[whatwg] Introduction of media accessibility features

Jonas Sicking jonas at sicking.cc
Sun Apr 11 14:59:26 PDT 2010

On Sun, Apr 11, 2010 at 5:30 AM, Silvia Pfeiffer
<silviapfeiffer1 at gmail.com> wrote:
f>> Is it expected that all of TTML will be required? The proposal suggests
>> 'starting with the simplest profile', being the transformation profile. Does
>> this mean only the transformation profile is needed to provide subtitle
>> features equivalent to SRT?
> That is also something that still has to be discussed further. Initial
> feedback from browser vendors was that the full TTML spec is too
> complicated and too much to support from the start. Thus, the
> implementation path with the TTML profiles is being suggested.
> However, it is as yet unclear if there should be a native parsing
> implementation of TTML implemented in browsers or simply a mapping of
> TTML markup to HTML/CSS/JavaScript. My gut feeling is that the latter
> would be easier, in particular since such a mapping has been started
> already with Philippe's implementation, see
> http://www.w3.org/2009/02/ThisIsCoffee.html . The mapping would need
> to be documented.

Personally I'm concerned that if we start heading down the TTML path,
browsers are ultimately going to end up forced to implement the whole
thing. Useful parts as well as parts less so. We see this time and
again where if we implement part of a spec we end up forced to
implement the whole thing.

Things like test suites, blogging advocates, authoring tools, etc
often means that for marketing reasons we're forced to implement much
more than we'd like. And much more than is useful. This is why spec
writing is a big responseibility, every feature has a large cost and
means that implementors will be working on implementing that feature
instead of something else.

/ Jonas

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