INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
ORGANISATION INTERNATIONALE NORMALISATION
ISO/IEC JTC 1/SC 29/WG 11
CODING OF MOVING PICTURES AND AUDIO
ISO/IEC
JTC 1/SC 29/WG 11/N8687
October 2006, Hangzhou
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Title
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White Paper on the Multimedia Middleware
Part 1 - Architecture
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Source
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Systems
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Status
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Proposal
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Editors
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Martin Russ (BT), Johan Muskens & Jean Gelissen (Philips)
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1. Introduction
MPEG, a working group in ISO/IEC, has produced
many important international standards (for example: MPEG-1, MPEG-2, MPEG-4,
MPEG-7, and MPEG-21). One of the next steps in this process is the standardization
of an Application Programming Interface (API) for Multimedia Middleware (M3W)
allowing application software to execute multimedia functions with a minimum
knowledge of the inner workings of the multimedia middleware as well as to
support a structured way of updating, upgrading and / or extending the multimedia
middleware [1].
The standard that describes an MPEG Multimedia Middleware
(M3W) system is formally referred to as ISO/IEC 23004 [2]. It has the
general title Information Technology — Multimedia Middleware,
and consists of the following parts:
·
Part 1: Architecture
ISO/IEC 23004-1
·
Part 2: Multimedia API:
ISO/IEC 23004-2
·
Part 3: Component Model
ISO/IEC 23004-3
·
Part 4: Resource and Quality Management
ISO/IEC 23004-4
·
Part 5: Component Download
ISO/IEC 23004-5
·
Part 6: Fault Management
ISO/IEC 23004-6
·
Part 7: System Integrity Management
ISO/IEC 23004-7
·
Part 8: Reference software
ISO/IEC 23004-8
This white paper provides an overview of
the M3W Architecture (Part 1 of the standard), there are 6 additional white
papers describing the Parts 2 – 7 of the standard. Part 8 represents the reference
software that allows implementers to experiment with the standardized functional
and non-functional M3W interfaces and also provides sample applications illustrating
the provided functionalities.
2. Architecture
In an M3W system there are 3 distinct layers:
-
Applications: The type of applications
will depend on the appliance.
-
Middleware layer: This layer consists
of M3W and other middleware. M3W can be separated into two parts
- Functional part: This provides the applications and
other middleware with a multimedia platform. (‘Functional’ is used here
to indicate that multimedia ‘functionality’ is being provided.)
- Extra-functional part: This provides a means to manage
the lifetime of, and interaction with, realization entities. Furthermore
this enables management of extra-functional (‘support’) properties, e.g.
resource management, fault management and integrity management;
-
Computing platform: The platform will
depend on the appliance. The API of the computing platform is outside of
the scope of M3W. Different realizations of M3W for different platforms
will use different API's for these platforms.
The layers mentioned above are not strict
in the sense that applications and other middleware cannot use the computing
platform directly. However, the latter is not recommended. The software structure
of an M3W system is shown infigure 1.
Figure 1.
The software structure of an M3W system.
The scope of this standard is limited to
the specification of the M3W API and the specification of the realization
technology for M3W. In figure 1, this means the L-shaped yellow part and its
interfaces depicted by the green line.
The functional part of the M3W API, mentioned
above as the Multimedia Platform, is specified in M3W Part 2 (ISO/IEC 23004-2).
The non-functional parts, mentioned above as the Support Platform, as well
as the specification of the realization technology, are specified in M3W Parts
3, 4, 5, 6, and 7 (ISO/IEC 23004-3, ISO/IEC 23004-4, ISO/IEC 23004-5, ISO/IEC
23004-6 and ISO/IEC 23004-7).
The core of M3W is the component model and
core framework that provides the run-time-environment being responsible for,
amongst others, the life cycle management, interoperability support and communication
including remote method invocation. The core framework can be extended with
a number of optional frameworks (illustrated in figure 2):
Please note that these optional frameworks
are described in more detail in the M3W white papers on the respective subjects.
Figure 2. M3W frameworks.
3. Summary
M3W API is intended to be a generic API.
The M3W API can be suitable for use in multiple products with different capabilities.
Examples could include an analogue television product family, a digital television
product family, and a digital set-top box product family. These various families
and products have significant overlap in the functionality they require from
the platform, but there are also differences (e.g. some require an analogue
video decoder, others do not). Supporting multiple products with different
capabilities requires variation in the API; a single fixed API will not do.
M3W provides flexibility in components, roles, inner objects, and realization.
This diversity means that M3W can provide ease of use and broad compatibility.
3. References
[1] The Multimedia Middleware (M3W) requirements
are in the annex to the Multimedia Middleware (M3W) Requirements Document
Version 2.0 (ISO/IEC JTC1/SC29/WG11 N6981). A Call for Proposals derived from
these requirements was issued at the 70th MPEG Meeting in Palma,
Mallorca
[2] ISO/IEC 23004, Information
Technology — Multimedia Middleware, The M3W standard.