File Formats

File Formats
The table below provides information about a number of the more common file formats you will come across in your use of software in the Lab. It lists a mixture of application specific and more general formats. Application specific formats tend to change as the application that uses them develops -for instance the incorporation of the notion of grouping in versions of ArchiCAD after 5.0 meant that the file format for ArchiCAD plan files had to be modified. The result, of course, is that earlier versions cannot usually read files created with later versions, unless the information is intentionally saved in an earlier variation of the file format, or another format that is common to both versions of the application. As an application develops, it may lose the ability to read formats it used to be conversant with, including ealier versions of its native format. StrataStudio Pro 2.5.x is not able to read files created with StrataVision 2.5, even though there is a kind of evolutionary relationship between the two applications. The general formats that form a kind of family of standard interchange formats (for example AIFF for sound, TIFF for images, DXF for CAD) are also subject to evolutionary changes. However, successive variations normally represent a superset of the previous version -files in earlier formats can be read by applications using the newer format. When moving information between applications it is quite often necessary to find some common format that both applications can read. For instance, you may want to move an image from PhotoShop and use it in ArchiCAD. ArchiCAD cannot read the native PhotoShop file format, but it can read TIFF files. Open your document in PhotoShop, choose "Save as..." under the file menu, and then select TIFF from the list of available file formats. If TIFF is not available then you have probably incorporated information into your PhotoShop file that cannot be expressed in the TIFF format (layers are a good example of this). Try "Save a copy as..." from the file menu, and check the "flatten image" option in this dialogue box. TIFF should now be a valid option. This example demonstrates another point in the interchange of information -native file formats will generally hold more information in them than can be transmitted to other applications. In the example above, PhotoShop features such as layers and filter masks cannot be expressed in the TIFF format, so are lost when the file is saved in a format that ArchiCAD can read.
name	extension	mime type	description
Access database	.mdb	application/vnd.ms-access	The MicroSoft Access native file format -a database containing any combination of tables, queries and forms.
Acrobat or Portable Document Format	.pdf	application/pdf	The Adobe acrobat format allows you to deliver multimedia information electronically so that it is formatted
ArchiCAD Archive	.pla	-	An ArchiCAD project and the associated library (parts) compacted into a single file.
ArchiCAD Project	.pln	-	An ArchiCAD project file. This format has been modifed with each successive major release of ArchiCAD.
ASCII	-	-	Like binary (see below), ASCII is a mode of transport rather than a format. All text/XXXX mime types are transferred over networks using the ASCII transport. This differs from binary in that the way line feeds are handled differs between operating systems, and the data being transferred is all readable text. All serial line and modem transfers between machines used to use the ASCII transport. Many mail packages use encoding methods for attachments that convert attched data to an ASCII format. Examples of this include uuencoding and binhex. Problems can occur when a file that should be transferred as a binary format, is transferred using ASCII. Examples include HTML, DXF (some forms) and RTF.
Audio interchange file format or "AIFF"	.aif .aiff .aifc	audio/aiff	Audio format that stores digital samples or recordings of the original sound -ie. unlike MIDI or some other formats it is not a description of how to make the sound. Audio information can be stored in a number of ways with variations in the sampling rate, the sample size, the number of tracks or channels (generally mono or stereo) and the presence, absence and/or type of compression. If you intend to put audio information onto a CD, you would use the AIFF file format. The audio information would normally be stereo, sampled at 44kHz with 16bit samples...
AutoCAD Drawing file or "DWG file"	.dwg	image/vnd.dwg	The native drawing/model file format for AutoCAD. Almost every release of AutoCAD has seen a modification to this file format.
Binary	-	-	Not a format, rather a mode of information transfer. Binary data transfers across a network without any intermediary translation, etc. Binary compatible formats are formats that behave the same way in different operating systems, or on different hardware platforms. Examples include JPEG, GIF (in fact most image formats) and Acrobat. If the option arises to choose between ASCII or binary, and you are not sure, choose binary!
Binhex	.hqx	text/plain	Binhex is a format used to transfer files between Macintosh systems, or between Macs and other types of hardware and operating systems via the internet, serial connections or over a modem. Files and applications are converted to an ASCII format (ie. the result can be read with a text editor). The resulting file has a readable note explaining that the information following is binhexed, and suggesting what can be done to recover the information contained. Binhex is similar to uuencoding, but differs in that it is able to transfer macbinary information -a peculiarity of the Mac, where applications and some document files are actually made up of two files, a resource fork and a data fork.
CSV (Comma Separated Values)	.csv	text/plain	A table or schedule of information arranged so that records are separated by new lines, and individual fields are separated by commas. This format is often used as a way of moving information between database and/or spreadsheet applications.
Director Movie (Macromedia Director)	.dxr .dir .dcr	application/x-director	Interactive media content. This is similar to, and indeed part of the same family as, shockwave flash.
DXF (Drawing eXchange Format)	.dxf	application/dxf image/vnd.dxf	Text based drawing interchange format, used as a way of moving CAD information between different CAD packages. Like the DWG format, DXF is modified with almost every new release of AutoCAD. As DXF is commonly used as a way of moving information between different CAD packages the version of DXF used is important. Earlier versions wil be compatible with a wider range of software than later variants.
