- From: John Simmons <johnsim@microsoft.com>
- Date: Wed, 3 Apr 2013 17:16:21 +0000
- To: Janina Sajka <janina@rednote.net>, Mark Watson <watsonm@netflix.com>
- CC: Glenn Adams <glenn@skynav.com>, Henri Sivonen <hsivonen@iki.fi>, "Steve Faulkner" <faulkner.steve@gmail.com>, HTMLWG WG <public-html-media@w3.org>, HTML Accessibility Task Force <public-html-a11y@w3.org>
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. 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/
Received on Wednesday, 3 April 2013 17:17:37 UTC