Adobe Flash: Difference between revisions

Adobe Flash
	Adobe Flash 8 Professional
Developer(s)	Adobe Systems
Stable release	8 (9) / September 30, 2005 (June 27th, 2006)
Operating system	Windows (no native Windows XP Professional x64 Edition support) and Mac OS X
Type	Multimedia Content Creator
License	Proprietary
Website	adobe.com

Browse history interactively

← Previous edit Next edit →

Content deleted Content added

VisualWikitext

Inline

Revision as of 16:34, 17 October 2006

Adobe Flash (formerly Macromedia Flash and before that FutureSplash), or simply Flash, refers to both the Adobe Flash Player and to a multimedia authoring program used to create content for the Adobe Engagement Platform (such as web applications, games and movies). The Flash Player, developed and distributed by Adobe Systems (which bought Macromedia), is a client application available in most dominant web browsers. It features support for vector and raster graphics, a scripting language called ActionScript and bidirectional streaming of audio and video.

Strictly speaking, Adobe Flash is an integrated development environment (IDE) while Flash Player is a virtual machine used to run, or parse, the Flash files, but in contemporary colloquial terms "Flash" can refer to the authoring environment, the player or the application files.

Since its introduction in 1996, Flash technology has become a popular method for adding animation and interactivity to web pages; several software products, systems, and devices are able to create or display Flash. Flash is commonly used to: create animation, advertisements, various web-page components, integrate video into web pages, and more recently, develop rich Internet applications such as portals.

The Flash files, traditionally called "flash movies", usually have a .swf file extension and may be an object of a web page or strictly "played" in the standalone Flash Player.

History

In December 1996, Macromedia acquired a vector-based animation software called FutureSplash and later released it as Flash 1.0.
Macromedia Flash 2 was released in 1997 with features such as support of stereo sound and enhanced bitmap integration.
Initially, the Flash Player plug-in was not bundled with popular web browsers and users had to visit Macromedia website to download it, but as of year 2000, the Flash Player was already being distributed with all AOL, Netscape and Internet Explorer browsers. Two years later it shipped with all releases of Windows XP.
Macromedia Generator was the first initiative from Macromedia to separate design from content in Flash files. Generator 2.0 was released in April 2000 and featured real-time server-side generation of Flash content in its Enterprise Edition. Generator was discontinued in 2002 in favor of new technologies such as Flash Remoting, which allows for seamless transmission of data between the server and the client, and ColdFusion Server.
In October 2000, usability guru Jakob Nielsen wrote a polemic article regarding usability of Flash content entitled "Flash 99% Bad". (Macromedia later hired Nielsen to help them improve Flash usability.)
In September 2001, a survey made for Macromedia by Media Metrix showed that out of the 10 biggest web sites in the United States, 7 were making use of Flash content.^{[citation needed]}
On March 15, 2002, Macromedia announced the availability of Macromedia Flash MX and Macromedia Flash Player 6, with support for video, application components, and accessibility.
Flash MX 2004 was released in September 2003, with features such as faster runtime performance up to 8 times with the enhanced compiler and the new Macromedia Flash Player 7, ability to create charts, graphs and additional text effects with the new support for extensions (sold separately), high fidelity import of PDF and Adobe Illustrator 10 files, mobile and device development and a forms-based development environment.
On December 3, 2005, Adobe Systems acquired Macromedia and its product portfolio (including Flash). [1]

Programming language

File:As2 bounceball.png

Creating ActionScript 2.0 in Macromedia Flash MX Professional 2004 for Mac OS X 10.4. The code creates a simple bouncing ball that can be picked up and released.

Initially focused on animation, early versions of Flash content offered few interactivity features and thus had very limited scripting capability.

More recent versions include ActionScript, a scripting language which has syntax similar to JavaScript and so supporting JSON syntax (a variation on ECMA), but a much different programming framework and set of class libraries. ActionScript is used to create almost all of the interactivity (buttons, text entry fields, pick lists) seen in many Flash applications.

New versions of the Flash Player and authoring tool have strived to improve on scripting capabilities. Flash MX 2004 introduced ActionScript 2.0, a scripting programming language more suited to the development of Flash applications. As seen in the image to the right, it's often possible to save a lot of time by scripting something rather than animating it, which usually also retains a higher level of editability.

Of late, the Flash libraries are being used with the XML capabilities of the browser to render rich content in the browser. Since Flash provides more comprehensive support for vector graphics than the browser and because it provides a scripting language geared towards interactive animations, it is being considered a viable addition to the capabilities of a browser. This technology, which is currently in its nascent stage, is known as Asynchronous Flash and XML, much like AJAX, but with possibly greater potential.

