4. Create Video Description file: not needed for talking heads, not needed if description of video elements including slide text, graphs, charts, etc. are provided as part of the audio narration (i.e. spoken word); otherwise you are required to describe key visual elements needed for comprehension of your video content such as: on-screen text or dialogue, sounds, settings, background, actions, expressions, graphics, and more. You can also combine the descriptive Text Transcript (text of the spoken word) with your Video Description (what is taking place in video) as a single HTML file. Sample of combined document is available at:
W3C WAI WCAG Curriculum
5. Create Audio Description (TBD: on hold until final release of Section 508 Refresh in 2013)
6. Publish content together, HTML is the preferred format for text files.
Audio-only file with descriptive Text Transcript in HTML format;
Video-only file with Video Description in HTML format;
Captioned Audio/Video file with Text Transcript in HTML format and Video Description in HTML format (can be combined as one HTML file). Note: for audio+video content, the transcribed audio serves two purposes: it is used to create the synchronized caption file, and it is used to create the descriptive Text Transcript in HTML format.
YouTube and 508 Compliance
YouTube: allows options for delivery of 508 compliant content including captioned video, Text Transcript, Video Description and built-in Interactive Text Transcript; however, end-user experience (i.e. ability to access your compliant content) may vary widely depending on browser/version, lack of keyboard accessibility, difficulty locating certain icons for some screen readers. Important to be aware of this.
In general, it is possible to deliver captioned Audio/Video files via YouTube, where YouTube (in some cases) will also auto-generate an Interactive Text Transcript, and you can also upload a Video Description (in YouTube "description" field); however, it isn't guaranteed that your audience will be able to locate or access each of these elements within the YouTube interface. For example: last week several of us tried to access the same 508-compliant video on YouTube; some couldn't get the CC (closed captions) to work and others couldn't get the "Interactive Transcripts" to work. It's important to be aware this may happen to your audience, as well. Evenso, we should still provide 508-compliant features for our YouTube content; it not only allows us to be 508-compliant, but it also has proven to be very beneficial for those who can access the captions, transcripts and descriptions.
There is a very good resource available from Ohio State University called:
Captioning YouTube Video and Providing Accessible Controls
Web Accessibility Group, Co-Leader
Digital Media Professional
107 Hoke Smith Annex
University of Georgia
Athens, GA 30602