Re: Action-219: Draft Response to MSE on Bug 23661

Does HTML5 have a similar note? I feel like this is unfair to force MSE to
include this if HTML5 does not already satisfy this and have a solution for
these use cases. The extensions to AudioTrack and VideoTrack have nothing
to do with enabling accessability. They were added to allow kind
information present in a DASH manifest to be reflected by these objects in
the case where the kind information was not present in the initialization
segments. It is not intended to add extra functionality aside from allowing
the string returned from the kind attribute to be changed programatically.

I object to adding this note to the MSE spec. This is an attempt to give
weight to an accessiblity issue that should be solved by the spec that
defines HTMLMediaElement behavior (ie HTML5 & HTML.next) and not an
extension spec that is simply providing an alternate way to supply media to
the HTMLMediaElement. MSE allows multiple tracks to be supported and simply
hooks into whatever multi-track functionality that is specified in HTML5. I
don't believe MSE should be in the business of specifying/requiring extra
multi-track behavior.

Aaron



On Thu, Dec 12, 2013 at 8:54 AM, Paul Cotton <Paul.Cotton@microsoft.com>wrote:

> FYI.    The original message on the A11Y TF list is:
> http://lists.w3.org/Archives/Public/public-html-a11y/2013Dec/0051.html
>
> Basically the A11Y TF would like the Media TF to consider adding a
> non-normative note to MSE to cover the use case described in Bug 23661.
>  Note that the TF is also working on opening a bug on HTML5 to ensure this
> item is covered there as well.
>
> I will add this item to the Media TF agenda for Tue Dec 17 but I encourage
> the Editors to review this item ASAP.
>
> /paulc
>
> Paul Cotton, Microsoft Canada
> 17 Eleanor Drive, Ottawa, Ontario K2E 6A3
> Tel: (425) 705-9596 Fax: (425) 936-7329
>
>
> -----Original Message-----
> From: Janina Sajka [mailto:janina@rednote.net]
> Sent: Wednesday, December 11, 2013 11:49 PM
> To: HTML Accessibility Task Force
> Subject: Action-219: Draft Response to MSE on Bug 23661
>
> Colleagues:
>
> Herewith, a proposed response to the HTML-WG's Media Task Force and our
> comments on their MSE specification as provided in Bug 23661:
> https://www.w3.org/Bugs/Public/show_bug.cgi?id=23661
>
> MSE Specification:
>
> https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source-cr.html
>
> The HTML-A11Y Task Force has previously discussed our willingness to
> accept the Media Task Force assertion (in response to Bug 23661) that the
> javascript approach detailed in the MSE specification is sufficient to meet
> accessibility requirements for alternative media, and especially for
> simultaneous video streams as is required to support Sign Language
> Translation
> http://www.w3.org/TR/media-accessibility-reqs/#sign-translation
>
> The HTML-A11Y Task Force believes it important, however, that the core
> technical specification implementing media support in HTML 5 explicitly
> acknowledge both the alternative media requirements and the sufficiency of
> its specification to successfully deploy multiple media streams, especially
> multiple video streams, to users who require alternative media.
>
> We propose, therefore, a brief note in the introductory section of the MSE
> specification stating:
>
>         "NOTE: This specification directly supports multiple tracks. It
>         explicitly extends the AudioTrack and VideoTrack interfaces to
>         allow programmatic control of track kind to enable ,a
>         href="http://www.w3.org/TR/media-accessibility-reqs/">Alternative
>         Media</a> scenarios, including simultaneous multiple video
>         tracks in support of <a
>         href="
> http://www.w3.org/TR/media-accessibility-reqs/#sign-translation">Sign
>         Language Translation video tracks</a>."
>
> The Task Force recalls that our requirements for alternative media support
> were conveyed to the wider HTML-WG in 2010:
> http://lists.w3.org/Archives/Public/public-html/2010Aug/0327.html
>
> 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
>         Indie UI                        http://www.w3.org/WAI/IndieUI/
>
>
>