Macromedia Flash 0 and Generator 0

Macromedia Flash 5.0 and Generator 2.0

Flash 5 and Generator 2 are two authoring tools of Macromedia web site development products. The former provides a platform to create animated, vector-based web content. It also has a custom language “ActionScript”, which is based on JavaScript specification, supporting simple interactivity. The later is aimed at providing a template mechanism to automate content updates. With Generator integrated with Flash, user can not only design rich media content of text, graphics, animation and audio objects but also convert them into Generator objects when prototypes are needed for dynamic content delivering. The methodology of Macromedia Flash and Generator can be a useful reference for designing high quality, complex distance learning authoring system. In this report, I will first summarize the features and key technologies of Flash and Generator, and then comment on some insufficient factors based on my experience of using both tools. At last, a comparison of Flash format (SWF) and Scalable Vector Graphics (SVG) will be briefly discussed.

Flash 5.0 is a vector-based technology that supports animation, sound and interactivity. It evolved from a product “Splash” in the mid 90s and aims at delivering scalable and high quality web content over the Internet.

Flash file format (.swf) is currently the most widely used vector graphics and animation format on the web. In April 1998, Macromedia announced to make SWF an open source for becoming an Internet standard of vector graphics and animation. In early 2000, the following SDK’s  Macromedia Flash Player source code SDK and Macromedia Flash File Format (SWF) SDK are released for open access (with Source Code License Agreement). The above tools and documentation make Flash Player platform independent and also extend ways for developers to write SWF files.

Flash 5 features a user-friendly interface that provides a powerful development tool for creating artwork, streamlining workflow and creating interactivity.

User-friendly Interface

The Stage  the rectangular area where the movie plays

The Timeline  where graphics are animated over time

Symbols  the reusable media assets of a movie

The Library window  where symbols are organized

The Movie Explorer  providing an overview of a movie and its structure

Floating, dockable panels  elements properties and authoring environment settings

Floating, dockable Panels

Stage

Movie Explorer

Enhanced capability of creating artwork

Drawing  provides various tools for drawing freeform or precise lines, shapes, and paths, and painting filled objects.

Symbol  a symbol is a reusable image, animation, or button

Instance  an instance is an occurrence of a symbol on the Stage. Symbols help to create sophisticated interactivity, reduce a file’s size and simplify editing a movie

Layers  structure as transparent stacked sheets on top of each other and it helps to organize the artwork in a movie by separating objects on different level

Type  the text block object where properties such as size, typeface, style, spacing, color and alignment can be set. Sophisticated transform can be applied like shape object.

Buttons  the objects (with four statuses: Up, Over, Down and Hit) trap mouse clicks and trigger the interaction with Flash movie.

Sound  the object can be integrated into a Flash layer. There are two types: event sounds (a complete pre-download before playing and independent to the Timeline) and stream sounds (synchronized to the Timeline)
Animation  tweening is an essential technique for creating animation. It defines starting and ending states of an instance, group, or text block and use transformation matrix to do the calculation and interpolates the values or shapes for the frames (cells on the Timeline) in between. There are two types of tweened animation in Flash: tweening motion (position and shape) and tweening color. Here is an example of a tweening motion along a straight path (Figure 3).

Frame 1 Frame 5

to path

Interactivity and ActionScript

Key technologies of Flash 5

Vector graphics is perhaps the most important technique used by Flash 5. Although there is other leading designing tools that build up on vector graphics, such as CorelDRAOW 10 graphics suite, Macromedia Flash is the very first one who uses vector based graphic design in generating web contents and delivering them over the Internet.

The Macromedia Flash (SWF) file format was designed to deliver vector graphics and animation over the Internet. It features with extensibility (a tagged format), efficiency (a binary format), simplicity (a simple format) and scalability (vector based graphics). SWF structure is consists of a Header and a series of tagged data blocks (Figure 4). There are two types of tag  definition tag (defining the content of a Flash movie) and control tag (manipulating characters and controlling the flow of the movie).

File Compression

Compression  Shapes are using delta encoding scheme, which assumes the first coordinate of a line to be the last coordinate of the previous one and distances are expressed by relative position to the previous one

Shape Data Structure  uses a unique structure to minimize the size of shapes and to efficiently render anti-aliased shapes on the screen

Change Encoding  SWF files only store the changes between states.

