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

Colleagues:

Resending (with apologies) to correct editorial issues flagged by
Charles and Katie. If you've already submitted your opinion on this CfC,
you needn't resend.  Voting responses previously received WILL be counted.

However, if you responded to the effort to re-argue longdesc in this
CfC, but did not directly indicate whether you agree, or disagree with
this CfC, your response cannot be counted because it requires a
judgement call. Therefore, please be clear on whether you support, or do
not support this CfC. Comments are OK, but specific responses are needed
in order to judge whether this CfC does, or does not represent
consensus. It's clear it will not be a unanimous consensus, should we
achieve consensus.


***What

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. We offer our assistance on this point.

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 server.

	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 Media Accessibility
	User Requirements (MAUR) note[1]. 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

[1] http://www.w3.org/TR/media-accessibility-reqs/


-- 

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