Content protection

Many times, Flash authors will decide that while they desire the advantages that Flash affords them in the areas of animation and interactivity, they do not wish to expose their images and/or code to the world. However, once a .swf file is saved locally, it may then quite easily be decompiled into its source code and assets. Some decompilers are capable of nearly full reconstruction of the original source file, down to the actual code that was used during creation.

In opposition to the decompilers, SWF obfuscators have been introduced to provide a modicum of security, some produced by decompiler authors themselves. The higher-quality obfuscators use traps for the decompilers, making some fail, but none have definitively been shown to protect all content.

Competition

Format and plug-in

Compared to other plug-ins such as Java, Acrobat Reader, QuickTime or Windows Media Player, the Flash Player has a small install size and fast initialization time. However, care must be taken to detect and embed the Flash Player in (X)HTML in a W3C compliant way [2].

SMIL is a W3C Recommendation that provides some of the same capabilities as Flash.

The use of vector graphics (like PostScript, SVG and PDF)—especially when combined with program code—allows Flash files to translate to small file sizes which take less bandwidth to transmit than bitmaps or video clips do. In many cases, Flash is a very attractive solution for delivering mixed content. If the content is purely one format (such as text, video or audio), other alternatives may provide better outcome. Also, depending on the type of application or animation created (in particular, transparency or large screen updates as in photographic or text fades) a Flash movie may need more CPU power than alternatives.

In addition to a vector rendering engine, the Flash Player includes a virtual machine called the ActionScript Virtual Machine (AVM) for scripting interactivity at run-time, support for video, MP3-based audio, and bitmap graphics. As of Flash Player 8, it offers two video codecs: On2 VP6 and Sorenson Spark, and run-time support for JPEG, Progressive JPEG, PNG, and GIF. In the next version, Flash is slated to use a Just In Time compiler for the ActionScript engine.

Flash as a format has become very widespread on the desktop market. According to NPD study, 98% of US Web users have the Flash Player installed [3], with 45%-56%[4] (depending on region) having the latest version. Numbers vary depending on the detection scheme and research demographics.

Flash players exist for a wide variety of different systems and devices. Flash content can run consistently on Microsoft Windows and Mac OS (Macromedia has created or licensed players for the following operating systems: Windows, Mac OS 9/X, Solaris, HP-UX, Pocket PC, OS/2, QNX, Symbian, Palm OS, BeOS and IRIX). See also Macromedia Flash Lite for Flash compatibility on other devices. Flash players are used throughout the internet to view games

Many feel that Adobe has completely abandoned the Linux market, having not released a new version of the player for Linux since the 2004 release of Flash Player 7. Increasingly, websites insist on the use of newer players, which weakens Adobe's claim that their Flash Player is "Linux compatible." Linux users seeking to upgrade to Flash Player 8 are instead redirected to a download page for Flash Player 7.

Adobe offers the specifications of the Flash file format (excluding specifications of related formats such as AMF) to developers who agree to a license agreement that permits them to use the specifications only to develop programs that can export to the Flash file format. The license forbids the use of the specifications to create programs that can be used for playback of Flash files.

Since Flash files do not depend on a truly open standard such as SVG, this reduces the incentive for non-commercial software to support the format, although there are several third party tools which use and generate the SWF file format and a large and vibrant open source community. Apparently, the Flash Player cannot ship as part of a pure open source, or completely free operating system, as its distribution is bound to the Macromedia Licensing Program and subject to approval.

Free software alternatives

There is, as of late 2006, no complete free software replacement which offers all the functionality of Adobe Flash. A promising project, Gnash, based on GameSWF is under development and has the support of Free Software Foundation (FSF). Before Gnash, FSF supported the GPLFlash project; however, this did not progress very far. A notable previous attempt is the swfdec software package.

A full end-to-end implementation of the W3C SVG specification would offer close competition for most of the features of Flash in an open, standard way. Adobe used to develop and distribute the 'Adobe SVG Viewer' client plug-in for MS Internet Explorer, but has recently announced its discontinuation^[1]. It has been noted by industry commentators^[2] that this is probably no coincidence at a time when Adobe have moved from competing with Macromedia's Flash, to owning the technology itself. Meanwhile, Firefox's built-in support for SVG continues to grow^[3].

