Lecture 4: Multimedia Hardware

Introduction

The word platform was traditionally associated with hardware: the computer platform.

However, it can also describe software as well as hardware (Mac platform vs. Windows platform)

WWW: the platform is the combination of browser, computer and OS (+ plug-ins)

Introduction

For an offline application the OS and computer is generally enough but sometimes more detail, such as the graphics adapter, is important

Definition: The platform is whatever you have to specify in order to run the application

What kind of display is needed, or how big hard disk, or how fast Internet connection

Introduction Three options that will be discussed in

relation to platforms: The delivery platform: what does your

user have to use in order to see your application?

The delivery medium: how do you get the application to the user?

The development and testing platform: what do you need to use in order to make the application in the first place?

Selection of the proper platform Selection of the proper platform for

developing your multimedia project may be based on your personal preference of computer your budget constraints project delivery requirements the type of material and content in the project

Today you can produce multimedia projects with equal ease in either the Windows or Macintosh environment

Memory and storage devices

RAM and ROM Hard drives CD-ROM, DVD, BlueRay USB memory modules

Input devices Keyboards Mice Touchscreens Magnetic Card Encoders and Readers Graphics Tablets Flat-bed Scanners OCR Devices (Optical CharacterRecognition) Infrared Remotes Voice Recognition Systems Digital Still and Video Cameras

Output hardware

Audio Devices Amplifiers and Speakers Monitors Video Devices Projectors Printers

Communication devices

Cable Modems xDSL technologies Wireless (WLAN) 3G/4G etc…

Online delivery WWW is somewhat simple for publishing since all web

browsers understand HTML; the web is the most cross-platform format (despite some issues with JavaScript and ActiveX etc).

Issues affecting the delivery on Internet: Speed of access Updating Security/payment The “unlimited” size of the data space than can be

provided online You can restrict access, charge users for access, and

even keep track of who has accessed your information and when

Online delivery The speed with which your potential users can access

your application is unpredictable; tens of Kbps – tens of Mbps

The bottleneck is the end-user’s web connection Do what you can: have a fast server and a fast Internet

connection Streaming and buffering are methods that try to remove

the problem of download times

ONLINE DELIVERY PRO’S &CONS? (groupwork)

Online delivery – pros and cons Pros

A low cost and sophisticated possibilities The application can be fixed at any time Potentially an infinite amount of space to hold

information The web’s reach is global and instant

Cons a heterogeneous user base you need to decide how much you can cater for

the differences in the users’ systems Security implications Slow connections

Mobile multimedia Mobile applications do not differ that

much from conventional computer delivery

The bandwidth problem is more important, since it may be very dependent on your distance from a base station

At least the billing is easy since the system always tracks down the user

Interactive television The arrival of digital television brings with it

the possibility of interactive services Set-top boxes for televisions; also

integrated models are available; IPTV Video-on-demand (VOD) may provide

another market for interactive services on the TV or via net to a PC (push and pull models)

Today’s set-top boxes use push model

Delivery medium Besides deciding on what computer

platform the end-user will actually use your production, there is the question of how you will actually distribute the content.

If it’s a web page, then the WWW is the medium

To a certain extent this will depend on the size of the application, and might even have been specified up front

Optical disks This medium has become universal; it may

never lose its supremacy as a carrier Different incarnations: CD-ROM, DVD,

BlueRay DVD and BlueRay are higher-density

formats than CD (the basics of the technologies are quite similar)

Replication of optical disks is cheap Especially for movie delivery

Hybrid delivery

Sometimes you can use both on- and offline delivery (quite common today)

Web links can be part of DVDs DVDs are often updated from the web

(fixes and additions are saved on the hd)

Platforms for development and testing You do not have to develop your application

on the delivery platform A cross-platform application is usually

developed on one and tested on all delivery platforms (even a low-level code can be produced on a different computer using a cross-compiler)

Even though majority of multimedia applications are created for Windows, they are quite often developed on Macintosh (not that much anymore, but few years ago the software was usually first released for Mac)

Platforms for development and testing Create and manipulate your assets (sound,

graphics etc) in the highest convenient standard and convert down, if necessary, at the last moment

You must have at least one workstation that is similar to the delivery platform so that you can test the performance and carry out debugging

Remember that you can never have all possible platform combinations

Author once and deliver everywhere We need techniques that allow us to author

once an deliver on many platforms XML is one part of the solution to this: it

allows the content structure to be separated from the way it is laid out; layout can change depending on the platform

Although we are talking about media convergence, the range of platforms available is still increasing