Just Solve the File Format Problem - User contributions [en]

VP8

2023-09-16T15:51:15Z

Eiim: Add more infobox data

{{FormatInfo
|formattype=electronic
|subcat=Video
|mimetypes={{mimetype|video/VP8}}
|wikidata={{wikidata|Q1063970}}
|kaitai struct=vp8_ivf
}}
'''VP8''' is a video codec (compressed stream format) developed by Google, as a successor to various earlier-numbered VP formats (originally developed by On2 Technologies, which was acquired by Google). It is used (among other places) in the [[WebM]] container format. It is intended to be able to be used in a free and open manner, with Google pledging free licensing of its related patents. [[VP9]] was later released as a successor to it.

== Links ==
* [[Wikipedia:VP8|Wikipedia article]]
* [http://www.webmproject.org/ The WebM Project]
* [http://www.webmproject.org/code/specs/ VP8 specs, code, etc.]
* [http://x264dev.multimedia.cx/archives/377 Technical analysis of VP8]

[[Category:Google]]

WAV

2023-09-16T15:47:32Z

Eiim: Add Kaitai Struct

{{FormatInfo
|subcat=Audio and Music
|extensions={{ext|wav}}, {{ext|wave}}
|mimetypes={{mimetype|audio/x-wav}}, {{mimetype|audio/vnd.wave}}, {{mimetype|audio/wav}}, {{mimetype|audio/wave}}, {{mimetype|audio/x-pn-wav}}
|locfdd={{LoCFDD|fdd000001}}, {{LoCFDD|fdd000002}}, {{LoCFDD|fdd000356}}, {{LoCFDD|fdd000357}}
|wikidata={{wikidata|Q217570}}
|pronom={{PRONOM|fmt/6}}, {{PRONOM|fmt/141}}, {{PRONOM|fmt/142}}, {{PRONOM|fmt/143}}, others
|released=1991
|kaitai struct=wav
}}
The '''Waveform Audio File Format''' ('''WAV''' or '''WAVE''') is a widely used audio format, originally developed by Microsoft and IBM and based on the [[RIFF]] wrapper format. The usual audio encoding in a .wav file is [[LPCM]], considered an 'uncompressed' encoding. Because of large file sizes, WAV is not well-suited for distributing audio such as songs or podcasts. WAV is used in MS-Windows to store sounds used in applications. It is also used as an archival format for first-generation (master) files, often with a metadata chunk as specified in the Broadcast Wave ([[BWF]]) standard.

== Identification ==
Files begin with bytes {{magic|'R' 'I' 'F' 'F' ?? ?? ?? ?? 'W' 'A' 'V' 'E'}}.

== See also ==
* [[Exif]]
* [[WAV (Applications)]] – List of applications known to use WAV

== Specifications ==
* [http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html Format spec]
* [http://www.textfiles.com/programming/FORMATS/riffform.txt File format info]
* [http://www.textfiles.com/programming/FORMATS/wavformat.pro Another file format info text file]
* [https://msdn.microsoft.com/en-us/library/aa904731%28v=vs.80%29.aspx MSDN: Registered FOURCC Codes and WAVE Formats]
* [http://www.iana.org/assignments/wave-avi-codec-registry/wave-avi-codec-registry.xml WAVE and AVI Codec Registries (Historic Registry)]

== Metaformat files ==
* {{Synalysis|wav}}

== Sample files ==
* https://telparia.com/fileFormatSamples/audio/wav/

== External links ==
* [[Wikipedia: WAV]]
* [http://imgur.com/a/PbN8H#0 WAV101 an audio file walkthrough]
* [http://wiki.dpconline.org/images/4/46/WAV_Assessment_v1.0.pdf Format preservation assessment]

[[Category:Microsoft]]
[[Category:IBM]]
[[Category:Windows]]
[[Category:RIFF based file formats]]

STL

2023-09-16T15:44:31Z

Eiim: Add Kaitai Struct

{{FormatInfo
|formattype=electronic
|subcat=3D and CAD/CAM Models
|extensions={{ext|stl}}
|pronom={{PRONOM|x-fmt/108}}, {{PRONOM|fmt/865}}
|wikidata={{wikidata|Q1238229}}
|locfdd={{LoCFDD|fdd000504}}
|kaitai struct=stl
}}
:''For another "STL" format, see [[STL (ZX Spectrum)]]. There are also some [[Video#Subtitle formats|Subtitle formats]] named STL.''

'''STL''' (StereoLithography) is a CAD/CAM format also used for downloadable object files to be sent to 3-D printers. It is based on the vertex coordinates of triangles, and can be saved in binary or [[ASCII]] form.

== Identification ==

Windows will mis-identify STL files as Certificate Trust Lists, since those use the same extension.

STL files in ASCII form start with "solid" followed by a space and an optional name.

Binary form files have an 80-character header that is generally ignored, but shouldn't start with "solid" so that the file is not mistaken for the ASCII form.

== Specs ==
* [http://www.ennex.com/~fabbers/StL.asp STL format specs]

== Metaformat files ==

* {{Synalysis|stl}}

== Sample files ==
* [http://www.thingiverse.com/ Thingiverse: lots of 3D model downloads]
* [http://www.thingiverse.com/uck/designs Universal Construction Kit downloads]
* [http://www.hovalin.com/ 3D-printable violin]

== Import/export info ==
* [http://www.protocam.com/html/stl.html How to export STL files from various programs]

== Other links ==
* [[Wikipedia:STL (file format)|Wikipedia article]]
* [http://gigaom.com/2013/11/04/free-3d-printing-encryption-tool-for-your-stl-mesh-files/ Free 3D printing encryption tool for your STL mesh files]

MIDI

2023-09-16T15:43:18Z

Eiim: Add Kaitai Struct, Wikidata

{{FormatInfo
|subcat=Audio and Music
|extensions={{ext|mid}}, {{ext|midi}}
|mimetypes={{mimetype|audio/midi}} {{mimetype|audio/mid}} {{mimetype|audio/x-midi}} {{mimetype|audio/m}} {{mimetype|application/x-midi}}
|locfdd={{LoCFDD|fdd000102}} {{LoCFDD|fdd000119}}
|pronom={{PRONOM|x-fmt/230}}
|wikidata={{wikidata|Q80535}}
|kaitai struct=standard_midi_file
}}
'''Musical Instrument Digital Interface''' ('''MIDI''') is an industry specification that permits digital musical instruments, computers and other related devices to connect and communicate with one another. The MIDI Specification was published in August 1983, and is widely used in electronic music.

For many, the name "MIDI" is associated with music synthesized with cheesy, lifeless software instruments from the 90's. There is considerable confusion resulting in the conflation of several things:

* The core MIDI protocol, which is a real-time messaging format that encodes musical events such as note on/note off, velocity, tempo, controls, etc.
* The '''General MIDI''' sub-specification of MIDI, which associates MIDI program numbers with a specific bank of 175 instruments such as oboes, pianos, drums, and so forth.
* The MIDI file format, officially '''SMF''' (Standard MIDI Format), which is simply a score of timed MIDI messages. MIDI files may or may not be intended for interpretation as General MIDI.
* The synthesis methods used to realize MIDI and/or General MIDI as audio, which run the whole spectrum from cheesy to non-cheesy.

Back in the day, high-quality audio files were a bit large to send over the Internet, so nerds would listen to MIDI file renditions instead. Since MIDI itself does not specify how program numbers map to instruments, General MIDI ensures that the Third Eye Blind song you send to your buddy over AOL will not inexplicably have bagpipes in it. Nowadays, MIDI files are used primarily as a storage and interchange format for music producers rather than an consumers. In music production, the synthesizer associated with a given MIDI channel is generally known ''a priori'', so the interopability of General MIDI is less useful. The ghost of bad General MIDI synthesizers nevertheless persists in the public view of MIDI.

"Black MIDI" is a style of MIDI music that has notes so densely placed that a graphical rendition has large patches of solid black.

== Alternative formats ==
As well as the standard MIDI specification, a number of (often proprietary) MIDI clones and variants have been created over the years. These include:

== Sound Fonts ==
Originally created and used by Emu and Creative Labs software and equipment, [[SoundFont_1.0|sound fonts]] are instrument description extensions, or voice files, used, usually, for a cleaner high quality sound. Sound fonts are available from and for: Rolland, Yamaha, Allen Organ, and Wurlitzer, among others.

* [[Compact MIDI]]
* [[GMD]]
* [[HMI]]
* [[HMP]]
* [[HMZ]]
* [[KAR]]
* [[MIDS]]
* [[MIZ]]
* [[MSS (MIDI)|MSS]]
* [[RIFF MIDI]]
* [[Scalable Polyphony MIDI]]
* [[Synthetic Music Application Format]]
* [[Doom MUS]]

== External links ==
* [[Wikipedia:MIDI]]
* [http://localhostr.com/file/LJUEw0K/midiformat.pdf Standard MIDI-File Format Spec. 1.1]
* [http://www.midi.org/techspecs/midispec.php The Complete MIDI 1.0 Detailed Specification] Available for purchase from MMA (MIDI Manufacturers Association)
* [http://www.blitter.com/~russtopia/MIDI/~jglatt/tech/midispec.htm The MIDI Specification] Not the official specification, but an adaptation.
* [http://www.digitalpreservation.gov/formats/fdd/fdd000102.shtml MIDI Sequence Data, from Library of Congress resource on Sustainability of Digital Formats]
* [http://www.digitalpreservation.gov/formats/fdd/fdd000119.shtml Standard MIDI File Format, from Library of Congress resource on Sustainability of Digital Formats]
* [ftp://ftp.modland.com/pub/documents/format_documentation/MIDI%20(General%20MIDI%20Level%201%20Spec)%20(.mid).txt Brief Overview of Proposed General MIDI Level 1 Spec]
* [ftp://ftp.modland.com/pub/documents/format_documentation/MIDI%20(Sample%20Dump%20Standard)%20(.mid).txt MIDI Sample Dump Standard]
* [ftp://ftp.modland.com/pub/documents/format_documentation/MIDI%20(The%20Usenet%20MIDI%20Primer)%20(.mid).txt The USENET MIDI Primer]
* [https://www.techdirt.com/blog/innovation/articles/20130412/09091522689/heres-another-inventor-who-willingly-gave-his-greatest-idea-away-order-to-establish-it-as-global-standard.shtml Inventor of MIDI willingly gave idea away to establish it as a standard]
* [http://rhizome.org/editorial/2013/sep/23/impossible-music-black-midi/ The impossible music of black MIDI]
* [https://www.youtube.com/watch?v=FqjSYtKWyX8 Black MIDI songs will kill your brain and your computer]

Scream Tracker 3 module

2023-09-16T15:41:10Z

Eiim: Add Kaitai Struct, Wikidata

{{FormatInfo
|formattype=electronic
|subcat=Audio and Music
|extensions={{ext|s3m}}
|pronom={{PRONOM|fmt/718}}
|wikidata={{wikidata|Q1461901}}
|kaitai struct=s3m
}}
== Description ==

'''.s3m''' (Scream Tracker 3 Module) files are modules created by Scream Tracker v3.0 and up. It was developed for DOS by Finnish demo group Future Crew.

Scream Tracker 3 modules support up to 100 8-bit samples, 32 channels, 100 patterns and 256 order positions. FM instruments can also be specified, although not all implementations support this feature.

Versions of Scream Tracker prior to v3.0 created [[Scream Tracker 1 & 2 module|STM]] modules.

