TITLE:Flash SWF 仕様 - 仕様書 -- http://www.adobe.com/devnet/swf/ --- flash_fileformat_specification.pdf ---- 以下、(自分に)必要な文章だけ抜粋して意訳。 #contents * Instoduction [#intro] - SWF ファイルフォーマットはインターネット上でベクター画像/ビデオ/音声を運ぶもの。 - 運ぶものであって、画像エディターで画像をやり取りするものではない。 - 以下の目標をもってデザインされている - On-screen display -- The format is primarily intended for on-screen display and supports anti-aliasing, fast rendering to a bitmap of any color format, animation, and interactive buttons. - Extensibility -- The format is a tagged format, so it can be evolved with new features while maintaining backward compatibility with earlier versions of Flash Player. - Network delivery -- The format can travel over a network with limited and unpredictable bandwidth. -- The files are compressed to be small and support incremental rendering through streaming. -- The SWF file format is a binary format and is not human readable like HTML. -- The SWF file format uses techniques such as bit-packing and structures with optional fields to minimize file size. - Simplicity -- The format is simple so that Flash Player is small and easily ported. -- Also, Flash Player depends upon a limited set of operating system features only. - File independence -- The files display with minimal dependence on external resources such as fonts. - スケーラビリティ -- The files work well on limited hardware, and can take advantage of better hardware when it is available. -- This ability is important because computers have different monitor resolutions and bit depths. - 速さ -- The graphics described by SWF files render quickly. - スクリプト対応 -- The format includes tags that provide sequences of byte codes to be interpreted by a stack machine. -- The byte codes support the ActionScriptR language. -- Flash Player provides a runtime ActionScript object model that allows interaction with drawing primitives, servers, and features of Flash Player. - SWF files have the extension .swf and a MIME type of application/x-shockwave-flash. - The SWF format has evolved through several versions. - Through SWF 5, substantial additions were made to the SWF tag set. - Starting with SWF 6 and later, the SWF format changes less, as more new features are implemented partly or entirely at the ActionScript level. - Starting with SWF 9, the ActionScript 3.0 language, which employs the new ActionScript Virtual Machine 2 (AVM2) can be used. - Anyone planning to generate SWF file content that uses newer features should become familiar with the ActionScript object model that Flash Player exposes. - Some references for this information are Programming ActionScript 3.0 (see www.adobe.com/go/learn_fl_cs4_programmingAS3_en), ActionScript 3.0 Language Reference (see www.adobe.com/go/learn_flashcs4_langref_en), and the Adobe ActionScript Virtual Machine 2 Overview (PDF file) at www.adobe.com/go/avm2overview. - Adobe seriously considers all feedback to the SWF file format specification. - E-mail any unclear or potentially erroneous information within the specification to Adobe at flashformat@adobe.com. - All such email submissions shall be subject to the Submitted Materials guidelines in the Terms of Use at www.adobe.com/misc/copyright.html. ** What’s new in SWF 10 [#whats-new-swf10] * Basic Data Types [#basic-data-types] ** Coordinates and twips [#cord-twips] - SWF ファイルフォーマットは x-y 座標を(通常、twip と呼ばれる)整数で保存する。 - SWF ファイルフォーマットの twip は論理 pixel の 1/20 である。 - 論理 pixel はスクリーン上で(拡大縮小せずに)100% スケールで再生したときの pixel である。例えば、800 twips x 400 twips の長方形は、40 x 20 の論理 pixel にレンダリングされる。 - 少数点以下の pixel サイズはアンチエイリアシングで近似される。790x390 twips ( 39.5 x 19.5 pixels) は少しぼやけたエッジで表される。 - twips はサイズと精度の良い折衷案である。これによって、極小な座標を処理している間も、ズーミングやオブジェクトの正確な配置に際して、sub-pixel(訳注: 1 pixel 以下)に対する正確さがもたらされる。 - Coordinates in the SWF file format use the traditional graphics axes: x is horizontal and proceeds from minimum values at the left to maximum values at the right, and y is vertical and proceeds from minimum values at the top to maximum values at the bottom. ** Integer types and byte order [#int-byteorder] |