Re: Subtitle/caption styling + TTML + CSS

One other thing to bear in mind is that TTML defines some vocabulary using XSL but the overall coverage of XSL is very limited. In almost all cases there is a close alignment between the XSL feature and an equivalent CSS feature. So the case we are considering here is far from being a fully featured generic XSL to CSS conversion. 

It seems to be the general case now that the XSL features' semantics are defined with reference to CSS for those features used by TTML2. 

I would second the request for any concrete cases where a conversion to CSS involves a complex mapping or if no mapping is possible, or if it appears that a simple mapping would work but would in fact result in incorrect presentation. 

Nigel

> On 22 Dec 2016, at 21:48, L. David Baron <dbaron@dbaron.org> wrote:
> 
>> On Thursday 2016-12-22 21:13 +0000, Pierre-Anthony Lemieux wrote:
>> Hi fantasai,
>> 
>>> between the two, so such a mapping would most
>>> definitely not be "straightforward".
>> 
>> My experience with imscJS has been that the mapping from TTML to CSS was
>> straightforward with the exception of two features that were not defined in
>> CSS but deemed important to captions: linePadding and multiRowAlign.
>> 
>> Did you have other examples in mind?
> 
> I think things are very different if you're trying to create an
> implementation that fully conforms to the specification rather than
> an implementation that covers the features in the specification but
> gets wrong the large number of detailed differences between these
> technologies.
> 
> -David
> 
>> 
>> Best,
>> 
>> -- Pierre
>> 
>> 
>> On Thu, Dec 22, 2016 at 12:49 PM fantasai <fantasai.lists@inkedblade.net>
>> wrote:
>> 
>>>> On 12/12/2016 12:04 AM, Pierre-Anthony Lemieux wrote:
>>>> 
>>>> 
>>> 
>>>> TTML is based on XSL, which is based on CSS, and so the mapping has
>>> 
>>>> been straightforward
>>> 
>>> 
>>> 
>>> XSL is very loosely "based" on CSS, and there is much divergence
>>> 
>>> between the two, so such a mapping would most definitely not be
>>> 
>>> "straightforward".
>>> 
>>> 
>>> 
>>> ~fantasai
>>> 
>>> 
> 
> -- 
> 𝄞   L. David Baron                         http://dbaron.org/   𝄂
> 𝄢   Mozilla                          https://www.mozilla.org/   𝄂
>             Before I built a wall I'd ask to know
>             What I was walling in or walling out,
>             And to whom I was like to give offense.
>               - Robert Frost, Mending Wall (1914)

Received on Friday, 23 December 2016 09:21:46 UTC