- From: Jon Gunderson <jongund@staff.uiuc.edu>
- Date: Wed, 14 Apr 1999 21:16:06 -0500
- To: allan_jm@tsb1.tsbvi.edu, WAI UA group <w3c-wai-ua@w3.org>
- Cc: Geoff Freed <Geoff_Freed@wgbh.org>
Thanks, Jon At 04:51 PM 4/13/99 -0500, James Allan wrote: >Geoff Freed (WGBH) and I review the section dealing with multimedia as part >of a different task. below are some comments/thoughts/explanations. > >from http://www.w3.org/TR/1999/WAI-USERAGENT-19990331/ > >Guideline 5.2 Ensure user control over alternative representations of >content >User agents must give users access to author-supplied alternative >representations of content (descriptions of images, captions for video or >audio, etc.) since some users cannot perceive the primary content due to a >disability or a technological limitation (e.g., browser configured not to >display images). See also guideline 5.3. > >General checkpoints: > >5.2.1 [Priority 1] >Ensure that the user has access to alternative representations of content >(e.g., the value of "alt" in HTML or SMIL ><note>there is no "alt" in SMIL, perhaps "captions or audio description in >SMIL"</note>, >the resource designated by "longdesc", or the content of OBJECT in HTML 4.0, >the "summary" attribute for tables in HTML, etc.). > ><new>Checkpoints for images: </new> ><note>these two checkpoints seem to deal specifically with images, so we >grouped them together, as well as changed/inserted the groupings of other >media types.</note> > >5.2.2 [Priority 2] >When no alternative text representation has been specified, indicate what >type of object is present. ><note>possible technique-indicate what alternatives are available from the >source in SMIL player</note> > >5.2.3 [Priority 3] >When alternative text has been specified explicitly as empty (i.e., an empty >string), render nothing. > ><new> Checkpoints for Multimedia: >Multimedia includes audio and video information with specific alternative >representation of information. Alternative representations of audio includes >other audio language tracks and captions (also in other languages). >Alternative representations of video include other audio language tracks, >captions and audio description. > >Checkpoints for captions: </new> ><note>We thought it made sense to have specific checkpoints for captions. >They are text representations of audio information. Alternative audio >representations (other audio languages) are found in the Checkpoints for >audio section. A person from the A/V field would categorize the information >in this manner. </note> > ><note>Moved from checkpoints for audio</note> >5.2.5 [Priority 2] >Allow the user to specify that captions for audio be rendered at the same >time as the audio. ><note> separated captions from audio description and made 2 separate >checkpoints. Audio description is alternative content for video and should >be included in that section (see 5.2.9).</note> > ><note>Moved from checkpoints for video</note> >5.2.6 [Priority 1] >If a technology allows for more than one caption track (e.g., text, >alternative language (subtitle), etc.), allow the user to choose from among >tracks. ><note> separated captions from audio description and made 2 separate >checkpoints. Audio description is alternative content for video and should >be included in that section (see 5.2.9a).</note> > >Checkpoints for audio: > ><note>Moved from checkpoints for video</note> >5.2.7 [Priority 1] >If a technology allows for more than one audio track (alternative language >or overdub) for video, allow the user to choose from among tracks. > >Checkpoints for video: > >5.2.9 [Priority 1] >Allow the user to specify that audio descriptions for video be rendered at >the same time as the video. ><note>separated the captions, see 5.2.5</note> > ><new> >5.2.9a [Priority 1] >If a technology allows for more than one audio description track for video, >allow the user to choose from among tracks.</new> ><note>mirroring caption checkpoints</note> > ><new>5.2.x [Priority 2] >Allow the user to specify that sign language video track (if available) be >rendered at the same time as the video. </new> ><note>this was not specified before. it is possible with in the SMIL spec to >provide this capability</note> > > >Jim Allan, Statewide Technical Support Specialist >Texas School for the Blind and Visually Impaired >1100 W. 45th St., Austin, Texas 78756 >voice 512.206.9315 fax: 512.206.9453 http://www.tsbvi.edu/ >"We shape our tools and thereafter our tools shape us." McLuhan, 1964 > Jon Gunderson, Ph.D., ATP Coordinator of Assistive Communication and Information Technology Division of Rehabilitation - Education Services University of Illinois at Urbana/Champaign 1207 S. Oak Street Champaign, IL 61820 Voice: 217-244-5870 Fax: 217-333-0248 E-mail: jongund@uiuc.edu WWW: http://www.staff.uiuc.edu/~jongund http://www.als.uiuc.edu/InfoTechAccess
Received on Wednesday, 14 April 1999 10:15:36 UTC