Techniques for Creating Accessible, Closed Captioned WebBased Video

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Techniques for Creating Accessible, Closed
Captioned Web-Based Video
David Klein K. Fritz Thompson

• California State University - Northridge22nd
  Annual International Technology and
• Persons with Disabilities Conference
• Los Angeles, California
• March 22, 2007
• http//disability.law.uiowa.edu/lhpdc/publications
  /kleinpubs.html

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Interactive

• Who are you?
• Why are you here?
• What would you like to know?
• What are your expectations from this workshop?

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Overview

• Introduction to accessible web-based video
• Creating captions with MAGpie (activity)
• QuickTime (activity)
• (Break?)
• Windows Media Player (activity)
• Using a Flash player (activity)
• Embedding content in a web page
• Process and Compression

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Introduction

• Law, Health Policy Disability Center
• Grant-funded research, technical support,
  training

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Our Needs

• Accessible web-based training
• Quality video
• Closed captions
• Transcripts
• Supporting documents (PowerPoints, Handouts)
• Different formats
• QuickTime
• Windows Media Player
• Flash)
• Efficient production, development, and deployment

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Our Video

• http//disability.law.uiowa.edu/dpn/video/
• Over 100 hours of online video for training
• Mostly talking heads

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Characteristics

• User choice
• Start with most accessible player Flash
• Multiple players and configurations
• Embedded vs. Standalone players
• Automatic play vs. press a key to start
• Resizable Players
• Uncaptioned versions
• Platform agnostic (Windows, OS X, Linux)
• Available metadata, transcript, supporting
  documents

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Overview of the Technologies
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Players

• QuickTime
• Windows Media Player
• Real Player
• Flash Player(s)
• Others

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The Technologies

• Clients and servers
• Plugins or whatever
• Downloading
• Embedding video in web pages
• Flash

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Clients vs. Servers
Server
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Clients vs. Servers
Servers
Server
Clients
Clients
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Server

• Server
• Stores HTML, video, caption text, other files
• Files can be stored on different servers
• Files
• HTML page
• Video file
• Caption text file
• Combining file
• Supporting files (transcript, handouts,
  PowerPoint)

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Client

• Displays HTML in browser
• Launches players
• Assembles and displays the pieces
• Video
• Caption text
• Video player and its controls
• HTML and surrounding content

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Client View
Browser Window
Video
Captions
Embedded Player with Controls
Links to supporting documents
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Embedded Captioned Video
Server
Client
Video File
Embed in HTML File
Combine Files in Player
Caption File
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Captioning Technologies

• Open formats
• XML
• Extensible Markup Language
• SMIL
• Synchronized Multimedia Integration Language
• DFXP
• Distribution Format Exchange Profile of the
  timed-text authoring format (TT AF)
• Proprietary formats
• QuickTime caption file
• Apple proprietary format
• SAMI
• Microsoft Synchronized Accessible Media
  Interchange

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Download and Play

• Wait for file to download before playing
• Can be a long time
• Freezes possible but can play back without
  freezes
• Download and store for later play
• No copy protection
• Archive only

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Streaming

• Short wait for start of video
• High bandwidth required
• Fast server or multiple servers
• Special network settings may be needed (multiple
  connections)
• Fast connections
• Freezes not uncommon
• Problems at client end (firewalls)
• Can copy protect
• Required for live video
• Possible for archived video

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Progressive download

• Short wait for start of video, depending on
  bandwidth
• Slow connection possible
• Freezes possible but can be replayed without
  freezes
• Download and store for later play
• Copy resistance
• Archive only

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Open Captioning

• Simpler
• Smaller file size
• Embedded (burned in)
• Static
• May be hard to read
• Doesnt compress well

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Closed Captioning

• Captions can be closed
• Benefit for people who would be distracted by
  captions
• Not much other difference on the Web