- From: Matt Hammond <matt.hammond@rd.bbc.co.uk>
- Date: Fri, 08 Apr 2011 10:03:16 +0100
- To: "Clarke Stevens" <C.Stevens@cablelabs.com>, "public-web-and-tv@w3.org" <public-web-and-tv@w3.org>, "Olivier Carmona" <ocarmona@awox.com>, "Russell Berkoff" <r.berkoff@sisa.samsung.com>, "Bob Lund" <B.Lund@cablelabs.com>
- Cc: "Giuseppe Pascale" <giuseppep@opera.com>
We also see facilitating discovery of content on the home network from the browser to be important. There is also the issue of security and privacy - a user should be able to determine what devices, applications and web pages have permission to control another device and discover content. As a broadcaster we deliver to multiple platforms over which we have no direct control (terrestrial, cable and satellite transmission all operated by different companies/consortia). Our interest is closer to the scenario 2(b) that you outline. What is not clear to me is whether the DLNA/UPnP capabilities for discovering and playing content also work for a box that does not have the capability to serve or stream off-air broadcast content on the home network (for example, a TV with integrated tuner). This is one of the reasons why we have an interest in a simplified abstraction that negates the need for a controlling device to concern itself with the source and delivery method of a piece of content (as well as its format, codecs, device profiles etc) There is also potential to enable a substantial accessibility win here too if UI can be independent of the device(s) it is controlling. When considering the Remote UI as mentioned here, perhaps there are at least 3 related strands to this? Discovery/security; remote control; device-served remote UI. regards Matt On Thu, 07 Apr 2011 20:14:19 +0100, Bob Lund <B.Lund@cablelabs.com> wrote: > To amplify on Clarke's point a bit, it's useful to break down the > broadcast/cloud UI into more specific scenarios: > 1) Broadcast content directly from the cloud, UI from the cloud > 2) Broadcast to a UPnP media server that proxies the content on the home > network via content directory service, remote UI from the cloud > > Scenario 1 is the web, nothing special needs to be introduced. > Scenario 2 is more of a DLNA/UPnP model. There are two ways the UI > served from the cloud can gain the links to refer to the media server > content: > a) A back channel from the media server hosting the CDS to the cloud > server constructing the UI page. If the service provider controls both > the media server software implementation and the cloud UI server this > back channel can be service provider specific. The cloud UI server > constructs UI that references the home network content. There are some > subtleties around how the media LAN side IP address is referenced in the > UI page but it's doable. > b) The UI page served by the cloud server to the home network device > contains JavaScript that uses the discovery API that is being proposed > to discover the CDS and the content therein. The UI page JavaScript can > provide whatever degree of integration is desired between the local > content discovered and the cloud content referenced on the UI page. > > Bob Lund > >> -----Original Message----- >> From: public-web-and-tv-request@w3.org [mailto:public-web-and-tv- >> request@w3.org] On Behalf Of Clarke Stevens >> Sent: Thursday, April 07, 2011 11:05 AM >> To: Matt Hammond; public-web-and-tv@w3.org; Olivier Carmona; Russell >> Berkoff >> Cc: Giuseppe Pascale >> Subject: RE: [HOME_NETWORK_TF] Home Network Technologies >> >> Matt, >> >> UPnP currently defines a way to discover remote user interfaces, but it >> is pretty generic. Here are the specs: >> >> http://upnp.org/specs/rui/remoteui/ >> >> In this group, we're hoping to make this a bit more concrete by using >> HTML browsers, CSS, JavaScript, and providing some APIs for discovering >> and using devices and services on the home network. The back channel to >> the cloud service would just be a URL. That's maybe a bit oversimplified >> as there are other issued related to a commercial service offering, but >> that's the basic idea. >> >> As