diego r. lopez, rediris josé maría fontanillo, rediris francisco cruz, uc3m nicolás ibáñez,...
TRANSCRIPT
Diego R. Lopez, RedIRISJosé María Fontanillo, RedIRISFrancisco Cruz, UC3MNicolás Ibáñez, UC3M JRES2005, Marseille
ARCAFederated Access to Multimedia Content
Internet2 Member Meeting. October 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
Internet2 Member Meeting. October 2007
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• The result is the continuous re-building of central repositories of data Almost automatically outdated with respect to their once local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
Internet2 Member Meeting. October 2007
Federating Is Divine
• The federated model comes into play once again• Accessing or collecting using 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
• Keeping It Simple!
Internet2 Member Meeting. October 2007
ARCA• “Ark” in Spanish• Agregador RSS para la Comunidad Académica
(RSS Aggregator for the Academic Community) http://arca.uc3m.es/ http://arca.rediris.es
• Main goals Harmonize and centralize all the information about available
multimedia content. Up-to-date information
• Specially, with respect to changes in each institution 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
http://arca.terena.org
Internet2 Member Meeting. October 2007
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(s) As well as data for all the items to be transmitted
through a given channel By means of RSS elements
Internet2 Member Meeting. October 2007
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
Internet2 Member Meeting. October 2007
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 four
different namespaces are in use: Yahoo media RSS: Data about multimedia content Itunes RSS: Data about multimedia content and podcasting Google base RSS: Data about programmed events, dates and
locations... GeoRSS: Data about geographical information.
• New namespaces can be included as the system requirements evolve
Internet2 Member Meeting. October 2007
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
Internet2 Member Meeting. October 2007
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
Internet2 Member Meeting. October 2007
The ARCA Portal
• Supports different search/browsing paradigms Lists of events Calendar Queries on metadata Browsing through different classifications
• Searches can be constrained according to institution, type of content, categories in a classification,...
• Multilingual support Currently: Castilian, Catalan, Basque, Galician and
English
Internet2 Member Meeting. October 2007
The ARCA Portal - II
• Offers live RSS creation for queries It is possible to subscribe to specific feeds
• Item playing Embedded in the portal External viewers
• Supports direct playing of podcasts The portal can act as an “universal podcast player”
• Podcast friendly The RSS for podcasts can be directly fed into readers Tested with iTunes and many others
• Admin interface Manage data sources Manage categories
Internet2 Member Meeting. October 2007
Some Facts and Figures
• Based on open software Apache, PHP5 and MySQL
• Twelve institutions currently participating• + 2000 items available• Two classifications in operation
Spanish Higher Education directives UNESCO thematic classification
• Supported formats Flash MP3 MP4 Quicktime RealPlayer Windows Media
Internet2 Member Meeting. October 2007
Already in the Federation
• Universities Universidad de Cantabria Universidad Carlos III de Madrid Universidad Politécnica de Madrid Universidad del País Vasco Universidad Rey Juan Carlos Universidad de Vigo UNED The Madroño library consortium
• NRENs and regional networks RedIRIS CESGA
• Content providers Liceu de Barcelona, for the Opera Oberta project
• Contacts with TERENA ISPs Several other universities
Internet2 Member Meeting. October 2007
Community Software
• Channel statistics module Already included in the portal URJC
• ARCA item builder Provides a simple GUI for channel and item definitions UNICAN
• Joomla agent able to export to ARCA UPM
• PuMuKIT System for media cataloging Compatible with any streaming technology Able to generate local content portals And ARCA channel descriptions UVIGO
Internet2 Member Meeting. October 2007
ARCA + PuMuKIT Ecosystem
ARCA Server RSS
Institution 1
Institution 2
WEB-TV
PuMuKIT
PuMuKIT StreamingServer A
WEB-TV
RSS
ARCA Portal
StreamingServer B
Internet2 Member Meeting. October 2007
ARCA vs Others
• A federation, not a central service Flexibility Local autonomy Scalability Diversity preservation
• Provides live events with geo-location (GeoRSS)• Allows dynamic subscription using search results• Can build podcast definitions for any media type
supported by the system• Can feed or be fed by any other portal using compatible
RSS descriptions• Can be used by any RSS aggregator
Internet2 Member Meeting. October 2007
How To Federate
• Provide ARCA-compatible feeds at known URLs A single RSS feed per channel Several feeds per channel
• One per item type, one per year/month/day,...• The only requirement is to use the same channel title
• Use whatever combination of the four supported namespaces Yahoo Media RSS: Media characteristics, rights, keywords,
thumbnails, credits and roles, languages and playing choices. Google Base RSS: Dates (for an event or a video), location,
