Definition
Audio descriptions are available (e.g., via an [HTML] track element with its kind attribute set to "descriptions").
Examples
Example 1 — EPUB 3
<meta property="schema:accessibilityFeature">
audioDescription
</meta>
Example 2 — EPUB 2
<meta name="schema:accessibilityFeature"
content="audioDescription"/>
Example 3 — Audiobooks
"accessibilityFeature": ["audioDescription"]
Explanation
The audioDescription
value is used to indicate that description tracks are included for any video sources that
require them.
Audio descriptions differ from captions and subtitles in that they describe the actions that are occurring in the video (i.e., they provide more information that just what is being spoken). Audio descriptions are most helpful when the content cannot be seen.
Audio description provided for an HTML video using a track
element.
<video>
<source src="speech.mp4" type="video/mp4"/>
<track src="description.vtt" kind="descriptions" srclang="en" label="English"/>
</video>
Note
The HTML audio
element cannot be used to render audio descriptions, as it
does not provide a display area for them.
Related Links
- Schema.org — accessibilityFeature
- Schema.org Accessibility Vocabulary — audioDescription