Comments on Media Source Extensions

Hi,

although these comments come from the HTML Accessibility Task Force they
are effectively comments from some individuals since we did not make a
formal Call for Consensus on them.

The commenters are concerned about enabling alternative tracks such as
captions, or sign-language interpretation.

There are two related areas of concern.

The first is that it seems the first real paragraph in section 2.2 only
requires 1 video stream to be supported. This would restrict sign-language
interpretation to that actually encoded directly into the video stream,
which is problematic for localisation and in general for the provision of
accessibility enhancement by third parties.

The second is that while it appears that the purpose of section 2.4.4 is
to ensure that all "necessary" tracks render in synch, and it appears that
this also applies when the user e.g. seeks to a new position in a
"primary", i.e. controlling track, it doesn't say anywhere that this
happens. Reading the algorithms is a very complex way to understand what
is actually happening, and a simple informative paragraph explaining the
effects would be appreciated - especially for this use case, but possibly
in other parts of the specification as well.

For more information on requirements for sign lanugage in particular,
please see http://www.w3.org/WAI/PF/media-a11y-reqs/#sign-translation

On behalf of (individual participants in) the HTML Accessibility Task Force

chaals

-- 
Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
           chaals@yandex-team.ru         Find more at http://yandex.com

Received on Thursday, 17 October 2013 22:48:31 UTC