A.3 WCAG 2.1 Success Criterion 1.2.8 − Media Alternative (Prerecorded)

This success criterion is meant to target at users with impaired hearing and vision. This "alternative" is not like a caption or a subtitle. Instead, full descriptions are provided for all visual information, including visual context, actions and expressions of actors, and any other visual materials. In addition, non-speech sounds (laughter, off-screen voices, etc.) are described, and transcripts of all dialogues are included. The media alternative is generally provided in text so it can be read using assistive technologies.

Before Rectification

When video content is displayed as above, a visually impaired person will only hear the audio and a hearing impaired person will only see the pictures.

After Rectification

To improve accessibility, a text version is added. However, this text version is more than a transcript of the audio. It also describes what is taking place within the video.

WCAG 2.1 Reference:

https://www.w3.org/WAI/WCAG21/Understanding/media-alternative-prerecorded