SWF

SWF (/ˈswɪf/ SWIF)[3] is an Adobe Flash file format used for multimedia, vector graphics and ActionScript.[4] Originating with FutureWave Software, then transferred to Macromedia, and then coming under the control of Adobe, SWF files can contain animations or applets of varying degrees of interactivity and function. They may also occur in programs, commonly browser games, using ActionScript.

For other uses, see SWF (disambiguation).
Small Web Format (SWF)
Filename extension
.swf
Internet media type
application/vnd.adobe.flash-movie
Magic numberCWS,FWS[1] or ZWS[2]
Developed byFutureWave Software,
later taken over by Macromedia and
Adobe Systems
Type of formatVector graphic animation
Container forShockwave Flash, later called Macromedia Shockwave Flash then Adobe Flash.

Programmers can generate SWF files from within several Adobe products, including Flash, Flash Builder (an IDE), Adobe Animate (the replacement for Adobe Flash as of Feb. 2016), and After Effects, as well as through MXMLC, a command-line application compiler which forms part of the freely-available Flex SDK. Although Adobe Illustrator can generate SWF format files through its "export" function, it cannot open or edit them. Other than using Adobe products, one can build SWFs with open-source Motion-Twin ActionScript 2 Compiler (MTASC), the open-source Ming library and the free-software suite SWFTools. Various other third-party programs can also produce files in this format, such as Multimedia Fusion 2, Captivate and SWiSH Max.

The term "SWF" has originated as an abbreviation for ShockWave Flash.[5] This usage was changed to the backronym Small Web Format to eliminate confusion with a different technology, Shockwave, from which SWF derived.[6][7] There is no official resolution to the initialism "SWF" by Adobe.[8]

History

The small company FutureWave Software originally defined the file format with one primary objective: to create small files for displaying entertaining animations.[9] The idea involved a format which player software could run on any system and which would work with slower network connections. FutureWave released FutureSplash Animator in May 1996. In December 1996 Macromedia acquired FutureWave and FutureSplash Animator became Macromedia Flash 1.0.

The original naming of SWF came out of Macromedia's desire to capitalize on the well-known Macromedia Shockwave brand; Macromedia Director produced Shockwave files for the end user, so the files created by their newer Flash product tried to capitalize on the already established brand. As Flash became more popular than Shockwave itself, this branding decision became more of a liability, so the format started to be referred to as simply SWF.[5]

Adobe acquired Macromedia in 2005.[10]

On May 1, 2008, Adobe dropped its licensing restrictions on the SWF format specifications, as part of the Open Screen Project. However, Rob Savoye, a member of the Gnash development team, has pointed to some parts of the Flash format which remain closed.[11] On July 1, 2008, Adobe released code to Google and Yahoo, which allowed their search engines to crawl and index SWF files.[12]

Description

The main graphical primitive in SWF is the path, which is a chain of segments of primitive types, ranging from lines to splines or bezier curves. Additional primitives like rectangles, ellipses, and even text can be built from these. The graphical elements in SWF are thus fairly similar to SVG and MPEG-4 BIFS. SWF also uses display lists and allows naming and reusing previously defined components.[13]

The binary stream format SWF uses is fairly similar to QuickTime atoms, with a tag, length and payload – an organization that makes it very easy for (older) players to skip contents they don't support.[13]

Originally limited to presenting vector-based objects and images in a simple sequential manner, the format in its later versions allows audio (since Flash 3) and video (since Flash 6).

Adobe introduced a new, low-level 3D API in version 11 of the Flash Player. Initially codenamed Molehill, the official name given to this API was ultimately Stage3D. It was intended to be an equivalent of OpenGL or Direct3D.[14]:9 In Stage3D shaders are expressed in a low-level language called Adobe Graphics Assembly Language (AGAL).[14]:57[15]

Adoption

Adobe makes available plugins, such as Adobe Flash Player and Adobe Integrated Runtime, to play SWF files in web browsers on many desktop operating systems, including Microsoft Windows, Mac OS X, and Linux on the x86 architecture and ARM architecture (Google Chrome OS only).

