Re: Liaison Statement to W3C (SC 29 N 13268)

On Feb 20, 2013, at 4:37 PM, Bob Lund <B.Lund@CableLabs.com<mailto:B.Lund@CableLabs.com>> wrote:



From: <Vickers>, Mark Vickers <mark_vickers@cable.comcast.com<mailto:mark_vickers@cable.comcast.com>>
Date: Wednesday, February 20, 2013 2:16 PM
To: Jean-Claude Dufourd <jean-claude.dufourd@telecom-paristech.fr<mailto:jean-claude.dufourd@telecom-paristech.fr>>
Cc: "<public-web-and-tv@w3.org<mailto:public-web-and-tv@w3.org>>" <public-web-and-tv@w3.org<mailto:public-web-and-tv@w3.org>>
Subject: Re: Liaison Statement to W3C (SC 29 N 13268)
Resent-From: <public-web-and-tv@w3.org<mailto:public-web-and-tv@w3.org>>
Resent-Date: Wednesday, February 20, 2013 2:16 PM

The last time, the W3C response to MMT was quite delayed. I suggest we get a quick response out on the two cited use cases. I understand that the MPEG MMT group may be issuing an updated spec in March, so if we can get a quick answer out in a week or two, it will have maximum impact.

The basic response is whether or not the two cited use cases can be implemented in HTML5 and related specifications. Here's the main text of the email:
MPEG has identified a set of use cases for which the MMT technology is being developed for. We strongly believe that HTML 5 is a powerful tool to define composition and layout of multimedia content and that it is able to address most of the needs and requirements of the MMT composition layer. However, we were not able to map two particular requirements/use cases to the current HTML 5 specification.
Those requirements/use cases are as follows:
1.     The ability to accurately time the playback of different media elements (for instance using wall clock time) in the document in a declarative manner, i.e. without reverting to scripting in a way similar to SMIL. MMT does not require a scripting engine.
2.     The ability to address devices with multiple screens, allowing the content author to request rendering some parts of the document in a view/frame that is to be displayed at a specific time on a secondary screen.
We appreciate your offer to work on the use cases that have led us to work on extensions to HTML 5 and we are looking forward to guidance from W3C regarding those particular use cases and we are eager to collaborate on any extensions that might become necessary to address them.
We hope that MPEG and W3C will be able continue their collaboration on MPEG-MMT and HTML 5 related topics.

1.     The ability to accurately time the playback of different media elements (for instance using wall clock time) in the document in a declarative manner, i.e. without reverting to scripting in a way similar to SMIL. MMT does not require a scripting engine.
I'm not sure why scripting is optional in MMT. Can someone familiar with SMIL describe what declarative form they're looking for here?

2.     The ability to address devices with multiple screens, allowing the content author to request rendering some parts of the document in a view/frame that is to be displayed at a specific time on a secondary screen.
I would think this could be done via two windows that communicate. Thoughts?

Yes – a Web page in one window causing DOM elements (presumably no JS objects since no scripting) to render in another window in another browser. Various mechanisms (Web Intents, Network Discovery API, Web Sockets) could be used to create the connection. The underlying question is how the one window identifies the specific target window on the specific secondary screen. It's not clear this could be done in a declarative manner. Even with script, this is a complex task.

Where the use case says "ability to address devices with multiple screens," I interpreted that as each of the devices has multiple screens, not multiple devices with single screens. In this case, it's one app and one browser, like this example [1], so we don't have to worry about discovery and networking. I don't know of a standard way to position a window on a particular screen. I suppose that could be just using a continuous coordinate system to cover all the screens of the device.

http://stackoverflow.com/questions/5277482/can-i-control-two-browser-windows-with-one-html5-app



Thanks,
mav


On Feb 20, 2013, at 5:18 AM, Jean-Claude Dufourd <jean-claude.dufourd@telecom-paristech.fr<mailto:jean-claude.dufourd@telecom-paristech.fr>> wrote:

This is a liaison document from MPEG to Web and TV on DASH.
MPEG is extending DASH and sends us the latest docs.
I have also forwarded this to the HTML group chairs in case they are interested.
Best regards
JC

---------- Forwarded message ----------
From: WATANABE Shinji <watanabe@itscj.ipsj.or.jp<mailto:watanabe@itscj.ipsj.or.jp>>
Date: Tue, Feb 19, 2013 at 7:25 AM
Subject: Liaison Statement to W3C (SC 29 N 13268)
To: timbl@w3.org<mailto:timbl@w3.org>
Cc: leonardo@chiariglione.org<mailto:leonardo@chiariglione.org>, sc29-sec@itscj.ipsj.or.jp<mailto:sc29-sec@itscj.ipsj.or.jp>, yklwhite@gmail.com<mailto:yklwhite@gmail.com>, jc@dufourd.org<mailto:jc@dufourd.org>, chris@w3.org<mailto:chris@w3.org>


Dear Mr. Tim Berners-Lee,

In accordance with Resolutions taken at the 103rd
SC 29/WG 11 Meeting, 2013-01-21/25, Geneva, Switzerland,
I am pleased to send attached Liaison statement.

If you have any questions, please do not hesitate to contact me.
Thank you for your cooperation.

Best regards,
Shinji Watanabe

-----
WATANABE Shinji
Assistant Secretary, ISO/IEC JTC 1/SC 29
IPSJ/ITSCJ
308-3 Kikai-Shinko-Kaikan Bldg.
3-5-8 Shiba-koen, Minato-ku, Tokyo 105-0011 Japan
Tel: +81-3-3431-2808 Fax: +81-3-3431-6493
Mail: watanabe@itscj.ipsj.or.jp<mailto:watanabe@itscj.ipsj.or.jp>

<29n13268.zip>