- From: Glenn Adams <glenn@skynav.com>
- Date: Sun, 6 Apr 2014 06:28:33 -0600
- To: David Singer <singer@apple.com>
- Cc: Silvia Pfieffer <silviapfeiffer1@gmail.com>, Jim Ley <jim.ley@gmail.com>, Aaron Colwell <acolwell@google.com>, "<public-html-media@w3.org>" <public-html-media@w3.org>
- Message-ID: <CACQ=j+eXvsF=oHZnEvYSzGJejxNOdOzPCdtFsv8dw2ypjUSMbQ@mail.gmail.com>
On Sun, Apr 6, 2014 at 3:45 AM, David Singer <singer@apple.com> wrote: > I think that adding/removing tracks, or reloading the entire video > element, are cleaner and more direct ways to get the UA to re-evaluate what > it is playing. Switching a track to russian and then saying “oh, I > switched you to russian, hope you don’t mind” seems rather roundabout and > an un-needed duplication of this functionality. > I suspect you are right. > > On Apr 6, 2014, at 8:21 , Silvia Pfeiffer <silviapfeiffer1@gmail.com> > wrote: > > > On Sun, Apr 6, 2014 at 4:12 PM, Glenn Adams <glenn@skynav.com> wrote: > >> > >> On Sat, Apr 5, 2014 at 11:55 PM, Silvia Pfeiffer < > silviapfeiffer1@gmail.com> > >> wrote: > >>> > >>> On Thu, Apr 3, 2014 at 12:20 AM, Jim Ley <jim.ley@gmail.com> wrote: > >>>> On 2 April 2014 09:26, Silvia Pfeiffer <silviapfeiffer1@gmail.com> > >>>> wrote: > >>>>> > >>>>> On Wed, Apr 2, 2014 at 6:04 PM, Jim Ley <jim.ley@gmail.com> wrote: > >>>>>> > >>>>>> Isn't the use case for language being mutable simply live subtitles > >>>>>> of a > >>>>>> live "channel" that has programmes in different languages and > >>>>>> therefore > >>>>>> has > >>>>>> closed captions / subtitles in different languages. > >>>>> > >>>>> Each one of those subtitle languages would be a different track, so > >>>>> there is no need for mutability. > >>>> > >>>> > >>>> No they're not, some shows are in English, some are in Welsh, the > >>>> subtitle > >>>> track is a single one for the live broadcast, similarly with audio, > the > >>>> broadcast audio changes languages. > >>> > >>> Every show should have its own subtitle track. > >> > >> > >> That is an operational policy issue that shouldn't be determined by the > >> technology. For example, TTML explicitly supports the presence of > multiple > >> languages in a single TTML document. The user of TTML decides how to > use it: > >> whether to create different TTML files for different languages, or > whether > >> to merge different languages into the same TTML document (allowing > selection > >> to occur at processing or rendering time). > > > > You can do that if you just deliver content and leave the rendering to > > the application. > > > > In the discussed case, the user of the technology is the browser user > > and there are certain assumptions under which content is consumed. > > > > I explained the poor consequences that a mid-change of track language > > and kind can have on the example of a blind user. Do you disagree with > > that example? > > > > > >> It should not be construed to be poor practice of a TTML author merges > >> different languages into the same file, > > > > That may be as is. > > > >> which translates to a single track > >> using HTML5 mechanisms. > > > > At the point where you hook into HTML5, you have to deal with the > > content consumption approach of HTML5. A TTML file with cues of > > multiple languages should be converted into as many tracks as there > > are languages in use. This is a requirement of the way in which tracks > > are consumed in a HTML5 browser. A TTML mapping into HTML5 would need > > to provide for this functionality. > > > > Regards, > > Silvia. > > David Singer > Manager, Software Standards, Apple Inc. > >
Received on Sunday, 6 April 2014 12:29:22 UTC