== Information ==

* [http://hackipedia.org/File%20formats/Music/Sample%20based/html/s3mformat.html S3M Specifications]
* [http://wiki.multimedia.cx/index.php?title=Scream_Tracker_3_Module MultimediaWiki - Scream Tracker 3 Module]
* [http://hackipedia.org/File%20formats/Music/Sample%20based/text/Scream%20Tracker%203.01%20BETA%20File%20Formats%20And%20Mixing%20Info.ascii.txt.utf-8.txt ScreamTracker 3.01 BETA File Formats and Mixing Info]
* [http://hackipedia.org/File%20formats/Music/Sample%20based/text/Scream%20Tracker%203.20%20file%20format.cp437.txt.utf-8.txt Scream Tracker 3.20 File Formats And Mixing Info]
* [http://www.textfiles.com/programming/FORMATS/s3m-form.txt Another copy of this file]
* [http://www.textfiles.com/programming/FORMATS/stracker.pro Still another version]
* [http://16-bits.org/s3m/ The above, with some additional notes / corrections]
* [ftp://ftp.modland.com/pub/documents/format_documentation/FireLight%20S3M%20Player%20Tutorial.txt S3M Player Tutorial by FireLight] - step-by-step guide to writing an S3M player. The [ftp://ftp.modland.com/pub/documents/format_documentation/FireLight%20MOD%20Player%20Tutorial.txt MOD Player Tutorial] should be read prior to this.
* [http://www.textfiles.com/programming/FORMATS/admusfmt.pro 1994 discussion of "advanced music formats" that covers Scream Tracker 3.0]

== Software ==

=== Scream Tracker ===
* [ftp://ftp.modland.com/pub/software/trackers/DOS/Scream%20Tracker%203/ ScreamTracker v3.01 beta, v3.03 beta, v3.20 and v3.21]
* [http://www.scene.org/file.php?file=%2Fdemos%2Fgroups%2Ffuture_crew%2Fother%2Fscrmt321.zip&fileinfo Scream Tracker v3.21]

=== Playback ===
* [http://mikmod.shlomifish.org/ MikMod] - Linux
* [http://xmp.sourceforge.net/ Extended Module Player]
* [https://zxtune.bitbucket.io/ zxtune]

=== Other ===
* [http://www.modplug.com/trackerinfo.html MODPlug Tracker] allows you to compose and convert in a number of module formats, including S3M

== Sample files ==
* https://telparia.com/fileFormatSamples/music/s3m/
* [ftp://ftp.modland.com/pub/modules/Screamtracker%203/ Example .s3m files]

== See Also ==

* [[Scream Tracker 1 & 2 module]]

QuickTime

2023-09-16T15:40:09Z

Eiim: Add Kaitai Struct

{{FormatInfo
|formattype=electronic
|subcat=Video
|extensions={{ext|mov}}
|mimetypes={{mimetype|video/quicktime}}
|pronom={{PRONOM|x-fmt/384}}
|wikidata={{wikidata|Q942350}}
|kaitai struct=quicktime_mov
}}
:''"MOV" redirects here. For another MOV format, see [[Electronic Arts MOV]]. For movie formats in general, see [[Video]].''

'''QuickTime''' is a container format developed by Apple Computer, Inc. It is usually used to wrap video content, but can also be used to wrap sound and still image data.

The QuickTime format was used as the basis for the international standard [[MPEG-4]] format.

A now-deprecated related format for still images taken from a QuickTime video is [[QTIF]].

==History==

QuickTime was originally released in 1991 following years of internal development.
QuickTime exists in 7 minor format releases from 1991 (1.x) through 2016 (7.x).
A major upgrade to the platform occurred in 2009 with QuickTime X.
The current version of classic QuickTime is 7.7.9 as of 2016.
QuickTime X is At version 10.5

== Format ==
See [[boxes/atoms format]]. Starting in 2004, the QuickTime movie file specification has been based on [[ISO Base Media File Format]], with a brand of "<code>qt  </code>".

== Quicktime VR ==
In the past, the Quicktime format has been used as a container for so called Virtual Reality (or rather, 360 degree panorama) data. Not clear how to identify. File extensions usually just .mov, but may be .qt or more specifically .qvr (possibly .qtvr?).

* [http://www.mactech.com/articles/mactech/Vol.12/12.05/QTVRTutorial/index.html Getting started with QuickTime VR] - tutorial from February, 1996.]
** Mentions "creator/file type of the downloaded movie to QuickTime VR’s 'vrod'/'MooV'", which may be the type?
** ffprobe shows "Stream #0:1(eng): Data: none (pano / 0x6F6E6170), 0 kb/s", so I presume 'pano' is the ftyp/FourCC?
** "The media type of the panorama track is 'pano'." from Quicktime file format specification, page 289.
* [http://www.synthetic-ap.com/qtvr/qtvrsamp.html Example Quicktime VR files]

== Specifications ==

* [https://developer.apple.com/standards/classic-quicktime/ QuickTime File Format Specification (classic, 2001)]
* [https://developer.apple.com/library/content/documentation/QuickTime/QTFF/ QuickTime File Format Specification (current version)]

== Metaformat files ==

* {{Synalysis|qt}}

== Software ==
* [[Konvertor]]
* [http://archive.org/download/PowerPlay0597/PowerPlay0597.iso01.iso/TOOLS/Qtime/QT32INST.EXE QuickTime 2.1.2 for Windows (c. 1997)]
* [http://www.apple.com/quicktime/download/ Current QuickTime download]
* [[FFmpeg]]

== Sample files ==
* [http://support.apple.com/kb/HT1425 Apple's sample QuickTime files in several encodings]
* https://telparia.com/fileFormatSamples/video/mov/
* http://samples.mplayerhq.hu/mov/

== See also ==
* [[Boxes/atoms format]]
* [[ISO Base Media File Format]]
* [[MPEG-4]]
* [[PICT]]
* [[QTIF]]
* [[QuickTime Animation]]

== Links and references ==

* [http://www.apple.com/quicktime/ Official site]
* [[Wikipedia:QuickTime|QuickTime : Wikipedia]]
* {{EGFF|quicktime|QuickTime File Format Summary}}, from the [[Encyclopedia of Graphics File Formats]]
* [http://scarygoround.com/index.php?date=20110408 Even comic-strip people can have trouble getting those things to play...]

[[Category:Apple]]
[[Category:Box file format]]

Ogg

2023-09-16T15:39:34Z

Eiim: Add Kaitai Struct

{{FormatInfo
|subcat=Audio and Music
|extensions={{ext|ogg}}, {{ext|ogx}}, {{ext|ogv}}, {{ext|oga}}, {{ext|spx}}, {{ext|ogm}}, {{ext|opus}}
|mimetypes={{mimetype|application/ogg}}, {{mimetype|audio/ogg}}, {{mimetype|video/ogg}}
|locfdd={{LoCFDD|fdd000026}}
|pronom={{PRONOM|fmt/944}}
|kaitai struct=ogg
|released=1993
}}
'''Ogg''' is a multimedia container format, most commonly used with [[Vorbis]] and other codecs developed by the Xiph.Org Foundation.

Although the initial specification and IANA registration called for the .ogg extension and application/ogg MIME type, regardless of the type of media in the container, the September 2008 RFC 5334 changed that recommendation and registered audio/ogg and video/ogg MIME types with corresponding .oga and .ogv extensions for content that is primarily audio or video respectively. The .ogx extension was introduced for use with content that incorporated the [[Ogg Skeleton]] and for which application/ogg remained appropriate. The .ogg extension was grandfathered to refer to Ogg audio with a Vorbis audio encoding. The .spx extension should be used for an Ogg audio file using the [[Speex]] codec.

Because Ogg formats are free and open-source, not proprietary as many other formats are, they are preferred by many "free-media" projects including Wikipedia, but this causes some issues for people attempting to view/listen to them, since some devices (e.g., Apple's iOS devices) don't support the Ogg formats, and others (e.g., Windows PCs) don't have "out-of-the-box" support until you install codecs, plug-ins, or software for it. Some of the proprietary formats have wider support in consumer devices in their default configurations.

== Related formats ==
* [[Ogg Skeleton]]
* [[OGM]]

==Streams that can be placed in Ogg==
* Audio
** [[Speex]]
** [[Vorbis]]
** [[FLAC]]
* Video
** [[Dirac]]
** [[Theora]]
* Other
** [[Kate]]

== Identification ==
Ogg files start with the magic number "{{magic|OggS}}".

In rare cases, this signature may be preceded by an ID3v2 segment; see [[ID3#Identification]].

== Specifications ==
* [https://www.xiph.org/ogg/doc/ Ogg documentation from xiph.org]
* [https://wiki.xiph.org/MIMETypesCodecs MIMETypesCodecs] - MIME types and codec identifiers
* RFC 3533: The Ogg Encapsulation Format Version 0
* RFC 5334: Ogg Media types. Redefines application/ogg and registers video/ogg and audio/ogg.

== Software ==
* [[Konvertor]]
* [http://www.xiph.org/dshow/ Windows Media Player codecs for some Ogg formats]
* [http://xiph.org/quicktime/ Ogg QuickTime components (OSX, Windows)]
* [http://www.mirovideoconverter.com/ Miro Video Converter] (watch out for attempts to install annoying toolbars in installer, as is regretfully common these days)

== Utilities ==
* [http://www.oggconvert.com/ Online audio format converter]

== Links ==
* [https://wiki.xiph.org/Ogg xiph.org wiki page for Ogg]
* [[Wikipedia: Ogg]]
* [http://hardwarebug.org/2010/03/03/ogg-objections/ Ogg objections] and [https://people.xiph.org/~xiphmont/lj-pseudocut/o-response-1.html Chris Montgomery's response]

[[Category:Video]]
[[Category:Metaformats]]

ID3

2023-09-16T15:36:47Z

Eiim: Missed one

{{FormatInfo
|formattype=electronic
|subcat=Metadata
|extensions={{ext|mp3}}, others
|locfdd={{LoCFDD|fdd000106}}, {{LoCFDD|fdd000107}}, {{LoCFDD|fdd000108}}
|released=1996
|kaitai struct=id3v1_1
|wikidata={{wikidata|Q1054220}}
}}
'''ID3''', or '''ID3 tag''', is a metadata format, mainly used in [[MP3]] audio files. It stores information such as the song title, artist, and album.

Although designed for use with (and named after) MP3, ID3 is sometimes used with other audio formats. This can be done in two fundamental ways:
* Embedding the ID3 data inside the file, in a manner appropriate for that audio format. For example, [https://samples.libav.org/asf-wmv/wma_with_cover_art/wma_with_ID3_APIC.wma here] is a [[WMA]] file containing ID3 data.
* Prepending and/or appending the ID3 data to the file, MP3-style. This practice is not necessarily approved by any standard, but it has been done, for example with [[Ogg]] and [[FLAC]]. Here, the tail is wagging the dog, and ID3 can be thought of as a container format for an arbitrary audio format.

== Format details ==
There are two major versions. ID3v1 defines a fixed-length data block that is always placed at the end of the file. ID3v2, which has very little in common with ID3v1, defines a block with variable-length frames and allows more flexibility and verbosity. ID3v2 data usually appears at the beginning of the file. It is possible, and common, for a file to have both ID3v1 and ID3v2 metadata.

As of 2017, there are three versions of ID3v2 to be aware of: v2.2.x, v2.3.x, and v2.4.x. These formats have some critical differences, and are definitely ''not'' compatible with each other.

== Identification ==
For an MP3 file with an ID3v1 tag, ASCII "{{magic|TAG}}" appears beginning 128 bytes from the end of the file.

An MP3 file with an ID3v2 tag usually begins with ASCII "{{magic|ID3}}".

Alternatively, the signature "{{magic|3DI}}" could appear 10 bytes from the ''end'' of the file, or 138 bytes from the end of the file if there is also an ID3v1 tag. This is much less likely.

There are other (rare) ways to use ID3v2, not covered by the above identification logic.

=== How to skip past an ID3v2 segment ===
To identify an audio file's format, it is best to skip past any ID3v2 segment at the beginning of the file before looking for a magic signature, and not just assume that ID3 implies MP3. Unfortunately, doing so is not trivial. Here is an attempt to summarize the algorithm:
* Let OFFSET = 0.
* Read and remember the first 10 bytes of the file.
* If bytes 0-2 are not ASCII "ID3", stop. An ID3v2 segment is not present.
* Let OFFSET = 10 (for the 10-byte header).
* Decode bytes 6-9 as a 32-bit "synchsafe int" (refer to any ID3v2 spec). Let OFFSET = OFFSET + this decoded int.
* If the 0x10 bit of byte 5 is set, let OFFSET = OFFSET + 10 (for the footer).
OFFSET is now the file offset of the payload audio data.

== Specifications ==
* [http://id3.org/Developer%20Information ID3.org Developer Information]
** [http://id3.org/ID3v1 ID3v1]
** [http://id3.org/id3v2-00 ID3v2.2.0]
** ID3v2.3.0: [http://id3.org/d3v2.3.0 Plain text] · [http://id3.org/id3v2.3.0 HTML]
** ID3v2.4.0: [http://id3.org/id3v2.4.0-structure Main Structure] · [http://id3.org/id3v2.4.0-frames Native Frames]
* [http://id3lib.sourceforge.net/id3/id3v2-00.txt ID3 tag version 2] (Another copy of v2.2.0)
* [http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm#MPEGTAG MPEG Audio Tag ID3v1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v1 Hydrogenaudio Knowledgebase: ID3v1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v1.1 Hydrogenaudio Knowledgebase: ID3v1.1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v2 Hydrogenaudio Knowledgebase: ID3v2]
* [https://formats.kaitai.io/id3v1_1/ Kaitai Struct: ID3v1.1]
* [https://formats.kaitai.io/id3v2_3/ Kaitai Struct: ID3v2.3]
* [https://formats.kaitai.io/id3v2_4/ Kaitai Struct: ID3.2.4]

== Software ==
* [http://id3lib.sourceforge.net/ id3lib]
* [http://taglib.github.com/ TagLib]
* [https://www.logipole.com/metadata++-en.htm Metadata++]

''[Ed. note: There are many utilities that can read and write ID3 tags, including Windows Explorer to some extent. We suggest searching the web.]''

