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Success Criterion:

Atomic Rules:

Description

This rule checks that video elements have an alternative for information conveyed through audio

Accessibility Requirements

This conformance rule relates to:

Aggregation Definition

Applicability

The rule applies to every [non-streaming][#non-streaming-video-element] video element that is visible, where the video contains audio.

Expectation

For each test target, the outcome of at least one of the following rules is passed:

Assumptions

This rule assumes that the video element is used to play a video (for example, not only used to display an image), and that there is a mechanism to start the video.

Accessibility support

There are no major accessibility support issues known for this rule.

Background

Test Cases

Passed

Passed example 1

A video element with an associated track element that contains captions for all the audio.

Code Snippet:
 <video src="../test-assets/perspective-video/perspective-video.mp4" controls>
  <track src="/test-assets/perspective-video/perspective-caption.vtt" kind="captions">
</video>
 
Example Output: Open in a new tab/ window

Passed example 2

A video element that describes some of the text on the same page. The text on the page labels the video as an alternative.

Code Snippet:
 <p>Not being able to use your computer because your mouse 
  doesn't work, is frustrating. Many people use only the keyboard to navigate 
  websites. Either through preference or circumstance. This is solved by keyboard compatibility. 
  Keyboard compatibility is described in WCAG.
  See the video below to watch the same information again in video form.</p>
<video src="../test-assets/perspective-video/perspective-video.mp4" controls>
</video>
 
Example Output: Open in a new tab/ window

Failed

Failed example 1

A video element without any form of captions.

Code Snippet:
 <video src="../test-assets/perspective-video/perspective-video.mp4" controls></video>
 
Example Output: Open in a new tab/ window

Failed example 2

A video element that describes some of the text on the same page. The video contains more information than the text does.

Code Snippet:
 <p>Not being able to use your computer because your mouse 
  doesn't work, is frustrating. Either through preference or circumstance. This is solved by keyboard compatibility. 
  Keyboard compatibility is described in WCAG.
  See the video below to watch the same information again in video form.</p>
<video src="../test-assets/perspective-video/perspective-video.mp4" controls>
</video>
 
Example Output: Open in a new tab/ window

Inapplicable

Inapplicable example 1

A video element without that is not visible on the page.

Code Snippet:
 <video src="../test-assets/perspective-video/perspective-video.mp4" controls style="display: none;"></video>
 
Example Output: Open in a new tab/ window

Inapplicable example 2

A video element without audio.

Code Snippet:
 <video src="../test-assets/perspective-video/perspective-video-silent.mp4" controls>
</video>
 
Example Output: Open in a new tab/ window

Glossary

Visible

Content perceivable through sight.

Content is considered visible if making it fully transparent would result in a difference in the pixels rendered for any part of the document that is currently within the viewport or can be brought into the viewport via scrolling.

Content is defined in WCAG.

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