- From: John Foliot <jfoliot@stanford.edu>
- Date: Wed, 20 Apr 2011 17:20:39 -0700 (PDT)
- To: "'HTML Accessibility Task Force'" <public-html-a11y@w3.org>
All,
Minutes from the April 20 2011 HTML Accessibility Task Force Media
sub-Team Weekly teleconference are now available:
http://www.w3.org/2011/04/20-media-minutes.html
They are also available as plain text following this announcement -- as
usual, please report any errors, omissions, mis-attributions,
clarifications and the like by replying-to this announcement on-list.
____________________
Media Subteam 20 April 2011
20 Apr 2011
See also: [2]IRC log
[2] http://www.w3.org/2011/04/20-media-irc
Attendees
Present
Bob, Eric_Carlson, Frank, John_Foliot, Judy, Sean, mark,
silvia
Regrets
Chair
John
Scribe
Sean
Contents
* [3]Topics
1. [4]Identify Scribe
2. [5]Issue-152 Multitrack
http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_
Proposals_Summary
* [6]Summary of Action Items
_________________________________________________________
Identify Scribe
<judy> Sean will scribe, Judy will fill in when Sean is commenting
<scribe> scribe: Sean
Issue-152 Multitrack
[7]http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_Proposals
_Summary
[7]
http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_Proposals_Summa
ry
Silvia and JF catching up on email
Ian has introduced some changes
yes please
Judy recommends that we maintain formal and informal communication
Judy: Good to record out discussion
Frank: On track to have a single coherent proposal, would like our
CP to be against whats in the spec, rather than a CP against a CP
to consolidate into one single change
JF: if there is still difference between this group and Ian, how do
we capture that
we should not let anything slip
Mark: arent we required to produce a CP against the current W3C spec
<silvia> +q
Judy, yes; typically what we do against a rolling editors vresion is
comment wrt to a time stamped version
Silvia. the Wiki page is a formal record to some extent
have removed things as Ian has added them
Ian's CP is in the WHATWG spec
ours is in the Wiki
the changes are not uncontrolled
SJudy: That can be tricky
multiple moving targets dont give the record trail
unless you dive into the histories of the individual pages
email also gives some trail
we need to send things that are static
<silvia>
[8]http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_Propos
als_Summary#Proposal_4:_Controller_proposal
[8]
http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_Proposals_Summa
ry#Proposal_4:_Controller_proposal
Silivia: working to that
see urL
ask to work through the 'silvia's notes section
this is the proposal we are going to submit
work through the 7 points
and Silvia can prepare the email
for dicussion
all: general agreement
point 1.
make track more like text track, now recorded as a bug
Silvia - tracklist has a set of getXX functions
these are different to how text track is defined
where they are attributes
Philip suggest making a list of object with attributes for
consistency
we dont need to record this as its a separate bug
JF: Q: What are the pros and cons
if it goes after LC
Eric. the issue is that philip has already filed a bug, and its just
a change to the interface
we dont need to restate it
<silvia> [9]http://www.w3.org/Bugs/Public/show_bug.cgi?id=12530
[9] http://www.w3.org/Bugs/Public/show_bug.cgi?id=12530
move on and leave point 1
Item 2.
it should include id, label and kind
JF: Ian was unclear about kind
what are we discussing?
Silvia its about adding ID and kind
to get a unique identifier to create a fragment url
Sean: should also have a getFragmentIRL function
Siliva: agree, but ID is still needed
Sean: have both
Eric: prefer to not have the function
problem is that there are files for which the URL for the track is
not the same as the parent movie
which is another file on the server
asking a track for a URL, if its a reference to a different file;
this needs to be resolved
it is also a problem that the fragment spec is not final
it seems to be something that could be done in a JS library/
Silvia can find outr which tracks exist
composing the fragment url to combine in one URL
Sean: do we need additional information?
Eric: Asking a track for a reference to itself
refering to the track from the outside is unambiguous
from the inside there is a possibility of confusion
defintion of the attribute needs to say what it refers to
Silvia getID we definitley want
get URL may be a convenience
we dont need to agree on it now to resolve 152
we need to look at the current src to see if its adequate prefix to
a #id
<JF> +1 to @kind
Silvia: kind is required to discover what the content is intended
for
<frankolivier> +1 to @kind
all: agree kind is necessary
Eric: one problem is how we define the media information to a kind
doesnt exist in in MP4 and Quicktime
we are working on a proposal
but hasnt been defined yet
secondly, no authoring tools to let you add it
maybe some command line tools
so it will be a while before this data shows up in files
but agree its important, but will be difficult for a while
Silvia: need it in the spec for interoperability
JF: if the additional data is in the wrapper, how is it exposed to
the player
SIlvia: is the data- attribute appropriate?
