Slide 1

Accessible Video in a Diverging
Web Environment
David Klein
K. “Fritz” Thompson
CSUN Conference:
Technology and Persons with Disabilities

Los Angeles, CA
March 16, 2005

Overview
Introduction
 Web-based video players
 The technology
 Creating accessible video
 Flash video
 Our Flash player
 Future of Web-based video


Introduction
Law, Health Policy & Disability Center
 Training


 Work

Incentive Grantees
 Disability Program Navigators

Standup training at conferences
 Accessible video of talking heads for
further training


Our Needs


Provide accessible Web-based training
 High

quality video with quality audio
 Closed captions
 Transcripts
 Supporting documents

Different formats (QuickTime, Windows
Media Player)
 Efficient development and deployment


Players
QuickTime
 Windows Media Player
 Real Player
 Others


 Flash
 Java

?

Players Shared Advantages
QuickTime, Windows Media, Real
Capable of High Quality audio/video
 Free plugin/player (may autoinstall/update)
 Streaming or progressive download
 Cross platform availability (with caveats)
 Ability to “protect” content from download
 Large installed base


Players Captioning Capabilities
QuickTime, Windows Media, Real



All can handle captioning
All can use “component-based” captioning





Multiple files used
text-track captioning also available in QT

All supported by existing captioning tools

Players Comparison
QuickTime Advantages






“Pro” version available ($30)
Ability to "scrub" while viewing
Ability to FF/Rewind (with audio) while viewing
Ability to have multiple videos playing simultaneously
Free multi-platform streaming server software

QuickTime Disadvantages




Free player bugs you to upgrade to pro
Some useful features limited to pro version
iTunes may be bundled with player (Windows version)

Players Comparison
Windows Media Player Advantages





Feature rich
Pre-installed (on Windows Platform)
Easy, automatic upgrades
Free streaming server software (Windows server only)

Windows Media Player Disadvantages




No ability to “scrub”
One movie at a time
Inconsistent feature implementation

Players Comparison



Real Player Advantages
Feature rich
Large content providers vested
Real Player Disadvantages



May be difficult to find free download







Pro version promoted heavily

Not typically pre-installed
One movie at a time
Streaming server costs

Flash Player Advantages





Installed base – 98%
Arguably easier to upgrade
Loads quickly
New version – MX 2004







Incorporates QuickTime
Simulates a stream
Includes Controls component

Can build in compatibility with other players
Possible to add features

Flash Player Disadvantages
Not highly accessible, though getting
better
 Cost (Flash MX 2004)
 Initial development time
 Expertise required
 Upgrading plugin


 Manually

controls

added accessible text to video

The Technology
Clients and servers
 Plugins or whatever
 Downloading
 Embedding video in Web pages
 Captioning
 Flash


Understanding how the pieces fit together
helps for producing accessible video

Clients vs. Servers
Server

Clients

Clients

Clients vs. Servers


Server





Stores HTML, video, caption text, other files
Files can be stored on different servers

Client




Displays HTML in browser
Launches players
Assembles/packages the pieces
Video
 Caption
 Video Player
 HTML


Client View
Browser Window

Embedded Player

Video

Captions

The Player / Plug-in



Embeds the player in the browser
ActiveX




Plug-ins







Internet Explorer
Netscape
Firefox
Opera

Need to account for both in the HTML
User must install if not available

Web-based Video Delivery
Download
 Streaming
 Progressive download


Download




Provide a link
Entire movie on client hard drive
Benefits






Minimizes low bandwidth
Multiple views from same download
Distribute to others

Disadvantages





Usability
Requires hard drive space
Captioning not always possible
Distribute to others

Streaming
Server controls content
 Active client-server connection
 Benefits


 Live

broadcasts
 Low client hard drive space usage


Disadvantages
 High

bandwidth needed
 Troubleshooting
 May require local network setup (firewalls)

Progressive Download



Play video while downloading
Benefits







Maximizes experience – bandwidth vs. wait time
Can be saved and redistributed
Can be protected from saving by users
Easiest for users

Disadvantages





Uses hard drive space (but temporarily)
Starts and stops
Still a problem for captioning when downloaded

Accessible Video and Web Pages
See www.warp.webaim.org
 Standalone players


 Real

 Windows



Media Player

Embedded
 QuickTime

 Flash

Embedded Captioned Video
Server

Client

Video File

Combining File

Caption File

HTML File

Embedded Players


Different technologies among browsers
