Call for Consensus (CfC): Comments on the MSE CR

Colleagues: This is a Call for Consensus (CfC) to the Accessible
Platform Architectures (APA) Working Group (still functioning as the
Protocols and Formats Working Group), and to the HTML-A11Y Task Force to
test whether we have group consensus on the following comments on the
MSE Candidate Recommendation published at:

http://www.w3.org/TR/2015/CR-media-source-20151112/


***Background Information

The comments proposed below are the result of several conversations
including:

APA's Action-1742:
http://lists.w3.org/Archives/Public/public-pfwg/2015Nov/0281.html

The APA/PF regular teleconference meeting of 9 December:
                http://www.w3.org/2015/12/09-pf-minutes.html#item04

The HTML-A11Y Task Force regular teleconference meeting of 10 December:
http://www.w3.org/2015/12/10-html-a11y-minutes.html#item03

***Proposed Comments

The Accessible Platform Architectures (APA) Working Group and the
HTML-A11Y Task Force offer the following accessibility related comments
on the MSE Candidate Recommendation (URI above):

1.)	The diagram in this document should have a longdesc. If
possible, the diagram itself should also be created using accessible SVG
markup.

2.)	We would request greater use of prose to describe what the API
is doing. This is needed both to help the reader understand what is
being specified, but also to test whether the proposed API actually
meets its intended purpose.

3.)	We believe the MSE is not the appropriate specification to show
how multiple media objects, such as the primary video plus a
sign-language translation video plus captions plus described video are
unencrypted (EME) and synchronized, even when each comes from a
different servers. However, we believe the W3C needs to provide an
high-level overview of how various specifications fit together to
deliver this total user experience However, we believe the W3C needs an
high-level overview of how our various specifications fit together to
deliver the total user experience defined by HTML and by the MAUR. We
request your assistance in creating this high-level overview document,
and in using alternative media examples where appropriate across W3C
media specifications in ourder to illustrate for authors and user agent
developers how W3C specifications work together to meet the widest
possible assortment of user needs.

***ACTION TO TAKE

According to agreed Consensus Procedures, this CfC is now open for
objection, comment, as well as statements of support via email. Silence
will be interpreted as support, though messages of support are certainly
welcome.

If you object to this proposed action, or have comments concerning this
proposal, please respond by replying on list to this message no later
than 23:59 (Midnight) Boston Time, Thursday 17 December.

Janina


-- 

Janina Sajka,	Phone:	+1.443.300.2200
			sip:janina@asterisk.rednote.net
		Email:	janina@rednote.net

Linux Foundation Fellow
Executive Chair, Accessibility Workgroup:	http://a11y.org

The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
Chair,	Protocols & Formats	http://www.w3.org/wai/pf