- From: <bugzilla@jessica.w3.org>
- Date: Tue, 16 Nov 2010 16:24:11 +0000
- To: public-html@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=11326
Summary: A proposal to add web application access to home
network A/V devices and content
Product: HTML WG
Version: unspecified
Platform: PC
OS/Version: Windows XP
Status: NEW
Severity: normal
Priority: P2
Component: HTML5 spec (editor: Ian Hickson)
AssignedTo: ian@hixie.ch
ReportedBy: b.lund@cablelabs.com
QAContact: public-html-bugzilla@w3.org
CC: mike@w3.org, public-html-wg-issue-tracking@w3.org,
public-html@w3.org
Cable operators currently deliver video services to browsers via video plugins
and wish to deliver program guides with full video services to HTML5 browsers.
CableLabs® (www.cablelabs.com), on behalf of its cable operator member
companies, is in the process of becoming a W3C member and would like to propose
an extension to HTML5 to meet this important goal. As a key requirement of
current program guides, cable operators want to expose home network devices
(such as set top boxes), services and content to web applications. This need
was also identified in the recent W3C Web on TV workshop in Tokyo. CableLabs’
OpenCable Home Networking specifications define the use of UPnP protocols for
such access.
Exposing home network devices, services and content to web applications has
these requirements:
1) User agents need to provide an API to JavaScript for discovering home
network web-servers that host applications which advertise content and other
services. Such servers are called remote user interface servers in UPnP. UPnP
provides the ability to discover such servers as described in detail in
http://upnp.org/specs/rui/UPnP-rui-RemoteUIServer-v1-Service.pdf.
2) User agents should provide an API to JavaScript for discovery and control of
home network devices, services and content. OpenCable Home Networking uses
several UPnP APIs:
- Device and service discovery
(http://upnp.org/specs/arch/UPnP-arch-DeviceArchitecture-v1.1.pdf)
- Content discovery
(http://upnp.org/specs/av/UPnP-av-ContentDirectory-v3-Service.pdf,
http://upnp.org/specs/av/UPnP-av-ContentDirectory-v3-Service-AnnexA-20101006.pdf)
- A/V connection management
(http://upnp.org/specs/av/UPnP-av-ConnectionManager-v2-Service.pdf,
http://upnp.org/specs/av/UPnP-av-ConnectionManager-v2-Service-AnnexA-20101006.pdf)
- A/V transport (http://upnp.org/specs/av/UPnP-av-AVTransport-v2-Service.pdf,
http://upnp.org/specs/av/UPnP-av-AVTransport-v2-Service-AnnexA-20101006.pdf)
3) A web application needs to determine if the user agent supports transport
protocols and content formats for content presented in a web page or discovered
over the home network. It appears that media.canPlayType(type) can be used to
query the user agent if it supports “type”, where “type” can come from the type
attribute of the source element for HTML page content or can be generated from
UPnP content res property information (Section B.2 and table B-5 of the content
discovery reference above). There is no method for determining what URI
schemes (equivalent to UPnP transport protocol) are supported by the user
agent. Rather than querying the user agent for each content type, and because a
URI scheme method is required, a new interface, UserAgentCapabilities for
example, could be defined and implemented by the (JavaScript) global object.
The interface would define two methods, supportedMimeTypes() and
supportedURISchemes(), which would return MIME types and URI schemes supported
by the user agent.
It does not appear that HTML5 or other W3C API specs provide the functionality
to meet requirements 1 and 2 above. Possible implementations that could meet
these requirements are:
a) An API that exposes the referenced UPnP protocols.
b) A more general home networking API for user-agents that could support UPnP,
Bonjour and other home networking protocols (this is the approach taken in the
OpenCable Home Networking API spec
(http://www.cablelabs.com/specifications/OC-SP-OCAP-HNEXT-I05-100603.pdf)
c) General, low-level networking tools, like WebSocket, upon which JavaScript
could build UPnP, Bonjour or other home networking applications.
More information regarding CableLabs OpenCable Home Networking can be found
here http://www.cablelabs.com/specifications/OC-SP-HOST-HN2.0-I04-100507.pdf.
More information on the W3C Web on TV workshop including the request for home
networking APIs can be found here:
http://www.w3.org/2010/09/web-on-tv/summary.html.
Thank you in advance for consideration of this proposal.
Bob Lund
CableLabs
b.lund@cablelabs.com
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Received on Tuesday, 16 November 2010 16:24:14 UTC