudovariables and there's no workaround.
For example, in this case I need rtpproxy_offer() and rtpproxy_answer() to accept an IP address argument that is retrieved from a database. However, this won't work.
rtpproxy_offer("", $var(src_ip)); # Config compilation error
rtpproxy_offeR("", "$var(src_ip)"); # Results in $var(src_ip) # literally being placed in the # SDP body.
I understand it is difficult to go back and update all legacy functions to accept PVs everywhere. But isn't it possible to provide a wrapper/compatibility function in the core that will parse a PV and generate as a result something that other functions can see as a string literal?