Re: how does EME/DRM effect captioning

John Simmons writes:
> As a data point, the Common File Format used by UltraViolet (which is fragmented MP4 for a reason) prohibits the encryption of closed captioning.
> 
> In general, the model that works best for the web is one where "late binding" of tracks from a variety of sources are combined together into a composition. One of those tracks could be captioning, and with late binding, there is no upper limit on the number of captioning tracks that can be defined to be included in that composition.
> 
Excellent to hear, thank you.

Also, I like the term "late binding." It's new to me. But, if that's the
generally understood industry term, we'll update our User Accessibility
Media Requirements doc accordingly:

http://www.w3.org/TR/media-accessibility-reqs/

Also, as an additional data point, let me note that there are a myriad
set of alternative media types that need to be bindable, not just
captions. The above (emerging) W3C note addresses those.

Janina

> 
> John C. Simmons | Media Platform Architect | Microsoft Corporation | direct 425-707-2911 | mobile 425-269-5759
> 
> 
> -----Original Message-----
> From: Janina Sajka [mailto:janina@rednote.net] 
> Sent: Wednesday, April 03, 2013 8:50 AM
> To: Mark Watson
> Cc: Glenn Adams; Henri Sivonen; Steve Faulkner; HTMLWG WG; HTML Accessibility Task Force
> Subject: Re: how does EME/DRM effect captioning
> 
> Mark Watson writes:
> snip ...
> 
> > ... we deliver captions/subtitles separately in a (unencrypted) TTML 
> > file.
> > 
> 
> Seems to me this is the optimal approach.
> 
> 1.)	Minimizes any potential barriers for users
> 2.)	Benefits service providers by supporting open ansillary
> services, like indexing.
> 
> Am I wrong? Is there any actual use case for encrypting captions? What did I miss here?
> 
> Janina
> 
> 
> -- 
> 
> Janina Sajka,	Phone:	+1.443.300.2200
> 			sip:janina@asterisk.rednote.net
> 		Email:	janina@rednote.net
> 
> Linux Foundation Fellow
> Executive Chair, Accessibility Workgroup:	http://a11y.org
> 
> The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
> Chair,	Protocols & Formats	http://www.w3.org/wai/pf
> 	Indie UI			http://www.w3.org/WAI/IndieUI/
> 
> 
> 
> 

-- 

Janina Sajka,	Phone:	+1.443.300.2200
			sip:janina@asterisk.rednote.net
		Email:	janina@rednote.net

Linux Foundation Fellow
Executive Chair, Accessibility Workgroup:	http://a11y.org

The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
Chair,	Protocols & Formats	http://www.w3.org/wai/pf
	Indie UI			http://www.w3.org/WAI/IndieUI/

Received on Wednesday, 3 April 2013 19:37:03 UTC