- From: Christian Vogler <christian.vogler@gallaudet.edu>
- Date: Tue, 29 Nov 2011 12:13:07 -0500
- To: David Singer <singer@apple.com>
- Cc: public-texttracks@w3.org
I misunderstood the question. SMPTE-TT has a provision for this type of caption that avoids duplicate text. Ditto CEA-608 and CEA-708. As for current web captioning practice, I don't know. But as was mentioned elsewhere, it might be a good idea to keep in mind that one of the envisioned uses for WebVTT will be TV broadcasts, which depending on country is even required by law. Christian On Tue, Nov 29, 2011 at 12:09 PM, Christian Vogler <christian.vogler@gallaudet.edu> wrote: > Silvia's proposal avoids the duplicate text. > > (at the beginning of this thread) > > Christian > > On Tue, Nov 29, 2011 at 12:05 PM, David Singer <singer@apple.com> wrote: >> At the moment, I can't think of a way of doing even jump-scroll without repeating text, unless (as is very likely) I am being dense. >> >> Maybe someone could correct me if the best practice on jump-scroll is something other than repeat? >> >> >> On Nov 29, 2011, at 17:40 , Christian Vogler wrote: >> >>> This is not quite true if the text is duplicated in the WebVTT file. >>> This would present serious accessibility issues for people who use >>> screenreaders (and that includes the deaf-blind population). It also >>> would make searching and indexing harder if text were duplicated. >>> >>> Christian >>> >>> On Tue, Nov 29, 2011 at 11:33 AM, David Singer <singer@apple.com> wrote: >>>> I think a fundamental question that needs addressing is whether we expect roll-up to be (a) 'part of' the core VTT vocabulary or (b) a presentational issue that is 'optional'? >>>> >>>> I tend to think the latter. Yes, maybe smooth roll-up is easier on the eye than jump-scroll, but the same information is presented. >>>> >>>> If that is the case, I think using CSS transitions is a good candidate.. Alas, we don't use CSS positioning (for obvious reasons -- positioning DOES have to be part of the core of VTT). But that doesn't hose us. >>>> >>>> Consider a stream that has Line1, Line2, …. LineN, showing in a three-line area. A simple way to jump scroll that is simply to repeat each line, every time it 'moves' in the 3-line display. >>>> >>>> <blank> >>>> <blank> >>>> Line1 >>>> >>>> then >>>> >>>> <blank> >>>> Line1 >>>> Line2 >>>> >>>> Line1 >>>> Line2 >>>> Line3 >>>> >>>> Line2 >>>> Line3 >>>> Line4 >>>> >>>> displayed simply, the lines appear to jump. >>>> >>>> If we can convince the CSS engine that Line1 in the first cue is the same as Line1 in the second, we could ask for a transition on, say, 'y'. That's pretty easy to do with markup -- if a line of text in two consecutive cues has the same marked-id, then it's the same, and any CS transitions declared on its class apply, if you use CSS. >>>> >>>> Saying CSS transitions can be used to smooth out display transitions also allows for fade-in/fade-out (transition on color), and so on. >>>> >>>> >>>> David Singer >>>> Multimedia and Software Standards, Apple Inc. >>>> >>>> >>> >>> >>> >>> -- >>> Christian Vogler, PhD >>> Director, Technology Access Program >>> Department of Communication Studies >>> SLCC 1116 >>> Gallaudet University >>> http://tap.gallaudet.edu/ >>> VP: 202-250-2795 >> >> David Singer >> Multimedia and Software Standards, Apple Inc. >> > > > > -- > Christian Vogler, PhD > Director, Technology Access Program > Department of Communication Studies > SLCC 1116 > Gallaudet University > http://tap.gallaudet.edu/ > VP: 202-250-2795 -- Christian Vogler, PhD Director, Technology Access Program Department of Communication Studies SLCC 1116 Gallaudet University http://tap.gallaudet.edu/ VP: 202-250-2795
Received on Thursday, 1 December 2011 09:21:10 UTC