eric: we need a mechanism to express a kind of an inband track
this is not on the markup
its in the media
Eric we have a bit of chicken and egg problem, but it will get
solved
Silivia: there are slots in media files, but we need time to
establish usage
Eric: there are fields in Quicktime files, but not standard values
mark: in mpeg-DASH they have been looking at this, and will add the
necessary annotations
JF: so we do need @kind
did we not have other kinds
Silvia: thise were for text
this is AV
we need to think about other kinds
sean: clear audio sould be a kind
speech only
JF: lang, ISO language codes, there doesnt seem to be consistency
do we need to specify language codes for sign
Silvia: yes the latest ones are fairly complete for sign
so not a problem
Mark: are there others like no repetetive stimulis
non-strobe
Eric: that's not really a kind, but a characteristic of the asset
so slightly orthogonal issues
JF: +1
these issues need to be considered, but its not an @kind value
Eric: D Singer and I have never gotten any traction on it
we cant do it in the next 48 hrs
JF: do we have a final list
Sean: should this be an open ended list
Silvia: yes
JF: agree
Judy: can you restate the issue
eric: there is a need for content authors to decalre tha
accessiility reqs that content meets, but also markup content to let
the UA pick the content the user does not want
do the UAAG WG have anything relevant
Eric: the issue is that the content author needs to be able to
describe the content
Mark: MPEG-DASH is defining these roles, and sent a liaason on this
question and multiple roles can be assigned
Judy: can I be put on that htread
Mark: the liason should come formally soon
it was addressed to this group
Silvia: I think there are some open issues, but we can maybe pursue
them separately
maybe as a media query
Judy: the restatement was helpful
can you send the materials
Silvia: added clear audio
JF: done with kind
next item, loop
Silvia: loop is currently disabled for a combined set of elements
we have discussed how it should work
maybe we can leave it for now and discuss with ian
do we actually want loop to be solved
JF: straw poll of opinion
Eric: we should hhave it
Frank: agree
Sean: no reason not to
mark, Judy: no opinio
consensus we should have it
net item : autoplay
Judy can we be clear on the question
eric: should we ever allow autoplay for a group of media resources
silvia: we have it in the requirements
its done by single and inband multi track
but not by slaved elements
do we want it
Judy: current wording?
JF: is selective switching possible?
<silvia>
[10]http://www.whatwg.org/specs/web-apps/current-work/multipage/vide
o.html#media-controllers - you need to scroll down to where
"autoplay" is mentioned
[10]
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#med
ia-controllers
Judy: its a distraction issue, and its not always easy to figure out
how to switch it off
Eric: a non issue as it would be foolish to have separate ungrouped
elements with media that should be synchronised
you always want them to play in sync
its just a question of enablement
JF: need to move on
do we have a solution today?
Eric: no
its about user agent preferences
<silvia> A
[11]http://www.whatwg.org/specs/web-apps/current-work/multipage/vide
o.html#mediacontroller is a blocked media controller if the
[12]http://www.whatwg.org/specs/web-apps/current-work/multipage/vide
o.html#mediacontroller is a
[13]http://www.whatwg.org/specs/web-apps/current-work/multipage/vide
o.html#paused-media-controller, or if any of its
[14]http://www.whatwg.org/specs/web-apps/current-work/multipage/vide
o.html#slaved-media-elements
are[15]http://www.whatwg.org/specs/web-apps/c
[11]
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#med
iacontroller
[12]
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#med
iacontroller
[13]
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#pau
sed-media-controller
[14]
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#sla
ved-media-elements
[15] http://www.whatwg.org/specs/web-apps/c
Judy: need to defer this and go to the other issues
item: some attributes are missing in the controller
Silvia. we had request to add some events, but these relate to the
readyState, so we need to decide whether we need a combined
readystate
it seems readystate is inconsistent
so perhaps we dont really need it,
but we can wait till the result of the bug
Eric: i think its useful
on the media controller, its not possible to find out the combined
state otherwise
Frank: agree with Eric, but need more discussion
JF: does it go in the CP?
Frank: could it go in as a bug outside the CP
JF: not sure,
easier to delete it later
general consensus: should go on the controller
Silvia: will add to the CP
item 7
backup
ended state
Silvia: : the onended event is not included, as Ian not clear what
it means
think it is necessary
Eric: ended is required
Bob: agree, Mark: no opinion
consensus : keep it in
item 7
how to create controls for the combined grou
Silvia: how are the automatic controls created for a combined
resource
Ian seems to thin its possible on each video element, and they will
control the controller
this seems like an OK solution
its probably not possible to create one over multiple elements
Eric: my interpretation is that if show for any element, it works
for all the elements
from a display point of view they will cover only one video element
JF: so this is a solved problem
return to autoplay
Judy: can we restate the question
silvia: should the controller have an autoplay idl attribute
representing all the slaves
Judy: I think so
<judy> Sean: concerned that we are not clear about the semantics of
the idl attribute
<judy> ...will it be controlling all of the elements, or only the
first?
<judy> [others had stated that they support idl, or that they likely
do]
<frankolivier> (Need to drop for another meeting)
<judy> [discussion about (un)clarity in semantics of autoplay, and
how that relates to the question on which we are trying to agree on
a position ]
<judy> bob: the behavior on autoplay should be the same as it would
be if the media player were invoked manually
<judy> several: need communication with ian
<judy> silvia: writing him a letter
<judy> john: we seem to agree on what's needed
<judy> ...and we've gone through all 7 of silvia's bullet points
<judy> silvia: yup, have my notes, will draft letter, circulate it
within the next hour
<judy> john: let's agree to state that as a consensus of the
accessibility sub-group
<judy> ...let's give people 24 hours to agree on that
<judy> ...any tweaks needed, ask silvia to help with
<judy> ...for all, please send a +1 back to the list
<judy> ...thank you everyone so much, good process, good effort
<judy> judy: thanks all
<JF> hi friend
<JF> so the only thing i have not done is tell rrsagent to p art
<JF> scared to do so
Summary of Action Items
[End of minutes]
============================
John Foliot
Program Manager
Stanford Online Accessibility Program
http://soap.stanford.edu
Stanford University
Tel: 650-468-5785
Soap Is a program directed by the
Vice Provost for Student Affairs
============================
Received on Thursday, 21 April 2011 00:21:08 UTC