Web and TV Interest Group Report 201109

From Web and TV IG
Jump to: navigation, search

Web and TV IG Interim Report (September, 2011)

This version:
   http://www.w3.org/2011/webtv/wiki/Web_and_TV_Interest_Group_Report_201109
Latest version:
   http://www.w3.org/2011/webtv/wiki/Web_and_TV_Interest_Group_Report
Previous version:
   http://www.w3.org/2011/webtv/wiki/Web_and_TV_Interest_Group_Report_201104
Editors:
   Yosuke Funahashi, Tomo-Digi
   Giuseppe Pascale, Opera Software
   Clarke Stevens, CableLabs
   Kazuyuki Ashimura, W3C/Keio

Status of this Document

The current version of the IG report covers what has been accomplished thus far, and includes the results of the Hollywood workshop and the F2F meeting held between the 19th and 22nd of September, 2011.

The IG members reviewed the draft version of this document between 15th and 22nd of September, and approved its publication at the F2F meeting. Interest group members also agreed to include the Hollywood workshop and F2F meeting results in the report.

Important: The editors included the summary of the Hollywood workshop and the F2F meeting in the 'Web and TV Topics in Brief' section only. Other sections of the report were written prior to the workshop, and sections of the report will be updated in the next publication.

Web and TV Topics in Brief

Author: Kazuyuki Ashimura

Topics discussed in the Web and TV Workshops

As recorded in the minutes (Tokyo workshop, Berlin workshop, Hollywood workshop) and summaries (Tokyo workshop, Berlin workshop, Hollywood workshop), we had discussions on the following topics during the three workshops:

  • Web and CE devices in Home Network
  • Adaptive Streaming
  • Social TV
  • Disaster prevention and response
  • Captioning
  • Metadata
  • Accessibility
  • Content/service Protection:
  • Parental Control
  • Profiling
  • Testing
  • Relationship with existing IPTV standards - including possible liaison
  • API to access low level functionalities on TV devices
  • Best Practices for content developers

Two priority topics handled by dedicated Task Forces

As mentioned in the IG Charter, our strategy is creating a dedicated Task Force to hold detailed discussion to clarify actual requirements for each topic. And we did create the following two Task Forces for "Web and CE devices in home netwok" and "video streaming", because we thought they were the highest priority:

The Home Network Task Force has completed its activity, and the requirements collected based on the Task Force discussion are put together as the Home Network TF Requirements.

The Media Pipeline Task Force has been discussing requirements for video, audio and media interfaces in the Web and TV context, and is now generating a draft document for the MPTF Requirements.

Regarding HTML5 extension, the discussion of both of the above Task Forces includes some proposals on HTML5 extensions, e.g., the HTML5 video and audio elements. Also the Media Pipeline Task Force sent comments to the HTML WG, because the HTML5 specification has reached its Last Call Working Draft stage and our sending comments was strongly encouraged by the HTML WG.

Discussions on the remaining topics during the group's first F2F meeting in Hollywood

The Interest Group held its first F2F meeting on 21-22 September 2011, and clarified what should be done as the next steps for remaining topics—including hot topics in the Hollywood workshop—as follows:

  • Social TV
    • More discussion needed on the public mailing list to clarify if a new TF is needed. [Pablo Cesar will lead this.]
  • Disaster prevention and response
    • We already have a draft charter.
    • More discussion needed to clarify the scope before creating a new TF. [Yosuke Funahashi will lead this.]
  • Captioning
    • A community group will be created. (AP: send info to ws participants) [David Singer will lead this.]
  • Adaptive Streaming
    • already being discussed in the Media Pipeline Task Force
  • Metadata
    • More discussion needed on the public maling list
    • Should be handled by the Home Network Task Force as part of the HTML5 discussion?
  • Accessibility
    • The group had been considering to create a Task Force to discuss Accessibility topics because there was hot discussion on the IG public list.
    • However, the group discussed how to deal with it during the Hollywood F2F meeting and the conclusion was that we should rather create a Community Group for the discussion on captioning (see 'Captioning' above), because there are various communities who should participate in the discussion.
    • Other use cases on accessibility are already discussed in the Media Pipeline Task Force.
    • The group will let the Hollywood workshop participants know about the above decision.
  • Content/service Protection
    • already being discussed in the Media Pipeline Task Force
  • Parental Control
    • The Media Pipeline Task Force will start investigation (focusing on in-band content advisory)
    • The broader discussion on parental control may need a new Task Force.
    • Extraction of PC setting may be in scope of Device API discussion (see 'API to access low level functionalities on TV devices)
  • Profiling
    • Is in scope of W3C? W3C should at least discuss it.
    • What is profiling? Different things.
      1. Which parts of W3C specs MUST be supported by a TV device?
      2. Subset of W3C specs for low-end devices
      3. Metadata and query mechanisms for feature support?
    • More discussion needed on the public maling list, maybe a TF created.
    • Profiles (the above #2) may cause more fragmentation.
  • Testing
    • There is already a proposed Testing IG within W3C
      • People may get involved in the above IG to discuss new requirements.
    • But what about certification?
      • Not should be done in W3C due to lack of expertise.
      • W3C may be willing to cooperate with other organizations on this.
  • Relationship with existing IPTV standards - including possible liaison
    • No Task Force is needed
    • Maybe in scope for each and every group if needed.
  • API to access low level functionalities on TV devices
    • More discussion needed on the list
    • Device settings (parental control setting, preferred language, etc.),
    • Tuner control
  • Best Practices for content developers
    • Already done for mobile, could be done for “TV”
    • New Task Force/Working Group/Interest Group? → discuss more on the mailing list

