Multiplatform Applications Lecture 1: Introduction

Today’s Session Module Information Mobile Platforms Television Platforms

What is the module about? Delivering applications and content on multiple platforms Computers (you already know this bit) Mobile Devices such as phones and PDAs Interactive Television Other devices Understanding the constraints different platforms impose on the design process One size does not fit all!

Assessment The module has a 50:50 split Unseen examination in January Coursework assignment Design and build a prototype of an application designed for multiple platforms

Module Resources Teaching material on moodle.bolton.ac.uk Bookmarks: delicious.com/adamisherwood/mwd3002 Facebook Add me facebook.com/adam.isherwood Fan site: Multiplatform Applications Free Microsoft Software

Level 3 In the final stretch leading to your degree Not enough just to pass the module any more You are expected to read the related material Cannot achieve a 1 st or a 2:1 just by repeating what is said in the lectures Your answers and assignments must demonstrate synthesis and understanding

Prior Learning Assume you understand XML and XML Schema Assume you can handle CSS and XHTML Assume you can use Visual Studio.Net and a database

Practical Skills Publishing using XML, CSS and XSLT Mobile publishing using WAP and XHTML-MP User Interface Considerations

Theory Interactive Television Enhanced Television Smartphone Application Development

Introduction to Mobile Platforms

Publication Mechanisms Write content using WAP/WML Publish web pages Mobile version or standard Write custom applications

In the beginning… WAP: Wireless Application Protocol WML: Wireless Markup Language Early tool for delivering content to mobile handsets Supported by large number of phones – even relatively simple or older handsets

Design Goals Low bandwidth – 9.6kbps Low colour/monochrome Runs in little memory on slow processors Rudimentary graphics support (WBMP format)

WML XML based format using defined set of tags Scripting support Intended for Tables, Links, Forms and simple graphics Uses Deck of Cards metaphor for content design Single page can contain multiple cards in one deck User can step through cards as a form of navigation Next & Previous buttons + named anchors to jump to specific cards

WAP Gateway

Limitations Designed late 1990s Phones had very limited spec compared to modern devices: Monochrome or greyscale display Typically 5 lines of text on screen 14.4k Modem for data access No longer a mainstream platform

Modern Phones 3G gives greater bandwidth Larger screen resolution and greater colour depth Embedded Web browsers Closer to computer experience

Mobile-specific pages Version of XHTML for the Mobile Platform XHTML-MP Similar implementation of CSS-MP Broadly similar capabilities to conventional web browsers Design considerations for mobile content to be covered later

Custom Applications Networks like 3 offer apps such as Skype and MSN Apps like Facebook or Twitter widely offered with high-end phones/contracts Multitude of iPhone apps to access eBay, Amazon, Facebook etc.

Pushing data not format Apps send data to a programme running on the phone Layout can use GUI elements from Java, Flash or Cocoa as supplied by the phone OS Delivers better interaction for customers by exploiting phone functionality to the full Further details in another lecture

Interactive TV

Platforms There are several major platforms in use in the UK (the most developed Digital TV country in the world) Sky Digital – 9.2 million subscribers Virgin Media– 3.6 million Freeview – 17.7 million Freesat – 0.6 million Source: OFCOM April

Platform issues Each platform has different operating systems and technologies employed Virgin media (formerly NTL/Telewest) use the Liberate system which uses HTML Freeview uses MHEG 5 and open standard Sky uses the OpenTV OS but their interactive services can be built in OpenTV or in the new WML for Sky language

Virgin Media This system is the closest to web technology Operates on a two way interactive broadband link (usually 512K+) Uses HTML and liberate specific extensions Homepage for development hints is that supported by NTL at Includes a downloadable emulator

Freeview system Overtaken Sky Will probably becomes the dominant platform over the course of next 10 years Uses MHEG 5 open standard technology Multimedia and Hypermedia information coding Expert Group See for a definitionhttp://en.wikipedia.org/wiki/MHEG-5 Works using a carousel – play out of data with no return

Sky System Uses Proprietary OpenTV technology and WML based SkyWAP browser (WTVML) for some content Works using a carousel but can also use a 28.8k modem built into the box (mostly for back channel work) More details (and developers tools) at efault.htm efault.htm

Design considerations TV screens are often physically large – 32” (80cm) common Broadcast TV is lower resolution than a computer monitor Analogue TV heritage introduces problems They have some real issues as display devices

Display considerations TVs are interlaced That means they build the frame one line at a time with alternate lines with each pass Odd numbered lines used for first field, even for the second Uses less transmission bandwidth for analogue broadcast Older CRT televisions rely on afterglow and persistence of vision to give flicker-free effect Less appropriate for LCD TV and digital broadcast Still an issue with HD – 1080i vs 1080p

Screen size A PAL screen is.... (come on remember!) But that does not mean you have that to use A safe area is defined in the centre where you can display content This avoids the problems of over scanning or under scanning of the picture This overcomes the problems you will have with the wide range of qualities and age of TV's

Safe and Title Area The Action safe area of a screen is approximately 90% of the screen so on PAL that is 648 x 519 or rounded to 650 x 520 The Title safe area is smaller but again is approximated at 80% of the screen 576 x 461 or rounded to 575 to 460 Pixel size is different (1.06 width pixel onTV) Good outline at

Buzzing Ever seen someone on tv in a tweed jacket What happens? Because of the low resolution of screen odd numbered thickness lines cause bussing Remember don't use single lines in display Also causes problems with text All text and graphics must be anti aliased

Colours Colours bleed into one another Particularly primary colours High contrast between colours causes problems (white and black bleed together) All designs must be tested through a tv first Test colour combinations