Identifying descriptions in Media Overlays

[HadrienGardeur]

Section

No response

Describe the problem

When working with highly illustrated content in Media Overlays, a number of <audio> elements or <text> elements could be descriptions.

For example in a comic book:

• I could describe the panel first
• then provide textual or audio equivalent for captions and speech bubbles

You can take a look at the Accessible Comic that I've created for another PR to see how this would work: https://github.com/HadrienGardeur/accessible-epub-comics

A dyslexic reader won't necessarily need these descriptions and it would be useful if reading systems could offer skippability on such elements.

With our current list of terms in SSV, I don't see any element that could be a good fit.

Describe the fix or new feature you propose

I'd like to introduce a new epub:type value for this purpose: description

Here's an example of how this could work in SMIL:

<seq epub:type="panel" epub:textref="page1-script.xhtml#page1-panel2">
  <par epub:type="description">
    <img src="page1.jpg#xywh=42,694,296,297"/>
    <text src="page1-script.xhtml#page1-panel2-description"/>
    <audio src="audio/page1-panel2-description.mp3"/>
  </par>
  <par epub:type="balloon">
    <img src="page1.jpg#xywh=42,694,296,297"/>
    <text src="page1-script.xhtml#page1-panel2-bubble"/>
    <audio src="audio/page1-panel2-bubble.mp3"/>
  </par>
</seq>

I'll update my full example to reflect this proposal.