for more information on DLNA CVP, here's an announcement: >> >> http://www.dlna.org/news/pr/view?item_key=e2c163bfab8076edc2b33eba8293e8 >> 2cd2f11e3e >> >> It looks like DLNA doesn't yet have CVP for sale from its web site but >> W3C could encourage them to provide some more information, timelines, >> etc. >> >> Hope this helps. >> >> Thanks, >> -Clarke >> >> -----Original Message----- >> From: Matt Hammond [mailto:matt.hammond@rd.bbc.co.uk] >> Sent: Thursday, April 07, 2011 8:11 AM >> To: public-web-and-tv@w3.org; Olivier Carmona; Russell Berkoff; Clarke >> Stevens >> Cc: Giuseppe Pascale >> Subject: Re: [HOME_NETWORK_TF] Home Network Technologies >> >> Hi Clarke, >> >> >> Could you explain how this model where a remote user interface is served >> from the cloud would work for broadcast services? Does it require some >> kind of back channel between the rendering device and the cloud service? >> >> I would also like to understand what services CVP enables. Are the >> guidelines publicly available anywhere? >> >> regards >> >> >> >> Matt >> >> >> On Thu, 07 Apr 2011 13:40:12 +0100, Clarke Stevens >> <C.Stevens@cablelabs.com> wrote: >> >> > I think some of the functionality you want is already defined in >> > DLNA/UPnP and the rest will be very soon. As I mentioned earlier, the >> > URL that points to the content does not need to be on the home >> network. >> > This allows for content that can be offered from service providers. >> > Similarly, a service provider could serve a remote user interface from >> > the cloud. Features such as volume change and mute are already >> > provided, so a "second screen" could get a user interface from a >> > service provider and point to content remotely served by that service >> provider. >> > >> > >> > There is also a DLNA guideline called CVP specifically designed for >> > content service providers. The first version is available now but is >> > somewhat limited. The second version is in development and I believe >> > it provides the remainder of the services you are looking for. >> > >> > Thanks, >> > -Clarke >> > >> > -----Original Message----- >> > From: public-web-and-tv-request@w3.org >> > [mailto:public-web-and-tv-request@w3.org] On Behalf Of Matt Hammond >> > Sent: Thursday, April 07, 2011 2:52 AM >> > To: public-web-and-tv@w3.org; Olivier Carmona; Russell Berkoff >> > Cc: Giuseppe Pascale >> > Subject: Re: [HOME_NETWORK_TF] Home Network Technologies >> > >> > Hi Russell, >> > >> > Your description matches my understanding of DLNA/UPnP - which is >> > useful confirmation for me - many thanks! >> > >> > I agree that this model works well for streaming between home devices. >> > But it makes the assumption that all content is streamable between >> > home devices. A TV or set-top-box that can receive broadcast or IP >> > delivered TV or radio does not necessarily match this. In order to be >> > able to implement some of the second-screen scenarios presented at the >> > last workshop, I would hope that APIs for home networking are also >> > able to query and control TV functions such as changing channel or >> > retrieving broadcast programme metadata. >> > >> > This is why I am interested in APIs that can support both in (if >> > possible) a single simple unified way. The approach we took at the BBC >> > with our Universal Control (UC) API is one possible way to achieve >> this. >> > >> > If a TV implementing UC API needed to be able to discover and stream >> > content on other devices in the home then it would almost certainly >> > use DLNA/UPnP or other similar technologies to do this, but the >> > client/controller device does not need to know the difference. From >> > the perspective of a client of the UC API implementing TV, streamed >> > content is discoverable and selectable for playback in the same way as >> > a television channel or programme would be. >> > >> > regards >> > >> > >> > >> > Matt >> > >> > On Thu, 07 Apr 2011 08:39:18 +0100, Russell Berkoff >> > <r.berkoff@sisa.samsung.com> wrote: >> > >> >> Hi Matt, >> >> >> >> >> >> Let me try to answer "frame" your question/observation and hopefully >> >> provide some brief answers: >> >> >> >> >> >> Q1: Does DLNA/UPnP distinguish between the description of content, >> i.e. >> >> metadata describing content (title, description, available media >> >> formats) and the device actually supplying the content? >> >> >> >> >> >> Q2: Does DLNA/UPnP allow metadata and content to reside on separate >> >> devices on the home network? >> >> >> >> >> >> Q3: Does DLNA/UPnP allow the remote commanding of playback devices? >> >> >> >> >> >> >> >> A1: Yes...DLNA/UPnP has a distinct metadata service (ContentDirectory >> >> Service). The metadata provided by this service can refer to content >> >> elsewhere on the home network. >> >> >> >> >> >> A2: Yes >> >> >> >> >> >> A3: Yes...UPnP/DLNA allows remote commanding of playback devices. A >> >> Digital Media Controller can obtain descriptive content metadata and >> >> tell a playback device to "pull" a piece of content from a distinct >> >> "content source" on the home network. >> >> >> >> >> >> The Digital Media Controller in this scenario would examine the >> >> metadata from both the Playback Device (Digital Media Renderer) and >> >> from the metadata service (Digital Media Server - ContentDirectory >> >> Service) and insure a media format is chosen that both the Content >> >> Source can provide and the Playback Device can render. Once a match >> >> is found the Digital Media Controller, would command the Playback >> >> device to fetch the content from the Content Source. >> >> >> >> >> >> Regards, >> >> >> >> Russell Berkoff >> >> >> >> Samsung Electronics >> >> >> >> >> >> >> >> >> >> -----Original Message----- >> >> From: Matt Hammond [mailto:matt.hammond@rd.bbc.co.uk] >> >> Sent: Wednesday, April 06, 2011 5:03 AM >> >> To: public-web-and-tv@w3.org; Olivier Carmona >> >> Cc: Russell Berkoff; Giuseppe Pascale >> >> Subject: Re: [HOME_NETWORK_TF] Home Network Technologies >> >> >> >> >> >> Hi Olivier, >> >> >> >> >> >> On Wed, 06 Apr 2011 12:22:38 +0100, Olivier Carmona >> >> <ocarmona@awox.com> >> >> >> >> wrote: >> >> >> >> >> >>> >> >> >> >>> Hi Matt, >> >> >> >>> >> >> >> >>> DLNA 1.0 is about two-box pull model: on one side you have a Digital >> >> >> >>> Media Player (a client in your description) and on the other side >> >>> you >> >> >> >>> have a Digital Media Server (a rendering device in your >> description). >> >> >> >>> DMP discovers and then browses DMS, and can request one of the >> >>> browsed >> >> >> >>> items to be played. The only difference with your model is that this >> >>> the >> >> >> >>> DMP that based on the information exposed by the DMS, decides >> >>> wherever >> >> >> >>> it can play the content. >> >> >> >> >> >> My explanation was not as clear as it should have been - please >> >> accept my >> >> >> >> apologies for that. The client that I described does not display >> >> media and >> >> >> >> does not send or receive media streams. It is the server that will >> >> >> >> render/display media, and it is up to the server to work out what >> >> media is >> >> >> >> available to it and to arrange to stream (or otherwise obtain) it. >> >> This >> >> >> >> aspect would be completely opaque to this client. The server/renderer >> >> >> >> could well use DLNA to discover and stream that content from a 3rd >> >> device, >> >> >> >> but the client would not be aware of this. >> >> >> >> >> >> For me, the attraction of this model is that it is more abstract that >> >> just >> >> >> >> streaming and can easily subsume access to local storage but also >> >> access >> >> >> >> to services such as live television broadcast. A television programme >> >> is >> >> >> >> just another item of content that the server reports it has available >> >> to >> >> >> >> it, and which the client can ask it to display. >> >> >> >> >> >> >> >> >> >> regards >> >> >> >> >> >> >> >> Matt >> >> >> > >> > >> >> >> -- >> | Matt Hammond >> | Research Engineer, BBC R&D, Centre House, London >> | http://www.bbc.co.uk/rd/ -- | Matt Hammond | Research Engineer, BBC R&D, Centre House, London | http://www.bbc.co.uk/rd/
Received on Friday, 8 April 2011 09:09:47 UTC