mgcp_codec: fix codec decision
Unfortunately OsmoMGW was never really tested with multiple different
codecs on either side of the connection. While OsmoMSC and OsmoBSC only
assign exactly one codec on each side this has never been a problem,
however it might become a problem when a call agent assigns multiple
codecs on one side. This has been observed in a setup where OsmoMGW had
one leg towards an external call agent. Also due to recent upgrades to
the TTCN3 tests we are now able to simulate different codecs on both
sides to pinpoint issues.
Testing has shown that OsmoMGW has difficulties with multiple codecs.
The reason for this is that the function that makes the codec decision
was not fully finished. So let's finish the codec decision function and
let's also use that decision when patching the payload type of outgoing
RTP packets.
Related: OS#5461
Change-Id: I6c3291f825488e5d8ce136aeb18450156794aeb5
8 files changed