== Resources ==
* [http://id3.org/ ID3.org]
* [[Wikipedia:ID3|Wikipedia article]]
* [http://www.codinghorror.com/blog/2006/08/a-spec-tacular-failure.html Coding Horror: A Spec-tacular Failure]
* [https://underjord.io/id3-specification-and-speculation.html What ID3v2 could have been]

[[Category:Audio and Music]]

ID3

2023-09-16T15:36:01Z

Eiim: Add Kaitai Struct links under specifications

{{FormatInfo
|formattype=electronic
|subcat=Metadata
|extensions={{ext|mp3}}, others
|locfdd={{LoCFDD|fdd000106}}, {{LoCFDD|fdd000107}}, {{LoCFDD|fdd000108}}
|released=1996
|kaitai struct=id3v1_1
|wikidata={{wikidata|Q1054220}}
}}
'''ID3''', or '''ID3 tag''', is a metadata format, mainly used in [[MP3]] audio files. It stores information such as the song title, artist, and album.

Although designed for use with (and named after) MP3, ID3 is sometimes used with other audio formats. This can be done in two fundamental ways:
* Embedding the ID3 data inside the file, in a manner appropriate for that audio format. For example, [https://samples.libav.org/asf-wmv/wma_with_cover_art/wma_with_ID3_APIC.wma here] is a [[WMA]] file containing ID3 data.
* Prepending and/or appending the ID3 data to the file, MP3-style. This practice is not necessarily approved by any standard, but it has been done, for example with [[Ogg]] and [[FLAC]]. Here, the tail is wagging the dog, and ID3 can be thought of as a container format for an arbitrary audio format.

== Format details ==
There are two major versions. ID3v1 defines a fixed-length data block that is always placed at the end of the file. ID3v2, which has very little in common with ID3v1, defines a block with variable-length frames and allows more flexibility and verbosity. ID3v2 data usually appears at the beginning of the file. It is possible, and common, for a file to have both ID3v1 and ID3v2 metadata.

As of 2017, there are three versions of ID3v2 to be aware of: v2.2.x, v2.3.x, and v2.4.x. These formats have some critical differences, and are definitely ''not'' compatible with each other.

== Identification ==
For an MP3 file with an ID3v1 tag, ASCII "{{magic|TAG}}" appears beginning 128 bytes from the end of the file.

An MP3 file with an ID3v2 tag usually begins with ASCII "{{magic|ID3}}".

Alternatively, the signature "{{magic|3DI}}" could appear 10 bytes from the ''end'' of the file, or 138 bytes from the end of the file if there is also an ID3v1 tag. This is much less likely.

There are other (rare) ways to use ID3v2, not covered by the above identification logic.

=== How to skip past an ID3v2 segment ===
To identify an audio file's format, it is best to skip past any ID3v2 segment at the beginning of the file before looking for a magic signature, and not just assume that ID3 implies MP3. Unfortunately, doing so is not trivial. Here is an attempt to summarize the algorithm:
* Let OFFSET = 0.
* Read and remember the first 10 bytes of the file.
* If bytes 0-2 are not ASCII "ID3", stop. An ID3v2 segment is not present.
* Let OFFSET = 10 (for the 10-byte header).
* Decode bytes 6-9 as a 32-bit "synchsafe int" (refer to any ID3v2 spec). Let OFFSET = OFFSET + this decoded int.
* If the 0x10 bit of byte 5 is set, let OFFSET = OFFSET + 10 (for the footer).
OFFSET is now the file offset of the payload audio data.

== Specifications ==
* [http://id3.org/Developer%20Information ID3.org Developer Information]
** [http://id3.org/ID3v1 ID3v1]
** [http://id3.org/id3v2-00 ID3v2.2.0]
** ID3v2.3.0: [http://id3.org/d3v2.3.0 Plain text] · [http://id3.org/id3v2.3.0 HTML]
** ID3v2.4.0: [http://id3.org/id3v2.4.0-structure Main Structure] · [http://id3.org/id3v2.4.0-frames Native Frames]
* [http://id3lib.sourceforge.net/id3/id3v2-00.txt ID3 tag version 2] (Another copy of v2.2.0)
* [http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm#MPEGTAG MPEG Audio Tag ID3v1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v1 Hydrogenaudio Knowledgebase: ID3v1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v1.1 Hydrogenaudio Knowledgebase: ID3v1.1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v2 Hydrogenaudio Knowledgebase: ID3v2]
* [https://formats.kaitai.io/id3v1_1/ Kaitai Struct: ID3v1.1]
* [https://formats.kaitai.io/id3v2_3/ Kaitai Struct: ID3v2.3]

== Software ==
* [http://id3lib.sourceforge.net/ id3lib]
* [http://taglib.github.com/ TagLib]
* [https://www.logipole.com/metadata++-en.htm Metadata++]

''[Ed. note: There are many utilities that can read and write ID3 tags, including Windows Explorer to some extent. We suggest searching the web.]''

== Resources ==
* [http://id3.org/ ID3.org]
* [[Wikipedia:ID3|Wikipedia article]]
* [http://www.codinghorror.com/blog/2006/08/a-spec-tacular-failure.html Coding Horror: A Spec-tacular Failure]
* [https://underjord.io/id3-specification-and-speculation.html What ID3v2 could have been]

[[Category:Audio and Music]]

ID3

2023-09-16T15:33:48Z

Eiim: Add Kaitai Struct, Wikidata

{{FormatInfo
|formattype=electronic
|subcat=Metadata
|extensions={{ext|mp3}}, others
|locfdd={{LoCFDD|fdd000106}}, {{LoCFDD|fdd000107}}, {{LoCFDD|fdd000108}}
|released=1996
|kaitai struct=id3v1_1
|wikidata={{wikidata|Q1054220}}
}}
'''ID3''', or '''ID3 tag''', is a metadata format, mainly used in [[MP3]] audio files. It stores information such as the song title, artist, and album.

Although designed for use with (and named after) MP3, ID3 is sometimes used with other audio formats. This can be done in two fundamental ways:
* Embedding the ID3 data inside the file, in a manner appropriate for that audio format. For example, [https://samples.libav.org/asf-wmv/wma_with_cover_art/wma_with_ID3_APIC.wma here] is a [[WMA]] file containing ID3 data.
* Prepending and/or appending the ID3 data to the file, MP3-style. This practice is not necessarily approved by any standard, but it has been done, for example with [[Ogg]] and [[FLAC]]. Here, the tail is wagging the dog, and ID3 can be thought of as a container format for an arbitrary audio format.

== Format details ==
There are two major versions. ID3v1 defines a fixed-length data block that is always placed at the end of the file. ID3v2, which has very little in common with ID3v1, defines a block with variable-length frames and allows more flexibility and verbosity. ID3v2 data usually appears at the beginning of the file. It is possible, and common, for a file to have both ID3v1 and ID3v2 metadata.

As of 2017, there are three versions of ID3v2 to be aware of: v2.2.x, v2.3.x, and v2.4.x. These formats have some critical differences, and are definitely ''not'' compatible with each other.

== Identification ==
For an MP3 file with an ID3v1 tag, ASCII "{{magic|TAG}}" appears beginning 128 bytes from the end of the file.

An MP3 file with an ID3v2 tag usually begins with ASCII "{{magic|ID3}}".

Alternatively, the signature "{{magic|3DI}}" could appear 10 bytes from the ''end'' of the file, or 138 bytes from the end of the file if there is also an ID3v1 tag. This is much less likely.

There are other (rare) ways to use ID3v2, not covered by the above identification logic.

=== How to skip past an ID3v2 segment ===
To identify an audio file's format, it is best to skip past any ID3v2 segment at the beginning of the file before looking for a magic signature, and not just assume that ID3 implies MP3. Unfortunately, doing so is not trivial. Here is an attempt to summarize the algorithm:
* Let OFFSET = 0.
* Read and remember the first 10 bytes of the file.
* If bytes 0-2 are not ASCII "ID3", stop. An ID3v2 segment is not present.
* Let OFFSET = 10 (for the 10-byte header).
* Decode bytes 6-9 as a 32-bit "synchsafe int" (refer to any ID3v2 spec). Let OFFSET = OFFSET + this decoded int.
* If the 0x10 bit of byte 5 is set, let OFFSET = OFFSET + 10 (for the footer).
OFFSET is now the file offset of the payload audio data.

== Specifications ==
* [http://id3.org/Developer%20Information ID3.org Developer Information]
** [http://id3.org/ID3v1 ID3v1]
** [http://id3.org/id3v2-00 ID3v2.2.0]
** ID3v2.3.0: [http://id3.org/d3v2.3.0 Plain text] · [http://id3.org/id3v2.3.0 HTML]
** ID3v2.4.0: [http://id3.org/id3v2.4.0-structure Main Structure] · [http://id3.org/id3v2.4.0-frames Native Frames]
* [http://id3lib.sourceforge.net/id3/id3v2-00.txt ID3 tag version 2] (Another copy of v2.2.0)
* [http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm#MPEGTAG MPEG Audio Tag ID3v1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v1 Hydrogenaudio Knowledgebase: ID3v1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v1.1 Hydrogenaudio Knowledgebase: ID3v1.1]
* [http://wiki.hydrogenaud.io/index.php?title=ID3v2 Hydrogenaudio Knowledgebase: ID3v2]

== Software ==
* [http://id3lib.sourceforge.net/ id3lib]
* [http://taglib.github.com/ TagLib]
* [https://www.logipole.com/metadata++-en.htm Metadata++]

''[Ed. note: There are many utilities that can read and write ID3 tags, including Windows Explorer to some extent. We suggest searching the web.]''

== Resources ==
* [http://id3.org/ ID3.org]
* [[Wikipedia:ID3|Wikipedia article]]
* [http://www.codinghorror.com/blog/2006/08/a-spec-tacular-failure.html Coding Horror: A Spec-tacular Failure]
* [https://underjord.io/id3-specification-and-speculation.html What ID3v2 could have been]

[[Category:Audio and Music]]

Extended Module

2023-09-16T15:31:28Z

Eiim: Add Kaitai Struct, Wikidata

{{FormatInfo
|formattype=electronic
|subcat=Audio and Music
|extensions={{ext|xm}}
|pronom={{PRONOM|fmt/323}}
|kaitai struct=fasttracker_xm_module
|wikidata={{wikidata|Q376852}}
}}

:''Not to be confused with the Sirius XM satellite radio service, with which it has nothing to do.''

'''XM''' (extended module) is an audio format introduced by (and primarily produced by) FastTracker 2, a now defunct tracker for [[MS-DOS]]. The format is also used by other trackers, such as [[DigiTracker]] and [[MilkyTracker]].

== Information ==

The tracker which produced the file can be identified by means of the 20-byte string at offset 38 (0x26):

{| class="wikitable" style="text-align:center; width:200px; height:200px;"
|+ Tracker / Identifying string
|-
!
! String
|-
! DigiTracker
| Composer's name
|-
! FastTracker 2
| "FastTracker II"
|-
! OpenMPT
| "OpenMPT " and then the version number
|-
! AmigaMML
| By default, "AmigaMML " and the version number; can be changed
|-
! MilkyTracker
| "MilkyTracker " (with 8 padding spaces)
|}

* [https://pastebin.com/F5S0Nbn9 Original file format documentation by Mr.H of Triton (1994), included with the FT2 distribution as "Xm.txt"]
* [http://16-bits.org/xm/ The above, with a number of corrections and additions] (link seems to be dead?)
* [https://ftp.modland.com/pub/documents/format_documentation/FastTracker%202%20(.xm)%20%232.txt Errors in the XM format documentation]
* [https://ftp.modland.com/pub/documents/format_documentation/FastTracker%202%20v2.04%20%28.xm%29.html Mr.H documentation with corrections by Guru and Alfred of Sahara Surfers (1995)] ([https://pastebin.com/FP8XXgVu pastebin mirror])
* [http://zzo38computer.org/textfile/music/xm-form.txt Further corrected version of the above] ([https://pastebin.com/pEi8Ehzd pastebin mirror])
* [http://jss.sourceforge.net/moddoc/xm-form.txt A more complete file format documentation, by ccr@tnsp (2001)] ([https://pastebin.com/rFWAhEEr pastebin mirror])
* [https://www.celersms.com/doc/XM_file_format.pdf "The Unofficial XM File Format Specification"], ''Vladimir Kameñar'', 2007

== Software ==

* [https://ftp.modland.com/pub/software/trackers/DOS/FastTracker%202/ FastTracker 2]
* [https://archive.org/details/msdos_Fast_Tracker_2_1994 FastTracker 2 in-browser emulation]
* [http://xmp.sourceforge.net/ Extended Module Player]
* [http://zzo38computer.org/prog/amigamml.zip AmigaMML]
* [https://ufmod.sourceforge.io/ uFMOD]
* [https://zxtune.bitbucket.io/ zxtune]

== Sample files ==
* https://telparia.com/fileFormatSamples/music/xm/
* [ftp://ftp.modland.com/pub/modules/Fasttracker%202/ Example .xm files]

== Links ==
* [http://www.textfiles.com/programming/FORMATS/xmformat.mus Format info]

Creative Voice File

2023-09-16T15:11:36Z

Eiim: Add Kaitai Struct

{{FormatInfo
|formattype=electronic
|subcat=Audio and Music
|mimetypes={{mimetype|audio/x-voc}}
|extensions={{ext|voc}}
|wikidata={{wikidata|Q27967410}}
|pronom={{PRONOM|fmt/1736}}
|kaitai struct=creative_voice_file
}}

== Format Information ==

* [ftp://ftp.modland.com/pub/documents/format_documentation/Creative%20Voice%20File%20(.voc)%20%232.txt Creative Voice File (VOC) Format]
* [http://www.textfiles.com/programming/FORMATS/vocform.pro Greg figures out most of the .VOC Format]
* [http://www.textfiles.com/programming/FORMATS/vocform2.pro John chimes in with further analysis of the .VOC Format]
* [https://raw.githubusercontent.com/kaitai-io/kaitai_struct_formats/master/media/creative_voice_file.ksy KaiTai structure format]

==Format Details==
VOC files begin with the ascii {{magic|Creative Voice File}}

== Software ==
* [http://sox.sourceforge.net/ SoX]

== Sample files ==
* http://cd.textfiles.com/animfestival/AUDIO/VOC/
* http://cd.textfiles.com/vgaspectrum/sound/voc1/
* https://telparia.com/fileFormatSamples/audio/voc/

BLEND

2023-09-16T15:10:37Z

Eiim: Add Wikidata

{{FormatInfo
|formattype=electronic
|subcat=3D and CAD/CAM Models
|extensions={{ext|blend}}
|pronom={{PRONOM|fmt/902}}, {{PRONOM|fmt/903}}
|kaitai struct=blender_blend
|wikidata={{wikidata|Q15671948}}
}}
[[BLEND]] is a scene description format associated with the ''[http://www.blender.org Blender]'' 3d modeling and animation software by the Blender Foundation.

