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Adobe Flash

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Macromedia Flash is a vector graphics based graphics animation program by Macromedia. The resulting files, sometimes called "flash files", may be included in a web page to view in a web browser, or they may be played on a standalone player (see Flash players). The most common use is in animated advertisements on web pages, although prank flash has become common.

Pros and Cons

Advantages

The Macromedia Flash file format has several advantages over "regular" HTML pages that make it an extremely popular option for ad creation and for some other types of sites.

  • Like PostScript, SVG and PDF, Flash allows exact specification of where the various page elements are, and so it gives the designer a great degree of control over how the user interface looks. In some people's opinions, it is much more difficult if not impossible to do the same with HTML and CSS.
  • Unlike PostScript, SVG and PDF, Flash supports streaming by default (frames are loaded individually).
  • Again, like PostScript, SVG and PDF Flash uses vector graphics; they may translate into small file sizes which take less bandwidth to transmit than bitmaps do.
  • The Flash file format has been opened by Macromedia, and compatible third-party tools exist.
  • Flash's file format is not platform-dependent; Flash Players exist on Microsoft Windows, Mac OS, Linux and various other Unix systems.
  • Flash allows the embedding of images, sounds, movies and simple HTML files. These abilities make it a good multimedia platform. Flash Player 6 also supports two-way streaming of sound and video, thus being an excellent platform for high-level multi-user applications.
  • Flash's embedded ActionScript language (an application of the ECMAScript programming language) allows the creation of simple fill-in-the-blank forms.
  • Flash is a highly ubiquitous format. According to Macromedia, Flash Player penetration is well over 95%. Flash Players exist for, and are integrated into PDAs, cellular phones and there is an implementation for the Java platform.

In Flash MX, the ActionScript language has been extended to the proposed ECMA Script 4 standard and can be used to create extensive event driven GUI's. Flash MX 2004 introduced ActionScript 2.0, which features strong types, interfaces, inheritance and other features of advanced object-oriented programming languages.

Macromedia is moving Flash away from the simple animations of web ad banners and move toward true application development.

Disadvantages

There are also some disadvantages to Flash and these have caused some of the initial surge in use outside ads to decline, as the negative consequences of Flash use were seen:

  • Flash circumvents browser controls which block the display of animation on web pages, allowing ads to display animation even when the end user has turned off the capability in the browser.
  • Unlike HTML pages, Flash pieces are oftem one monolithic file, thus users cannot bookmark or pass around URLs pointing to specific content.
  • Users cannot easily navigate through content because individual Flash designers may not choose to include support concepts such as Back buttons.
  • Flash does not obey browser settings for font size, etc, so text may appear tiny for vision impaired people or those with high resolution screens.
  • Many Flash pieces reinvent common HTML and browser conventions such as scroll bars, leaving the user to figure out how to get around, and disabling features such as mouse wheels.
  • Flash is not an easily human-readable format, taking away a level of control over content for the end user.
  • Flash content is not accessible to most search engines, so sites using Flash experience decreased visibility in search engines unless redesigned to allow for this problem. So far, at least Google (example: [1]) will try to read flash files (much like PDFs). This doesn't matter for ads, so use in ads hasn't been affected.
  • Viewer plugins don't exist for 'all' systems, officially for: GNU/Linux x86, Windows, Mac OS 9/X, Solaris, HP-UX, Pocket PC, OS/2, and IRIX operating systems. Oliver Debon wrote an open source version of the Flash 3 player and it has been ported to just about every OS including the Amiga.
  • The Flash Player is not installed on all computers, particularly non-enthusiasist systems.
  • Because the flash movie is played from a user agent plug-in, limited memory resources are available to the flash-movie. This is the amount of memory the user agent allocates for the plugin. This amount depends on the user agent used.
  • Though the flash file format is ostensibly "open", it is still controlled by Macromedia and not based upon a truly open standard such as SVG, which reduces the incentive for non-commercial software to support it. The Macromedia player can not be shipped as part of a pure open source, or completely free operating system.
  • Due to Flash's graphical nature, it does not degrade gracefully to disabled users. It is possible to overcome this only by providing alternative content (for example in HTML). See also computer accessibility.
  • Flash does not support internationalization thoroughly.
  • Flash demands significant CPU power to display, as it uses a very high degree of graphic abstraction that many video cards are not able to accelerate. Particularly, the anti-aliasing utilized by the Flash Player is heavy on the computer.
  • The browser plug-in may store and retrieve information on the user's computer, acting much like HTTP cookies and with similar advantages and disadvantages; however, data size restrictions are set independently by the player.
  • Although this has never been an actual problem, the plug-in has had security flaws which theoretically may open up a computer to remote attack (e.g., see [2] and [3] for a December 2002 problem). Note this problem has been fixed with newer versions of the flash player.
  • Because Flash's user friendliness also enables people that do not necessarily have a formal design education or knowledge of interface design to quickly create complete websites some critics tend to generalize that "Flash sites are ugly and unusable".
  • The .swf files it makes aren't secure. There are several commercial programs out there that can allow someone to extract graphics, sounds, etc. from a .swf file and also view its ActionScript. There's even an open source program called flasm that allows someone to extract ActionScript from a .swf file as "bytecode", edit it, and then reinsert it into the file. However, the swf obfuscation makes the extraction not feasible in most cases.
  • Flash does not respect browser settings which prevent animation from displaying, one reason why it is commonly used for animated ads.
  • Microsoft Internet Explorer gives a security warning which asks for permission to let a site run ActiveX controls. The warning doesn't specify which site or which controls, so a prudent end-user must look at the source code of all parts of the page before allowing Flash to run, in case the site, one of the ads on it or a pop-up or pop-under is also using a control which is a security problem.

