ARCA Federated Access to Multimedia Content

Lyngby, May 2007Diego R. Lopez, RedIRISFrancisco Cruz, UC3MCatalin Meirosu, TERENA

JRES2005, Marseille

ARCAFederated Access to Multimedia Content

TNC. Lyngby, May 2007

Extending media services

• Requirements are growing beyond the live netcasting and/or streaming availability

• Authors want content accessed• Consumers want content accessible• The obvious response is the access portal

The broader the better

• Simple to use Plug-and-play Plug-and-be-played


The fate of common directories

• Common directories are the usual answer to the problem of resource location in broad communities But they face data partition Formats, protocols, security (and privacy) considerations

• Participation requires a high effort Staff and/or technological And related to local visibility

The result is the continuous re-building of central repositories of data Almost automatically outdated with respect to their once local

sources Momentum decreases with time


Federating is divine

• The federated model comes into play once again• Accessing or collecting using a trusted links

And a common language for data exchange

• Maintaining total autonomy for the federated repository Policies Methods Interfaces Local visibility

• Offering a common view of information That can be enhanced for particular communities


ARCA

• “Ark” in Spanish• Agregador RSS para la Comunidad Académica

(RSS Aggregator for the Academic Community) http://arca.uc3m.es/ http://www.rediris.es/pruebas/arca/

• Main goals Harmonize and centralize all the information about available

multimedia content. Up-to-date information

• Specially, with respect to changes in each institution schedules Flexibility for participating institutions, so they can change

announcements on their own• And keep their own announcement systems

• In use by the RedIRIS community• Being currently evaluated by TERENA


The architecture

• The system is divided into channels. A channel represents a source of multimedia content

• Every institution is associated with one or more channels

• Each channel contains a series of events, retransmissions and/or multimedia contents, called “channel items”

• Each institution must generate data about its own channel, as well as data for all the items to be transmitted through the channel By means of RSS elements


On RSS

• ARCA uses RSS 2.0 as exchange format XML as markup The more widespread format for content syndication and re-

diffusion

• It allows for collecting data using off-the-shelf software (RSS aggregators)

• Validation is simple, so it is possible to guarantee that each participant is making a correct data export

• Each participant can include additional information to its RSS description without affecting system behavior

• It allows for simple extension of system functionality


RSS formats

• A general RSS format has been defined, with specific labels for each content type (direct, VoD, podcast)

• UTF-8 is required• No single RSS fulfills system requirements, so three

different namespaces are in use: Yahoo media RSS: Data about multimedia content Itunes RSS: Data about multimedia content and podcasting Google base events RSS: Announcements of programmed

events

• New namespaces can be included as the system requirements evolve


The ARCA database

• RSS descriptions are collected at well-defined endpoints

• The ARCA aggregator periodically connects and retrieves them

• The system consolidates into a single database all the information collected from the participating sources

• Through this database, information about channels and items can be accessed by means of the different ARCA search and browsing facilities


Topology

ARCA Server

Internet

RSS Cataloging/ Production Systems

Updated every N hours

Client.RSS Reader

for PDA/PPC

Client.RSS

Reader

Client.ARCAPortal

University

ResearchCenter

University

University

ResearchCenter

University

Multimedia

Servers


The ARCA portal

• Supports different search/browsing paradigms Lists of events Calendar Queries on metadata Browsing different classifications

• Searches can be constrained according to institution, type of content, categories in a classification,...

• Multilingual support Currently: Castilian, Catalan and English


The ARCA portal -II

• Offers live RSS creation for queries It is possible to subscribe to specific feeds

• Playing of all items either embedded or via external viewers

• Supports direct playing of podcasts The portal can act as an “universal podcast player”

• iTunes friendly The RSS for podcasts can be directly fed into

• Admin interface Manage data sources Manage categories


Some facts and figures

• Based on open Apache, PHP5 and MySQL• Seven institutions currently participating

Plus the biggest Spanish virtual university (UNED) that committed to join along June

• ~700 items available• Two classifications in operation

Spanish Higher Education directives UNESCO codes

• Other components available Statistics (URJC) Joomla agent (UPM) Item builder (UNICAN)


And more to come

• Dynamic endpoint definition• Ad-hoc creation for items dealing with sparse

live events at the portal• Enhanced admin interface, including detailed

statistics • Support for groups of events (courses,

workshops,...) when searching/browsing• Display of related items• Support for OMPL and (possibly) ATOM 1.0


The long awaited demo

Documents

ARCA Federated Access to Multimedia Content