Re: Requirements for external text alternatives for audio/video

On Mar 25, 2010, at 10:21 AM, Sean Hayes wrote:

> The semantics of TTML is specified in terms of XSL:FO, it does not  
> require an XSL:FO implementation.  The majority of the style  
> features in TTML are already found in CSS. The W3C has an  
> implementation of TTML based on conversion into HTML & CSS.

Is it a correct implementation? How well does the XSL:FO formatting  
model map to CSS? Is there any documentation (even informative) on  
implementing TTML/DFXP using a CSS formatter?

Regards,
Maciej

>
> From: public-html-a11y-request@w3.org [mailto:public-html-a11y- 
> request@w3.org] On Behalf Of Eric Carlson
> Sent: 25 March 2010 15:46
> To: Silvia Pfeiffer
> Cc: Geoff Freed; HTML Accessibility Task Force; Matt May
> Subject: Re: Requirements for external text alternatives for audio/ 
> video
>
>
> On Mar 24, 2010, at 9:29 PM, Silvia Pfeiffer wrote:
>
>
> In summary - I would suggest keeping the File Format requirement at
> http://www.w3.org/WAI/PF/HTML/wiki/Media_TextAssociations#File_Formats
> with supporting both, srt and dfxp (or ttml as Sean clarified).
>
>
>   What DFXP profile are you suggesting we mandate?
>
>   As Maciej noted [1], even the presentation profile requires XSL- 
> FO. Does anyone actually think it is reasonable to require a UA to  
> implement this substantial spec just to style captions?
>
> eric
>
> [1] - http://lists.w3.org/Archives/Public/public-html-a11y/2010Mar/0103.html