nigelmegitt
commented
5 years ago Thanks for raising this @a11ycob
As discussed on the call on Monday, this is something I think we do not need to address with any detailed technical solutions in the first version, however we could certainly add a note that player implementations may reasonably offer a mode in which the main media playback is paused until a description has completed, whether that description is provided as pre-recorded audio or by text to speech, or indeed by rendering onto a Braille display.
I do not think any change to the document format is needed for this, but I'd happily take any feedback from implementers. For example, do we need a semantic indication to determine whether an element with an audio child requires pausing until completion?
From an implementation perspective I would be interested to know if the required information is available at playback time to know when the description has been completed:
- For an
audioelement, the referenced audio has a knowable duration (either aclipBeginandclipEndtime or the native duration of the referenced audio) - For a description being spoken with text to speech, for example using the Web Speech API, is there a "speaking completed" event?
- For a description being presented by a screen reader, is there a "screen reader presentation completed" event?
Extended video descriptions, as a concept, has existed for some time. However, it is not currently reflected in a meaningful way in any of the W3C work (that I am aware of). Is there an opportunity to explore this topic? Questions: Is this functionality that needs to be described by this document, or is it a player level solution?