The blend file format is not a true file interchange format, rather it dumps internal data structures from directly from memory to disk. A blend file’s structure may therefore be unique to each version of Blender. Despite this, blend files are both [http://www.blendernation.com/2008/12/01/blender-dna-rna-and-backward-compatibility/ backward and forward compatible] between versions, and between different hardware and operating systems. This is made possible by the addition of metadata, known as [http://wiki.blender.org/index.php/Dev:Source/Architecture/SDNA_Notes Struct DNA], that allows conversion when loading the file.

Since no standard blend file format specification exists, the Blender source code must serve as the definitive specification. Blender also allows option while saving to "compress" file with gzip, retaining .blend extension.

== Sample files ==
* http://download.blender.org/demo/

== Software ==
* [http://www.blender.org/download/ Blender source code and binaries]

== Links ==
* [http://www.atmind.nl/blender/mystery_ot_blend.html The mystery of the blend: the blend file format explained]
* [http://www.atmind.nl/blender/blender-sdna-256.html Blender 2.56 Internal SDNA stuctures]
* [http://wiki.blender.org/index.php/Dev:Source/Architecture/SDNA_Notes Notes on SDNA]
* [http://github.com/ldo/blendhack blendhac blender file parser]
* [http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Hacking_Blender Hacking Blender]

AVI

2023-09-16T15:09:40Z

Eiim: Fix Wikidata

{{FormatInfo
|subcat=Video
|extensions={{ext|avi}}
|mimetypes={{mimetype|video/avi}}, {{mimetype|video/x-msvideo}}, {{mimetype|video/vnd.avi}}, {{mimetype|video/msvideo}}
|locfdd={{LoCFDD|fdd000059}}
|pronom={{PRONOM|fmt/5}}
|kaitai struct=avi
|wikidata={{wikidata|Q209054}}
|released=~1992
}}
'''Audio Video Interleave''' ('''AVI''') is a multimedia container format originally developed by Microsoft and IBM and based on the [[RIFF]] wrapper format. AVI is itself a wrapper that can enclose video and audio bitstreams in many encodings, including [[Indeo]], [[Sorenson]], and [[Cinepak]].

== Identification ==
Files begin with bytes <code>'R' 'I' 'F' 'F' ?? ?? ?? ?? 'A' 'V' 'I' 0x20</code>.

== Specifications ==
* [https://msdn.microsoft.com/en-us/library/windows/desktop/dd318189(v=vs.85).aspx Windows Dev Center → DirectShow → AVI RIFF File Reference]
* [http://www.opennet.ru/docs/formats/avi.txt AVI description] Probably extracted from Video for Windows Programmer's Guide
* [http://mediaxw.sourceforge.net/files/doc/Video%20for%20Windows%20Reference%20-%20Chapter%204%20-%20AVI%20Files.pdf Copy of Chapter 4: AVI Files from Video for Windows Programmer's Guide] 1993
* [http://pvdtools.sourceforge.net/aviformat.txt RIFF-AVI FILE FORMAT]
* [http://abcavi.kibi.ru/developer.htm Documention page from abcAVI Tag Editor site] Has links to copies of AVI documentation at bottom.
* [http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/DVAVSPEC.RTF DV Data in the AVI File Format Specification, Version 1.01] Microsoft, 1997
* [http://www.iana.org/assignments/wave-avi-codec-registry/wave-avi-codec-registry.xml WAVE and AVI Codec Registries (Historic Registry)] Hosted by IANA. Implies use of video/vnd.avi as mimetype.

== Sample files ==
* https://telparia.com/fileFormatSamples/video/avi/
* http://samples.mplayerhq.hu/avi/

== Links ==
* [[Wikipedia: Audio Video Interleave]]
* [http://www.jmcgowan.com/avi.html Overview of Video for Windows, DirectShow (ActiveMovie), and AVI] by John F. McGowan, 1996-2004

[[Category:RIFF based file formats]]
[[Category:Microsoft]]
[[Category:IBM]]
[[Category:Windows]]

AVI

2023-09-16T15:08:56Z

Eiim: Add Wikidata

{{FormatInfo
|subcat=Video
|extensions={{ext|avi}}
|mimetypes={{mimetype|video/avi}}, {{mimetype|video/x-msvideo}}, {{mimetype|video/vnd.avi}}, {{mimetype|video/msvideo}}
|locfdd={{LoCFDD|fdd000059}}
|pronom={{PRONOM|fmt/5}}
|kaitai struct=avi
|wikidata=Q209054
|released=~1992
}}
'''Audio Video Interleave''' ('''AVI''') is a multimedia container format originally developed by Microsoft and IBM and based on the [[RIFF]] wrapper format. AVI is itself a wrapper that can enclose video and audio bitstreams in many encodings, including [[Indeo]], [[Sorenson]], and [[Cinepak]].

== Identification ==
Files begin with bytes <code>'R' 'I' 'F' 'F' ?? ?? ?? ?? 'A' 'V' 'I' 0x20</code>.

== Specifications ==
* [https://msdn.microsoft.com/en-us/library/windows/desktop/dd318189(v=vs.85).aspx Windows Dev Center → DirectShow → AVI RIFF File Reference]
* [http://www.opennet.ru/docs/formats/avi.txt AVI description] Probably extracted from Video for Windows Programmer's Guide
* [http://mediaxw.sourceforge.net/files/doc/Video%20for%20Windows%20Reference%20-%20Chapter%204%20-%20AVI%20Files.pdf Copy of Chapter 4: AVI Files from Video for Windows Programmer's Guide] 1993
* [http://pvdtools.sourceforge.net/aviformat.txt RIFF-AVI FILE FORMAT]
* [http://abcavi.kibi.ru/developer.htm Documention page from abcAVI Tag Editor site] Has links to copies of AVI documentation at bottom.
* [http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/DVAVSPEC.RTF DV Data in the AVI File Format Specification, Version 1.01] Microsoft, 1997
* [http://www.iana.org/assignments/wave-avi-codec-registry/wave-avi-codec-registry.xml WAVE and AVI Codec Registries (Historic Registry)] Hosted by IANA. Implies use of video/vnd.avi as mimetype.

== Sample files ==
* https://telparia.com/fileFormatSamples/video/avi/
* http://samples.mplayerhq.hu/avi/

== Links ==
* [[Wikipedia: Audio Video Interleave]]
* [http://www.jmcgowan.com/avi.html Overview of Video for Windows, DirectShow (ActiveMovie), and AVI] by John F. McGowan, 1996-2004

[[Category:RIFF based file formats]]
[[Category:Microsoft]]
[[Category:IBM]]
[[Category:Windows]]

AU

2023-09-16T15:07:25Z

Eiim: Add Kaitai Struct

{{FormatInfo
|formattype=electronic
|subcat=Audio and Music
|extensions={{ext|au}}, {{ext|snd}}
|mimetypes={{mimetype|audio/basic}}
|pronom={{PRONOM|x-fmt/139}}
|wikidata={{wikidata|Q672985}}
|kaitai struct=au
}}
'''Sun Microsystems audio file''' ('''.au''') is an audio file format commonly used on Sun & NeXT operating systems.

== Format ==
Files have a 24-byte header, followed by a optional description field of at least 4 bytes, then the audio data.

== Identification ==
Files begin with signature bytes <code>2e 73 6e 64</code> ("<code>.snd</code>").

== Specifications ==
* [http://docs.oracle.com/cd/E36784_01/html/E36882/au-4.html Oracle Solaris 11.2 man pages: au(4)]
* http://pubs.opengroup.org/external/auformat.html

== Software ==
* [http://sox.sourceforge.net/ SoX - Sound eXchange]

== Sample files ==
* https://hg.java.net/hg/solaris~on-src/file/b23a4dab3d50/usr/src/cmd/audio/samples/au
* https://telparia.com/fileFormatSamples/audio/au/

== Resources ==
* [[Wikipedia:Au file format]]
* [http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/AU/AU.html Audio File Format Specifications: AU or NeXT/Sun sound file]

[[Category:Sun]]

XWD

2023-09-15T01:59:37Z

Eiim: Add Kaitai Struct, Wikidata

{{FormatInfo
|formattype=electronic
|subcat=Graphics
|extensions={{ext|xwd}}
|pronom={{PRONOM|fmt/401}}, {{PRONOM|x-fmt/300}}
|wikidata=Q105601274
|kaitai struct=xwd
}}
'''XWD''' ('''X Window Dump''') is a raster image file format used by the [[X Window System]].

There are two versions of it: X10 and X11. They have different header formats and capabilities.

There is no official specification, and it is challenging to decode all the possible types of XWD images.

Some sources list '''.xdm''' as an alternate file extension, but others imply that xdm files have a different format.

== Specs ==
* [http://www.fileformat.info/format/xwd/spec/index.htm Specs as .h file]

== Software ==
* [[ImageMagick]]
* [[Konvertor]]
* [[Netpbm]]
* [[XnView]]
* xwd (X Window Dump): [http://cgit.freedesktop.org/xorg/app/xwd/ git repo], [http://www.x.org/releases/individual/app/ tarball releases]
* xwud (X Window Un-Dump): [http://cgit.freedesktop.org/xorg/app/xwud/ git repo], [http://www.x.org/releases/individual/app/ tarball releases]

== Sample files ==
* http://www.fileformat.info/format/xwd/sample/index.htm
* http://stuff.mit.edu/afs/athena/contrib/graphics/images/xpix/
* https://telparia.com/fileFormatSamples/image/xwd/

== Resources ==
* {{EGFF|xwd|XWD File Format Summary}}, from the [[Encyclopedia of Graphics File Formats]]
* [http://wiki.multimedia.cx/index.php?title=XWD MultimediaWiki article]
* [[Wikipedia:xwd|Wikipedia: xwd]]

[[Category:X Window System]]

TGA

2023-09-15T01:58:17Z

Eiim: Add Kaitai Struct

{{FormatInfo
|formattype=electronic
|subcat=Graphics
|extensions={{ext|tga}}, {{ext|icb}}, {{ext|vda}}, {{ext|vst}}
|locfdd={{LoCFDD|fdd000179}}, {{LoCFDD|fdd000180}}
|pronom={{PRONOM|x-fmt/367}}, {{PRONOM|fmt/402}}
|wikidata={{wikidata|Q1063976}}
|released=1984
|kaitai struct=tga
}}
'''TGA''' ('''Targa''') is a raster image file format developed by Truevision, Inc. (then named EPICenter) in 1984. Designed for use with MS-DOS color applications, TGA is the native format of Truevision's TARGA (Truevision Advanced Raster Graphics Adapter) boards, which were some of the first graphic cards for IBM-compatible PCs to support 24-bit RGB color encoding (sometimes termed ''truecolor'').

Most TGA files are quite simple, but the format has the potential to be fairly complex.

TGA images are either uncompressed, or compressed with [[run-length encoding]].

== Format details ==
Files begin with an 18-byte fixed header, sometimes followed by other segments, followed by the pixel data. After the pixel data, there may be additional data elements referred to by an optional 26-byte file footer.

