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Techniques for Creating Accessible, Closed Captioned Web-Based Video California State University - Northridge 21st Annual International Technology and Persons with Disabilities Conference Los Angeles, California March 22, 2007 http://disability.law.uiowa.edu/lhpdc/publications/kleinpubs.html David Klein K. “Fritz” Thompson
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QuickTime Text Track Embedded Open (Burned In) Captioning QuickTime Pro required Embedded in video file itself Video & captions self-contained Hard to modify Captions can’t be eliminated without separate video or script Easier to deploy (1 file), unless script used May start faster in browser
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Embedded Closed Captioning QuickTime Text Track Demo of embedding text track into QuickTime (see “extras” folder on CD) Also see WebAIM: http://www.webaim.org/techniques/captions/q uicktime/add_captions.php http://www.webaim.org/techniques/captions/q uicktime/add_captions.php http://www.webaim.org/techniques/captions/q uicktime/add_captions.php Also see Accessible Digital Media http://ncam.wgbh.org/publications/adm/index. html (link in Resources page) http://ncam.wgbh.org/publications/adm/index. html http://ncam.wgbh.org/publications/adm/index. html
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QuickTime Captioned Video SMIL file option Requires 3 files Relatively easy to modify captions and video Video and caption files can be reused Captions separate, so Can be eliminated Easy to edit Can be reformatted Harder to deploy than open captioned QuickTime
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Embedded Captioned Video – Multiple Files Embed in HTML File ServerClient Video File Caption File Combine Files in Player
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QuickTime Captioning & Deployment Files Video .mov file and others (.mpg,.m4v, etc.) Caption file .txt QuickTime caption file format SMIL .smi,.sml, or.mov Integrates video and caption files HTML Integrates video, captions, player, text, other files
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Final Assembly (QuickTime) The video - videoname.mov The caption file – videoname.en_US.qt.txt The SMIL file – videoname.sml Avoid.smi file extension .mov or.sml extension elicits QT playback Captions display automatically as part of SMIL standard
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SMIL File Characteristics Use XML standards (mostly) Tags case sensitive All elements closed xxx (open and close tags) (no explicit close tag; use the slash) “SMILText” identifier specific to QuickTime playback
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SMIL File Layout SMILtext SMILtext <smil> </smil>
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SMIL File “SMILText” tag, encoding, QuickTime association Header Metadata (video name, copyright info) Player layout (“region” sizes, background / text colors) Container IDs for linking parts Body Video duration Start (and end) times File locations Links to regions
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SMIL and the Player Layout Root Layout Video region Text region
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SMIL File Activity Handout: QuickTime SMIL Activity - Assemble files Objective: Modify MAGpie files to assemble a captioned QuickTime video.
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