An introduction to the Presentation API

Outline

• W3C & the Web
• Multi-device scenarios
• Towards a standard solution
• Today & Tomorrow

W3C

• Standards setting body for the Web
• 400 Members, with most key players in ICT
• 70+ staff, mostly technical
• Founded by Web inventor, Tim Berners-Lee
• Key foundational principles:
  1. Interoperability
  2. Openness
  3. Royalty-free patent policy

Presentation

Source: "Enabling second display use cases on the web" — Dominik Röttsches, Anssi Kostiainen (Intel Corporation), Fourth W3C Web and TV Workshop

Media "flinging"

Source: "Enabling second display use cases on the web" — Dominik Röttsches, Anssi Kostiainen (Intel Corporation), Fourth W3C Web and TV Workshop

Problem is « bootstrapping »

Starting point

An app running on a first device wants to create a multi-device experience with a second device.

Final point

The two devices are able to exchange messages over some communication channel

Network Service Discovery

• An API to discover and communicate with services discovered on the current network
• Lots of enthusiasm initially
• CORS support required to address security & privacy issues
• No support for legacy devices as a consequence
• Spec is stalled, not implemented

Web Intents

• A service discovery and light-weight RPC mechanism for web apps
• Lots of enthusiasm initially
• Hard to provide a compelling user experience (UX)
• Spec is stalled, not implemented

From devices/services to screens

• Devices/Services are too broad
• Restricts the scope of potential issues
• Screens are more user- and scenario-focused
• Allows to abstract away the attachment method

Attachment methods

The Presentation API

• Mechanism to request display of Web content on a second screen
• Browser used as mediator
• Discovery logic not exposed to Web apps
• Abstracts away the screen's attachment method
• Not necessarily restricted to the local network

Working Group discussions

• How to handle multiple devices controlling one session
• Compatibility with HbbTV
• How to present audio/video content?
• Can a page turn itself into a presentation session?
• Can a page add cloud-based screens to the UA list?
• Interoperability?

What could come next?

• Extension to non-screen devices (Web of Things)
• Synchronization across devices (Multi-Device Timing CG)
• Mechanism to author multi-device apps (CSS? Web components?)
• How to handle more than 2 screens at once

Thanks!

• Slides: http://www.w3.org/2015/Talks/fd-secondscreen-mws/
• Twitter: @tidoust
• Email: fd@w3.org

This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement 610404