Re: Timed tracks

On Sat, May 8, 2010 at 10:24 PM, Sean Hayes <Sean.Hayes@microsoft.com>wrote:

> To quote Maciej " Standards experts will be *extremely* picky about whether
> the layout behaviour in a browser precisely matches the spec, ... There
> isn't really room to fudge it." That doesn't jibe very well with " the
> status of the specs matters very little, what matters is that it is already
> implemented and shipped in browsers ".  So which is it?
>

They're both true. Let me try to clarify:
1) implementing TTML using a CSS layout engine isn't an a good long term
solution unless TTML's behaviour precisely matches CSS behaviour (and we
have a foolproof process in place to ensure that remains true forever*).
2) the maturity of a spec is better judged by comparing its implementation
in browsers than by looking at the W3C's label.

* The only really effective way to do that would be to define TTML in terms
of CSS by reference.

If the CSS specs change, as seems likely from a WD status, then those
> implementations will not be compliant.


Properties already widely and interoperably implemented are unlikely to
change. Many CSS2.1 and CSS3 properties already fall into that category.


> However, be that as it may, if as you say the CSS3 text and box specs are
> widely implemented, and the same  in Opera and Gecko, WebKit and IE, then
> you already have the tools to implement TTML - so all is goodness.
>

Only if TTML is defined in terms of CSS.

Rob
-- 
"He was pierced for our transgressions, he was crushed for our iniquities;
the punishment that brought us peace was upon him, and by his wounds we are
healed. We all, like sheep, have gone astray, each of us has turned to his
own way; and the LORD has laid on him the iniquity of us all." [Isaiah
53:5-6]