- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Fri, 22 Apr 2011 17:16:50 +1000
- To: Maciej Stachowiak <mjs@apple.com>
- Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>, Eric Carlson <eric.carlson@apple.com>
Ow... sorry - that went totally to the wrong list! Thanks for noticing! Silvia. On Fri, Apr 22, 2011 at 2:47 PM, Maciej Stachowiak <mjs@apple.com> wrote: > > Hi Silvia, > > Could you please also post these messages to public-html so the whole WG is aware? > > Thanks, > Maciej > > On Apr 21, 2011, at 9:20 PM, Silvia Pfeiffer wrote: > >> This is a reply by Eric and myself. >> >> Eric and I hereby confirm that we withdraw our change proposal 3 >> http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_Proposal >> since we are in amicable consensus with change proposal 4, even if the >> 5 changes listed below are not applied immediately, but registered as >> bugs on the spec and dealt with post LC. >> >> Best Regards, >> Silvia & Eric. >> >> >> On Fri, Apr 22, 2011 at 2:12 PM, Silvia Pfeiffer >> <silviapfeiffer1@gmail.com> wrote: >>> (sending this on behalf of the accessibility task force) >>> >>> Dear HTML WG chairs, >>> >>> The undersigned members of the media subgroup of the accessibility >>> task force have come to a consensus on ISSUE-152, which we'd like to >>> share with the larger group through this email. >>> >>> We appreciate the extra time provided to us by the chairs to further >>> discuss the submitted four change proposals and come to an agreement. >>> There have indeed been lengthy discussions during the provided time >>> frame and we have made great progress. >>> >>> The group has come to a consensus on which proposal to support. While >>> some of our feedback on that change proposal has already been taken on >>> board, there is still a list of 5 outstanding changes that need to be >>> addressed for the specification text to be complete. >>> >>> The four proposals on the table are as follows: >>> >>> 1. Audio Track Selecction for Media Element >>> submitted by: Frank Olivier >>> http://lists.w3.org/Archives/Public/public-html/2011Feb/att-0363/CP_Issue152.htm >>> >>> 2. Media Multitrack Change Proposal 2: Synchronize separate media >>> elements through attributes >>> submitted by: Sean Hayes >>> http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_Proposal_2 >>> >>> 3. Media Multitrack Change Proposal: Synchronize separate media >>> elements through attributes >>> submitted by: Silvia Pfeiffer and Eric Carlson >>> http://www.w3.org/WAI/PF/HTML/wiki/Media_Multitrack_Change_Proposal >>> >>> 4. Proposal for Audio and Video Track Selection and Synchronisation >>> for Media Elements >>> submitted by: Ian Hickson >>> http://lists.w3.org/Archives/Public/public-html/2011Mar/0436.html >>> >>> >>> CONSENSUS >>> The undersigned members of the media subgroup of the accessibility >>> task force have agreed to withdraw proposals 1-3 in favor of proposal >>> 4 with the following additions to be made to the proposal: >>> >>> (1) track kind for in-band tracks: >>> >>> At this point, it is also not possible to discover the functionality >>> that a in-band track provides through script. A similar problem was >>> solved for the TextTrack object by introduction of a kind attribute. >>> This is also necessary for the TrackList object, in particular to >>> introduce a standard naming scheme across different media container >>> formats for exposing the kind of data that their tracks provide. >>> >>> Therefore, we request addition of a getKind(in unsigned long index) >>> function to the TrackList object, or something of equivalent >>> functionality. >>> >>> The proposed list of values that kind should understand are: >>> for video: >>> * sign language video (in different sign languages as provided through >>> getLanguage()) >>> * captions (as in: burnt-in video that may just be overlays) >>> * different camera angles >>> * video mosaic >>> for audio: >>> * audio descriptions >>> * language dub >>> * commentary (such as director's commentary) >>> * clear audio (see >>> http://www.w3.org/WAI/PF/HTML/wiki/Media_Accessibility_Requirements#Clear_audio) >>> >>> >>> (2) loop attribute for grouped multitrack: >>> >>> The MediaController object currently does not allow for looping of the >>> grouped resource. This is inconsistent with what is possible on >>> individual media elements and also inconsistent with what is possible >>> on in-band multitrack media resources. The same behavior that an >>> in-band multitrack resource exposes on looping needs to also be >>> possible on a grouped multitrack resource. >>> >>> Therefore, we request addition of a loop IDL attribute on the >>> MediaController object. >>> When it is set to true, playback on the grouped multitrack must >>> restart after all slave elements have ended. >>> >>> It is set to true when at least one of the media elements in the group >>> have a loop IDL attribute that is set to true, false otherwise. >>> Alternatively, it would also be acceptable to set it to true only when >>> all of the media elements in the group have a loop IDL attribute that >>> is set to true, though that seems overly verbose. >>> >>> >>> (3) autoplay attribute for grouped multitrack: >>> >>> The MediaController object currently always autoplay without a means >>> to control this autoplay behaviour and without consistent autoplay >>> across all the slave elements. This is inconsistent with in-band >>> multitrack media resources. One of the main use cases for the >>> introduction of autoplay attributes was that this allows the UA to >>> expose a user setting that disables autoplay behaviour, which is >>> particularly useful to vision-impaired users who cannot easily locate >>> autoplaying media elements. >>> >>> Therefore, we request addition of a autoplay IDL attribute on the >>> MediaController object. >>> When it is set to true, playback of the grouped multitrack must start >>> once all slave elements have reached a readyState of HAVE_ENOUGH_DATA >>> and can play through. >>> >>> It is set to true when at least one of the media elements in the group >>> have a autoplay IDL attribute that is set to true, false otherwise. >>> Alternatively, it would also be acceptable to set it to true only when >>> all of the media elements in the group have a autoplay IDL attribute >>> that is set to true, though that seems overly verbose. >>> >>> >>> (4) readyState for grouped multitrack: >>> >>> The MediaController object currently does not expose an aggregate view >>> of the readyState of the slave media elements. It is, however, >>> impossible for a developer to reliably aggregate the readyState from >>> the individual slave media elements, since their states may continue >>> to change. The media framework inside the UA is the only place where >>> such aggregation is sensibly possible. >>> >>> Therefore, we request addition of a readyState IDL attribute on the >>> MediaController object. >>> It must represent the minimum state that all the slave media elements >>> have achieved. >>> >>> >>> (5) onended event: >>> >>> The MediaController object currently does not expose an onended event. >>> This is inconsistent with in-band multitrack media resources and a >>> convenience event that is useful when reacting to the situation of all >>> slave elements being finished. This would for example be the case for >>> a grouped multitrack resource with an ordinary video track and a sign >>> language track, where the ordinary video track should get a display of >>> further related videos once all tracks have finished playing. It would >>> e.g. wait until the sign language track is finished before it >>> displayed further information. >>> >>> Therefore, we request addition of a onended event to the MediaController object. >>> >>> >>> Best Regards, >>> >>> Media Subgroup of the Accessibility Task force >>> >>> Judy Brewer >>> Janina Sajka >>> John Foliot >>> Sean Hayes >>> Frank Olivier >>> Eric Carlson >>> Mark Watson >>> Bob Lund >>> Silvia Pfeiffer >>> >> > >
Received on Friday, 22 April 2011 07:17:37 UTC