audio or video that plays automatically does not exceed 3 seconds


Description

content that plays automatically does not output audio for more than 3 seconds.

Applicability

This rule applies to any audio or video element that has:

  • an autoplay attribute that is equal to true, and
  • both paused and muted attributes equal to false, and
  • either a src attribute or a child source element that references content with a duration of more than 3 seconds that contains audio.

Note:

The default value of both paused and muted attributes is false.

Expectation

For each test target the total audio output does not last more than 3 seconds.

Note:

This rule does not cover single audio instances that play repeatedly for more than three seconds, or multiple audio instances for more than three seconds. The WCAG Understanding documentation for 1.4.2 Audio Controls is ambiguous about how to handle these scenarios.

Assumptions

There are currently no assumptions

Accessibility Support

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

Background

Test Cases

Passed

Passed Example 1

The <audio> element does not play automatically for more than 3 seconds.

<audio src="../test-assets/moon-audio/moon-speech.mp3#t=25" autoplay="true"></audio>

Passed Example 2

The <video> element audio output does not last longer than 3 seconds.

<video autoplay="true">
	<source src="../test-assets/rabbit-video/video.mp4#t=8,10" type="video/mp4" />
	<source src="../test-assets/rabbit-video/video.webm#t=8,10" type="video/webm" />
</video>

Failed

Failed Example 1

The audio element plays automatically for more than 3 seconds.

<audio src="../test-assets/moon-audio/moon-speech.mp3" autoplay="true" controls></audio>

Failed Example 2

The video element automatically plays some audio for more than 3 seconds.

<video autoplay="true">
	<source src="../test-assets/rabbit-video/video.mp4" type="video/mp4" />
	<source src="../test-assets/rabbit-video/video.webm" type="video/webm" />
</video>

Inapplicable

Inapplicable Example 1

The video element is muted.

<video autoplay="true" muted="true">
	<source src="../test-assets/rabbit-video/video.mp4" type="video/mp4" />
	<source src="../test-assets/rabbit-video/video.webm" type="video/webm" />
</video>

Inapplicable Example 2

The video element src file has no audio output.

<video autoplay="true">
	<source src="../test-assets/rabbit-video/silent.mp4" type="video/mp4" />
	<source src="../test-assets/rabbit-video/silent.webm" type="video/webm" />
</video>

Inapplicable Example 3

The audio element does not autoplay.

<audio src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>

Glossary

Outcome

key: outcome

A conclusion that comes from evaluating an ACT Rule on a test subject or one of its constituent test target. An outcome can be one of the three following types:

  • Inapplicable: No part of the test subject matches the applicability
  • Passed: A test target meets all expectations
  • Failed: A test target does not meet all expectations

Note: A rule has one passed or failed outcome for every test target. When there are no test targets the rule has one inapplicable outcome. This means that each test subject will have one or more outcomes.

Note: Implementers using the EARL10-Schema can express the outcome with the outcome property. In addition to passed, failed and inapplicable, EARL 1.0 also defined an incomplete outcome. While this cannot be the outcome of an ACT Rule when applied in its entirety, it often happens that rules are only partially evaluated. For example, when applicability was automated, but the expectations have to be evaluated manually. Such "interim" results can be expressed with the incomplete outcome.


Useful Links



Acknowledgements

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