Progress Made Thus Far

Author: Yosuke Funahashi

In the Beginning

First Workshop Held

On September 2nd and 3rd, 2010, W3C held its first 'Web on TV' workshop in Tokyo, Japan, with the purpose of identifying key potential use cases and determining important requirements for smarter integration of existing Web standards, broadcasting, and non-PC devices such as televisions and cell phones. Discussions among participants led to the identification of 60 potential use cases which made it difficult to classify them effectively. From these discussions, the workshop attendees concluded that an interest group was necessary to deal with complex issues at hand. After some deliberation and a name change, the 'Web and TV' interest group was launched in February, 2011.

One hundred and forty-four representatives from 60 organizations attended the workshop, and provided a expansive view of the issues related to the 'Web on TV' knowledge domain. The following industries and agencies were represented at the workshop.

  • Broadcasters
  • Telecom companies
  • Content provider
  • Device vendors
  • Publishers
  • Software vendors
  • Standardization organizations
  • Web application providers
  • Researchers
  • Japanese Government agencies

Digital TV demonstrations by Japanese public and commercial broadcasters kicked off the workshop, and impressed the audience with the advances they had made in the DTV area. This was followed by six panel sessions consisting of brief presentations of the attendees' position statements, which in turn were followed by discussions on use cases and requirements for smarter integration of Web and TV. These panel discussions focused on the following topics:

  • Existing Digital TV approaches
  • Proposals for smarter integration of Web and TV from vendors' viewpoints
  • Proposals for smarter integration of Web and TV from research viewpoints
  • The role of HTML5 in the Web on TV, esp. expectation for HTML5 as UI
  • The role of HTML5 in the Web on TV, esp. TV as the hub within home network
  • The role of HTML5 in the Web on TV, esp. Device APIs for TV

Over the two-day workshop, the attendees produced 70 use cases and requirements. This number was more than expected and so the participants voted to determine the top categories based on their level of interest. The nine categories listed below in the order of most to least interest are the result of the vote.

  1. APIs for TV functions
  2. Richer user experience
  3. Smarter integration with CE (Consumer Electronics)
  4. Content rights
  5. Personalization
  6. TV as broadcasting service (rather than a device)
  7. Accessibility
  8. Relationship with existing approaches
  9. Security

For more details see W3C Web on TV Workshop.

IG Charter generation

After the Tokyo workshop, the W3C launched a public mailing list focusing on 'Web and TV' discussions. In this mailing list, use case discussions continued while at the same time we started drafting the initial charter. Most of the discussion related to the charter was on how to define the charter scope. Some participants preferred a more abstract definition because of the scale of the 'Web and TV' knowledge domain, while others preferred a specific definition to help the group focus on current topics more precisely. After three months of much back and forth discussion, the final draft of the charter was announced to all W3C AC representatives, some of whom made thoughtful comments which helped improve the published charter. The charter was completed at the end of January 2011, and on February 7, 2011 the IG was officially launched.

For more details see the charter

Following the Official Launch of IG

Immediately following the launch of the IG on February 7, the Berlin workshop was held on February 8-9.