== Variant formats ==
Some Truevision products used their own variant or subset of TGA: '''ICB''', '''VDA''', or '''VST'''. Those and other TGA variants are listed here.

=== ICB ===
* File extension: '''.icb'''
* Full name: '''Image Capture Board'''

=== VDA ===
* File extension: '''.vda'''
* Full name: '''Video Display Adapter'''

=== VST ===
* File extension: '''.vst'''
* Full name: '''TrueVista''' or '''Truevision Vista'''

[[XnView]] can read and write VST format. The format XnView supports seems to have more differences from TGA than are mentioned in the TGA 2.0 specification. There is an extra 18-byte header or ID field after the main header, with the signature "{{magic|IGCH}}" at file offset 20.

=== PIX, BPX ===
* File extensions: '''.pix''', '''.bpx'''

Refer to [[Lumena PIX/BPX]].

=== IVB ===
* File extension: '''.ivb'''

No details known. IVB is a file extension or variant format that [[XnView]] claims to support.

== Identification ==
TGA files have no signature at the beginning of the file. They can be identified fairly reliably by testing whether the first 18 bytes have sensible values for TGA format, but that is nontrivial.

Some, but not all, TGA files have a signature at the ''end'' of the file. In that case, the last 18 bytes of the file are the ASCII characters "<code>TRUEVISION-XFILE.</code>", followed by a NUL byte (<code>0x00</code>). An example of a file ending in <code>TRUEVISION-XFILE.[0x00]</code> is seen at telparia.com/fileFormatSamples/image/tga/ (linked below in §Sample files) > https://telparia.com/fileFormatSamples/image/tga/test.tga.

== Versions ==
The first TGA format is now known as ''Original TGA Format'', or (informally) ''TGA Version 1''. It is characterized by the lack of a ''New TGA Format'' signature.

''New TGA Format'', or ''TGA Version 2.0'', was released in 1989. It is characterized by a footer with a "TRUEVISION-XFILE" signature. It adds an optional "Extension Area" segment, with many standard metadata fields.

It also adds an optional "Developer Area" segment, which supports arbitrary custom data. A custom data item is tagged with a 16-bit integer identifier, similar to a [[TIFF]] tag. There does not appear to be any published list of TGA tags, though tag 20 seems to be used for [[Photoshop Image Resources]].

== Specifications ==
* Truevision TGA File Format Specification, Version 2.0: [http://googlesites.inequation.org/tgautilities PostScript] · [http://www.dca.fee.unicamp.br/~martino/disciplinas/ea978/tgaffs.pdf PDF] · [http://www.ludorg.net/amnesia/TGA_File_Format_Spec.html HTML]
* [http://www.martinreddy.net/gfx/2d/TGA.txt Information extracted by Martin Reddy from Appendix C of the Truevision Technical Guide]
* [http://www.textfiles.com/programming/FORMATS/targafor.pro Another copy of the file]
* [http://www.textfiles.com/programming/FORMATS/pix_fmt.txt Picture format docs (of a number of formats including this one)]

== Software ==
TGA is widely supported. Software listed here has been semi-arbitrarily selected.
* [[Netpbm]]: pamtotga, tgatoppm
* [[ImageMagick]]
* [[FFmpeg]]
* [[XnView]]
* [http://tgalib.sourceforge.net/ Libtga]
* {{Deark}}
* [http://snisurset.net/code/abydos/ abydos]
* [[GIMP]]

== Sample files ==
* http://www.fileformat.info/format/tga/sample/index.htm
* https://samples.libav.org/image-samples/TGA/
* http://links.uwaterloo.ca/Repository/TGA/
* http://downloads.oldschoolbg.com/cstrike/gfx/env/
* https://github.com/timfel/tombexcavator/tree/master/data/TGA
* https://telparia.com/fileFormatSamples/image/tga/

== Links ==
* [[Wikipedia:Truevision TGA|Truevision TGA: Wikipedia]]
* {{EGFF|tga|TGA File Format Summary}}, from the [[Encyclopedia of Graphics File Formats]]
* [http://www.paulbourke.net/dataformats/tga/ Creating TGA Image files] By Paul Bourke, 1996.
* [https://twitter.com/angealbertini/status/535565222652948480/photo/1 TGA format chart]

PIF (Portable Image Format)

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{{FormatInfo
|formattype=electronic
|subcat=Graphics
|extensions={{ext|pif}}
|released=~2022
|kaitai struct=pif
}}
:''For other "PIF" formats, see [[PIF]].''

'''PIF''' ('''Portable Image Format''', or maybe it's '''Portable Image File''') is a raster graphics format, designed for use with embedded systems. It was developed by a person known as gfcwfzkm.

== Identification ==
Files start with signature bytes {{magic|'P' 'I' 'F' 0x00}}.

== Specifications ==
* https://github.com/gfcwfzkm/PIF-Image-Format/tree/main/Specification

== Software ==
* [https://github.com/gfcwfzkm/PIF-Image-Format GitHub project]
* [http://jayakody2000lk.blogspot.com/2022/05/portable-image-file-pif-library-for.html Portable Image File (PIF) library for Lazarus and Delphi] ([https://github.com/dilshan/pascal-pif-library GitHub])

DCX

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{{FormatInfo
|formattype=electronic
|subcat=Graphics
|subcat2=Fax formats
|extensions={{ext|dcx}}
|pronom={{PRONOM|x-fmt/348}}
|kaitai struct=pcx_dcx
}}
'''DCX''' is an image file format based on [[PCX]]. It supports multiple images in a single file, and may be used for fax images.

== Format ==
DCX files begin with a 4-byte signature.

Following that is a list of up to 1023 4-byte file offsets, terminated by an offset of 0.

Following that are the individual images, stored as embedded [[PCX]] files. The first one usually starts at file offset 4100 (0x1004).

== Identification ==
Files begin with signature bytes <code>B1 68 DE 3A</code>.

== Specifications ==
* {{EGFF|pcx|PCX File Format Summary}}, from the [[Encyclopedia of Graphics File Formats]] (includes information about DCX)
* [http://www.martinreddy.net/gfx/2d/DCX.txt DCA/Intel Communicating Applications Specification] (page 54)

== Software ==
* [[ImageMagick]]
* [[Konvertor]]
* [[XnView]]
* [http://snisurset.net/code/abydos/ abydos]

== Sample files ==
* http://cd.textfiles.com/bhawk1197/FAX/FAX_N523.ZIP → SAMPLE.DCX
* [http://trac.imagemagick.org/browser/ImageMagick/branches/ImageMagick-6/PerlMagick/t/input.dcx input.dcx] (PerlMagick test file)
* https://telparia.com/fileFormatSamples/image/dcx/

[[Category:Fax]]

National Imagery Transmission Format

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{{FormatInfo
|formattype=electronic
|subcat=Graphics
|extensions={{ext|ntf}}
|mimetypes={{mimetype|application/vnd.nitf}}
|pronom={{PRONOM|fmt/364}}, {{PRONOM|fmt/365}}, {{PRONOM|fmt/366}}
|kaitai struct=nitf
}}
'''National Imagery Transmission Format''' ('''NITFS''', or '''NITF''') is a family of standards developed by the U.S. Department of Defense. It's a little difficult to figure out the scope of the standards, unless you are fluent in governmentese. In practice, it seems to be mainly used as a raster graphics file format, apparently for satellite imagery and the like.

This format is not related to [[News Industry Text Format]]. It is also apparently a different thing from the [[National Transfer Format]] (NTF), though this is also used in the geospatial area.

== Identification ==
Files begin with ASCII characters "<code>NITF</code>".

== Specifications ==
* [http://www.gwg.nga.mil/ntb/baseline/format.html Reference Library for NITFS Users: Format]

== Software ==
* [http://www.gdal.org/ GDAL]
* [[Konvertor]]
* [[XnView]] (uncompressed images only)

== Sample files ==
* http://download.osgeo.org/pub/gdal/data/nitf/

== Links ==
* [[Wikipedia:National Imagery Transmission Format|Wikipedia article]]

[[Category:Geospatial]]
[[Category:Military]]

JPEG

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{{FormatInfo
|formattype=electronic
|subcat=Graphics
|thiscat=JPEG
|extensions={{ext|jpg}}, {{ext|jpeg}}, {{ext|jpe}}, {{ext|jif}}
|mimetypes={{mimetype|image/jpeg}}
|locfdd={{LoCFDD|fdd000017}}, others
|pronom={{PRONOM|fmt/41}}, others
|wikidata={{wikidata|Q27996264}}
|released=1992
|kaitai struct=jpeg
}}
'''JPEG''' is a popular raster image format well-suited to photographic images. It usually uses lossy [[DCT compression]]. It is named after the Joint Photographic Experts Group, the organization which developed the format. It is sometimes called '''JPEG1''', '''JPEG-1''', or '''JPEG 1992''' to help disambiguate it. (Also see [[JPEG 2000]] and [[JP2]].)

== Terminology ==
''(In which we discuss the tired old question of whether JPEG is a file format, or a compression standard)''

In the original specification (ITU-T Rec. T.81), the term ''JPEG'' refers only to an organization. The serialized form of the compression format it defines is referred to only as the "interchange format".

The followup ITU-T Rec. T.84 document says that ''JPEG'' can also refer to a set of ''standards'', including at least Rec. T.81, Rec. T.83, and Rec. T.84. It also informally uses ''JPEG'' to refer to the Rec. T.81 interchange format.

ITU-T Rec. T.851 refers to the interchange format as ''JPEG-1''.

The interchange format is ''almost'' a full-fledged portable file format, lacking only standard conventions and/or standard metadata elements to tell how to interpret it as an image. The missing pieces can be added in various ways. Some file formats, including [[JFIF]], do so in such a way that the interchange format is used directly as a file format. In practice, the term ''JPEG'' often refers to the family of such file formats, and this usage does not seem unreasonable, especially since there is no other suitable name. The term '''JIF''' (for ''JPEG Interchange Format'') has been tossed around, but it is an ambiguous term that doesn't necessarily refer to a file format, and it's unusable in practice due to similarity to [[GIF]].

It could be that ''JPEG'' is sometimes misused to mean [[JFIF]], but such an accusation might be relying on the incorrect assumption that '''.jpg''' files always use JFIF format.

== Portability ==
In and of itself, JPEG is not really a suitable format for image interchange, for several reasons:
* It essentially only defines a way to store one or more arrays of numbers. It does not say how to interpret those numbers as an image. The decoder will just have to guess.
* It is large and general, and it might be unrealistic to expect every decoder to support all of it.
* It defines no standard metadata elements.

To address these issues, a number of JPEG subformats have been invented. [[JFIF]] is by far the most popular of them, though a significant minority of JPEG files use [[Exif]] instead. The [[SPIFF]] file format was intended as a replacement for JFIF, but never caught on.

In practice, a portable JPEG file is pretty much "whatever the libjpeg software supports". This includes some varieties (such as RGB color) that do not conform to JFIF, and excludes some (such as lossless JPEG) that do.

== Format ==
A JPEG file consists largely of a sequence of tagged segments. Each segment begins with a two-byte "marker". (The term "marker" is often used to refer to the entire segment.) The first byte of a marker is 0xff. The second may have any value except 0x00 or 0xff, and indicates the type of data stored in the segment. Segment types are assigned names; for example, 0xd9 is "SOI", and 0xe1 is "APP1".

Segment types 0x01, and 0xd0 through 0xd9, consist entirely of the two-byte marker. All other markers are followed by a two-byte integer indicating the size of the segment, followed by the payload data contained in the segment.

The image data is the exception to this segmented format. It appears following an "SOS" (0xda) segment, but there is no prefix to indicate its size. Instead, any 0xff bytes in the image data are escaped as 0xff 0x00, so that they won't be mistaken for markers. (Note that some JPEG-like formats, such as [[JPEG-LS]] and [[JPEG 2000 codestream]], use different rules for escaping 0xff bytes.)

=== Application segments ===
There are 16 segment types reserved for application-specific data: 0xe0 ("APP0") through 0xef ("APP15").

An APP segment's data often begins with NUL-terminated text string to identify the type of data contained in it. The actual payload data then begins after the NUL byte. This convention was standardized by ISO/IEC 10918-4:1999 (see ITU-T Rec. T.86), but is not as universal as one might hope. Most APP segments do have a signature of some sort, but because there is no simple matching algorithm that always works, identifying the signature can be difficult.

