Multimedia Databases & Multimedia System

and Architecture

ByVini Garg

Harshita Ved

A Multimedia database (MMDB) is a collection of related multimedia data, which include one or more primary media data types such as text , images,  graphic objects  (including drawings, sketches and illustrations) animation sequences, audio and video.

Multimedia Databases

A Multimedia Database Management System (MMDBMS) is a framework that manages different types of data potentially represented in a wide diversity of formats . It provides support for multimedia data types, and facilitate for creation, storage, access, query and control of a multimedia database.

A Multimedia Database (MMDB) hosts one or more multimedia data types . These data types are broadly categorized into three classes::

Static media  (time independent, constant, non interactive e.g. image and

graphic object ). Dynamic media  (time dependent, moving, interactive, e.g.  Audio , video and

animation). Dimensional media (3D game and computer aided drafting programs). E.g.

virtual reality, 9-D movies

Contents of MMDB

Multimedia Database (MMDB) needs to manage additional information pertaining to the actual multimedia data. i.e.

Media data: the actual data representing an object. Media format data: information about the format of the media

data after it goes through the processing, and encoding phases. It is used to present the retrieved information.

Media keyword data: the keyword descriptions, usually relating to the generation of the media data. It is used as indices for searching purpose.

Media feature data: It contains content dependent data such as contain information about the distribution of colors, the kinds of textures and the different shapes present in an image. It is also used as indices for searching purpose.

(The last three types are called metadata as they describe several different aspects of the media data. )

Contents of MMDB

Like the traditional databases, Multimedia databases should address the following requirements:

Integration Data items do not need to be duplicated for different programs invocations Ensures database consistency between transactions

Data independence Separate the database and the management from the application programs

Concurrency control Allows concurrent transactions

Persistence Data objects can be saved and re-used by different transactions and

program invocations Privacy

Access and authorization control Recovery

Failures of transactions should not affect the persistent data storage Query support

Allows easy querying of multimedia data.

Requirements of MMDB

Multimedia data consists of a variety of media formats or file representations including  TIFF, BMP, PPT , IVUE, FPX, JPEG , MPEG, AVI, MID, WAV, DOC, GIF, EPS, PNG, etc. Because of restrictions on the conversion from one format to the other, the use of the data in a specific  format has been limited.

Issues and challenges in MMDB

Usually, the data size of multimedia is large such as video; therefore, multimedia data often require a large storage.

Multimedia database consume a lot of processing time, as well as bandwidth.

Integrate different data models: Some data such as numeric and textual data are best handled using a relational database model, while some others such as video documents are better handled using an object-oriented database model. So these two models should coexist together in MMDBs.

Synchronization of different media types while presenting to user: It is likely that different media types corresponding to a single multimedia object are stored in different formats, on different devices, and have different rates of transfer. Thus they need to be periodically synchronized for presentation.

Contd.

Integrated administration of huge amounts of multimedia data

Optimized storage

Efficient access

Manifold complex search possibilities

Referential integrity of links

Transaction protected multiuser mode

Recovery

Advantages of MMDB

Digital Libraries- an organized collection of sources of information and similar

resources News-on-Demand Video-on-Demand allow users to select and watch/listen to  video or audio content

when they choose to, rather than having to watch at a specific broadcast time.

Music database- Collection of music and/or their lyrics. E.g. in Saavn webstore Geographic Information Systems (GIS)- system designed to capture, store, manipulate , analyze, manage,

and present all types of spatial or geographical data Telemedicine- use of telecommunication and information technologies in order to

provide clinical health care at a distance

Application areas

Multimedia System and Architecture

Categorised as ‘live’ or ‘orchestrated’ Live applications involve interaction among

users. Eg. Video Conferencing Orchestrated applications reproduces the

data that was previously generated and stored in some medium. Eg. Pay per view movies.

In order to satisfy the requirements of these categories various Multimedia Architectures are used.

Components of Multimedia System

In order to satisfy the requirements of these categories of applications, various Multimedia Architectures are used.

Multimedia systems can either be standalone , server or networked.

Standalone Multimedia System: consist of storage subsystem , which is a database and storage devices where media content resides.

Server Multimedia System: consist of both storage subsystem and networked subsystem in levels.

Networked Multimedia System: consist of both networked subsystem.

Real Time Multimedia Architecture

Layered architectureLower layer provide functionality to upper layers.

Storage Subsystem and Network Subsystem (Layer 1) :->

These services are central to multimedia system and is normally part of OS services.

End-To-End QoS (Layer 2) :-> This layer deals with maintaining connection between source of the multimedia content and the destination.

For Standalone system : Source -> multimedia database For Networked system : Source -> multimedia server QoS (Quality of Service) comprises of delay,

jitter, and packet loss probability.

Media Management (Layer 3) :-> It provides general services like media

synchronization and media stream management . Also it ensures temporal and spatial relationships between media streams.

Application Layer (Layer 4) :-> Interface with the user, to provide access

and control to the presentation.