Second Workshop Held

On February 8th and 9th, 2011, the W3C held its second 'Web and TV' workshop in Berlin, Germany. The purpose of the workshop was to follow-up on the topics raised at the Tokyo workshop, and to discuss new topics and use cases brought up on the public mailing list. The workshop also aimed at expanding the already existing community of interested parties created after the Tokyo workshop.

During the workshop, we had eight sessions consisting of brief presentations of the attendees' position papers followed by dedicated discussions on the topics.

The topics for the sessions were:

  • Web&TV: Use cases and Technologies
  • Second-Screen Scenarios
  • Panel on HTTP Adaptive Streaming
  • Content Protection
  • Metadata / Semantic Web
  • HTML5 and TV: Gap Analysis
  • Accessibility
  • Profiling / Testing

One of the sessions was a panel discussion that focused on DASH and Dynamic Adaptive Streaming over HTTP, and the audience agreed that a single solution on top of the HTML5 framework was necessary for proprietary solutions such as 3GPP DASH and MPEG DASH. In the wrap-up session of the workshop, the chairs decided to send liaisons to 3GPP and MPEG to seek cooperation.

The participants also agreed that some sub groups or task forces should be formed within the Web and TV IG to discuss specific topics more efficiently. As a result, the workshop chairs suggested the following candidate topics for possible IG task force or monitoring activity:

  • Adaptive streaming over HTTP
  • Home networking
  • Metadata
  • Accessibility
  • Profiling / Testing
  • Extensions to HTML5

For more details see Second W3C Web and TV Workshop.

Task Forces Launched

Home Network Task Force (HNTF)

During the 'Web and TV' workshops in Tokyo and Berlin, multiple-screen scenarios interested most participants, while at the Berlin workshop, discovery and control of devices and services in the local area IP network was identified as a prerequisite for most multiple screen scenarios. Some of the participants in Berlin expressed interest in outlining requirements and doing a gap analysis on currently available technologies to identify areas where some specification effort may be needed. To handle this discussion, the HNTF was created June 1, 2011.

For more details see further below and Task Forces: Home Network.

Media Pipeline Task Force (MPTF)

In both the first workshop in Tokyo and the second workshop in Berlin, many participants were interested in the relationship between 'Web and TV' and key enabling technologies such as DTV/IPTV/OTT, (e.g. streaming and broadcasting technologies.) The topic that spurred the most interest from the attendees was DASH. However, after the second workshop, it was decided by the co-Chairs that DASH was, although very interesting in and of itself, too specific a topic. A broader, more abstract theme, one that included not only DASH but also topics related to the HTML5 video tag, current streaming technologies, etc., would be better suited for a second task force. As a result, the MPTF was chartered on August 1, 2011, and soon after began its work.

For more details see further below and Task Forces: Media Pipeline.

Current status

Author: Yosuke Funahashi

Hollywood Workshop

Following the success of its workshops in Tokyo, Japan and Berlin, Germany, the W3C will host a third workshop on 'Web and TV' convergence in Hollywood, California on September 19-20, 2011. In the previous two workshops, participants identified opportunities for convergence of 'Web and TV' infrastructure and began identifying technical challenges. This third workshop will continue these efforts, with a particular focus on the needs of content creators and distributors. Additionally, there will be an opportunity to discuss and debate some of the initial requirements arising in the 'Web and TV' Interest Group. It is expected that starting this fall, these requirements will drive W3C Working Group activity, defining new standards for the Web.

For more details see "Entertaining Content"—The Third W3C Web and TV Workshop.

The First F2F Meeting

The IG will hold its first f2f meeting on September 21-22, 2011 immediately following the third 'Web and TV' workshop in Hollywood. Over the two days, the meeting will provide effective environment to discuss key topics and make key decisions on the future of the IG.

Main topics on the agenda are:

  • Home Networking Task Force: review of requirements specs, wrapping up, publication and next steps
  • Media Pipeline Task Force: further discussions on use cases and requirements
  • Other topics raised in the IG: assessing level of interest, initial inputs, next steps
  • Web and TV IG report: inputs, issues, publication and next steps
  • Third W3C Web and TV Workshop: integrating the results of workshop discussions
  • Web and TV eco-system and future plans for the IG activities

For more details see F2F Hollywood 2011.

Hot Topics

Additional Task Forces

Additional task forces are being considered by the co-Chairs. The f2f meeting will provide an opportunity for the participants to give their opinions on which of the topics require a task force.

