Text from 30 July 2004 Working Draft | Issues and Comments | Notes and proposals |
---|---|---|
Guideline 1.2 Provide synchronized media equivalents for time-dependent presentations. |
|
|
Editorial Note : To meet our publication deadline, resolution of issues for this guideline are deferred to our next Working Draft. The primary question is, "How do these success criteria apply to every Webcam, newscast, and home broadcast?" Options we are considering include moving existing success criteria from Level 1 to Level 2 or allowing conformance claims to exclude portions of a site, such as, "All pages and applications on this site meet the Level 1 guidelines of WCAG 2.0 except the Web cam at http://example.org/webcam/." | ||
Level 1 Success Criteria for Guideline 1.2 |
||
1. An audio description of visual events is provided for audio-visual media. [I] |
|
|
2. Captions are provided for all significant dialogue and sounds in time-dependent material. [I] |
|
|
3. Descriptions and captions are synchronized with the events they
represent. [I]
A text transcript or other non-audio equivalent does not need to be synchronized with the multimedia presentation if all four of the following statements are true:
Note: This exception applies to both success criteria 2 and 3 above. |
|
Descriptions and captions, by definition, are synchronized. This
seems to be a separate requirement that applies to alternatives to
the media - transcripts.
|
4. If the Web content is real-time video with audio, real-time captions
are provided. [I]
If the content is a music program that is primarily non-vocal, then captions are not required. |
|
handled by previous proposed criteria? the rebroadcast note should go here instead of later or be a separate criterion? |
5. If the Web
content is real-time, non-interactive video (for example, a Webcam
view of surrounding conditions such as weather information), then one
of the following is provided: [I]
|
|
|
6. If a presentation that contains only audio or only video
requires users to respond interactively at specific times during the
presentation, then a synchronized equivalent presentation (audio,
visual or text) is provided. [I]
If content that is rebroadcast from another medium or resource meets accessibility requirements for that medium, then the rebroadcast satisfies this checkpoint if it complies with other applicable sections of WCAG 2.0 |
|
|
Level 2 Success Criteria for Guideline 1.2 |
||
1. Synchronized captions are provided for all real-time broadcasts.
[I]
Editorial Note : There are questions about what is possible and what should be required for real-time audio description since there is no way to know when there will be gaps in audio (when descriptions could be read) and other issues with describing real-time events. |
|
|
Level 3 Success Criteria for Guideline 1.2 |
||
There are no Level 3 for Guideline 1.2 |
|
@@something about sign language track? |
Who Benefits from Guideline 1.2 (Informative)
People without disabilities also benefit from media equivalents :
|
|
|
Note:
Time-dependent presentations that require people to use a single sense to follow two or more things at the same time may present significant barriers to some users. Depending on the nature of the presentation, it may be possible to avoid scenarios where, for example, a user who is deaf would be required to watch an action on the screen and read the captions at the same time. However, this may not be available for live broadcasts (for example, a football game). Where possible (especially for education and training materials), provide content so that it does not require tracking multiple simultaneous events with the same sense, or, give the user the ability to freeze the video so that captions can be read without missing the video. |
|
|
Examples of Guideline 1.2 (Informative) |
||
Example 1: a movie clip with audio description and
captions.
A clip from a movie is published on a Web site. In the clip, a child is trying to attract a puppy to the child's bedroom by laying a trail of crumbs. Since the soundtrack includes only the child's mumbling, the audio description that is heard when the child stops mumbling says "Charlie puts a crumb on each stair leading to his room." The caption that appears as he mumbles reads, "[inaudible mumbling]." |
|
Example 1: a movie with audio description
Transcript of audio from the first few minutes of, "Teaching Evolution Case Studies, Bonnie Chen" (copyright WGBH and Clear Blue Sky Productions, Inc.) Describer: A title, "Teaching Evolution Case Studies. Bonnie Chen." Now, a teacher shows photographs. Bonnie Chen: These are all shot at either the Everglades...for today you just happen to be a species of wading bird that has a beak like this." Describer: wooden tongue depressors (will non-Americans know "wooden tongue depressors?") |
Example 2: a video clip of a news story.
