mg冰球突破豪华版试玩网站

書名： WebRTC Blueprints
作者名： Andrii Sergiienko
本章字?jǐn)?shù)： 989字
更新時間： 2021-07-16 11:42:51

What is WebRTC?

Web Real-Time Communication (WebRTC) is a new (still under development) open framework for the Web to enable browser-to-browser applications for audio/video calling, video chats, and peer-to-peer file sharing without any additional third-party software/plugins.

It was open sourced by Google in 2011 and includes the fundamental building components for high-quality communication on the Web. These components, when implemented in a browser, can be accessed through a JavaScript API, enabling developers to build their own rich media web applications. Google, Mozilla, and Opera support WebRTC and are involved in the development process.

The following are the major components of the WebRTC API:

getUserMedia: This component allows a web browser to access the camera and microphone
PeerConnection: This component sets up audio/video calls
DataChannels: This component allows browsers to share data through peer-to-peer connections

The WebRTC technology contains a complete stack for voice communications, which includes all the necessary codecs. In addition, it provides software-based AEC (acoustic echo cancellation), AGC (automatic gain control), and noise reduction/suppression.

WebRTC also provides the following modern and powerful possibilities to utilize video communications:

The VP8 codec
Conceal packet loss
Clean up noisy images
Capture and playback capabilities

Peer-to-peer connections can be established using the built-in key NAT/firewall traversal technology using ICE/STUN/TURN and support proxies. So, you don't need to use any special third-party technologies to build a peer-to-peer communication between the customers located behind a firewall or NAT.

To help mitigate the effects of packet loss and unreliable networks, WebRTC supports dynamic jitter buffers and error concealment techniques for audio or video communications.

Supported platforms and devices

WebRTC is a very new technology and is still being developed. Thus, right now, there are still platforms and web browsers that don't support it at all yet or support partially.

WebRTC is supported in the following desktop browsers:

Google Chrome Version 23 and higher
Mozilla Firefox Version 22 and higher
Opera Version 18 and higher
Internet Explorer doesn't support WebRTC yet, but this can be solved using the Chrome Component for IE

At the time of writing this book, the web browser WebRTC API is natively supported only in the Android platform.

Google Chrome Version 29 and higher
Mozilla Firefox Version 24 and higher
Opera Mobile Version 12 and higher
Google Chrome OS

Codecs that are supported in WebRTC

For audio calls, the supported codecs are Opus, G.711, G.722, iLBC, and iSAC.

For video communication, VP8 is the only supported codec at the moment.

Considering that WebRTC is still under development, the list of supported codecs may change in the future.

Why should I use WebRTC?

Currently, there are no easy-to-use, high quality, and complete solutions available that would enable communication using just a web browser. Until today, if you wanted to build a rich media cross-platform web application, you had to use Flash, Java Applets, and a bunch of third-party plugins to make it work. Such solutions usually are heavyweight and difficult to implement and support.

This leads to a situation where we have Internet access in almost every apartment across the world, but we still don't have a simple and effective solution for audio/video rich media applications.

WebRTC is a technology that is intended to solve this situation. It is already integrated with the best voice and video engines that have been deployed on millions of end points over recent years.

With this technology, you can use a universal API and a set of built-in technologies and components to build your applications, and you don't need to keep in mind a bunch of platforms and operating systems you would like your application to support.

Applications you can easily build using WebRTC

The following are the applications you can easily build using WebRTC:

Peer-to-peer audio/video conferences
Pre-recorded video streaming
Desktop screen casting
Peer-to-peer file sharing and transferring

More ideas

An interactive language school
Webinars
A job interview service
A distributed radio broadcasting service
A distance learning school
An interactive dating service

Again, you don't need to use any additional software or libraries. You have to use just the WebRTC API supported by most web browsers today. It works great for Windows, Linux, or Mac OS X without special efforts from the developer.

I believe that after reading this book, you'll want to build your next interactive media web application using WebRTC.

Benefits of using WebRTC in your business

The following are the benefits of using WebRTC in your business:

Reducing costs: WebRTC is a free and open source technology. You don't need to pay for complex proprietary solutions. IT deployment and support costs can be lowered because now you don't need to deploy special client software for your customers.
Plugins: You don't need plugins at all. Previously, you had to use Flash, Java Applets, and other tricky solutions to build interactive rich media web applications. Customers had to download and install third-party plugins to be able to use your media content. You also had to keep in mind different solutions/plugins for a variety of operating systems and platforms. Now you no longer need to care about this.
Peer-to-peer communication: In most cases, communication will be established directly between your customers and you don't need to have a middle point of contact.
Easy to use: You don't need to be a professional programmer or have a team of certified developers with some kind of specific knowledge. In a basic case, you can easily integrate the WebRTC functionality into your web services/sites by using the JavaScript API or even by using a ready-to-go framework.
A single solution for all platforms: You don't need to develop a special native version of your web service for different platforms (iOS, Android, Windows, and others). WebRTC is developed to be a cross-platform and universal tool.
WebRTC is open source and free: A community can discover new bugs and solve them effectively and quickly. Moreover, it is developed and standardized by the world software companies such as Mozilla, Google, and Opera.

官术网_书友最值得收藏!

WebRTC Blueprints