GNU has started developing a free software SWF player called Gnash under the GNU General Public License (GPL). Despite being a declared high-priority GNU project, funding for Gnash was fairly limited.[16] Another player is the LGPL-licensed Swfdec. Lightspark is a continuation of Gnash supporting more recent SWF versions.[16]

Adobe has incorporated SWF playback and authoring in other product and technologies of theirs, including in Adobe Shockwave, which renders more complex documents.[13] SWF can also be embedded in PDF files; these are viewable with Adobe Reader 9 or later.[17] InDesign CS6 can also produce some limited forms of SWF animations directly.[18]

Sony PlayStation Portable consoles can play limited SWF files in Sony's web browser, beginning with firmware version 2.71. Both the Nintendo Wii[19] and the Sony PS3[20] consoles can run SWF files through their Internet browsers.

Scaleform GFx is a commercial alternative SWF player that features full hardware acceleration using the GPU and has high conformance up to Flash 8 and AS2. Scaleform GFx is licensed as a game middleware solution and used by many PC and console 3D games for user interfaces, HUDs, mini games, and video playback.

The newer 3D features of SWF have been seen as an alternative to WebGL, with a spurt of 3D engines like Papervision3D,[21][22][23] Away3D,[21][24][25] Sandy 3D,[21][26] and Alternativa 3D targeting 3D SWF.[27] Although some of these projects started around 2005, until Flash Player 10 however they had no support of GPU acceleration, and even in that version of the Flash Player, shaders could be used for same materials, but vertex information still had to be processed on the CPU (using BSP trees etc.)[27] After version 11 of the Flash Player added the new Stage3D low-level API, some but not all of these projects migrated to the new API. One that did migrate was Away3D, version 4.[28]

Based on an independent study conducted by Millward Brown and published by Adobe, in 2010, over 99% of desktop web browsers in the "mature markets" (defined as United States, Canada, United Kingdom, France, Germany, Japan, Australia, and New Zealand) had a SWF plugin installed, with around 90% having the latest version of the Flash Player.[29]

Published specifications

Adobe makes available a partial specification of SWF,[30] most recently updated in January 2013 to reflect changes in SWF version 19.[31] SWF versions have been decoupled from Flash player versions after Flash 10. Afterwards the version number of the SWF progressed rapidly; SWF version 19 corresponds to the new features added in Flash Player 11.6.[32] Flash Player 14 uses SWF version 25.[33]

In 2008, the specifications document was criticized by Rob Savoye, the lead developer of the Gnash project, as missing "huge amounts" of information needed to completely implement SWF, omitting specifications for RTMP and Sorenson Spark.[11] The RTMP specification[34] was released publicly in June 2009. The Sorenson Spark codec is not Adobe's property.

Licensing

Until May 1, 2008, implementing software that plays SWF was disallowed by the specification's license.[35] On that date, as part of its Open Screen Project, Adobe dropped all such restrictions on the SWF and FLV formats.[36]

Implementing software which creates SWF files has always been permitted, on the condition that the resulting files render "error free in the latest publicly available version of Adobe Flash Player."[37]

Other formats related to SWF authoring in the Adobe tool chain remain without a public specification. One example is FLA, which is the editable version of SWF used by Adobe's Flash, but not by other Adobe tools that can also output SWF, albeit with fewer features.[38]