== Identifiers ==
{| class="wikitable"
! Format
! PRONOM
! LoCFDD
|-
|JPEG || {{PRONOM|fmt/41}} || {{LoCFDD|fdd000017}}
|-
|Baseline JPEG || || {{LoCFDD|fdd000149}}
|-
|Progressive JPEG || || {{LoCFDD|fdd000333}}
|-
|[[Lossless JPEG (original)|Lossless JPEG]] || || {{LoCFDD|fdd000334}}
|-
|Other JPEG || || {{LoCFDD|fdd000150}}
|-
|JFIF 1.00 || {{PRONOM|fmt/42}}
|-
|JFIF 1.01 || {{PRONOM|fmt/43}}
|-
|[[JFIF]] 1.02 || {{PRONOM|fmt/44}} || {{LoCFDD|fdd000018}}
|-
|Exif 2.0 JPEG || {{PRONOM|x-fmt/398}} ||rowspan="5"| {{LoCFDD|fdd000147}}
|-
|Exif 2.1 JPEG || {{PRONOM|x-fmt/390}}
|-
|[[Exif]] 2.2 JPEG || {{PRONOM|x-fmt/391}}
|-
|Exif 2.21 JPEG || {{PRONOM|fmt/645}}
|-
|Exif 2.3.x JPEG || {{PRONOM|fmt/1507}}
|-
|[[SPIFF]] || {{PRONOM|fmt/112}} || {{LoCFDD|fdd000019}}
|}

== Identification ==
JPEG files begin with bytes <code>ff d8 ff</code>.

However, this does not distinguish them from [[JPEG-LS]]. To do that reliably, one may have to scan the file to look for one of the valid SOF segment types.

== Types of JPEG files ==
The following types are not disjoint. For example, a progressive JPEG may use arithmetic coding.

Some JPEG images do not belong to any of these types. An SOF1 segment is used if no other SOF segment applies.

=== Baseline ===
JPEGs with an SOF0 segment are known as ''Baseline'' JPEGs. They are always lossy, not progressive, use Huffman coding, and have a bit depth of 8. Every application that supports JPEG is supposed to at least support Baseline JPEG.

=== Progressive ===
Progressive JPEG rearranges the image data, so that the the first part of it represents a very low quality version of the entire image, rather than a high quality version of a small part of the image.

A progressive JPEG is identified by the presence of an SOF2, SOF6, SOF10, or SOF14 segment.

=== Non-interleaved ===
Color JPEG images may be either ''interleaved'' or ''non-interleaved''.

In an interleaved JPEG, all the color components (e.g. Y, Cb, Cr) for a pixel are stored close together in the file.

In a non-interleaved JPEG, the image is separated into its color components, and each component is stored separately in the file.

Interleaving is not a simple yes/no option, because a single image may use both interleaved and non-interleaved scans (SOS segments) – in fact, progressive JPEGs usually do just that. Some JPEG decoders do not support non-interleaved images unless they use progressive encoding.

=== Arithmetic coding ===
Even lossy JPEG makes use of a lossless compression algorithm. The lossless algorithm is usually [[Huffman coding]], but [[arithmetic coding]] may be used instead. JPEG's arithmetic coding usually results in a smaller file size, but it is not as widely supported as one might hope, probably because it used to be encumbered by [[patents]].

An arithmetic-coded JPEG is identified by the presence of an SOF9, SOF10, SOF11, SOF13, SOF14, or SOF15 segment.

=== 12-bit ===
Except for Baseline JPEG, all lossy types of JPEG may use a bit depth of either 8 or 12 bits per sample. However, few applications support anything other than 8 bits.

Starting with version 9a, IJG libjpeg also supports bit depths of 9, 10, and 11. These depths are nonstandard, and libjpeg's implementation is nearly unusable in practice, because it only supports a single bit depth, which must be selected at compile time.

=== Lossless JPEG ===
:''Main article: [[Lossless JPEG (original)]]''

JPEG supports true lossless compression, but it is used so rarely that JPEG is commonly thought of as strictly a lossy format.

A lossless JPEG is identified by the presence of an SOF3, SOF7, SOF11, or SOF15 segment.

See also the [[Lossless JPEG|Lossless JPEG disambiguation page]], for other uses of the term.

=== Hierarchical ===
Also called "differential", hierarchical JPEG is vaguely similar to progressive JPEG, but geared toward storing multiple sizes of the same image, such that the decoder can select the size it prefers. Hierarchical JPEGs are, to a close approximation, nonexistent.

A hierarchical JPEG is identified by the presence of an SOF5, SOF6, SOF7, SOF13, SOF14, or SOF15 segment.

== Color format ==
There are five JPEG color types that are reasonably portable:
# Grayscale
# YCbCr
# RGB
# YCCK
# CMYK

To make the compression more effective, RGB images are almost always transformed to YCbCr format when they are written to a JPEG file. However, many applications will still report that such images use "RGB" color. This may be because their authors weren't aware of the transformation, or because they considered it to be an internal part of the compression algorithm as opposed to a different colorspace. Unfortunately, this inconsistent terminology can make it hard to distinguish YCbCr JPEGs from the rare JPEGs that really do use RGB color.

YCCK is a transformed version of CMYK, and the same terminology confusion exists as with YCbCr and RGB.

The JPEG format does not have any clear way to indicate the color type of an image. Decoders usually determine the color type based on several factors:
* The number of color components
* The presence of a JFIF application segment
* The "color transform" field of the APP14 "Adobe" segment, if present
* The component ID numbers ({82, 71, 66} suggests RGB)

== SmartScale ==
Starting with version 7 or 8, the IJG libjpeg software has been adding nonstandard "SmartScale" scaling and color transform features of debatable merit<ref>[http://www.libjpeg-turbo.org/About/SmartScale A Study on the Usefulness of DCT Scaling and SmartScale]</ref><ref>[http://hardwarebug.org/2010/02/01/ijg-swings-again-and-misses/ IJG swings again, and misses]</ref>.

Notably, it is possible to achieve lossless DCT compression by setting the DCT block size to 1, and using RGB color if necessary.

Version 9 introduced a "reversible color transform" feature that can improve the compression of RGB images. Files with this feature contain a JPG8 (0xf8) segment.

== Related Formats ==
* [[JFIF]] is a subformat and extension, and uses APP0 "JFIF" and APP0 "JFXX" segments.
* [[SPIFF]] is a subformat and extension, and uses an APP8 "SPIFF" segment.
* [[JPEG-HDR]] is an extension, and uses APP11 segments.
* [[JPEG XT]] is an extension.
* [[JPEG 360]] is an extension, and/or a metadata format.
* [[JPS]] is an extension, and uses an APP3 "_JPSJPS_" segment.
* [[Multi-Picture Format]] is an extension, and uses an APP2 "MPF" segment.
* The [[Exif]] standard uses an APP1 "Exif" segment.
* [[FlashPix]] data is contained in APP2 "FPXR" segments in Exif-compliant JPEGs. Refer to the [[Exif]] specification.
* [[Photoshop Image Resources]] is contained in an APP13 "Photoshop 3.0" segment.
* [[IPTC-IIM]] metadata often appears in JPEG files, embedded in [[Photoshop Image Resources]].
* [[XMP]] metadata is contained in an APP1 <nowiki>"http://ns.adobe.com/xap/1.0/"</nowiki> segment.
* [[ICC profile]] data is contained in an APP2 "ICC_PROFILE" segment.
* Many other file formats, such as [[TIFF]], [[MNG]]/[[JNG]], and [[PDF]], can contain JPEG-compressed data or encapsulated JPEG files.
* ''(And we heard you like JPEG...)'' JPEG files themselves often contain thumbnail images in the form of embedded JPEG files, via formats such as [[Exif]], [[Photoshop Image Resources]], or [[JFIF]].

Formats that are '''not''' compatible with JPEG include [[JPEG-LS]], [[JPEG 2000]], [[JPEG XR]], and presumably [[JPEG XL]].

== Specifications ==
* [http://www.w3.org/Graphics/JPEG/itu-t81.pdf ITU-T Rec. T.81] (originally CCITT Rec. T.81): The JPEG standard
* [http://www.itu.int/rec/T-REC-T.83/en ITU-T Rec. T.83]: Compliance testing
* [http://www.itu.int/rec/T-REC-T.84/en ITU-T Rec. T.84]: Extensions
* [http://www.itu.int/rec/T-REC-T.86/en ITU-T Rec. T.86]: Registration of JPEG Profiles, etc.
* [http://www.itu.int/rec/T-REC-T.851-200509-I/en ITU-T Rec. T.851]: (JPEG-1)-based still-image coding using an alternative arithmetic coder
* [http://www.itu.int/rec/T-REC-T.872/en ITU-T Rec. T.872]: Application to printing systems
* [http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#Adobe ExifTool: The APP14 "Adobe" segment]
* ISO/IEC 10918: Digital compression and coding of continuous-tone still images
** [http://www.iso.org/iso/catalogue_detail.htm?csnumber=18902 ISO/IEC 10918-1:1994] - Requirements and guidelines
*** [http://www.iso.org/iso/catalogue_detail.htm?csnumber=41504 ISO/IEC 10918-1:1994/Cor 1:2005] - Patent information update
** [http://www.iso.org/iso/catalogue_detail.htm?csnumber=20689 ISO/IEC 10918-2:1995] - Compliance testing
** [http://www.iso.org/iso/catalogue_detail.htm?csnumber=25037 ISO/IEC 10918-3:1997] - Extensions
*** ISO/IEC 10918-3:1997/Amd 1:1999 - Refer to [[SPIFF]]
** [http://www.iso.org/iso/catalogue_detail.htm?csnumber=25431 ISO/IEC 10918-4:1999] - Registration of JPEG profiles, ...
*** [http://www.iso.org/iso/catalogue_detail.htm?csnumber=59454 ISO/IEC 10918-4:1999/Amd 1:2013] - Application specific marker list
** ISO/IEC 10918-5:2013 - Refer to [[JFIF]]
** [http://www.iso.org/iso/catalogue_detail.htm?csnumber=59634 ISO/IEC 10918-6:2013] - Application to printing systems
** [https://www.iso.org/standard/75845.html ISO/IEC 10918-7:2019] - Reference software
* [https://jpeg.org/jpegsystems/index.html ISO/IEC 19566: JPEG Systems] (a collection of JPEG-related standards)
** [https://www.iso.org/standard/65348.html ISO/IEC 19566-1]: Packaging of information using codestreams and file formats
** [https://www.iso.org/standard/67704.html ISO/IEC 19566-2]: Transport mechanisms and packaging
** [https://www.iso.org/standard/73607.html ISO/IEC 19566-4]: Privacy, security and IPR features
** [https://www.iso.org/standard/73604.html ISO/IEC 19566-5]: JPEG Universal Metadata Box Format (JUMBF)
** ISO/IEC 19566-6 - Refer to [[JPEG 360]]
** [https://www.iso.org/standard/78466.html ISO/IEC 19566-7]: JPEG Linked Media Format
* [https://jpeg.org/downloads/jpeg/wg1n76028-CfP-JPEG-reference-software.pdf Final Call for Proposal for a JPEG Reference Software] (2017-07)

== Sample files ==
* https://telparia.com/fileFormatSamples/image/jpg/

== Metaformat files ==
* {{Synalysis|jpeg}}

== Software ==
Nearly all serious graphics applications, including web browsers, support JPEG. This section primarily lists libraries and tools.

* [http://www.ijg.org/ The Independent JPEG Group's software], commonly known as ''libjpeg'' or ''IJG libjpeg''
* [http://libjpeg-turbo.virtualgl.org/ libjpeg-turbo]
* [https://github.com/thorfdbg/libjpeg Thomas Richter's libjpeg]: C++ library that supports all of the JPEG standard
* [https://github.com/mozilla/mozjpeg/ mozjpeg: Improved JPEG encoding library from Mozilla]
** [http://calendar.perfplanet.com/2014/mozjpeg-3-0/ Info on mozjpeg 3.0]
* [https://research.googleblog.com/2017/03/announcing-guetzli-new-open-source-jpeg.html Guetzli] - JPEG encoder optimized for file size
** [https://github.com/google/guetzli Source code at GitHub]
* [http://coptr.digipres.org/Bad_Peggy Bad Peggy: scans images for problems]

== Notes ==
When saving a JPEG image from [[Twitter]] in Google Chrome / Chromium, it will save with the default extension '''.jpg-large'''. This is due to a [https://code.google.com/p/chromium/issues/detail?id=172529 known bug] (and one which shows no signs of being solved any time soon) in the way the browser sanitises Twitter image URLs (the filename is determined to be e.g. Xyzxyzxyz.jpg:large, which is sanitised to Xyzxyzxyz.jpg-large).

