- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Sat, 11 Dec 2010 15:43:54 +1100
- To: David Singer <singer@apple.com>
- Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>, Maciej Stachowiak <mjs@apple.com>, Ian Hickson <ian@hixie.ch>
On Thu, Dec 9, 2010 at 2:27 AM, David Singer <singer@apple.com> wrote: > I agree, a poster IS the video. we should not encourage bad practices by pretending/allowing otherwise. > > I have three questions about annotating audio/video resources: > can I > (a) provide a short "alt" text? for video > (b) provide a long description? > (c) link to a transcript? > > These seem to be more important, to me, than worrying about whether the poster is semantically different from the video. I couldn't agree more. In my view we should have the following: > (a) provide a short "alt" text? for video @aria-label would provide for this (alternative suggestions I have seen were: @alt or @title but they may be too confusing); essentially in typical video pages the "video title" and the @poster image normally provide a quick impression, so these need to be described in the short alternative text. > (b) provide a long description? @aria-described-by would provide for such IMO; alternatively, a @summary could be provided on the element, too, but it would be just as useful to sighted as to vision-impaired users, such that I would leave this to the Web page - often enough videos have a description underneath/aside them. > (c) link to a transcript? A "transcript" is a interesting different type of text alternative, actually. A transcript can be time-synchronized, in which case it becomes something akin to captions. However, transcripts typically appear as full text on the side of the video such that sighted people can use them, too. Better still they appear as interactive transcripts, see for example TED videos or YouTube videos e.g. http://www.youtube.com/watch?v=EDNZMw4_mJY and http://www.ted.com/talks/sheryl_wudunn_our_century_s_greatest_injustice.html (you have to open the interactive transcripts). I've experimented with interactive transcripts a bit for use in accessibility, see http://www.annodex.net/~silvia/a11y_bcp/ (I am hoping to put a few more best practices up there, but this is currently only a draft). You will notice that I distinguish between transcripts in a linked resource (which is in fact what a long description should be) and interactive transcripts. You will need to click around on the transcript and on the video a bit to understand what it does. I believe these are the two core use cases and they can already be satisfied with existing markup. But I would be happy for us to improve these ideas. Cheers, Silvia.
Received on Saturday, 11 December 2010 04:52:00 UTC