Understanding Success Criterion 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, except when the media is a media alternative for text and is clearly labeled as such.

Intent of Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded)

The intent of this Success Criterion is to provide people who are blind or visually impaired access to the visual information in a synchronized media presentation. This Success Criterion describes two approaches, either of which can be used.

One approach is to provide audio description of the video content. The audio description augments the audio portion of the presentation with the information needed when the video portion is not available. During existing pauses in dialogue, audio description provides information about actions, characters, scene changes, and on-screen text that are important and are not described or spoken in the main sound track.

The second approach involves providing all of the information in the synchronized media (both visual and auditory) in text form. An alternative for time-based media provides a running description of all that is going on in the synchronized media content. The alternative for time-based media reads something like a screenplay or book. Unlike audio description, the description of the video portion is not constrained to just the pauses in the existing dialogue. Full descriptions are provided of all visual information, including visual context, actions and expressions of actors, and any other visual material. In addition, non-speech sounds (laughter, off-screen voices, etc.) are described, and transcripts of all dialogue are included. The sequence of description and dialogue transcripts are the same as the sequence in the synchronized media itself. As a result, the alternative for time-based media can provide a much more complete representation of the synchronized media content than audio description alone.

If there is any interaction as part of the synchronized media presentation (e.g., "press now to answer the question") then the alternative for time-based media would provide hyperlinks or whatever is needed to provide the same functionality.

For 1.2.3, 1.2.5, and 1.2.7, if all of the information in the video track is already provided in the audio track, no audio description is necessary.

1.2.3, 1.2.5, and 1.2.8 overlap somewhat with each other. This is to give the author some choice at the minimum conformance level, and to provide additional requirements at higher levels. At Level A in Success Criterion 1.2.3, authors do have the choice of providing either an audio description or a full text alternative. If they wish to conform at Level AA, under Success Criterion 1.2.5 authors must provide an audio description - a requirement already met if they chose that alternative for 1.2.3, otherwise an additional requirement. At Level AAA under Success Criterion 1.2.8 they must provide an extended text description. This is an additional requirement if both 1.2.3 and 1.2.5 were met by providing an audio description only. If 1.2.3 was met, however, by providing a text description, and the 1.2.5 requirement for an audio description was met, then 1.2.8 does not add new requirements.

See also , and .

Benefits of Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded)

  • This Success Criterion may help some people who have difficulty watching video or other synchronized media content, including people who have difficulty perceiving or understanding moving images.

Examples of Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded)

Resources Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded)

Techniques for Success Criterion 1.2.3: Audio Description or Media Alternative (Prerecorded)

Sufficient Techniques

  1. Providing an alternative for time-based media including any interaction using one of the following techniques

  2. Linking to the alternative for time-based media using one of the following techniques

  3. G78: Providing a second, user-selectable, audio track that includes audio descriptions
  4. G78 AND SL1
  5. Providing a version of a movie with audio descriptions using one of the following:

  6. Providing a movie with extended audio descriptions using one of the following:

  7. G203

Advisory Techniques

  • H96
  • Providing audio description in multiple languages in SMIL 1.0 (future link)
  • Providing audio description in multiple languages in SMIL 2.0 (future link)

Failures