See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.
HTML5
This technique relates to:
The objective of this technique is to use the HTML5 track element to specify a captions timed text track for a video element. Caption timed text tracks contain transcription or translation of the dialogue, sound effects, relevant musical cues, and other relevant audio information, suitable for when sound is unavailable or not clearly audible.
The src attribute of the track element is a URL that is the address of the text track data.
The kind attribute of the track element indicates the kind of information in the timed text. captions text tracks provide a text version of dialogue and other sounds important to understanding the video. Subtitles contain only the dialogue. If other audio information is important to understanding the video, a subtitle track will not be sufficient to meet the success criteria.
Note: Some regions use the term "subtitle" for any visible text representation of the audio track. An author may mark up a timed text track in the language of the audio track as kind=subtitles, instead of kind=captions, and may include additional relevant audio information. It is not best practice to use subtitles in this situation, since it may confuse users who are trying to find captions, but such a timed text track would meet the requirements of Success Criterion 1.2.2.
A video element for a video in the English language with an English caption track. The captions are provided in the WebVTT format.
Example Code:
<video poster="myvideo.png" controls>
<source src="myvideo.mp4" srclang="en" type="video/mp4">
<track src="myvideo_en.vtt" kind="captions" srclang="en" label="English">
</video>
A video element for a video in the English language with an English caption track. The captions are provided in the WebVTT format.
Example Code:
<video poster="myvideo.png" controls>
<source src="myvideo.mp4" srclang="en" type="video/mp4">
<source src="myvideo.webm" srclang="fr" type="video/webm">
<track src="myvideo_en.vtt" kind="captions" srclang="en" label="English">
<track src="myvideo_fr.ttml" kind="captions" srclang="fr" label="French">
</video> Resources are for information purposes only, no endorsement implied.
For each video element used to play a video:
Check that the video contains a track element of kind captions in the language of the video.
Check #1 is true.
If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.