Need to make a video and audio calling sdk which can be integrated to any app/messenger app and can distribute the library.

Need to make a video and audio calling sdk which can be integrated to any app/messenger app and can distribute the library. To build our own chat client which will handle both chat, audio/video calling and database. Which can provide Skype like video quality and audio quality even on low network. We want to integrate this sdk to our messenger app for audio/video calling and chat features.