- From: Jim Allan <jimallan@tsbvi.edu>
- Date: Thu, 28 Oct 2010 10:55:42 -0500
- To: WAI-ua <w3c-wai-ua@w3.org>
ACTION-460 jallan to discuss EVD2 & 3 - add to IER to 4.9 SC or create new SC, also review CC2,3,4 This action was on Mark and myself. We were joined by Greg L. in crafting ideas and responses. (EVD-2) Support automatically pausing the video and main audio tracks in order to play a lengthy description. (EVD-3) Support resuming playback of video and main audio tracks when the description is finished. There is no standard way to automatically pause the main video and play the extended audio track and then restart the video (essentially, have the audio timeline control the video track). There are ways to mark up this kind of behavior in SMIL. However, there is no current player that will handle the markup. There are no good functional examples. NCAM has examples but they are mock ups, simulating the pausing of the movie to play the Extended Description (ED). In NCAM's demonstration the user must select an alternate movie that has the pauses for ED built in. WCAG20 has AA requirement for authors to accommodate this needed functionality for users. UAAG20 states users are able to select tracks and alternate tracks. The user can select the extended description track if provided by the author. It is not the UAWGs place to make new standards. UAAG20 will need 2 implementations for each SC. We don't see this feature being added in the near future (before we reach last call) Proposal: add ED information to 4.9.8 track manipulation - Intent/Example/Resources add to IER, use case - author created the ED as a separate track, then user can select the ED track. 4.9.8 Track Enable/Disable of Time-Based Media: During time-based media playback, the user can determine which tracks are available and select or deselect tracks. These selections may override global default settings for captions, audio descriptions, etc. Intent: Authors are able to create time-based media with video (perhaps multiple video tracks), multiple audio tracks ( e.g. different languages, video description, extended video description), and multiple caption tracks (e.g. different languages, text of video description, text of extended video description). Users should be able to identify and select from the available tracks. The user may also change their selections. The user agent must provide a mechanism to list the available author supplied tracks and allow the user to select which to play. Examples: Jose, a student with a hearing disability, sometimes misses parts of the dialog in movies because of the sound level or background noise. He can select the caption track to read the dialog and not miss anything. Lin, who is blind, cannot see all of the action in suspense movies. She can select the video description track in addition to the audio track, to hear the action and scenes described during the movie and not miss out on the suspense. Mary has an learning and attention problem. She needs more elaborate descriptions of what is happening in a movie of a science demonstration. The author provided extended descriptions for specific concepts. When Mary selects the extended descriptions the video pauses, while extra audio information about the concept is presented. The author also provided a caption track to go along with the extended descriptions so Mary can read along with the audio and focus on reading and listening to the content. Resources: HTML 5 Video Element http://www.w3.org/TR/html5/video.html#video -- Jim Allan, Accessibility Coordinator & Webmaster Texas School for the Blind and Visually Impaired 1100 W. 45th St., Austin, Texas 78756 voice 512.206.9315 fax: 512.206.9264 http://www.tsbvi.edu/ "We shape our tools and thereafter our tools shape us." McLuhan, 1964
Received on Thursday, 28 October 2010 15:56:12 UTC