Current candidates are:

  • Web and Broadcasting
  • Accessibility
  • Metadata
  • Profiling / Testing
  • Contents Protection
  • Web and IPTV
  • Social TV

Task Forces

Home Network

Author: Giuseppe Pascale, Francois Daoust
Summary

Charter

The Home Network Task Force (HNTF) was chartered a few weeks after the workshop in Berlin. As stated in the HNTF charter, the mission of this task force is to "identify use cases for devices, content and services discovery and control". The main deliverable of the task force is a Use Cases and Requirements document that includes a set of recommendations for the W3C Director for potential Recommendation track work within W3C that would address some (or all) of the requirements identified.

Timeline

The Home Network Task Force was created end of April 2011 for an initial duration of three months. Given the high level of interest in the task force (more than 20 participants and 25 use cases raised and discussed), it was extended until end of September.

The task force submitted a draft Requirements document to the rest of the Web and TV Interest Group for review on 8 September 2011. Several comments were raised. The Task Force is to review these comments and finalize the Requirements document accordingly during the face-to-face meeting of the Web and TV IG in Hollywood on 21-22 September 2011.

The Home Network Task Force will discuss its future during this meeting. Once the Requirements documents is published, possible options are:

  1. close the Task Force and encourage task force participants to join the working group(s) identified in the Requirements document
  2. or keep the task force alive to discuss additional use cases, refine already identified use cases, and/or monitor on-going standardization efforts in the home networking area, both in W3C and in external organizations.
Status

As of mid-September 2011, the Home Network Task Force has reviewed all of the use cases submitted by its participants, discussed and extracted requirements that need to be addressed within a technical specification to enable these use cases, and assigned priorities for next steps.

The draft Requirements document features 18 use cases deemed relevant for W3C and 23 requirements that would enable these use cases.

The document was shared with the rest of the Web and TV Interest Group on 8 September 2011. Feedback received will be reviewed and resolved during the group's face-to-face meeting end of September. The list of requirements and priorities may be adjusted as a result.

Preliminary Recommendations / Classification of use cases

Most of the requirements listed in the Requirements document prepared by the Home Network Task Force seem to fall in scope of the Device APIs Working Group Charter. Thus the main recommendation of the Home Network Task Force is that the Device APIs Working Group takes on the development of technical Recommendations that cover the requirements listed in the Requirements document.

While finalizing the document, the Home Network Task Force should also single out requirements that are out of scope for DAP, if any, and propose further courses of action, either through the identification of the relevant working group for them, or through the creation of a Working Group if needed and deemed relevant by W3C Members.

The Home Network Task Force did not explore topics such as access to a home network from outside the home, or concepts such as a group of homes. The Task Force believes that this is an area of extreme interest and suggests that DAP (or any other working group working on the requirements extracted from this document) investigates these areas. The Web and TV Interest Group may consider discussing these topics and provide feedback to one or more W3C Working Groups.

The preliminary categorization of requirements is presented below. This categorization is still subject to changes based on final discussions within the Web and TV Interest Group. Please check the Requirements document for latest version and full requirement statements.

The main criterion followed to set priorities was the degree to which each requirement enables use cases that cannot be done today (e.g. discover services running on devices connected to the home network, play media content stored on a home network media server, or control a TV through a second-screen). With this in mind, a feature that enables more use cases is of higher priority than a feature that enables a more limited subset of use cases.

The following requirements underpin most if not all of the use cases listed in this document, so they are considered to be the starting point of any technical work on the topic:

  • Service Discovery: Conforming specifications should provide a means for applications to discover devices and applications in the home network which advertise services. Details of the advertising protocol are out of scope for this document and the type and number of supported discovery protocols are user agent dependent. Nevertheless conforming specifications should provide a means for application to identify the type of discovered services that are available and to search for services of a specific type.
  • Content Discovery: Conforming specifications should provide a means for applications to discover devices in the home network capable of serving content (content servers). In addition, conforming specifications should provide a mechanism to retrieve a list of the available content, additional information (metadata) about it and negotiate a supported content type format.
  • Content Players Discovery: Conforming specifications should provide a means for applications to discover home network devices and applications which are able to playback content (content players).

These requirements are not enough on their own to enable useful scenarios. Most of the use cases also depend on other requirements. The requirements that seem most straightforward to address next are related to the control and query of media playback:

The remaining requirements enable applications to advertise and/or offer services and could be considered a "next step". They would allow developers to leverage Web technologies and create innovative types of mash-up applications that combine the Web and home networked devices:

The following requirements were not categorized:

Finally, Media Identification is a prerequisite for applications to be able to properly relate items of media content to a wider Web of data and content. This requirement is orthogonal to the others and can be discussed in parallel. Thus Media Identification has not been categorized either.

