Yes, there are several solutions:
First of all, there is no Apple API.
Secondly, OpenTok seems to easily solve your problem, client and server.
If you want to implement it yourself, I know Spirit and Vidyo , which are paid VoIP and video packages.
You can also use iDoubs or PJSip , both are open source solutions, but they use the x264 encoder , which is GPL licensed and not good enough for the AppStore.
In any case, for this you need a third-party library, and you should also have a server library (probably a SIP server),
If someone knows more open / paid solutions, share it.
avishic
source share