W3C home > Mailing lists > Public > public-html@w3.org > October 2008

Re: Accessibility of <audio> and <video>

From: Ian Hickson <ian@hixie.ch>
Date: Wed, 15 Oct 2008 09:18:47 +0000 (UTC)
To: Jim Jewett <jimjjewett@gmail.com>
Cc: HTML WG <public-html@w3.org>
Message-ID: <Pine.LNX.4.62.0810150908370.1237@hixie.dreamhostps.com>

On Tue, 14 Oct 2008, Jim Jewett wrote:
>
> In an ideal world, the accessibility features would be in the video.
> 
> In the real world, often they aren't.

Then the videos aren't accessible. This is a problem, that we should try 
to solve. HTML isn't involved in this scenario -- the videos aren't 
accessible in SVG or SMIL or anything else either.


> The page creator may not be able to modify the audio or video.

The video creator may not be able to modify the HTML either. Or it could 
be a publisher who can't modify the HTML nor the video.

If we are to assume that the video will be authored without accessibility 
aids, it seems odd not to also assume that the HTML will be authored 
without accessibility aids. If we are to assume that the HTML author cares 
enough to add accessibility aids to the HTML document, it seems just as 
sensible to assume that the video author will care enough to add 
accessibility aids to the video.


> By all means encourage authors to put the accessibility information 
> within the video.  But there needs to be a fallback for cases where that 
> doesn't happen.

I don't see why. We don't have a fallback for including a separate audio 
track for the case where the video doesn't have its own audio track, or a 
fallback for including an image's color palette for the case where an 
indexed color image doesn't have its own palette, or whatever.


> FWIW, this is probably a good example of why some accessibility folk get 
> so heated:
> 
> Everyone agrees that valid markup is best -- but it is settled that 
> HTML5 browsers will not require it.

But valid markup is still required of authors. There's no feature 
available only to authors who don't write valid markup, it's only error 
handling.


> Everyone agrees that valid SVG is best, but there were long discussions 
> about which requirements to ignore, in favor of the HTML leniency -- 
> even though existing content does not require it.

But valid SVG is still to be required of authors. There's no feature that 
is to be available only to authors who don't write valid SVG, it's only 
error handling.


> Everyone agrees that embedding accessibility information in the original 
> is best -- but existing content does not always do this.  So why is 
> accessibility the only case where the standard suggests "tough -- do it 
> right or not at all"?

It's the same here. We don't add extra features for people doing it the 
worng way. They're in the wrong, and what's left is error handling.


Accessible video is too important to allow it to be left up to some 
bolt-on fallback features in HTML. We have to have features that are 
embedded right at the video resource level, so that users never lose these 
aids even when they save the video files separately and reuse them.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Wednesday, 15 October 2008 09:19:24 UTC

This archive was generated by hypermail 2.3.1 : Monday, 29 September 2014 09:38:58 UTC