[Freeswitch-users] Modifying SDPs for SIPREC

Hi, I am trying to come up with a simplified SIPREC compliant client, which would playback an existing recorded file to a third party server. It is a requirement of SIP RFC that the INVITE message from the SIPREC client has SDP attributes such as a=sendonly, a=label and so on. Further Contact URI in the SIP header needs to be updated to include '+sip.src' feature tag, "siprec" option tag in the Require header etc. I was wondering if this is achievable in freeswitch in it's current state? Or am I required to come up with my own mod, such as mod_oreka, to send the INVITE with the required headers?