Authoring

In October 1998, Macromedia disclosed the Flash Version 3 Specification to the world on its website. It did this in response to many new and often semi-open formats competing with SWF, such as Xara's Flare and Sharp's Extended Vector Animation formats. Several developers quickly created a C library for producing SWF. February 1999 saw the launch of MorphInk 99, 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 to 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. Macromedia has made the Flash Files specifications for versions 6 and later available only as a PDF under a non-disclosure agreement, but is widely available from various sites.

Many shareware developers produced Flash creation tools and sold them for under $50 USD between 2000 and 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 developers to raise their prices, although many of the products still cost less than $100 USD and support ActionScript. As for open source tools, KToon can edit vectors and generate SWF, but its interface is very different from Macromedia's. Another, more recent example of a Flash creation tool is SWiSH Max made by an ex-employee of Macromedia.

Adobe wrote a software package called Adobe LiveMotion, designed to create interactive animation content and export it to a variety of formats, including SWF. LiveMotion went through two major releases, but failed to gain any notable user base. Adobe cancelled it in 2003. Also more recently, Adobe bought Macromedia Corporation and now owns Flash.

In February 2003, Macromedia purchased Presedia, which had developed a Flash authoring tool that automatically converted PowerPoint Files into Flash. Macromedia subsequently released the new product as Breeze, which included many new enhancements. Since that time, Macromedia has seen competing PowerPoint-to-Flash authoring tools from PointeCast (not to be confused with PointCast) and PresentationPro among others. In addition, (as of version 2) Apple's Keynote presentation software also allows users to create interactive presentations and export to SWF.

In April of 2006, the Macromedia Flash SWF file format specification was released with details on the then newest version format (Flash 8). Although still lacking specific information on the incorporated video compression formats (On2, Sorenson Spark, etc.), this new documentation covers all the new features offered in Flash v8 including new ActionScript commands, expressive filter controls, and so on. The file format specification document is typically obtainable by subscribing to Macromedia's membership system and license restrictions (which include a prohibition against using these specifications to develop a free alternative).

Criticisms

Usage

Due to the increase in the use of Flash in aggressive--and many argue intrusive--online advertising, tools have emerged that restrict Flash content in some or all web sites by temporarily or permanently turning Flash Player off depending on user requirements. Example of such tools are FlashBlock and Adblock for the Mozilla Firefox browser, both of which are commonly used in conjunction with each other to allow users to control what Flash content they see.

Many web sites rely on Flash being available by default on a user's web browser and will not check to see if it is available. If Flash is not used, users may be unable to access some Flash-dependent websites or site features. Tools such as Flashblock do alert the end user to the fact that Flash content is present on the site, allowing the user to view it if they wish.

Using Flash content stores the content of the web page in a binary file and the sections are not static like a webpage. Thus, Flash-based content is not easily suitable for indexing by search engines. However, this problem can be alleviated with correct web design.

Like most new technologies that are easy to learn, Flash has often been misused in a way that lacks customer focus. Flash, particularly in its early days, was used to create unusable and inaccessible sites. In recent years the Flash usage has matured and the quality is much higher.

Local Shared Objects

Flash Players from version 6 can store and retrieve persistent data without offering any visible signs to the user. This behavior enables web designers to create privacy issues similar to those of cookies. It is possible to clear the temporary files that Flash stores on your computer either through the Flash website, or by clearing the files manually. The default storage location for LSOs is operating-system dependent. For Windows XP, the location is within each user's Application Data directory, under Macromedia\Flash Player\#SharedObjects. Additional information is available at the Electronic Privacy Information Center's Local Shared Objects — "Flash Cookies" page.

Application flaws

Specially crafted files have been shown to cause Flash applications to malfunction, by allowing the execution of malevolent code. The Flash Player has a long history of security flaws that expose computers to remote attacks. However, exploitation of these flaws has remained at the proof-of-concept stage and has not escalated into a real-world problem.

In addition to entries in the Open Source Vulnerability Database, security advisories published in August 2002, December 2002, and November 2005 highlight three examples of reports about various Flash Player versions that allowed remote code execution.

Accessibility issues

Internet users who are visually-impaired, and who may rely on a screen reader, braille display or using larger text sizes and/or high-contrast colour schemes may find sites that make extensive use of Flash difficult or impossible to use [5]. While later versions (Flash Player 6 and onwards) support accessibility functions, site designers may not necessarily design the Flash content with these considerations in mind.

