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Macromedia Flash SWF File Format, Version 8

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name Macromedia Flash SWF File Format, Version 8
Description

Binary file format that Delivers vector graphics (especially animations) and other data types, including "bitmapped" video, over the Internet to the Flash Player. A more complete format description for Flash is offered for SWF_7, version 7 of the specification.

In 2005, Adobe purchased Macromedia and a branding changeover began. The documentation for the Flash (SWF) format, version 8, was disseminated from the Adobe Web site but still carried the Macromedia brand on the cover sheet.

The October 2005 issue of Macworld magazine reports that the Flash Professional 8 application offers a new video codec called VP6 from a company named On2.

Production phase Used for final-state, end-user delivery.
Relationship to other formats
    Has earlier version Macromedia Flash (SWF) Versions 3, 4, 5, and 6, not documented here.
    Has earlier version SWF_7, Macromedia Flash SWF File Format, Version 7
    Has later version SWF, versions 9, 10. Not yet documented.
    May contain Sorenson encoded video.1
    May contain Screen Video Bitstream Format (ScreenVideo), not documented here.
    May contain Raw PCM sampled audio content, not documented here.
    May contain ADPCM, Adaptive Differential PCM Sound Format
    May contain MP3_ENC, MP3 (MPEG Layer III Audio Encoding)
    May contain Nellymoser Asao (speech compression) audio content, not documented here.
    Used by QuickTime, Quicktime File Format
    Other FLA, Macromedia Flash FLA Project File Format

Local use Explanation of format description terms

LC experience or existing holdings See SWF_7
LC preference See SWF_7

Sustainability factors Explanation of format description terms

Disclosure Fully documented. Developed by Macromedia, Inc., now owned by Adobe Systems.
    Documentation The Macromedia Flash (SWF) and Flash Video (FLV) File Format Specification, Version 8, n.d. (copyright notice 2005). Available online in February 2007, but not in March 2009. Specification for SWF version 9 includes details for versions 6, 7, and 8. Specification for SWF version 10 includes definition of action models for previous SWF versions starting with version 3.
Adoption See SWF_7
    Licensing and patents Adobe offered the specification and the right to build tools to produce SWF files via a free license. The license limited creation of software to play SWF files. However, in May 2008, it removed remaining restrictions on use of the specifications. Former Adobe Open Screen FAQ page not found in 2013 (http://www.openscreenproject.org/about/faq.html).
Transparency Not transparent; proprietary binary format.
Self-documentation See SWF_7.
External dependencies None.
Technical protection considerations None known to the compilers of this document.

Quality and functionality factors Explanation of format description terms

Moving Image
Normal rendering Good support
Clarity (high image resolution) See SWF_7.
Functionality beyond normal rendering See SWF_7.
Sound
Normal rendering Good support
Fidelity (high audio resolution) See SWF_7.
Multiple channels See SWF_7.
Support for user-defined sounds, samples, and patches See SWF_7
Functionality beyond normal rendering See SWF_7.

File type signifiers Explanation of format description terms

Tag Value Note
Filename extension swf
From the Flash SWF Specification (version 7), p. 9. The Wikipedia article on Adobe Flash (consulted February 2007) includes a list of file types (with extensions) associated with the Flash family.
Internet Media Type application/x-shockwave-flash
From the Flash SWF Specification, version 7, p. 9.
Internet Media Type application/x-shockwave-flash2-preview
application/futuresplash
image/vnd.rn-realflash
Selected from The File Extension Source
Magic numbers Hex: 46 57 53
ASCII: FWS
For uncompressed files; from the Flash SWF Specification, version 8, p. 267. The next byte in the file provides the version number; for example, Hex 07 (0x07) for version 7.
Magic numbers Hex: 43 57 53
ASCII: CWS
For compressed files; from the Flash SWF Specification, version 8, p. 267. The next byte in the file provides the version number; for example, Hex 07 (0x07) for version 7.

Notes Explanation of format description terms

General SWF files are typically derived from a FLA file (Macromedia Flash Project File). See also SWF_7.
History See SWF_7.

Format specifications Explanation of format description terms


Useful references

URLs

1Flash documentation for version 8 does not state a number for "their" version of Sorenson but describes the codec as a variant of ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) recommendation H.263 (MPEG-4_V). In early 2006, one of Sorenson's compression applications to produce content for Flash offered the Sorenson_3 codec, described by experts as a variant of ITU-T H.264 (MPEG-4_AVC). By late 2006, Sorenson offered new compression applications with other outputs.


Last Updated: Friday, 08-Nov-2013 16:49:39 EST