We would like to have stand-alone client softphone application , develop in C or C++.
Sip based softphone with source code included, supporting voice and video.
Use open source sip stack like, SipXtapi or Osip.
Codec should support G729, G711, [url removed, login to view] and others.
Support OS are Windows, if possible, Linux and Mac.
It should come with Gui.