Liaison and Dependencies

The following groups are represented in the Home Network Task Force through some of their members: UPNP Forum, DLNA, Open IPTV Forum.

Contacts have been made with the chairs of the Device APIs Working Group since most of the requirements identified in the Home Network Task Force are in scope for this group.

Media Pipeline

Author: Clarke Stevens
Summary

Charter

The goal of the MPTF is to propose HTML5 video and audio element extensions to support new media formats and commercial video provider service requirements. We have clarified five key topics for this task force in the charter.

  • Script access to parameters controlling user agent adaptive bit rate algorithms.
  • User agent content splicing.
  • Browser handling of dynamic tracks in linear media streams of infinite length.
  • Enhancements to metadata track elements to support commercial video provider applications.
  • Other API changes that arise from use of media formats used by commercial video providers.

Currently, it is not considered within scope of this task force to specify HTML5 support for any particular adaptive streaming format. We will re-evaluate this preference as we agree on requirements and narrow in on specific potential solutions. We have also decided to include support for DRM in the scope of MPTF. As with adaptive streaming, the intention is to design a framework that is general enough to support any DRM system rather than endorse a particular DRM.

Deliverables

The MPTF will do the following:

Refine the requirements and design goals at: (http://www.w3.org/2011/webtv/wiki/MPTF/MPTF_Requirements). Candidate use cases will be developed and evaluated by the task force with the following objectives:

  • Identify clear gaps in the Open Web platform, and categorize all the use cases/requirements into the following categories:
    • Ignore
    • It's resolved already
    • Liaison with others
    • New requirements for existing Working Group
    • Requires new working group
    • We know it needs to go into a W3C working group we just don't know where
    • We don't know where it goes and need more research
  • Propose WG charter(s) to W3C Director for recommendation track work fulfilling some (or all) of those requirements.

TimeLine

The MPTF should deliver the above listed deliverables by the end date mentioned in the charter (i.e. Nov 2011). Evaluation of the use cases is expected to wind down by the time of the face-to-face meetings in September 2011. At that point, a draft requirements document will be created that captures the requirements from the accepted use cases. The remaining time in the life of the task force will be used in refining the requirements, coming to consensus and preparing a submission for the W3C working group(s) that will create the HTML5 documents according to the requirements.

Detailed timeline is available below:

  • September 2011 - Complete evaluation of the submitted use cases and create a draft requirements document
  • October 2011 - Refine the requirements document and begin to socialize the requirements with prospective W3C working group(s)
  • November 2011 - Finalize use case and requirements document and submit to prospective W3C working group(s). Dissolve the task force. Join the working group(s) and begin the development of the HTML5 specification changes.
Status

As of the current date (September 16, 2011), the Media Pipeline Task Force has accomplished the following:

  • We have been meeting regularly for 10 weeks.
  • 18 use cases have been submitted.
  • Additionally, a DRM proposed common requirements document has been submitted.
  • All use cases (except perhaps 1) have been reviewed by the task force.
  • Four use cases have been accepted and several more are likely to be accepted after minor changes.
  • A first draft of the requirements document is nearly complete.

Note: We will have a much more complete status update after the face-to-face meeting next week.

Next steps

Much progress is anticipated at the face-to-face meetings next week. We have the following goals:

  • Finish the evaluation of all submitted use cases.
  • Review the first draft of the requirements document.
  • Consider the various candidate alternatives and reach consensus on an approach to DRM integration.
  • Consider the various candidate alternatives and reach consensus on an approach to adaptive streaming integration.
  • Discuss the possible working groups that might develop the specification changes recommended by the task force and devise a standardization strategy.
  • Work out the detailed schedule for completion of the task force objectives.
Preliminary Recommandations / Classification of use cases

For the current status of the use cases, please see the following link: Use Cases

Liaison and Dependencies

Web and TV IG sent a liaison letter to 3GPP during the Berlin February workshop which was regarded as an unofficial letter. No reply has been received yet. Web and TV IG sent a liaison letter to MPEG DASH after the Berlin February workshop and received a cooperative reply.

Those two letters asked for input on ideas such as the necessity of a single solution for adaptive streaming under the new HTML5 framework, licensing status/terms for fundamental technologies, when W3C might reference such information, and an invitation for cooperation.