Flash Player on various platforms

The Macromedia flash player is mainly optimised for the Windows 32 bit platform. There is a 32 bit version for Mac OS X and an outdated version exists for Linux. Macromedia has been criticized for neglecting to optimize its products on non-Microsoft platforms. This has led to poor web surfing performance on Macintosh and Linux computers, since many websites use Flash animations for menus and advertisements. [6] [7]

Macromedia has rewritten the bitmap drawing routines in Flash Player 8 for Mac, using OpenGL planes via Quartz to draw the surfaces. The new drawing code is reported to be actually faster than its Windows counterpart, where JPEG, TIFF or other bitmap images are composited into the animation.

Flash Player 8 will not be released for Linux but instead Macromedia is planning to release Flash Player 9 for all the three major operating systems, but not necessarily at the same time [8]. The current (March 2006) Flash Player 7 for Linux has poor sound support (The sound may lag about a second behind the picture). Macromedia has not yet released any of their development software for any UNIX-like operating system except Mac OS X.

Although Windows, Linux and Mac have extensive 64 bit support, Macromedia has yet (August 2006) to release a flash player for the x86-64 architecture on any operating system.

"Click to activate and use this control"

As of April 11, 2006 (assuming all relevant patches from Microsoft have been applied), any file embedded using the default object/embed code and viewed in Microsoft Internet Explorer will prompt users to "click to activate and use this control", before it will run. This is due to a patent dispute between the University of California, Eolas and Microsoft [9] that has concluded by finding against Microsoft and awarding damages of $521 million against the company[10].

In an interview with eWeek, Eolas founder Michael Doyle said, "We have from the beginning had a general policy of providing non-commercial users royalty-free licenses ... the open-source community shouldn't have anything to fear from us"[11], so most other browsers should not be forced to follow suit.

The dispute was over the whole concept of embedded, interactive ActiveX controls in IE, using the object and similar HTML elements, which Michael Doyle patented for UC in 1993, then licensed exclusively to a company he founded (Eolas) in 1994[12]. There are potential workarounds for IE users, but implementing them will mean code alterations to countless web pages that currently make use of Flash and other embedded ActiveX applications.

There is a workaround for this issue, essentially using external JavaScript to place the necessary html tags and .swf file into a web document, rather than placing them inline. Adobe has posted instructions for implementing this workaround. [13]

Related file formats and extensions

Flash-specific file formats

Ext.	Explanation
.swf	.swf files are completed, compiled and published files that cannot be edited with Adobe Flash. However, many '.swf decompilers' do exist. Attempting to import .swf files using Flash allows it to retrieve some assets from the .swf, but not all.
.fla	.fla files contain source material for the Flash application. Flash authoring software can edit FLA files and compile them into .swf files. Proprietary to Adobe, the FLA format in no sense counts as "open".
.as	.as files contain ActionScript source code in simple source files. FLA files can also contain Actionscript code directly, but separate external .as files often emerge for structural reasons, or to expose the code to versioning applications. They sometimes use the extension .actionscript
.swd	.swd files are temporary debugging files used during Flash development. Once finished developing a Flash project these files are not needed and can be removed.
.asc	.asc files contain Server-Side ActionScript, which is used to develop efficient and flexible client-server Macromedia Flash Communication Server MX applications.
.flv	.flv files are Flash video files, as created by Adobe Flash, Sorenson Squeeze, or On2 Flix.
.swc	.swc files are used for distributing components; they contain a compiled clip, the component's ActionScript class file, and other files that describe the component.
.jsfl	.jsfl files are used to add functionality in the Flash Authoring environment; they contain Javascript code and access the Flash Javascript API.
.swt	.swt files are 'templatized' forms of .swf files, used by Macromedia Generator
.flp	.flp files are XML files used to reference all the document files contained in a Flash Project. Flash Projects allow the user to group multiple, related files together to assist in Flash project organisation, compilation and build.
.spl	.spl files are FutureSplash documents.
.aso	.aso files are cache files used during Flash development, containing compiled ActionScript byte code. An ASO file is recreated when a change in its corresponding class files is detected. Occasionally the Flash IDE does not recognize that a recompile is necessary, and these cache files must be deleted manually. They are located in %USERPROFILE%\Local Settings\Application Data\Macromedia\Flash8\en\Configuration\Classes\aso on Win32 / Flash8.
.sol	.sol files are Local Shared Object files, these files are the Flash equivalent to browser cookies.

