- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Wed, 8 Aug 2012 12:33:36 +1000
- To: Sean Hayes <Sean.Hayes@microsoft.com>
- Cc: "Goldstein, Glenn" <glenn.goldstein@viacom.com>, "public-tt@w3.org" <public-tt@w3.org>
Thanks, that really clarified it. Cheers, Silvia. On Wed, Aug 8, 2012 at 4:01 AM, Sean Hayes <Sean.Hayes@microsoft.com> wrote: > The processing happens so that at each time instant T, the TTML tree is > pruned to leave only elements temporally active at time T. Then what remains > gets laid out essentially as if it were HTML for each time T; (the actual > processing is simplified, because it is possible to compute the set of > ‘interesting’ times at which something changes). At each interesting time T > the region is effectively cleared and reflowed. > > > > In the example the timing is arranged on the <p> and <span>s such that each > word <span> appears sequentially, and each line <p> is timed to stay visible > for 11s. So for example at T=24 the top line has expired, and the remaining > markup would look like: > > > > <p > > > <span >with</span> > > <span >word</span> > > <span >at</span> > > <span >a</span> > > <span >time</span> > > <span >temporal</span> > > </p> > > <p > > > <span >placement</span> > > </p> > > > > The implementation can treat the points T and T+1 as key-frames in an > animation to smooth the transition, as this is apparently preferred by US > viewers, in the UK however line-at-a-time jumps are more common. > > > > From: Silvia Pfeiffer [mailto:silviapfeiffer1@gmail.com] > Sent: 06 August 2012 17:26 > To: Sean Hayes > Cc: Goldstein, Glenn; public-tt@w3.org > Subject: Re: Re: questions on simple profile - nested spans > > > > I have a question, too. > http://dvcs.w3.org/hg/ttml/raw-file/tip/ttml10-sdp/Overview.html > > The document presents this as an example for rollup captions: > > <p region='rollup' begin='00:00:13.000' dur='00:00:11.000'> > > <span begin='00:00:01.000'>rollup</span> > > <span begin='00:00:02.000'>style</span> > > <span begin='00:00:03.000'>caption</span> > > <span begin='00:00:04.000'>support</span> > > </p> > > <p region='rollup' begin='00:00:17.000' dur='00:00:11.000'> > > <span begin='00:00:01.000'>with</span> > > <span begin='00:00:02.000'>word</span> > > <span begin='00:00:03.000'>at</span> > > <span begin='00:00:04.000'>a</span> > > <span begin='00:00:05.000'>time</span> > > <span begin='00:00:06.000'>temporal</span> > > </p> > > <p region='rollup' begin='00:00:23.000' dur='00:00:11.000'> > > <span begin='00:00:01.000'>placement</span> > > <span begin='00:00:02.000'>this</span> > > <span begin='00:00:03.000'>could</span> > > <span begin='00:00:04.000'>go</span> > > </p> > > <p region='rollup' begin='00:00:27.000' dur='00:00:11.000'> > > <span begin='00:00:01.000'>on</span> > > <span begin='00:00:02.000'>all</span> > > <span begin='00:00:03.000'>day</span> > > </p> > > > Would you mind explaining how this works? > I am particularly confused about where the rollup happens. I assume that the > words within the <p> element are all on the same line, but appear one at a > time. > > > > That leads me to the conclusion that each <p> will be rendered on the same > default position. Does that mean that the <p> elements push each other out > of the way? > How does that work technically: when you add a <p> on top of an existing <p> > in the same location, is it added below and the previous <p> pushed upwards? > > > > I wasn't able to find that specified in the document. Sorry for my > ignorance. > > Regards, > Silvia. > >
Received on Wednesday, 8 August 2012 02:34:24 UTC