A video clip accompanies a news story about flooding in a major city. The reporter gives a verbal description of the scene. No audio description is necessary. The captions display what the reporter is saying. |
|
Example 2: a captioned tutorial
A video clip shows how to tie a knot. The captions read, "(music) USING ROPE TO TIE KNOTS WAS AN IMPORTANT SKILL FOR THE LIKES OF SAILORS, SOLDIERS, AND WOODSMEN." From Sample Transcript Formatting by Whit Anderson |
Example 3: a silent animation.
An animation shows a pantomime with a white face and black costume climbing an invisible ladder. There is no audio track for this animation. No captions or audio description are required. Instead, a text label and description are provided as required by guideline 1.1 . |
|
Example 3: Animation of how a car engine works
An animation shows how a car engine works. There is no audio and the animation is part of a tutorial that describes how an engine works. All that is needed is a description of the image. From "How car engines work: Internal combustion" (include some of the explanation? in fact, the explanation given is not complete, so this is hypothetical) |
Additional examples
|
||
Definitions from the glossary |
||
audio description - An audio description is a
verbal description of all significant visual information in scenes,
actions, and events that cannot be perceived from the sound track
alone to the extent possible given the constraints posed by the
existing audio track and limitations on freezing the audio visual
program to insert additional auditory description.
Note: When adding audio description to existing materials, the amount of information conveyed through audio description is constrained by the amount of space available in the existing audio track unless the audio/video program is periodically frozen to insert audio description. However, it is often impossible or inappropriate to freeze the audio/visual program to insert additional audio description. |
|
|
captions - Captions are text equivalents of auditory information from speech, sound effects, and ambient sounds that are synchronized with the multimedia presentation. | Captioning is the process of converting a program's dialogue, sound effects, and narration into words that appear on the screen. Captions are redered in the written language of the audio. | |
media equivalents -Media equivalents present essential audio information visually ( captions ) and essential video information auditorily ( audio descriptions ). |
|
Should be able to avoid using this term. |
real-time events - Real-time events are those that are based on the occurrence of events in real-time where the events are not under the control of the author. |
|
Should be able to avoid using this term. |
time-dependent presentation - A time-dependent
presentation is a presentation that
|
Should be able to avoid using this term. | |
include defn for multimedia, real-time, prerecorded | ||
General issues
|
|
References
What elements of a program are described?
(from "Described Media" a pamphlet produced by the National Captioning Institute)
Either through video clips or signing avatars. "However, not all documents are equally suitable to be delivered in signed form. Train timetables for example, or schedules are not very effective in signed form. In other cases, like for long, legal documents, it can become very tedious to have to go through a long winded signed clip (making abstraction of practical problems like filesizes etc) and it might be actually better to simply provide a short signed resume of the key points with pointers to further relevant information where needed." (from an email to w3c-wai-ig sent 12 April 2004 cmn forwarded but written by Guido Gybels)
Example | Audio | Video | Interaction | live program streamed live | live program stored and streamed later | pre-recorded program streamed as first broadcast | pre-recorded program stored and streamed later | captions | audio description | transcript or description | user agent/media player |
---|---|---|---|---|---|---|---|---|---|---|---|
John Slatin's performance at Kennedy Center | yes | yes | (only w/media player to pause and play) | yes | yes | no | no | provided | provided as part of the performance | provided | Real |
Panda cam | no | yes | no | yes | no | no | no | doesn't need, can't do | doesn't need, can't do | level 1: describe setting and some things may see. level 2: updated blog or summary of highlights | Real? |
Africam | no | yes | can send shots to "highlights" | yes | no | no | no | doesn't need, can't do | doesn't need, can't do | same as pandacam | Windows Media (?) |
DAISY book - MLK Jr's "I have a dream" speech (not streamed, although could be. Could be a VoiceXML application) | yes | no | yes? navigate between chapters | no | yes? originally a live event | no | yes | are provided by the highlighting of the text as it is read | don't need | since a stand alone app, no where to describe? is that part of the intro? | LPPlayer |
