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Re: 答复: second screen use case provided from Tencent.

From: Francois Daoust <fd@w3.org>
Date: Thu, 11 Jun 2015 16:37:34 +0200
Message-ID: <55799D2E.2040303@w3.org>
To: "lindayan(۳ѩ÷)" <lindayan@tencent.com>, "public-secondscreen@w3.org" <public-secondscreen@w3.org>, Oleg Beletski <o.beletski@samsung.com>
[+Oleg for bit on multiple presentation devices]

Dear Lindayan,

Thanks for sharing this use case. This is certainly something that I 
would like the Web to support in a short future!

Please see some comments inline.

On 2015-06-11 10:39, lindayan(۳ѩ÷) wrote:
> I received a rejection response, just to check my mail is wrong.
> Best Regards,
> Lindayan [鄢雪梅]
> 知识产权部patent.oa.com <http://patent.oa..com/>
> *发件人:*lindayan(鄢雪梅)
> *发送时间:*2015年6月11日16:30
> *收件人:*'public-secondscreen@w3.org'
> *抄送:*minren(任旻)
> *主题:*second screen use case provided from Tencent.
> Dears,
> we noticed that there is a specification define the use cases,
> requirements, examples and interfaces needed to enable web pages to
> display web content on secondary screens(please refer to the
> link:http://www.w3.org/2014/secondscreen/presentation-api/20140721/).

Note the link targets an already rather old version of the Presentation 
API. The latest Editor's Draft version is available at:


The use cases have been moved out of the specification, see:


> Specific Product Scenario:
> This is a scenario based on Mobile QQ(provided by Tencent, it is a SNS
> product to enable multiple user to communicate with each other) and the
> prototype demo has been completed. Without doubt, this scenarion can be
> applied any other internet service for users to interact with each other.
> Alice travels with her friends, Bob, Carol and David by train. Alice and
> her friends want to watch a movie together. However their seats are not
> in the same row, and the screen is too small for four people to watch
> together. Alice sends the video URL to the others’ smart devices which
> can access some kind of services(it is Mobile QQ in this instance) for
> the four people to interact with each other.

I find this starting point interesting because it provides a useful 
scenario where a Web application might want to start a presentation 
session on multiple devices at once, something that the current version 
of the Presentation API does not yet cover in a simple way (a page can 
call startSession 4 times to open sessions on 4 different screens, but 
that would trigger 4 user interactions. It cannot call startSession once 
to create the 4 sessions at once, which would only require 1 user 

Oleg, does it match what you have in mind for issue #97?


>After everyone receives and
> opens the URL, Alice will receive a notice. When the four people
> complete, Alice clicks the Play button and all the devices start to play
> the movie at the same time on their own screens. The process of watching
> movie and sharing their view about the movie, making some kinds of
> decision through the Mobile QQ, or interacting with the three other
> friends also takes place simultaneously, The movie is about a complex
> story, and they do not completely follow or understand it. And they
> decide to replay the previous episode. Alice rewinds the movie by 10
> minutes on her device, and then all the people watch the 10-minute movie
> clip again. Bob’s phone rings, and he has to leave for a while for the
> phone call. He clicks the Pause button, and movie playback is also be
> paused on the others' devices. 5 minutes later, Bob comes back and
> clicks the Play button again. The movie playback is resumed on every
> screen. Carol encounters a network problem, and she has to wait during
> movie data buffering. The others wait until Carol’s device continues
> playing the movie.

That second part is of course pretty useful. However, synchronization 
issues are not in scope of the Second Screen Working Group. The 
Multi-Device Timing Community Group explores these topics as you noted:

  Home page: http://www.w3.org/community/webtiming/
  Archives: https://lists.w3.org/Archives/Public/public-webtiming/

> This demo can be used to show how to share online videos in a temporary
> discussion group and how to synchronize operation among the discussion
> group, such as play, pause, playback simultaneously. The sharing party
> can control the Play, Pause, Fast Forward, and Rewind functions on
> multiple devices concurrently.

While the scenario makes sense as a whole, do you think you could 
provide an equivalent scenario that only touches upon the bootstrapping 
of the multiple presentation sessions and does not talk about 
cross-device synchronization, for inclusion in the use cases document?

Also, could you share the whole scenario with the Multi-Device Timing 
Community Group?

Best regards,
Received on Thursday, 11 June 2015 14:38:11 UTC

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