pictures Itunes: Media characteristics and compatibility with the iTunes
player GeoRSS: Geographical location
Internet2 Member Meeting. October 2007
Some Caveats
• ARCA mandates the use of UTF-8 Feeds must explicitly include it
<?xml version="1.0" encoding="UTF-8"?> The server must honor content encoding
• HTML code must use character entities To avoid confusing the parser Incorrect
<description> The workshop will discuss web 2.0 applications. The program is available <a href=“http://www.uc3m.es/jornadasW2/”>here</a>.</description>
Correct<description> The workshop will discuss web 2.0 applications. The program is available <a href="http://www.uc3m.es/jornadasW2/">aquí</a>.</description>
Internet2 Member Meeting. October 2007
Basic Description Structure
<?xml version=”1.0” encoding=“UTF-8” ?><rss version=“2.0” xmlns:media=“http://search.yahoo.com/mrss/” xmlns:g=“http://base.google.com/ns/1.0” xmlns:itunes=“http://www.itunes.com/dtds/podcast-1.0.dtd” xmlns:georss=“http://www.georss.org/georss/”> <channel> . . . <item> . . . </item> <item> . . . </item> <item> . . . </item> . . . </channel></rss>
Internet2 Member Meeting. October 2007
Defining a Channel
<title>Universidad Carlos III de Madrid</title><link>http://audiovisuales.uc3m.es/</link><description>Videos bajo demanda y eventos transmitidos por la Universidad Carlos III de Madrid</description><webMaster>[email protected]</webMaster><image> <url>http://audiovisuales.uc3m.es/logo.jpg</url> <title>Universidad Carlos III de Madrid. Audiovisuales</title> <link>http://audiovisuales.uc3m.es/</link></image>
• Optional: language, copyright, managingEditor, pubDate, lastBuildDate, generator, docs, ttl, textInput, category
Internet2 Member Meeting. October 2007
Defining an Item: General data
<title>Robótica: actuadores y sensores</title><link>http://roboticlab.uc3m.es/</link><description>Sensores de localización y...</description><author>[email protected] (Pablo Pérez)</author><comments>http://roboticlab.uc3m.es/cursopp/</comments><category domain=“unesco”>Ciencias tecnológicas</category><category domain=“directrices”>Enseñanzas Técnicas</category><category domain=“catre”>a03b11c32d05</category><g:image_link>http://roboticlab.uc3m.es/image1.jpg</g:image_link><g:image_link>http://roboticlab.uc3m.es/image2.jpg</g:image_link><media:thumbnail url=”http://roboticlab.uc3m.es/cursopp.jpg” width=“75” height=“50” /><media:keywords>sensores,actuadores,gps</media:keywords><media:copyright url=“http://es.creativecommons.org/”> Creative Commons</media:copyright>
Internet2 Member Meeting. October 2007
Defining an Item: Multimedia
<media:content url=“http://streamer.uc3m.es/cursopp1a.mov” fileSize=“12216320” type=“video/quicktime” medium=“video” isDefault=“true” expression=“full” bitrate=“128” framerate=“25” samplingrate=“44.1” channels=“2” duration=“185” height=“200” width=“300” lang=“es” />
Internet2 Member Meeting. October 2007
Defining an Item: Play choices
<media:group> <media:content url=“http://streamer.uc3m.es/cursopp1a.mpg” fileSize=“98216112” type=“video/mpeg2” medium=“video” bitrate=“2000” framerate=“25” samplingrate=“44.1”... />
<media:content url=“http://streamer.uc3m.es/cursopp1a.mov” fileSize=“12216320” type=“video/quicktime” medium=“video” bitrate=“128” framerate=“25” samplingrate=“44.1”... />
. . .
</media:group>
Internet2 Member Meeting. October 2007
Defining an Item: Credits/Roles
<media:credit role=”organizer”>Andrés Pérez</media:credit><media:credit role=“chair”>Carmen Gómez</media:credit><media:credit role=“speaker”>Silvia Toro</media:credit><media:credit role=“speaker”>Paco Puertas</media:credit><media:credit role=“speaker”>Nuria Prieto</media:credit>
Internet2 Member Meeting. October 2007
Defining a Live Event
<g:event_date_range> <g:start>2006-12-20T14:00:00</g:start> <g:end>2006-12-20T19:00:00</g:end></g:event_date_range>
<g:location> Plaza Manuel Gómez Moreno, s/n - Madrid</g:location>
<georss:point>40.331480 -3.766730</georss:point>
Internet2 Member Meeting. October 2007
Defining a VoD or Podcast
• General
<g:publish_date>2006-12-20</g:publish_date>
• Podcasts
<enclosure url=“http://pods.uc3m.es/cpp/cursopp1a.m4a” length="8727310" type="audio/x-m4a" />
• iTunes compatibility
<itunes:author>Pablo Pérez</itunes:author>
<itunes:subtitle>Módulo 1a</itunes:subtitle>
<itunes:summary> Sensores de localización y actuadores eléctricos</itunes:summary>
<itunes:duration>01:23:40</itunes:duration>
<itunes:keywods>sensores,actuadores,gps</itunes:keywords>
Internet2 Member Meeting. October 2007
And More To Come
• Dynamic endpoint definition• Push model• Ad-hoc creation for items dealing with sparse
live events at the portal• Support for groups of events (courses,
workshops,...) when searching/browsing• ARCA specific namespace• Different browsing alternatives• Display of related items• Support for other item types• Support for federated identity when searching,
browsing and playing content
Internet2 Member Meeting. October 2007
Concluding
• ARCA provides a new paradigm to access media content produced by the academic community Based on a federated approach Flexibility, local autonomy, scalability, diversity preservation
• Aligned with the EC goals on digital repositories in the VII Framework Program
• What we are seeking for Support for consolidating and deploying the technology Expanding the federation
http://arca.rediris.es/http://arca.uc3m.es/