W3C home > Mailing lists > Public > public-html-a11y@w3.org > March 2010

Re: Survey ready on Media Text Associations proposal

From: Philip Jägenstedt <philipj@opera.com>
Date: Thu, 11 Mar 2010 12:25:43 +0800
To: "Silvia Pfeiffer" <silviapfeiffer1@gmail.com>
Cc: "Michael Smith" <mike@w3.org>, "HTML Accessibility Task Force" <public-html-a11y@w3.org>
Message-ID: <op.u9dyk52latwj1d@philip-pc.oslo.opera.com>
On Thu, 11 Mar 2010 12:10:01 +0800, Silvia Pfeiffer  
<silviapfeiffer1@gmail.com> wrote:

> On Thu, Mar 11, 2010 at 2:56 PM, Philip Jägenstedt <philipj@opera.com>  
> wrote:
>> On Thu, 11 Mar 2010 07:46:01 +0800, Silvia Pfeiffer
>> <silviapfeiffer1@gmail.com> wrote:
>>
>>> + clarify that an "enabled" attribute in the markup expresses the
>>> intention of the page author to have this track activated. The UA may
>>> overrule this intent where it has extra knowledge about user
>>> preferences, e.g. for selecting a more appropriate alternative out of
>>> a trackgroup.
>>
>>> + update the selection algorithm for the trackgroup at
>>>
>>> http://www.w3.org/WAI/PF/HTML/wiki/Media_TextAssociations#Resource_selection_algorithm
>>> to basically signify:
>>>
>>> For each track in a trackgroup
>>>  - the UA can decide to set the enabled attribute based on 'lang'
>>> and/or 'media' attributes on track elements.
>>>  - If there exists tracks with the enabled attribute:
>>>      Select the first such track.
>>>    Else:
>>>      Do not use any of the tracks
>>
>>
>> Is the intention that we specify a track selection algorithm with exact
>> rules for which track to enable based on settings, or should this be  
>> left to
>> UAs to override ad-hoc?
>
> I don't think anything is prescribed to UAs in the HTML spec - if at
> all we can only make recommendations on what override rules a UA uses.
> No?

There are very clear rules for resource selection for <source> and no  
provision for the UA to override this. I'm asking if the intention is to  
specify with the same level of detail which <track> to select and not  
allow UAs to override this, or if we should simply say that the UA can do  
whatever it wants. I don't like the latter because it will certainly lead  
to poor interoperability.

-- 
Philip Jägenstedt
Core Developer
Opera Software
Received on Thursday, 11 March 2010 04:26:25 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 27 April 2012 04:42:03 GMT