SIA-R25<video> element visual content has audio description

Accessibility requirements

This rule is not required for conformance to any accessibility requirements.

Description

This rule checks that prerecorded <video> elements have all visual information also contained in the audio.

Applicability

This rule applies to every prerecorded <video> element that is visible where the video contains audio.

Expectations

  1. The visual information of each test target is available through its audio, or through an audio description track.

Assumptions

  • This rule assumes that a mechanism is available to start the video and that the video element is not simply used to display the poster.
  • This rule assumes that the language of each test target can be correctly determined (either programmatically or by analyzing the content), and sufficiently understood.

Accessibility support

There are only a few implementations of video players (without third party technologies) that support audio description tracks at the time of writing.

Examples

Acknowledgments

This document includes material copied from or derived from https://act-rules.github.io/rules/1ea59c/. Copyright © 2021 W3C® (MIT, ERCIM, Keio, Beihang).