- From: Pierre-Anthony Lemieux <pal@sandflow.com>
- Date: Fri, 17 Jan 2014 12:46:59 -0800
- To: Nigel Megitt <nigel.megitt@bbc.co.uk>
- Cc: Timed Text Working Group <public-tt@w3.org>
Hi Nigel, Is the plan to backport these changes to TTML 1.0? Thanks, -- Pierre On Fri, Jan 17, 2014 at 6:17 AM, Nigel Megitt <nigel.megitt@bbc.co.uk> wrote: > CONTEXT > > As discussed in yesterday's TTWG meeting, as part of the fulfilment of > actions 219 [1] and 221 [2] Glenn has edited the TTML2 editor's draft to > incorporate an algorithm for computing the value of line height, based on > the code used by Mozilla, blink and webkit. This can additionally be > considered part of the solution to the line height problem which has also > been raised in issues 275 [3] and 284 [4]. > > WHAT HAS CHANGED > > The algorithm can be found at [5] in section 8.2.13 tts:lineHeight. > > I won't attempt to repeat Glenn's explanation of this algorithm, which I > scribed as best I could yesterday, except to note what may appear at first > to be a substantive change to some, that the "125% of fontSize" rule does > not always apply, but applies only when the font is not associated with > "font metrics that specify altitude A, descent D, and line gap G". > > FOLLOW-UP > > This algorithm is absent from CSS but, if this group's members are happy > with it, we should communicate it to the CSS WG, to maximise the time for > them to raise any potential issues, or indeed choose to adopt it into their > own output documentation, which we could then potentially reference. > Formally they will report any problems anyway at Last Call stage but I'd > rather seek early agreement when possible. > > ACTION REQUIRED NOW > > Please notify the group if there are any queries or objections to this > algorithm as it stands. > > We noted in yesterday's call that it was not possible to verify that IE > adopts the same algorithm, so it would be particularly useful if someone > from Microsoft could confirm that they are happy with it – Jerry, this > probably means you! > > Rather than making this an open-ended action I'll close this off and state > that we have approval if there are no outstanding objections by the end of > our next call on 30th Jan 2014. > > > > This email satisfies Action-260 [6]. > > > References > > [1] Action-219 https://www.w3.org/AudioVideo/TT/tracker/actions/219 > [2] Action-221 https://www.w3.org/AudioVideo/TT/tracker/actions/221 > [3] Issue-275 https://www.w3.org/AudioVideo/TT/tracker/issues/275 > [4] Issue-284 https://www.w3.org/AudioVideo/TT/tracker/issues/284 > [5] TTML2 Editor's draft, section on lineHeight > https://dvcs.w3.org/hg/ttml/raw-file/default/ttml2/spec/ttml2.html#style-attribute-lineHeight > [6] Action-260 https://www.w3.org/AudioVideo/TT/tracker/actions/260 > > > > ---------------------------- > > http://www.bbc.co.uk > This e-mail (and any attachments) is confidential and may contain personal > views which are not the views of the BBC unless specifically stated. > If you have received it in error, please delete it from your system. > Do not use, copy or disclose the information in any way nor act in reliance > on it and notify the sender immediately. > Please note that the BBC monitors e-mails sent or received. > Further communication will signify your consent to this. > > ---------------------
Received on Friday, 17 January 2014 20:47:50 UTC