CSPAN coverage of 2004 US election debates | yes | yes | no | don't know | don't know if it was streamed online. it was broadcast live and recorded for later streaming. | no | no | real-time captions were part of live broadcast | description of movements and expressions could be useful | Transcripts provided | Real |
Live CNN Nasa briefing | yes | yes | no | yes | likely | no | no | similar to RNC speech | Not many crowd shots, mostly people on panel. None needed. | Transcript should be provided. | Real |
KEXP | don't need | don't need | would be great for interviews | Itunes, windows media, real | |||||||
KEXP - zero7 instudio | yes | no | no | yes | yes | no | no | don't need | don't need | would be great for interviews | windows media, real |
John's intro to the TT24 | yes | yes | no | no | no | no | yes? | should be | should be | transcript would be good. | |
D2 slideshow | no | kind of (more of an animated gif) | no | kind of | not so much a "program" as live images | no | no | browser with server-side push | |||
animation gallery | yes | yes | no | no | no | no | yes | should be | should be | flash plug-in | |
how stuff works, engine combustion | no | yes | no | no | no | no | yes | no (doesn't need) | existing description on rest of the page is almost enough | if were an img would recommend an alt-text, but it's flash | flash plug-in |
Satellite weather selector | no | yes (more like an animated gif) | yes - can select parameters of animation that is generated | kind of | kind of | no | no | doesn't need | could use description, but no way to do live | java applet | |
Aster demo | yes | images of equations | no | no | no | no | yes | don't need | transcript of audio clips should be provided | au audio file | |
Motorola high def DVR set-tops multimedia product demo | no | yes (video on the tv as well as text as part of slideshow) | yes | no | no | no | "programmed" instead of "recorded?" | don't need | could use to describe some of the things going on, although should need for text that appears (if read aloud by SR). Also not sure about the interaction | flash plug-in | |
game: magic ball | yes | yes | yes (it's a video game) | (if it were a multi-player, internet game, yes?) | no | no | no | ?? | ?? | shockwave | |
spider man: the peril of doc ock | yes (music. No dialog. Some sound effects, some grunting) | yes (lots of action) | not really (can send an email, rate or review) | no | no | no | yes | needs captions | could use description | shockwave | |
star wars gangsta rap se | yes animated music video, dialog | yes | no pause/play etc | no | no | no | yes | needs captions | could use descriptions (eg fight scene w/music) | shockwave | |
this land | yes - singing, music | yes - animation, humor | no | no | no | no | yes | needs captions the lyrics are priceless. Transcription would suffice. | needs description the visuals are priceless | shockwave | |
mtv live concert | |||||||||||
mtv - beastie boys video | yes | yes | no | no | no | no | yes | ||||
Coral reef connections | yes - bubbling sounds | animation | yes - "swim" around to find out about animals who live near the reef | no | no | no | yes? | none needed | descriptions of the animals are needed | flash plug-in |
Source | Provision(s) | Exclusions/Applicability |
---|---|---|
W3C - WCAG 1.0 (5 May 1999) [Web] |
|
|
US Access Board - Section 508 Standards, 1194.22 (Effective date: 20 Feb 2001) [Web] | (b) Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation |
|
JIS - JIS X 8341-3 Guidelines for older persons and persons with disabilities - Information and communications equipment, software and services - Part 3 : Web content (20 June 2004) [Web] | 5.4 d) Time-based non-text information, such as animated video, should be accompanied by synchronized alternative information, by adding caption, descriptive tracks, etc. Description of the content shall be provided in some form when synchronized alternative information cannot be provided. |
|
NCAM - Making Educational Software and Web Sites Accessible [Web and software applications] |
|
|
Australia, Canada, and European Union refer to WCAG 1.0 [Web] |
|
|
Tasmanian Government Captioning Policy (word) [broadcast] |
|
|
Accessible News - Issue #15 - November 2002 - reports on settlement between Canadian Broadcasting Corporation (CBC) and Canadian Human Rights Commission (CHRC) |
|
|
W3C WCAG 2.0 | Needs/differences from other policies:
|
Existing 1.1 Level 1:
Text-alternatives are explicitly associated with non-text content and one of the following is true: [I]
Proposed 1.2 Level 1:
Level 1 Success Criteria for Guideline 1.2
Possible combination 1:
Possible combination 2:
Level 1
Level 2
Level 3
Notes
Possible combination 3
Level 1
Level 2
Level 3
$Date: 2004/10/07 06:06:05 $ Wendy Chisholm