Excel	.xls .xlw	application/excel application/vnd.ms-excel	Microsoft Excel spreadsheet or workbook.
GIF	.gif	image/gif	Indexed colour image format. see http://www.soapplab.auckland.ac.nz/info/formats/gif.htm
HTML (HyperText Markup Language)	.htm .html	text/html	WWW formatting language.
JPEG (Joint Photographic Experts Group)	.jpg .jpeg	image/jpeg	24 bit colour image format. This format is highly compressible (ie. large images can be squeezed into small amounts of memory) which makes it ideal for use on the internet. see http://www.soapplab.auckland.ac.nz/info/formats/jpeg.htm
MicroStation desgn file	.dgn	-	The native drawing/model file format for MicroStation. The format is modified with successive releases of MicroStation.
MIDI	.mid .midi	audio/x-midi	Music format. Essentially a score that is rendered at the time of playback according to the ability of the hardware and software available. Rather than being a recording as is the case of the AIFF format, MIDI uses a machines ability to synthesise sound to generate music. Timing, the number of instruments (or voices) used, the instruments used, and the score itself are stored in the MIDI format. The quality of the sound produced will vary depending on the ability of the hardware used for playback. Where an instrument is requested that the hardware and software cannot produce, another will be substituted.
MPEG (Moving Picture Experts Group)	.mpg .mpeg .mpe	video/mpeg	Video format. There are several variations within the MPEG standard allowing for different qualities of content.
PhotoShop image	.psd	-	Adobe PhotoShop native image format. PhotoShop files will store layers, filter masks, etc.
PICT file	.pict .pct	image/x-pict	An image format native to the Macintosh operating system. PICT can store both raster and object information in a variety and combination of formats including JPEG.
Plot file	.plt	-	HPGL, a list of instructions for a plotter (or printer). This can be binary or ASCII.
Plotmaker drawing	.pmk	-	A drawing saved from PlotMaker or ArchiCAD, ready to be used in PlotMaker.
Postscript	.ps .eps	application/postscript	A hardware independant printer formatting language. An EPS document (encapsulated postscript) is an autonomous chunk of postscript that can be inserted into electronic documents. It can include drawing elements, text, font and style information, as well as image information.
PowerPoint slide show	.ppt	application/powerpoint application/vnd.ms-powerpoint	The native file format for powerpoint.
QuickTime	.mov .moov .qt	video/quicktime	QuickTime is a family of media formats and delivery systems, that includes the ability to express interactive 2 and 3D animation, immersive 3D environments, video content and audio content.
RTF (Rich Text Format)	.rtf	application/rtf text/rtf	A text format that includes formatting information such as font type and size, style, linespacing, margins, pagination, etc. This format is useful for moving information between different word processing applications where formatting is important.
Shockwave Flash	.swf	application/x-shockwave-flash	A format for 2D, animated interactive content. Shockwave flash is the internet deliverable version of Macromedia Flash. It can be used as a way of delivering a whole presentation, or as a component of a larger internet based presentation involving a range of media such as HTML and QuickTime content. Flash provides a simplified version of the features of Macromedia Director.
Studio Max file format	.max	-	The native file format for Studio Max.
Stuffit archive	.sit	application/stuffit	A file that contains compressed or compacted data. The content could be a number of files, or a single large file.
Text	.txt	text/plain	Plain text.
TIFF (Tagged Image File Format)	.tif	image/tiff	An image format. There are a variety of variations possible within the TIFF standard. A TIFF image can be compressed or uncompressed, 32 bit colour, 24 bit colour, indexed colour, greyscale or black and white.
Video for Windows or "AVI"	.avi	video/x-msvideo	Video/animation format.
Ulaw audio file	.au	audio/basic	Audio format that stores digital samples or recordings of the original sound -ie. unlike MIDI or some other formats it is not a description of how to make the sound. Audio information can be stored in a number of ways with variations in the sampling rate, the sample size, the number of tracks or channels (generally mono or stereo) and the presence, absence and/or type of compression.
Wave sound file	.wav	audio/x-wav	Audio format that stores digital samples or recordings of the original sound -ie. unlike MIDI or some other formats it is not a description of how to make the sound. Audio information can be stored in a number of ways with variations in the sampling rate, the sample size, the number of tracks or channels (generally mono or stereo) and the presence, absence and/or type of compression.
Windows Bitmap	.bmp	image/bmp	Windows bitmap image format. This can be indexed colour, or 24 bit colour. This format is generally not compressed, though later versions of windows included an ability to process run length encoded BMP files.
Word file	.doc	application/msword application/word	The word document format. This comes in a variety of variants ranging from DOS versions of word through to the currently used word97/98 format. Later versions of word will generally read files made with earlier versions. The later word versions (say word6.0 and over) can be swapped between versions of word in different operating systems without too much trouble. RTF provides an alternative way of moving information between different word processors.
Zip file	.zip	application/zip	A file that contains compressed or compacted data. The content could be a number of files, or a single large file.
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