== External links ==
* [[Wikipedia:JPEG|JPEG (Wikipedia)]]
* [http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html ExifTool JPEG Tags]
* [https://www.disktuna.com/list-of-jpeg-markers/ List of JPEG Markers]
* [http://blog.sucuri.net/2013/07/malware-hidden-inside-jpg-exif-headers.html Malware Hidden Inside JPG EXIF Headers]
* [http://www.theatlantic.com/technology/archive/2013/09/what-is-a-jpeg-the-invisible-object-you-see-every-day/279954/ What Is a JPEG? The Invisible Object You See Every Day]
* [http://l0ss.elliepritts.com/ Project L0SS], a collection of images demonstrating the glitches and artifacts caused by repeatedly recompressing JPEG images
* [http://thenextweb.com/insider/2014/03/05/mozilla-launches-jpeg-encoder-mozjpeg-improve-compression-rates-reduce-network-traffic-page-loads/ Mozilla launches JPEG encoder mozjpeg to reduce webpage loads, results show up to 10% decrease in file size]
* [http://andreasgal.com/2014/07/15/improving-jpeg-image-encoding/ Improving JPEG image encoding]
* [http://arstechnica.com/information-technology/2014/07/we-dont-need-new-image-formats-mozilla-works-to-build-a-better-jpeg/ We don’t need new image formats: Mozilla works to build a better JPEG]
* [http://www.ams.org/samplings/feature-column/fcarc-image-compression Explanation of JPEG compression algorithm]
* [https://github.com/lclevy/libcraw2/blob/master/docs/cr2_lossless.pdf Lossless JPEG decompression]
* [http://xooyoozoo.github.io/yolo-octo-bugfixes/ Online demonstrator]- shows quality differences between similarly-sized images in [[JPEG]], [[JP2]], [[WebP]] and [[BPG]] formats
* [https://github.com/mozilla/mozjpeg/issues/182 Method to improve JPEG compression that was the subject of a now-expired patent]
* [https://medium.freecodecamp.com/how-jpg-works-a4dbd2316f35 How JPG Works]
* [http://frdx.free.fr/JPEG_for_the_horseshoe_crabs.pdf JPEG for the horseshoe crabs]
* [http://cloudinary.com/blog/why_jpeg_is_like_a_photocopier Why JPEG is like a photocopier] - discussion of generation loss in JPEG and other lossy formats (with examples)
* [http://openpreservation.org/blog/2017/04/09/using-exiftool-to-address-tag-out-of-sequence-errors-in-images-and-a-101-level-dive-into-tags/ Using EXIFTool to address “Tag out of sequence” errors in images (and a 101 level dive into tags)]
* [https://openpreservation.org/blog/2019/11/07/jpeg-got-the-blues/ JPEG Got the Blues] - on properly rendering 32-bit (CMYK) JPEGs
* [https://yasoob.me/posts/understanding-and-writing-jpeg-decoder-in-python/ Understanding and Decoding a JPEG Image using Python]

== References ==
<references/>

[[Category:Compression]]
[[Category:JPEG (organization)]]

TERSE

2023-09-15T01:35:20Z

Eiim: Add more infobox data

{{FormatInfo
|formattype=electronic
|subcat=Compression
|released=1984?
|wikidata={{wikidata|Q28452000}}
|developed by=IBM
|reference impl=https://www.ibm.com/docs/en/zos/2.3.0?topic=aids-amaterse-pack-unpack-data-set
}}
'''TERSE''' is a data compression format used on OS/2, and on IBM mainframes. It is still in regular use on IBM mainframes to this day.

More research is needed to understand the scope of what TERSE was used for, and how many versions of it there are.

There appear to be two compression algorithms, called PACK and SPACK. There are also two different modes - native and compatibility. Native mode files would not necessarily be able to interpreted on a different machine than they were created on. As such, there aren't many examples of native mode files available.

It can at least be used for single-file compression, as is done by the Advantis software listed below. This file format does not appear to have a conventional filename extension – compressed files may keep their original name. However, the extensions .PACK, .SPACK, and .TRS have been observed (with filenames in all-caps per z/OS conventions).

== Identification ==
TERSE files use either a 4 or 12 byte header, depending on if it is using native or compatibility mode. Native mode have a header of either {{magic|01 89 69 A5}} or {{magic|07 89 69 A5}}, apparently depending on which version they were created with. Compatibility mode headers start with {{magic|02 00}} or {{magic|02 01}} for PACK and {{magic|05 00}} or {{magic|05 01}} for SPACK. In both cases, the second byte being 1 indicates [https://www.ibm.com/docs/en/zos/2.1.0?topic=options-record-format-recfm RECFM=V]. It is assumed the alternative is RECFM=U, but this is uncertain.

== Related formats ==
The [[ZIP]] format documentation (APPNOTE) lists two "TERSE" compression methods:

10 - PKWARE Data Compression Library Imploding (old IBM TERSE)
18 - File is compressed using IBM TERSE (new)

So, apparently, [[PKWARE DCL Implode]] is closely related to TERSE. It's possible that this distinction is or is related to the PACK/SPACK distinction in the file type.

[[BSQ (encoding)|BSQ]] is apparently related to TERSE. [https://archive.org/details/bsq-v-2.0]

== Software ==
* TERSE utility by Michael Nagy and Advantis
** [http://thorntonzone.com/afp/Mainframe/TERSE%20%28IBM%20mainframe%20compression%29/image-list.php?showsource=1] → [http://thorntonzone.com/afp/Mainframe/TERSE%20%28IBM%20mainframe%20compression%29/tersepc.zip tersepc.zip] - Collection of binaries for several platforms
** [https://www.sac.sk/download/pack/terse.zip terse.zip] - OS/2 binaries
** [https://www.ibm.com/support/knowledgecenter/SSB27H_6.2.0/fa2ut_part3_terse.html IBM Knowledge Center: Terse Utility]
* [https://github.com/openmainframeproject/tersedecompress TerseDecompress] – open source (Apache2 licensed) Java program, written by IBM, to decompress TERSE files for mainframe.
** [https://github.com/openmainframeproject/tersedecompress-testdata] Canterbury Corpus files compressed with both PACK and SPACK

== Links ==
* [[Wikipedia:Terse (file format)|Wikipedia article]]

[[Category:IBM]]
[[Category:OS/2]]

BSQ (W1GOH)

2023-09-14T01:56:59Z

Eiim: Add archive.org link, connection to TERSE.

{{FormatInfo
|formattype=electronic
|subcat=Transfer Encodings
|extensions={{ext|bsq}}
|released=1985
}}
'''BSQ''' (W1GOH Binary SQueeze) is a binary-to-text file encoding utility and format. It was developed by Steve Ward and "W1GOH". It has some connection to the amateur radio community.

In addition to encoding, it does simple data compression. This compression algorithm is apparently related to [[TERSE]].

== Identification ==
Version 1 files start with ASCII "{{magic|=== BSQ 1 FILE}}".

Version 2 files start with ASCII "{{magic|=== BSQ ver   2}}".

== Software ==
* {{CdTextfiles|simtel/simtel9211/msdos/packet/bsq.arc|bsq.arc}} - BSQ v2.0 (source code + binaries for DOS and CP/M)
* [https://archive.org/details/bsq-v-2.0 BSQ V2.0.zip] - BSQ v2.0 (source code, documentation, and binaries)

TERSE

2023-09-14T01:49:24Z

Eiim: Add more detail, mostly from open-source repo.

{{FormatInfo
|formattype=electronic
|subcat=Compression
|released=1984?
}}
'''TERSE''' is a data compression format used on OS/2, and on IBM mainframes. It is still in regular use on IBM mainframes to this day.

More research is needed to understand the scope of what TERSE was used for, and how many versions of it there are.

There appear to be two compression algorithms, called PACK and SPACK. There are also two different modes - native and compatibility. Native mode files would not necessarily be able to interpreted on a different machine than they were created on. As such, there aren't many examples of native mode files available.

It can at least be used for single-file compression, as is done by the Advantis software listed below. This file format does not appear to have a conventional filename extension – compressed files may keep their original name. However, the extensions .PACK, .SPACK, and .TRS have been observed (with filenames in all-caps per z/OS conventions).

== Identification ==
TERSE files use either a 4 or 12 byte header, depending on if it is using native or compatibility mode. Native mode have a header of either {{magic|01 89 69 A5}} or {{magic|07 89 69 A5}}, apparently depending on which version they were created with. Compatibility mode headers start with {{magic|02 00}} or {{magic|02 01}} for PACK and {{magic|05 00}} or {{magic|05 01}} for SPACK. In both cases, the second byte being 1 indicates [https://www.ibm.com/docs/en/zos/2.1.0?topic=options-record-format-recfm RECFM=V]. It is assumed the alternative is RECFM=U, but this is uncertain.

== Related formats ==
The [[ZIP]] format documentation (APPNOTE) lists two "TERSE" compression methods:

10 - PKWARE Data Compression Library Imploding (old IBM TERSE)
18 - File is compressed using IBM TERSE (new)

So, apparently, [[PKWARE DCL Implode]] is closely related to TERSE. It's possible that this distinction is or is related to the PACK/SPACK distinction in the file type.

[[BSQ (encoding)|BSQ]] is apparently related to TERSE. [https://archive.org/details/bsq-v-2.0]

== Software ==
* TERSE utility by Michael Nagy and Advantis
** [http://thorntonzone.com/afp/Mainframe/TERSE%20%28IBM%20mainframe%20compression%29/image-list.php?showsource=1] → [http://thorntonzone.com/afp/Mainframe/TERSE%20%28IBM%20mainframe%20compression%29/tersepc.zip tersepc.zip] - Collection of binaries for several platforms
** [https://www.sac.sk/download/pack/terse.zip terse.zip] - OS/2 binaries
** [https://www.ibm.com/support/knowledgecenter/SSB27H_6.2.0/fa2ut_part3_terse.html IBM Knowledge Center: Terse Utility]
* [https://github.com/openmainframeproject/tersedecompress TerseDecompress] – open source (Apache2 licensed) Java program, written by IBM, to decompress TERSE files for mainframe.
** [https://github.com/openmainframeproject/tersedecompress-testdata] Canterbury Corpus files compressed with both PACK and SPACK

== Links ==
* [[Wikipedia:Terse (file format)|Wikipedia article]]

[[Category:IBM]]
[[Category:OS/2]]

Talk:TERSE

2022-11-04T19:08:16Z

Eiim: Created page with "I've handled TERSE files with the .trs extension before, but I'm multiple layers removed from their origin, so I'm not certain if this is actually a standard extension added e..."

I've handled TERSE files with the .trs extension before, but I'm multiple layers removed from their origin, so I'm not certain if this is actually a standard extension added either on the mainframe or when transferring from the z/OS filesystem to a different filesystem, or if this is just something that was always manually added before I saw the files to make it clear what they were. [[User:Eiim|Eiim]] ([[User talk:Eiim|talk]]) 19:08, 4 November 2022 (UTC)

TERSE

2022-11-04T19:06:11Z

Eiim: Mention PACK/SPACK

Category:File formats with extension .ref

2022-11-04T18:54:09Z

Eiim: Created page with "R"

[[Category:File formats by extension|R]]

Category:File formats with extension .lxi

2022-11-04T18:54:01Z

Eiim: Created page with "L"

[[Category:File formats by extension|L]]

Category:File formats with extension .gdx

2022-11-04T18:53:48Z

Eiim: Created page with "G"

[[Category:File formats by extension|G]]

Category:File formats with extension .opt*

2022-11-04T18:53:15Z

Eiim: Not exactly sure how to handle this, the * is a wildcard. Someone smarter than me should probably fix this somehow.

[[Category:File formats by extension|O]]

Category:File formats with extension .gms

2022-11-04T18:49:54Z

Eiim: Created page with "G"

[[Category:File formats by extension|G]]

Programming Languages

2022-11-04T18:46:44Z

Eiim: Add GAMS

{{FormatInfo
|formattype=Languages
|thiscat=Programming Languages
|released=~1950
|image=Babbage difference engine drawing.gif
|caption=Babbage's Difference Engine
}}
'''Programming languages''' are languages expected to be executed (interpreted, compiled, etc.) by a machine in order to perform operations or algorithms. They are distinct from markup languages, which represent the structure of a document rather than specific operations to be performed, though it is possible to combine both in a document (e.g., HTML containing embedded JavaScript, or PHP code which includes HTML). Programming language code is stored as [[source code]] which may be directly interpreted by a machine or compiled or assembled into [[executables]].