Default values  some structures, like matrices and color transforms, share common field with default values

Reuse  by the character dictionary, a font, bitmap, shape, or button element can be stored once and referenced multiple times.

The dictionary is a repository of characters that have been defined, and are available for use by Control Tags. The structure and interaction between definition tags, control tags and the dictionary is showed in Figure 5.

The Macromedia Flash file format (SWF) SDK is a C++ Library that provides a set of tools for developers to write Macromedia Flash (SWF) files. There are two types of interfaces for writing SWF files, a high-level and a low-level manager. Both interfaces are in the same code base, but are used somewhat differently. The high-level manager presents a simple interface for writing SWF files, while the low-level manager presents an API for writing an arbitrary SWF file.

Generator 2.0 is a Web server production application written primarily in C++. When integrated with Flash, it can dynamically combine variable objects (text, graphics and sound) to build rich media content and deliver the final product over the Internet in animated or static formats.

The process of using Generator can be illustrated in the following authoring mode of operation (Figure 7).

There are two editions of Generator 2  the Enterprise Edition and the Developer Edition. They are different in performance, scalability and online production.

The Developer Edition is a data-driven, automatic updates solution. It processes requests one at a time, therefore, it is only used in offline mode (Figure 9). Generator 2 Developer Edition also includes some new objects and an extensible API.

Macromedia Flash 5.0 and Generator 2.0 are powerful tools for designing and delivering web contents. Especially the Vector Graphics and Template technologies that they use bring highlights to the system. However, there are still some insufficient factors in the perspective of view of designing general web authoring tools. For example, dynamic positioning of web contents is a very important feature for automatic batch processing and rendering of the general web authoring system. It is not obvious that Flash and generator provide such interface. Although Macromedia made Flash File Format (SWF) an open standard, being a commercial product, there are still constrains in developing and delivering the customized application that build on top of Flash.

In November 2000, W3C proposed a new version of Scalable Vector Graphics (SVG) Specification. Compared with Flash SWF files (a compact binary file format that requires an additional browser plug-in to be available in order for displaying a movie), SVG is an XML-compliant open standard. The non-proprietary formats of SVG would provide developers a choice of vector graphics and movie formats.

Appendix

System requirements

Microsoft Windows 95, NT 4.0 or later; A PowerPC with System 8.1 or later;

32 MB of RAM, 40 MB of available disk space;

A color monitor with resolution 800x600; and a CD-ROM drive.

Microsoft Windows 95, NT 4.0 or later; A PowerPC with System 8.1 or later;

Netscape 3, Internet Explorer 3.02 or later.

32 MB of RAM, 40 MB of available disk space;

A color monitor with resolution 800x600; and a CD-ROM drive.
For Generator templates authoring and previewing

Microsoft Windows 95, 98, 2000, or NT 4.0 with Service Pack 5 or later;

or A PowerPC with System 8.1 or later and Mac OS Runtime for Java 2.1 or later;

32 MB of RAM, 40 MB of available disk space;

A color monitor with resolution 800x600; and a CD-ROM drive.
For Generator content serving

Microsoft Windows:

NT 4.0 Server (Service Pack 5) with Internet Information Server 4.0 or iPlanet4.0;

Or Windows 2000 with Internet Information Server 5.0;

Or Windows 95, 98 or NT 4.0 Workstation with Personal Web Server 4.0;

64 MB of RAM, 48 MB available disk space and 64 MB of swap space.

Solaris 2.6 or 7 with Apache HTTP server 1.2.6 or 1.3.x or later;

Or Netscape Enterprise 3.5 or later;

64 MB of RAM, 80MB available disk space and 128 MB of swap space.

Red Hat Linux 6.1 with Apache HTTP server 1.3.9 or later;

64 MB of RAM, 80MB of available disk space and 128 MB of swap space.

Demos of Flash and Generator

There are two demos made by using Flash 5.0 and Generator 2.0 to exploit the key functionalities provided. The following are snapshots of the demos.

Flash Movie Demo

Generator Template Demo

Reference

Macromedia Flash File Format (SWF) SDK

Macromedia FLASH5 Using Flash

Macromedia FLASH5 ActionScript Reference Guide

Macromedia GENERATOR2 (Developer Edition) Using Generator

Adobe Photoshop 6.0 User Guide