In Flash MX 2004, the latest release, several of the disadvantages have been addressed. See http://www.useit.com/alertbox/20001029.html for a discussion of Flash and usability.

Competition

In October of 1998 Macromedia disclosed the Flash Version 3 Specification to the world on its website in response to many new, and often semi open, competing formats to SWF such as; XARA's Flare and Sharp's Extended Vector Animation formats. Several developers quickly created a C library for producing SWF. In Feburary of 1999 MorphInk 99 was launched, the first non-Macromedia, or third party program to create SWF files. Macromedia also hired Middlesoft to create a freely available developers kit for the SWF file format versions 3-5. Many open and free libraries based on the information released to the public in 1998 and from later study of the SWF file Format, such as the Ming library, exist to produce SWF files on many platforms. The Flash Files specification for version 6 and later is available from Macromedia only as a PDF under a NDA agreement.

Many Shareware companies produced Flash creation tools and sold them for under $50 USD between 2000-2002. In 2003 competition and the emergence of free Flash creation tools, most notably OpenOffice.org, had driven many third party flash creation tool makers out of the market allowing the remaining makers to raise their prices, although many of the products remain under $100 USD and support Actionscript. F4L is also developing such a tool including an interface similar to the Macromedia's.

In November of 2003 Microsoft announced that it was working on competing product, Sparkle, whose release would coincide with that of their next-generation Windows OS codenamed Windows Longhorn. The purchase of Creature House Inc.'s assets in September of 2003 has lead to speculation that their Expression graphics engine would form the basis for the Sparkle product.

File types

  • .fla files are the source files, which contain source material for the flash application. Flash authoring software is used to edit FLA files and compile them into .swf files. FLA is not in any sense an open format; it is proprietary to Macromedia.
  • .as (or sometimes .actionscript) files are simple text files containing ActionScript source code. Actionscript can also be built directly into FLA files, but is often separated into external .as files for structural reasons, or to expose the code to versioning applications, and so on.
  • .swf files are completed, published files that cannot be edited. "swf" is sometimes pronounced "swiff".
  • .flv files are Flash video files, that can be created by Macromedia Flash or Sorenson Squeeze.

Later versions of Flash can also create files in a variety of static or animated formats.

See also: limited animation, Shockwave, Weebl and Bob (Flash cartoon)

Flash players

Creating Flash files

Format documentation

Communities

Art

Security

Games

Flash and e-learning

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