== Programming languages ==

* [[ABC (programming language)]]
* [[ActionScript]] (Flash)
** [[ActionScript Byte Code]]
* [[Ada]]
* [[ALGOL]]
* [[Anim8or Scripting Language]]
* [[APL]]
* [[APT (programming language)|APT]]
* [[AppleScript]]
* [[Arduino programming language]]
* [[Assembly language]] (.asm, .s) (various versions for different machine architectures)
* [[Aussie++]]
* [[AutoHotkey]]
* [[AutoLISP]]
* [[AWK]]
* [[B]]
* [[BASIC]] (Beginner's All Purpose Symbolic Instruction Code) (.bas) -- See also [[Tokenized BASIC]]
* [[Batch file]] (DOS, Windows, OS/2)
* [[BCPL]]
* [[BLISS]]
* [[Blitz BASIC]]
** [[Blitz3D]]
* [[BlooP, FlooP, and GlooP]]
* [[Bourne shell script]] (.sh)
* [[Brainfuck]]
* [[Breder]]
* [[C]] (.c, .cc, .h)
* [[Ć]]
* [[C Sharp|C#]] (.cs)
* [[C shell script]]
* [[C++]] (.cpp, .cxx)
* [[C+=]]
* [[CakeML]]
* [[CEEMAC]]
* [[CFEngine]]
* [[CHIP-8]]
* [[ChordQL]]
* [[Clipper (programming language)]]
* [[Clojure]]
** [[ClojureScript]]
* [[COBOL]] (COmmon Business-Oriented Language)
* [[CoffeeScript]]
* [[ColdFusion]]
* [[COMAL]]
* [[COMIT]]
* [[COW]]
* [[Coq]]
* [[CPL]]
* [[Crystal]]
* [[Cython (Pyrex)]]
* [[D]]
* [[Dart]] (was Dash)
* [[Dern]]
* [[dBase programming language]]
* [[Dylan]]
* [[Elixir]]
* [[Elm]]
* [[Erlang]]
* [[Expect]]
* [[F Sharp|F#]]
* [[Fantom]]
* [[Fish shell]] (*.fish)
* [[Flare]]
* [[Flow]]
* [[Forth]]
* [[FORTRAN]] (FORmula TRANslation)
* [[FoxPro programming language]]
* [[Free Pascal]]
* [[GAMS]] (.gms)
* [[GDL Script]] - scripting language used in ARCHICAD (.gdl)
* [[Gherkin]]/Cucumber
* [[Go]]
* [[Graphics Programming Language]] (GPL) (mid-level language on TI computers)
* [[Groovy]]
* [[HamsterSpeak]]
* [[Haskell]]
* [[Haxe]]
* [[High Level Shading Language]] (HLSL)
* [[Hoon]]
* [[Hopscotch]]
* [[HyperTalk]]
* [[IDL]]
* [[INTERCAL]]
* [[Ioke]]
* [[Java]] (.j, .jav, .java)
* [[JavaScript]] (JScript, [[ECMAScript]]) (.js)
** [[Node.js]]
** [[React]]
** [[TypeScript]]
* [[JCL]] (Job Control Language; used on IBM mainframes)
* [[JOSS]]
* [[JSONata]] [http://jsonata.org/]
* [[JSX]]
* [[Julia]]
* [[Kotlin]]
* [[LISP]]
* [[LiveScript]]
* [[Logo]]
* [[LOLCODE]]
* [[Lollipop]]
* [[Lua]]
* [[Lurk]]
* [[Machine language]] (various versions for different machine architectures)
* [[MATLAB script file]] (.m)
* [[MDL (programming language)|MDL]] (.mud)
* [[Microcode]]
* [[mIRC scripting language]]
* [[ML]]
* [[MUMPS]] (Massachusetts General Hospital Utility Multi-Programming System)
* [[Music Macro Language]] (.mmi)
* [[Nim]]
* [[Nock]]
* [[NetLogo]]
* [[Object Pascal]] (including Delphi)
* [[Objective-C]] (.m, .h) (used in Mac and iOS development)
* [[OCaml]]
* [[OpenGL Shading Language]] (GLSL)
* [[P (Microsoft programming language)|P]] (Microsoft)
* [[Pascal]] (.pas)
* [[Pawn]]
* [[Perl]] (.pl, .pm)
* [[PHP]] (.php)
* [[PikaScript]]
* [[Pixie (programming language)|Pixie]]
* [[Pixilang]] (.pixi)
* [[PL/I]]
* [[PLASMA]]
* [[PostScript]]
* [[PowerShell]]
* [[Processing]]
* [[Programmable Command Language]] (PCL), for TOPS-20
* [[Prolog]]
* [[Pyramid]]
* [[Python]] (.py, .pyc, .pyo, .pyd)
* [[QML]]
* [[Q Sharp|Q#]]
* [[Quorum]]
* [[R]]
* [[Raku]]
* [[Rant]]
* [[Ratfor]]
* [[Redcode]]
* [[RenderWare object]] (.rwx)
* [[RobotWar]]
* [[RPG]]/RPGLE/RPG IV/RPG ILE (.rpgle, .sqlrpgle)
* [[Ruby]]
* [[Rust]]
* [[S]]
* [[SAIL]]
* [[Scala]]
* [[Scheme]]
* [[SCODL]]
* [[Scratch]]
* [[Server Side Includes]]
* [[Shen]]
* [[Sikuli]]
* [[Skip]]
* [[Smalltalk]]
* [[SNOBOL]]
* [[Solidity]]
* [[Squirrel]]
* [[Standard ML]]
* [[StarLogo]]
* [[Swift]] (Apple) (.swift)
* [[Swift (parallel scripting)]]
* [[SYSDOOM]]
* [[Tcl]]
* [[TRAC programming language]]
* [[TUTOR]]
* [[TypeScript]]
* [[Verilog]]
* [[vim script]]
* [[Visual Basic]]
* [[VBScript]]
* [[Vue.js]] component files
* [[WaveGL]]
* [[WebAssembly]]
* [[Wenyan]] (文言)
* [[Windows Script File]]
* [[WMLScript]]
* [[Wolfram Language]]
* [[Wuffs]]
* [[ZAP]]
* [[Z-code]]
* [[ZIL]]

== Logical assertion languages ==
* [[SNARK]]

== Query languages ==
* [[Fauna Query Language]] (FQL)
* [[SPARQL]]
* [[SQL]]

== Templates, macros, preprocessors, etc. ==
* [[Cascading Style Sheets|CSS]]
* [[doT]]
* [[DSSSL]]
* [[Jinja]]
* [[Jsonnet]] [https://jsonnet.org/]
* [[Liquid]] (.liquid)
* [[M4]] (.m4)
* [[Pug]]
* [[Smarty]]
* [[XSL]]
* [[XSLT]]

For additional macro formats, especially binary formats, see [[Executables#Macros or automated scripting]].

See also [[Web#Scripts/Applets/Plug-Ins/Frameworks/APIs/Templating]].

See [[Wikipedia:Category:Template engines]] for another list of template systems.

== Other/Miscellaneous ==
* [[Nomyx language]]
* [[Programmable calculators]]

== See also ==
* [[Development]]
* [[Executables]]
* [[Interactive Fiction]] engines often use specialized programming languages for game development.
* [[Resources]]
* [[Source code]]

== External links ==
===Resources===
* A comprehensive list of over 2000 programming languages and a small sample programs for each of them is available [http://www.99-bottles-of-beer.net/ here]
* [http://rosettacode.org/ Rosetta Code] attempts to present solutions to the same task in different programming languages.
* [http://storify.com/carlzimmer/coding-for-middle-school-girls?utm_content=storify-pingback&utm_source=t.co&utm_campaign=&awesm=sfy.co_s2LP&utm_medium=sfy.co-twitter Coding for middle-school girls] (tips on introducing them to programming)
* [http://langpop.corger.nl/ Programming language popularity chart (based on Github and StackOverflow activity)]
* [http://hivelogic.com/articles/top-10-programming-fonts Top 10 programming fonts]
* [http://www.integralwebsolutions.co.za/Blog/EntryId/901/What-s-The-Most-Popular-Programming-Language.aspx What’s The Most Popular Programming Language?]
* [http://lifehacker.com/which-programming-language-should-i-learn-first-1477153665 Which programming language should I learn first?]
* [http://exple.tive.org/blarg/2013/10/22/citation-needed/ Why array indices start at zero; historical info]
* [http://www.codecademy.com/ Code Academy: learn to code interactively online]
* [http://howto.cnet.com/8301-11310_39-57615356-285/best-free-sites-for-learning-how-to-write-code/ Best free sites for learning how to write code]

=== Commentary ===
* [http://boingboing.net/2013/02/27/what-most-schools-should-reall.html Why you should learn to program]
* [http://mentalfloss.com/article/53160/meet-refrigerator-ladies-who-programmed-eniac Meet the 'Refrigerator Ladies' Who Programmed the ENIAC]
* [http://devblog.avdi.org/2014/01/31/the-moderately-enthusiastic-programmer/ The Moderately Enthusiastic Programmer]
* [http://techcrunch.com/2013/10/10/my-experience-as-a-fourth-grade-hacker/ My Experience As A Fourth Grade Hacker]
* [https://medium.com/learning-to-code/565fc9dcb329 Things I Wish Someone Had Told Me When I Was Learning How to Code]
* [http://michaelochurch.wordpress.com/2012/01/15/the-problem-with-programming-language/ A problem with the term, programming “language”]
* [http://animalnewyork.com/2014/artists-notebook-ramsey-nasser/ Discussion of creating programming languages in Arabic]
* [http://www.viva64.com/en/b/0260/ The Last Line Effect]
* [http://bost.ocks.org/mike/algorithms/ Visualizing algorithms]
* [http://www.playthepast.org/?p=4982 Excavating Code: An Archaeological Record of Software Development]
* [https://medium.com/towards-a-remarkable-career/the-art-of-the-bug-ac5a535315fa The art of the bug: Failure should be fun]
* [https://speakerdeck.com/craigstuntz/incredibly-strange-programming-languages Incredibly Strange Programming Languages (presentation)]

===Humor===
* [http://james-iry.blogspot.com/2009/05/brief-incomplete-and-mostly-wrong.html A Brief, Incomplete, and Mostly Wrong History of Programming Languages]
* [http://colinm.org/language_checklist.html Programming Language Checklist]
* [http://www.quora.com/Programming-Languages/If-there-is-a-war-of-programming-languages-who-would-you-support-and-why/answer/Prithviraj-Udaya?srid=LZ&st=ns Programming languages as Tolkien characters]
* [http://programmingisterrible.com/post/65781074112/devils-dictionary-of-programming Devil's Dictionary of Programming]
* [http://9gag.com/gag/av0z0Bn?ref=fb.s This Is Why You Shouldn't Interrupt A Programmer]
* [http://kingjamesprogramming.tumblr.com/ Random mashup generator of the King James Bible and a programming book]
* [http://moviecode.tumblr.com/ What the computer code seen on screens in movies and TV shows actually does]

===Misc.===
* [http://abcnews.go.com/Politics/video/obama-slow-man-27453525 President Obama writes a line of code (video)]
* [https://medium.com/@3fingeredfox/margaret-hamilton-lead-software-engineer-project-apollo-158754170da8 Picture: Margaret Hamilton, lead software engineer, Project Apollo, with source code from moon landing mission]
* [http://www.watchpeoplecode.com/ Watch People Code (live video streams)]

GAMS

2022-11-04T18:44:32Z

Eiim: Create page from my minimal knowledge and searching of GAMS.

{{FormatInfo
|formattype=Languages
|subcat=Programming Languages
|extensions={{ext|gms}}, {{ext|opt*}}, {{ext|gdx}}, {{ext|inc}}, {{ext|lst}}, {{ext|lxi}}, {{ext|efi}}, {{ext|ref}}
|released=1978
}}
[[GAMS]] is a programming language and software suite to model mathematical optimization problems. It enables a wide variety of models to be described with many thousands of variables. Running a GAMS problem solves the models described in the source code, but can also do other things. The language is proprietary. A number of file types and extensions are used by GAMS:

=== .gms ===
The main source code for a GAMS project is in one or more text files ending with .gms extensions. This defines variables, equations, and other important parts of the model definition.

=== .opt ===
These are options files for specific solvers in GAMS. They may have secondary extensions after the <code>.opt</code> to distinguish them, as their file name determines which solver they affect. For example, a CPLEX options file may be named <code>CPLEX.opt</code>, or <code>CPLEX.opt.foo</code> to distinguish it from other options files for that solver. According to GAMS, these may also end in <code>.op*</code> or <code>.o*</code>.

=== .gdx ===
GDX files are binary data files. These can be read and edited with GAMS, or with other programming languages using libraries that are included as part of GAMS.

=== .inc ===
"Include files." I have no idea what these are, but they're apparently text files.

=== .lst, .lxi, .ref ===
These are text files created by GAMS. <code>.lst</code> files show logs and results from the solving process. <code>.lxi</code> files are a sort of intermediate language. <code>.ref</code> files are used for debugging. LST files are also called "MASM Listing" files, however, they should not be confused with Microsoft Assembler files (also called MASM).

=== .efi ===
Short for "External files", these are text files which denote which files need to be sent when using cloud computing.

=== Other files ===
GAMS also may use a [[YAML]] file called <code>gamsconfig.yaml</code>, and supposedly also <code>.ref</code> "reference" files, but I don't know anything about that one.

== References and more information ==
* [https://en.wikipedia.org/wiki/General_algebraic_modeling_system GAMS on Wikipedia]
* [https://www.gams.com/latest/docs/UG_MAIN.html#UG_Language_Environment GAMS language documentation]
* [https://gams.com/latest/docs/UG_GDX.html#UG_GDX_GeneralNotesOnGDXFiles GDX files]
* [https://www.gams.com/41/docs/UG_studio_tutorial.html?search=lst Short info and examples for .lst and .lxi files]
* [https://www.gams.com/latest/docs/gamside/reference_window.htm .ref files in the GAMS viewer]
* [https://www.gams.com/latest/docs/T_STUDIO.html Some info on .efi files]