Extension Explanation
.swf .swf files are completed, compiled and published files that cannot be edited with Adobe Flash. However, several non-Adobe '.swf decompilers' exist (like that of Sothink) to convert SWF back to the FLA format,[39] or to the more recent Apache Flex format.[40] Attempting to import .swf files using Flash allows it to retrieve some assets from the .swf, but not all.[41]
.FXG FXG is a unified xml file format being developed by Adobe for Flex, Flash, Photoshop and other applications.
.fla .fla files contain source material for the Flash application. Flash authoring software can edit FLA files and compile them into .swf files. The Flash source file format is currently a binary file format based on the Microsoft Compound File Format. In Flash Pro CS5, the fla file format is a zip container of an XML-based project structure.
.xfl .xfl files are XML-based project files that are equivalent to the binary .fla format. Flash authoring software uses XFL as an exchange format in Flash CS4. It imports XFL files that are exported from InDesign and AfterEffects. In Flash Pro CS5, the xfl file is a key file which opens the "uncompressed FLA" file, which is a hierarchy of folders containing XML and binary files.
.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.
.mxml .mxml files are used in conjunction with ActionScript files (and .css files), and offer a markup-language-style syntax (like HTML) for designing the GUI in Flex. Each MXML file creates a new class that extends the class of the root tag, and adds the nested tags as children (if they are descendants of UIComponent) or members of the class.
.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.
.abc .abc files contain actionscript bytecode used by the Actionscript Virtual Machine AVM (Flash 8 and prior), and AVM2 (Flash 9 or later).
.amf .amf files containing Action Message commands for transacting with a FMS.
.flv .flv files are Flash video files, as created by Adobe Flash, ffmpeg, Sorenson Squeeze, or On2 Flix. The audio and video data within FLV files are encoded in the same way as they are within SWF files.
.f4v .f4v files are similar to iTunes M4V files which are based on MP4 and can be played back by Flash Player 9 Update 3 and above. F4V file format is second container format for Flash video and it differs from FLV file format. It is based on the ISO base media file format.[42][43]
.f4p .f4p files are an Adobe suffix for media encrypted with the Adobe Access digital rights management scheme which is based on the same protection scheme that their RTMP protocol uses.[43]
.f4a .f4a files are an Adobe suffix for iTunes M4A files that contain only audio streams.[43]
.f4b .f4b files are an Adobe suffix for iTunes M4B audiobook files.[43]
.f4m .f4m files are XML manifest files. Containing base64 FLV onMetaData headers for an Adobe version of bit rate control HTTP Live Streaming.
.f4f .f4f files are MP4 atom-ized fragmented files. Containing FLV packets.
.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 organization, compilation and build.
.spl .spl files are FutureSplash Animator 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 created by Adobe Flash Player to hold Local Shared Objects (data stored on the system running the Flash player).
gollark: Yes, *that's* ridiculous, but sometimes it isn't.
gollark: JS actually is faster than python generally.
gollark: Or you write still less-performant high-level code, which is what you actually need most of the t ime.
gollark: Assembly is obviously better for... I don't know, when you actually need to implement interrupt handlers or something, or when you have a small bit of computing which needs to be run as fast as possible, but most practical stuff is *not* that.
gollark: Actually, it might be better to write it as OpenCL if it parallelizes well enough to run on GPUs.

See also
Adobe Flash
Other
  • OpenLaszlo
  • Personal video recorders – some possibly record and play swf files
  • Vectorian Giotto
  • SWF2EXE Software
  • FutureSplash Animator
  • SWFTools
  • SWiSH Max