Generic file formats used by Flash

Ext.	Explanation
.avi	AVI file is a video file, standing for Audio Video Interleave. Flash includes some compression codecs, including some from Radius.
.gif	GIF image, can be a single static frame or animated.
.png	.png files are Portable Network Graphics
.jpg	.jpg files are [JPEG] Joint Photographic Expert Group, a popular lossy 24bit image compression format.
.ssk	.ssk files are SmartSketch drawings.
.3ds	Some third-party software converts animated 3D file formats, notably the common 3D Studio Max format, to SWF files as rendered vector animations.

Product history (Authoring Tool)

File:FutureSplash-icon.gif

Future Splash

File:Macromedia Flash 5 and below excluding FutureSplash.jpg

Flash 1-5

File:Macromedia Flash MX 2004.png

Flash MX & MX 2004

File:Macromedia Flash 8 Professional.png

Flash 8

FutureSplash Animator (Spring 10 April 1996) - initial version of Flash with basic editing tools and a timeline
Flash 1 (December 1996) - a Macromedia re-branded version of the FutureSplash Animator
Flash 2 (June 1997) - Released with Flash Player 2, new features included: the object library
Flash 3 (31 May 1998) - Released with Flash Player 3, new features included: the movieclip element, JavaScript plug-in integration, transparency and an external stand alone player
Flash 4 (15 June 1999) - Released with Flash Player 4, new features included: internal variables, an input field, advanced Actionscript, and streaming MP3
Flash 5 (24 August 2000) - Released with Flash Player 5, new features included: ActionScript 1.0 (based on ECMAScript, making it very similar to JavaScript in syntax), XML support, Smartclips (the precursor to components in Flash), HTML text formatting added for dynamic text
Flash MX (ver 6) (15 March 2002) - Released with Flash Player 6, new features included: a video codec (Sorenson Spark), Unicode, v1 UI Components, compression, ActionScript vector drawing API
Flash MX 2004 (ver 7) (9 September 2003) - Released with Flash Player 7, new features included: Actionscript 2.0 (which enabled an object-oriented programming model for Flash), behaviors, extensibility layer (JSAPI), alias text support, timeline effects
Flash MX Professional 2004 (ver 7) (9 September 2003) - Released with Flash Player 7, new features included all Flash MX 2004 features plus: Screens (forms for non-linear state-based development and slides for organizing content in a linear slide format like PowerPoint), web services integration, video import wizard, Media Playback components (which encapsulate a complete MP3 and/or FLV player in a component that may be placed in a SWF), Data components (DataSet, XMLConnector, WebServicesConnector, XUpdateResolver, etc) and data binding APIs, the Project Panel, v2 UI components, and Transition class libraries.
Flash Basic 8 (released on September 13 2005) - A less feature-rich version of the Flash authoring tool targeted at new users who only want to do basic drawing, animation and interactivity. Released with Flash Player 8, this version of the product has very limited support for video and advanced graphical and animation effects.
Flash Professional 8 (released on September 13 2005) - Released with the Flash Player 8, Flash Professional 8 added features focused on expressiveness, quality, video, and mobile authoring. New features included Filters and blend modes, easing control for animation, enhanced stroke properties (caps and joins), object-based drawing mode, run-time bitmap caching, FlashType advanced anti-aliasing for text, On2 VP6 advanced video codec, support for alpha transparency in video, a stand-alone encoder and advanced video importer, cue point support in FLV files, an advanced video playback component, and an interactive mobile device emulator.

Future developments

Adobe Labs (Previously Macromedia labs) is a source for early looks at emerging products and technologies from Adobe-Macromedia, including downloads of the latest software and plugins. Flash 9, Flex 2, and ActionScript 3.0 are discussed.

The code name for the next release of the Flash authoring tool, ver 9.0, is "BLAZE" as explained in this post in Flash Product Manager Mike Downey's weblog. This next release is expected to focus on designer/developer workflow and integration with other Adobe Systems creative suite products. The new version of Flash will be known as Adobe Flash after the recent acquisition of Macromedia.

A project currently in development at Adobe Labs is the Apollo Project which is intended as an application runtime environment for Flash-based applications. While features of Apollo are still being fully defined, the project aims to extend the capabilities of current web-based Flash applications to produce desktop applications. A similar open-source project currently in development is the Screenweaver Project.

External links

[1] ttp://www.adobe.com/svg/eol.html

[2] ttp://www.mail-archive.com/svg-developers@yahoogroups.com/msg10051.html

[3] ttp://svg.org/story/2006/7/13/85643/0175

[1]

[2]

[3]