0_0... Ho-How did you create a client for something that didn't have a server at this point in time, and is proprietary (Obviously you don't have access to the source code, or you'd have a server)? If you created a client, you should be able to do the reverse. And if you've created the client, and it's not just some TOY application that does nothing, you'll know how to write a server for your own client.
No one can assist you in this matter, especially since you just said you WROTE THE CLIENT, no one can create a server backend for you with a client that you've made and haven't shared lol, how would anyone know what calls to make availlable?
Basically, you did this backwards, you need to write the SERVER first, then the client. Writing server software, isn't difficult, and in your case, you'd essentially have the server open a FIFO and pipe the streamer's data to it, then have the server read the contents of that FIFO out to all clients watching the same endpoint. (Or, you could have the server write the client's video data to the server's hard disk, and read it out to stream it)