W3C home > Mailing lists > Public > public-secondscreen@w3.org > November 2014

Liaison letter from DVB TM-CSS group

From: Francois Daoust <fd@w3.org>
Date: Fri, 21 Nov 2014 11:09:54 +0100
Message-ID: <546F0F72.5070400@w3.org>
To: "public-secondscreen@w3.org" <public-secondscreen@w3.org>
Hi Second Screen Presentation WG participants,

The Web and TV IG received a liaison letter from the DVB Technical 
Module Ad-Hoc Group on Companion Screens and Supplementary Streams 
(TM-CSS, nothing to do with Cascading Style Sheets!), asking for 
"details of any relevant work [W3C is] undertaking".

My understanding is that the main focus of the group is on specifying 
low-level audio/video cross-device synchronization protocols (Part 2 in 
the extract below), which is out of scope for the Second Screen 
Presentation Working Group. The DVB TM-CSS group also works on discovery 
aspects using UPnP (Part 3 in the extract below), more relevant to the 
Presentation API but not yet available.

The Web and TV IG will prepare a reply to that letter. It seems 
important to mention the Presentation API in that response. Do we have 
more specific details to share?

Quoting from the letter (see attached PDF file for the full letter):
Work is largely complete and all parts will eventually be passed to ETSI 
for final publication, although some parts have been made available now 
in final draft form.

Part 1 is a non-normative description of the overall architecture and 
provides explanatory examples of how the rest of the specification can 
be implemented to meet various use cases.

Part 2 defines broadcast signalling and protocols and interactions 
between broadcaster, television device and companion device via the home 
network to identify content on the television and synchronise to it. 
This part is available now via the DVB website as Bluebook 167-2 [1].

Part 3 defines the use of UPnP to discover the television device via the 
home network.


We are in the process of defining more detailed outputs and timescales 
over which this work will take place.

We would be grateful if you can provide details of any relevant work you 
are undertaking.

[1] DVB Bluebook A167-2 "DVB Companion Screens and Streams; Part 2: 
Content ID and Media Synchronisation" Available at: 



Received on Friday, 21 November 2014 10:10:07 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 17:18:43 UTC