Re: Media Capture and Streams Last Call review; deadline May 15 ( LC-3013)

Dear WebRTC Group,

Thank you for your response to my comment. I agree that the current WD
does not deal with streams of data related to the media, so in that sense
you have provided an accurate answer. However I am far from certain that
this is acceptable. As far as I can see this constraint prevents WebRTC
both from being augmented with accessibility data for example
subtitles/captions and from being augmented with other data-based
functionality such as the display of text or graphics not associated with
accessibility.

I note that the Working Group Charter lists a dependency on WAI Protocols
and Formats Working Group: "Reviews from the WAI PF Working Group will be
required to ensure the APIs allow to create an accessible user
experience." I am not a member of WAI PFWG but have copied in
public-pfwg@w3.org to this message to ensure they have visibility of my
comment: at present I believe that the APIs do not "allow to create an
accessible user experience."

I would suggest it should be a matter of priority for the Working Group to
consider adding this capability. You request a proposal for a specific
solution for this. One possible solution would be to extend the
MediaStreamTrack.kind attribute to permit the value "data" and to have a
further more specific type so that user agents can process data tracks
successfully. It may also be helpful or necessary to expose a common clock
with which such data may be synchronised - further design work to
establish the importance of this would be needed.

An example of the usage scenario could be the provision of a sequence of
TTML or WebVTT documents which, on presentation, provide
subtitles/captions for the video or audio content. This could be achieved
by having a MediaStreamTrack of kind "data" and subtype "ttml+xml" in the
case of TTML.

Kind regards,

Nigel

-- 
Nigel Megitt
Executive Product Manager, BBC Engineering





On 07/07/2015 14:14, "dom@w3.org" <dom@w3.org> wrote:

> Dear Nigel Megitt ,
>
>The Web Real-Time Communications Working Group has reviewed the comments
>you sent [1] on the Last Call Working Draft [2] of the Media Capture and
>Streams published on 14 Apr 2015. Thank you for having taken the time to
>review the document and to send us comments!
>
>The Working Group's response to your comment is included below, and has
>been implemented in the new version of the document available at:
>http://w3c.github.io/mediacapture-main/archives/20150629/getusermedia.html

>.
>
>Please review it carefully and let us know by email at
>public-media-capture@w3.org if you agree with it or not before 17 July
>2015. In case of disagreement, you are requested to provide a specific
>solution for or a path to a consensus with the Working Group. If such a
>consensus cannot be achieved, you will be given the opportunity to raise a
>formal objection which will then be reviewed by the Director during the
>transition of this document to the next stage in the W3C Recommendation
>Track.
>
>Thanks,
>
>For the Web Real-Time Communications Working Group,
>Dominique Hazaël-Massieux
>Vivien Lacourba
>W3C Staff Contacts
>
> 1. http://www.w3.org/mid/D1543486.1E5DD%nigel.megitt@bbc.co.uk
> 2. http://www.w3.org/TR/2015/WD-mediacapture-streams-20150414/

>
>
>=====
>
>Your comment on the document as a whole:
>> Does this work include the capture of related streams of media and/or
>> data
>> with common timing references, such as captions or subtitles?
>
>
>Working Group Resolution (LC-3013):
>This document does not deal with streams of data related to the media.
>Such
>functions could be contemplated as further work once this document is
>done,
>but the Working Group does not suggest adding this functionality at this
>time.
>
>The Working Group does not contemplate any change based on this comment.
>
>----
>
>

Received on Friday, 10 July 2015 14:11:35 UTC