=Paper=
{{Paper
|id=Vol-233/paper-14
|storemode=property
|title=Extensibility of Adaptation Capabilities in the CAIN Content Adaptation Engine
|pdfUrl=https://ceur-ws.org/Vol-233/p29.pdf
|volume=Vol-233
|dblpUrl=https://dblp.org/rec/conf/samt/MolinaMVL06
}}
==Extensibility of Adaptation Capabilities in the CAIN Content Adaptation Engine==
https://ceur-ws.org/Vol-233/p29.pdf
Extensibility of Adaptation Capabilities in the
CAIN Content Adaptation Engine
Javier Molina, José M. Martínez, Víctor Valdés, Fernando López
Abstract—This paper describes the extensibility mechanism II. CAIN SYSTEM OVERVIEW
that has been incorporated to the CAIN Adaptation Engine, that
provides audiovisual content adaptation based on user A. CAIN Architecture
preferences, network capabilities and terminal limitations. The
CAIN is a complete multimedia Adaptation Engine
integration of new adaptation modules needs no code
modifications in the core system, so it does not have to be integrating different content adaptation approaches[3]. It is
recompiled for adding or modifying adaptation modules. constituted by three main modules: the DM (Decision
Module), the EM (Execution Module), and the “battery” of
Index Terms—Adaptative Signal Processing, Multimedia CATs (Content Adaptation Tools), that is, the set of CATs
Systems. CAIN can use for content adaptation and made available to
CAIN thanks to the extensibility mechanism explained in III.
Currently we have integrated CATs belonging to the four
I. INTRODUCTION categories considered in the design of CAIN: ‘Transcoder
CATs’, ‘Scalable Content CATs’, ‘Real-time Content-driven
T he development of both, new access networks providing
multimedia capabilities, and a wide and growing range of
CATs’ and ‘Transmoding CATs’[4].
To make possible the work of the main modules, a set of
support modules are also necessary, which are basically
terminals, makes the adaptation of content an important issue MPEG-7/21 XML parsers to make data (that is, descriptions)
in future multimedia services. Content adaptation is the main accessible for the EM and the DM.
objective of a set of technologies that can be grouped under B. CAIN Adaptation Process
the umbrella of UMA (Universal Multimedia Access ) [1].
In order to perform content adaptation it is necessary to have First of all, we need a collection of CATs together with the
the description of the content and the description of the usage descriptions of their adaptation capabilities [5]. These
environment. To enhance the user’s experience [2], not only descriptions will be used by the DM, together with the content
terminal and network characteristics and conditions should be description and the usage environment description, in order to
taken into account when adapting, but also user preferences select the CAT that will perform the best adaptation.
and handicaps, as well as environmental conditions. All this For performing an adaptation we need to receive, at least,
information imposes some constraints to the content to be the input media content and a usage environment profile. It is
obtained after adaptation. In this paper section II presents the desirable, but unusual, to receive the associated content
current architecture of CAIN (Content Adaptation Integrator), description file. Therefore, the required media information
whilst section III details the differences with the previous description is usually extracted directly from the content,
version and therefore explains the extensibility mechanism. using ffmpeg library[6] .
Section IV presents some conclusions and future research The EM collects all the information extracted from the
work. required description files (media, usage environment, CAT
capabilities) and launches the DM. The DM selects both the
Manuscript received June 21, 2006. best CAT and its configuration parameters using a constraints
Javier Molina, Grupo de Tratamiento de Imágenes, EPS, Universidad satisfaction and optimization algorithm [7]. Afterwards the
Autonoma de Madrid, Madrid, Spain. phone: 0034-91-497-22-60; e-mail:
EM is able to execute the selected CAT, calling the adaptation
javier.molina@ uam.es).
J. M. Martínez, Grupo de Tratamiento de Imágenes, EPS, Universidad method (see section III.B) of the chosen CAT.
Autonoma de Madrid, Madrid, Spain. e-mail: jm.martinez@ uam.es).
V. Valdés, Grupo de Tratamiento de Imágenes, EPS, Universidad III. CAIN EXTENSIBILITY
Autonoma de Madrid, Madrid, Spain. phone: 0034-91-497-22-60; e-mail:
victor.valdes@ uam.es). CAIN considers the integration of new CATs, as well as the
F. López, Grupo de Tratamiento de Imágenes, EPS, Universidad Autonoma update of existing ones. For this purpose, it provides a flexible
de Madrid, Madrid, Spain. phone: 0034-91-497-22-60; e-mail: f.lopez@ extensibility mechanism in order to avoid recoding of the core
uam.es).
of CAIN as well as recompiling. One of the integration
requirements is to make the CAT´s capabilities accessible
from the DM. For this, we need to have a complete and lack
of ambiguity file, describing what transformations a concrete
CAT is able to do and with which input and output formats. IV. CONCLUSIONS AND FUTURE WORK
Another important requirement for CAT’s integration is the The proposed extensibility mechanism allows
compliance with interface defined for making the CAT implementation-agnostic integration of new CATs in order to
accessible by the CAIN core. incorporate new functionalities without prior knowledge of
A. Content Adaptation Tool Plug-in each tool capabilities and limitations. This allows to use CAIN
The main differences with the previous CAIN for service prototyping (as in currently being done in the EU
version[3][4][5][7] are the following: IST aceMedia Integrated Project), service deployment
(reducing the flexibility and numbers of CATs), and as a
x The integration of new CATs does not need any
benchmarking framework. For the later, it will be necessary to
modification in the system’s core. This allows to change
incorporate the modules required for providing as result of the
the set of available CATs before each execution of CAIN.
adaptation a report of resource consumption (CAT processing
x The conditions to be fulfilled when incorporating a new
time, CPU and memory use, power consumed, temporary
CAT are only to be compliant with a defined interface , to
storage space, …) as well as modules for comparing the
follow a certain naming policy (see sectionIII.B).
quality of different versions of adapted content, both being the
x The functionality of a working CAT is modifiable even same or different adaptations, taking into account not only
without recoding its own code. This is possible by the objective, but also subjective quality measures focus in the
edition of the correspondent CAT capabilities description user’s perceived quality even in the case of transmoding.
file. This edition may allow the restriction of certain
formats in the input or output. The adaptation schemes can
ACKNOWLEDGMENTS
also be modified in order to, for example, avoid certain
non-desired transcoding operations. This work is partially supported by the European Commission
6th Framework Program under project FP6-001765
B. Content Adaptation Tool’s Interface (aceMedia). This work is also supported by the Ministerio de
All the files implementing the CAT, or used by it, have to be Ciencia y Tecnología of the Spanish Government under
packaged in a *.jar file. This file has to share name with the project TIN2004-07860 (MEDUSA) and by the Comunidad
CAT it represents. de Madrid under project P-TIC-0223-0505 (PROMULTIDIS).
For integrating a new CAT we need, at least, two files: The authors want to thank Víctor Fernández-Carbajales for
x The CAT code in a *.java file, with the same name as the successful testing of the extensibility mechanism.
CAT. This code file should implement the
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