References
  1. "SWF File Format Specification Version 10" (PDF). Archived from the original (PDF) on 2012-01-31. Retrieved 2012-02-26.
  2. "SWF File Format Specification Version 19" (PDF). Archived from the original (PDF) on 2013-02-02. Retrieved 2013-02-17.
  3. "Adobe Flash Player Administration Guide for Flash Player 10.1" (PDF). Adobe Systems. 2010-06-10. p. 1. Retrieved 2011-03-10.
  4. Open Screen Project Archived 2014-08-18 at the Wayback Machine
  5. Mark Schaeffer (2007). Adobe Flash CS3 Professional How-Tos: 100 Essential Techniques. Adobe Press. ISBN 978-0-13-270129-7.
  6. "SWF Definition from PC Magazine Encyclopedia". Retrieved 2013-11-02.
  7. Jennifer Niederst (2001). Web Design in a Nutshell: A Desktop Quick Reference (2nd ed.). O'Reilly Media, Inc. p. 438. ISBN 978-0-596-00196-4.
  8. http://blogs.adobe.com/jd1/archives/2007/07/swf-stands-for.html. Retrieved 2016-09-15. Missing or empty |title= (help)
  9. "The History of Flash: The Dawn of Web Animation". Adobe Systems. Archived from the original on 2008-01-25. Retrieved 2008-01-21.
  10. "Adobe Fast Facts | Adobe". www.adobe.com. Retrieved 2018-10-28.
  11. "Free Flash community reacts to Adobe Open Screen Project". Archived from the original on 2008-09-28. Retrieved 2008-11-29.
  12. Streamingmedia.com: Google and Yahoo Roll out Flash Search
  13. C. Concolato and J. C. Dufourd. "Comparison of MPEG-4 BIFS and some other multimedia description languages". Workshop and Exhibition on MPEG-4, WEPM. 2002.
  14. Christer Kaitila (2011). Adobe Flash 11 Stage3D (Molehill) Game Programming Beginner's Guide. Packt Publishing Ltd. ISBN 978-1-84969-169-7.
  15. "What is AGAL - Adobe Developer Connection". www.adobe.com.
  16. Willis, Nathan. "Gnash, Lightspark, and Shumway". LWN.net. Retrieved 13 June 2014.
  17. "WordPress › Error". blogs.adobe.com.
  18. Christopher Smith; AGI Creative Team (2012). Adobe InDesign CS6 Digital Classroom. John Wiley & Sons. p. 391. ISBN 978-0-470-45128-1.
  19. "Wii Internet Channel". Archived from the original on 2008-02-23.
  20. Eric Lempel. "PS3 Firmware (v2.53) Update". Playstation.Blog. Retrieved 2009-03-12.
  21. Cheridan Kerr; Jonathan Keats (2009). The Essential Guide to Flash CS4. Apress. p. 286. ISBN 978-1-4302-2353-5.
  22. Michael Lively (2010). Professional Papervision3D. John Wiley & Sons. ISBN 978-0-470-97060-7.
  23. Paul Tondeur; Jeff Winder (2009). Papervision3d Essentials: Create Interactive Papervision3D Applications with Stunning Effects and Powerful Animals. Packt Publishing Ltd. ISBN 978-1-84719-573-9.
  24. Matthew Casperson (2011). Away3D 3.6 Essentials. Packt Publishing Ltd. ISBN 978-1-84951-207-7.
  25. Michael Ivanov (2011). Away3D 3.6 Cookbook. Packt Publishing Ltd. ISBN 978-1-84951-281-7.
  26. Doug McCune; Deepa Subramaniam (2009). Adobe Flex 3.0 For Dummies. John Wiley & Sons. pp. 388–389. ISBN 978-0-470-40789-9.
  27. Remi Arnaud (2011). "3D in a Web Browser". In Eric Lengyel (ed.). Game Engine Gems 2. CRC Press. pp. 207–212. ISBN 978-1-56881-437-7.
  28. http://www.airtightinteractive.com/2011/10/stage3d-vs-webgl-performance/
  29. "Flash content reaches 99% of Internet viewers". Adobe. Archived from the original on August 27, 2010. Retrieved 2010-09-10.
  30. "SWF and AMF Technology Center - Adobe Developer Connection". www.adobe.com.
  31. http://www.bytearray.org/?p=5162
  32. http://www.bytearray.org/?p=4848
  33. "Flash Player and Adobe AIR feature list - Adobe Developer Connection". www.adobe.com.
  34. "Real-Time Messaging Protocol (RTMP) specification - Adobe Developer Connection". www.adobe.com.
  35. "SWF and FLV File Format Specification License Agreement". Adobe Systems. 2007-06-27. Archived from the original on 2007-12-22. Retrieved 2008-01-05. You may not use the Specification in any way to create or develop a runtime, client, player, executable or other program that reads or renders SWF files.
  36. "Open Screen Project Press Release". Adobe Systems. 2008-05-01. Archived from the original on 2008-05-06. Retrieved 2008-05-01.
  37. "Adobe Player Licensing: Flash Player Developer SDKs". Adobe Systems. Archived from the original on January 15, 2008. Retrieved 2008-01-21.
  38. Richard Harrington; Marcus Geduld (2009). After Effects for Flash, Flash for After Effects: Dynamic Animation and Video with Adobe After Effects CS4 with Adobe Flash CS4 Professional. Adobe Press. p. 32. ISBN 978-0-321-60607-5.
  39. Brimelow, Lee (25 April 2008). "New Video Tutorial on Ethical SWF Decompiling". the Flash Blog. Adobe Systems. Archived from the original on 16 December 2012. Retrieved 28 October 2010.
  40. Shashank Tiwari; Elad Elrom; Charlie Schulze (2010). AdvancED Flex 4. Apress. p. 386. ISBN 978-1-4302-2484-6.
  41. Can a Flash Player movie (SWF) file be edited or imported?. Kb2.adobe.com. Retrieved on 2010-11-09.
  42. Adobe Systems Incorporated (November 2008). "Video File Format Specification, Version 10" (PDF). Adobe Systems Incorporated. Archived from the original (PDF) on 2010-09-23. Retrieved 2009-08-03. Cite journal requires |journal= (help)
  43. "New File Extensions and MIME Types". Kaourantin.net. 2007-10-31. Archived from the original on 2010-07-06. Retrieved 2010-12-04.
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