Concepts & Techniques for Accessible, Closed Captioned Web-Based Video David Klein K. “Fritz” Thompson 10th Annual Accessing Higher Ground: Accessible Media, Web and Technology Conference Boulder, Colorado November.
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Slide 1
Concepts & Techniques for
Accessible, Closed Captioned
Web-Based Video
David Klein
K. “Fritz” Thompson
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
Slide 2
Flash
Video is played back by Flash Player
Version 7 or above of the Flash Player required
for the end user
Interface (controls, layout) located in .swf file
Slide 3
Flash Video
De facto Web standard because of “player
wars”
Lack
of standards compliance
Continual, relentless upgrades
Difficulty in upgrading – pushing users toward
paid versions
Hijacking of media types / file extensions
People just want video to work
Slide 4
Flash History
Becoming more accessible by version 6
Full integration with video by version 7
Ubiquitous (around 97% share)
Handles video well
YouTube, MySpace
Sorenson Spark codec
ON2VP6 codec
Fast
Developer-level flexibility
Can revise interface as needed
Control over accessibility (within Flash capabilities)
Slide 5
Captioned Flash Video
Flash Video Player (ours)
CC for Flash / ccPlayer (National Center for
Accessible Media – WGBH)
FLVPlayback / FLVPlaybackCaptioning
Components for Flash (Adobe)
Slide 6
Flash Video Player
Allows captioned video without Flash
programming
Open source
Major or minor customization possible
Flash 7.0 and above
Slide 7
CC for Flash / ccPlayer
ccPlayer allows captioned video without Flash
programming
Flash components
Skins
Little Flash knowledge needed
Closed source, so customization is limited
DFXP caption files
Flash 8.0
Slide 8
FLVPlaybackCaptions
Flash programming required
Minimal Flash knowledge needed
Skins
Closed source, so customization is limited
DFXP caption files
Flash 9.0 (CS3)
Slide 9
Flash Files
Video
Caption file
Integrates video and caption files
Flash player (Shockwave)
We use the QuickTime caption file
XML configuration file
.flv
.swf compiled from Flash code
HTML
Flash code file (.fla)
Optional for further development
Slide 10
Flash Video Player Assembly
Flash program file videoname.swf
Video file videoname.flv
Caption file videoname_captions.txt
(Same file as used for QT)
Caption control file captions.xml
(Video and caption file locations)
Flash code file videoname.fla
(optional)
Slide 11
Captions.xml File Characteristics
Use XML standards
Tags case sensitive
All elements closed
xxx
(open and close tags)
(no explicit close tag; use the slash)
Slide 12
XML Configuration
captionfile.txt
video.flv
240
180
1948.03
Slide 13
Flash Video Player Activity
Handout: Activity 3: Flash Video Player
Objective:
Modify
an XML file and assemble the QuickTime
captions file with the Flash video player to create a
web-enabled, captioned, Flash video.
Slide 14
Flash Video Player Files
Place all files together in a folder
Video
(.flv)
Caption file (video_caption.txt)
XML file (caption.xml)
Flash video player file (.swf)
Slide 15
Flash Security
Keep files in same folder when possible
Use BASE attribute in HTML
Or
Test thoroughly, especially among browsers and browser
versions
More:
http://www.macromedia.com/devnet/flash/whitepapers/security.pdf
http://www.macromedia.com/devnet/flash/articles/fplayer_security.html
Concepts & Techniques for
Accessible, Closed Captioned
Web-Based Video
David Klein
K. “Fritz” Thompson
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
Slide 2
Flash
Video is played back by Flash Player
Version 7 or above of the Flash Player required
for the end user
Interface (controls, layout) located in .swf file
Slide 3
Flash Video
De facto Web standard because of “player
wars”
Lack
of standards compliance
Continual, relentless upgrades
Difficulty in upgrading – pushing users toward
paid versions
Hijacking of media types / file extensions
People just want video to work
Slide 4
Flash History
Becoming more accessible by version 6
Full integration with video by version 7
Ubiquitous (around 97% share)
Handles video well
YouTube, MySpace
Sorenson Spark codec
ON2VP6 codec
Fast
Developer-level flexibility
Can revise interface as needed
Control over accessibility (within Flash capabilities)
Slide 5
Captioned Flash Video
Flash Video Player (ours)
CC for Flash / ccPlayer (National Center for
Accessible Media – WGBH)
FLVPlayback / FLVPlaybackCaptioning
Components for Flash (Adobe)
Slide 6
Flash Video Player
Allows captioned video without Flash
programming
Open source
Major or minor customization possible
Flash 7.0 and above
Slide 7
CC for Flash / ccPlayer
ccPlayer allows captioned video without Flash
programming
Flash components
Skins
Little Flash knowledge needed
Closed source, so customization is limited
DFXP caption files
Flash 8.0
Slide 8
FLVPlaybackCaptions
Flash programming required
Minimal Flash knowledge needed
Skins
Closed source, so customization is limited
DFXP caption files
Flash 9.0 (CS3)
Slide 9
Flash Files
Video
Caption file
Integrates video and caption files
Flash player (Shockwave)
We use the QuickTime caption file
XML configuration file
.flv
.swf compiled from Flash code
HTML
Flash code file (.fla)
Optional for further development
Slide 10
Flash Video Player Assembly
Flash program file videoname.swf
Video file videoname.flv
Caption file videoname_captions.txt
(Same file as used for QT)
Caption control file captions.xml
(Video and caption file locations)
Flash code file videoname.fla
(optional)
Slide 11
Captions.xml File Characteristics
Use XML standards
Tags case sensitive
All elements closed
(open and close tags)
Slide 12
XML Configuration
Slide 13
Flash Video Player Activity
Handout: Activity 3: Flash Video Player
Objective:
Modify
an XML file and assemble the QuickTime
captions file with the Flash video player to create a
web-enabled, captioned, Flash video.
Slide 14
Flash Video Player Files
Place all files together in a folder
Video
(.flv)
Caption file (video_caption.txt)
XML file (caption.xml)
Flash video player file (.swf)
Slide 15
Flash Security
Keep files in same folder when possible
Use BASE attribute in HTML
Or
Test thoroughly, especially among browsers and browser
versions
More:
http://www.macromedia.com/devnet/flash/whitepapers/security.pdf
http://www.macromedia.com/devnet/flash/articles/fplayer_security.html