Checkpoint 1.2.3 Audio Description or Media Alternative (Prerecorded)

An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media. (Level A)

Rationale

People who are blind or visually impaired need access to the visual information that is provided in multimedia.

The visual information is described using one of the following:

  • An audio description (also called video description or descriptive narration) is either added to the existing audio track during pauses in the existing audio content or on an alternate audio track. A narrator describes the important visual details that are not already explained in the soundtrack, including information about actions, text information not verbally described, who is speaking, facial expressions, scene changes, and so on.
  • A full text alternative is a transcript that includes descriptions of all of the visual details, including the visual context, actions and expressions of the actors, and any other visual content, as well as the auditory information - the dialogue, who is speaking, sounds (as would be contained in captions). The goal is to give a person who is blind or visually impaired the same information a sighted user would get from the media. People who are deaf, hard of hearing, or who have trouble understanding audio information also benefit because they can read the text alternative as a transcript of the audio or video information.

Exception: When the media is a media alternative for text and is clearly labeled as such.

Note: This checkpoint overlaps with Checkpoint 1.2.5: Audio Description (Prerecorded). If an audio description is used to meet 1.2.3, 1.2.5 is also met. 

Refer to Understanding SC 1.2.3 for more information (external link to WCAG).

Development Techniques

Review the General techniques as well as other tabs applicable to your technology.  Prioritize the use of technology-specific techniques, and implement the General techniques as needed. You are always required to find, understand and implement accessible code techniques to meet the checkpoint. The documented techniques and supplements are not exhaustive; they illustrate acceptable ways to achieve the spirit of the checkpoint. If numbered, techniques are in order of preference, with recommended techniques listed first. Where used, IBM information that complements the WCAG techniques is indicated as supplemental.

Mobile (iOS) techniques

There are no specific Mobile Native iOS technniques for this checkpoint. However, in addition to the General and Web techniques, the techniques in this section provide additional information and context for hybrid applications.

Hybrid techniques

Meeting G173: Providing a version of a movie with audio descriptions using the following:

Hybrid supplements

H96: Using the track element to provide audio descriptions

Apple recommends using the HTML5 <audio>, <video>, and <track> elements for audio and video content on mobile Safari. These elements support audio and video playback natively in the browser  using the browser's  built-in controls.  Developers can also create their own customized media controllers for rich interactivity using web-standard CSS and JavaScript.  Developers should references Apple's "About HTML5 Audio and Video", "iOS-Specific Considerations", and "Use audio descriptions to hear narration describing a video clip, show, or movie" for proper implementation.

Eclipse techniques

There are no specific Eclipse techniques for this checkpoint. Refer to the General techniques section.

Windows-based (MSAA+IA2) techniques

There are no specific Windows-based (MSAA+IA2) techniques for this checkpoint. Refer to the General techniques section.


Most links in this checklist reside outside ibm.com at the Web Content Accessibility Guidelines (WCAG) 2.0. W3C Recommendation 11 December 2008: http://www.w3.org/TR/WCAG20/

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