Book Image

Getting Started with WebRTC

By : Rob Manson
Book Image

Getting Started with WebRTC

By: Rob Manson

Overview of this book

WebRTC delivers web-based real-time communication and is set to revolutionize our view of what the Web really is. Streaming audio and video from browser to browser, as well as opening raw access to the camera and microphone, is already creating a whole new dynamic web. WebRTC also introduces real-time data channels that will allow interaction with dynamic data feeds from sensors and other devices. This really is a great time to be a web developer! Getting Started with WebRTC provides all of the practical information you need to quickly understand what WebRTC is, how it works, and how you can add it to your own web applications. It includes clear working examples designed to help you get started building your own WebRTC-enabled applications right away. Getting Started with WebRTC will guide you through the process of creating your own WebRTC application that can be applied in a number of different real-world situations, using well documented and clearly explained code examples. You will learn how to quickly and easily create a practical peer-to-peer video chat application, an audio only call option, and how a Web-Socket-based signaling server can also be used to enable real-time text-based chat. You will also be shown how this same server and application structure can easily be extended to include simple drag-and-drop file sharing with transfer updates and thumbnail previews.
Table of Contents (15 chapters)
Getting Started with WebRTC
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Creating an offer in the caller's browser


As the caller, you are the person initiating the call. You visit the web page first and get call_token that you then share with the person to which you want to connect. But then your browser has to wait until the callee connects.

Once they do connect, their browser sends a signal to the signaling server letting it know that they have arrived, and this signal is then sent to your browser. Once your browser receives this callee_arrived signal, you can then initiate the JSEP offer/answer process by calling peer_connection.createOffer():

// handle signals as a caller
function caller_signal_handler(event) {
  var signal = JSON.parse(event.data);
  if (signal.type === "callee_arrived") {
    peer_connection.createOffer(
      new_description_created,
      log_error
    );
  } else …
}

If the offer is created successfully, then the resulting description is passed to the new_description_created() function. This calls peer_connection.setLocalDescription() to...