Concepts & Techniques for Accessible, Closed Captioned Web-Based Video 
10th Annual Accessing Higher Ground:
Accessible Media, Web and Technology Conference

Boulder, Colorado
November 7, 2007

http://disability.law.uiowa.edu/lhpdc/publications/kleinpubs.html
Interactive
•	Who are you?
•	Why are you here?
•	What would you like to know?
•	What are your expectations from this workshop?
Overview
•	Introduction to accessible web-based video
•	Compression
•	Captioning (activity)
•	(Break?)
•	QuickTime (activity)
•	Our Flash player (activity)
•	Embedding content in a web page
Introduction
•	Law, Health Policy & Disability Center

Grant-funded research, technical support, & training

Our Needs
•	Provide accessible web-based training
•	Quality video with high quality audio
•	Closed captions
•	Transcripts
•	Supporting documents (PowerPoints, Handouts, etc.)
•	Different formats (QuickTime, Windows Media Player, Flash)
•	Efficient production, development, and deployment
•	Frustrated with “player wars”

Our Video
•	http://disability.law.uiowa.edu/dpn/video/dpn_112004/dpn_112004_index.html
•	Over 100 hours of online video for training
•	Mostly talking heads
Feature Choices
•	Player choice
•	Flash player (default)
•	QuickTime 
•	Windows Media Player
•	Uncaptioned versions
•	Embedded in web page vs. standalone
•	Automatic play vs. user initiated
•	Resizable
•	Metadata, transcript, supporting documents

Players
•	QuickTime
•	Windows Media Player
•	Flash Player
The Technologies
•	Clients and servers
•	Plugins or whatever
•	Downloading
•	Embedding video in web pages
•	Captioning
•	Flash
Clients vs. Servers
Server vs. Client
•	Server 
•	Stores HTML, video, caption text, other files
•	Files can be stored on different servers
•	Some dynamic content (e.g., databases)
•	Client
•	Displays content
•	Interface to the user
•	Dynamic
•	Assembles files / content into a whole presentation
Client View
Embedded Captioned Video
Captioning Technologies
•	XML 
•	Extensible Markup Language
•	SMIL
•	Synchronized Multimedia Integration Language
•	SAMI
•	Microsoft® Synchronized Accessible Media Interchange 
•	QuickTime caption file
•	Apple
•	DFXP
•	Adobe Flash
Creating Accessible Video
•	Start with video / audio of highest possible quality
•	Acquire secondary audio source and/or CART (real-time caption) file if possible
•	Capture, edit and compress video
•	3 output formats: .mov, .wmv, and .flv
•	Attention to first frame
•	Black
•	Titling

Video Compression Examples
•	Find folder “ahg2007CD” on desktop
•	Open folder (double click)
•	Double click “index.html”
•	Select “Compare compression methods” 
Web-Based Video Methods
•	Download & play
•	Video downloads completely; then plays
•	Streaming
•	Server sends packets of video to client
•	“Progressive” download
•	Video downloads, but starts playing as soon as possible
Download & Play
•	Pros
•	Reduces bandwidth issues
•	Can play back without freezes
•	Download and store for later play
•	Cons
•	Wait for file to download before playing
•	Can be a long time
•	No copy protection
•	Archive only; not live video
Streaming
•	Pros
•	Short wait for start of video
•	Can start in middle of video
•	Cons
•	High bandwidth required
•	Freezes not uncommon
•	Problems at client end (firewalls)
•	Can be expensive
•	Can copy protect
•	Required for live video
•	Useful for archived video
“Progressive” download
•	Pros
•	Short wait for start of video, depending on bandwidth
•	Low bandwidth possible
•	Store for later play
•	Freezes possible but replay without freezes
•	Copy resistance but no protection
•	Archive only; no live video