Proposal from HbbTV

Dear Silvia,
 
My name is Alexander Adolf, and I am writing to you on behalf of the HbbTV Association (http://www.hbbtv.org), where I represent LG Electronics in the technical specification working group. We are working on the next version of our HbbTV specification for connected TV sets, and that is based on HTML5. Hence your work on a proposed mapping spec for the W3C HTML WG for sourcing in band media resource tracks from media containers into HTML is of great interest to us.
 
As I also happen to be the chairperson of the DVB signalling working group, and the editor of the DVB signalling specifications, I have been asked by the HbbTV colleagues to review your document, and to suggest how to also cover DVB services. The pull request I am sending you is the proposal of the HbbTV Association to also include DVB services. HbbTV does not have requirements to expose the full capabilities of the DVB broadcast system to HTML. As a result, the proposal does not cover all the functionality that your current document defines for the ATSC broadcast system. If you want to go further, you would have to contact DVB.
 
As you will see, I have restructured the section on MPEG-2 Transport Streams quite a bit to make room for DVB-specific stuff. I have retained your text in the ATSC parts. I have also added empty parts for the Japanese ISDB system. As I just saw on GitHub, user YosAwed has already picked that up and seems to be starting to fill in the ISDB stuff.
 
As well as the MPEG-2 transport stream section, the HbbTV proposal includes changes to the sections on MPEG-DASH and ISOBMFF. On MPEG-DASH, our proposal addresses alignment with the recently published DVB profile of MPEG DASH (https://www.dvb.org/resources/public/standards/a168_dvb-dash.pdf) and support for the DASH event stream mechanism added by MPEG in the second edition of the DASH specification. In the section on ISOBMFF, our proposal adds support for the EBU-TT-D profile of TTML alongside the SMPTE profile of TTML.
 
We are thus proposing the updates conveyed in my pull request for your kind review.
 
As my last merge from your repository was as far back as July 8th, please don't hesitate to ask me for help with integrating our proposed updates. Also, should you have any other questions or comments, please don't hesitate to let me know.
 
 
Thanks a lot in advance, and yours sincerely,
 
  --alexander adolf