View source for FourCC

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A '''FourCC''' (literally, '''four'''-'''c'''haracter '''c'''ode) is a sequence of four [[wikipedia:byte|bytes]] used to uniquely identify [[wikipedia:File format|data format]]s.
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=====Technical details===== __NOEDITSECTION__
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The byte sequence is usually restricted to [[wikipedia:ASCII#ASCII printable characters|ASCII printable characters]], with space characters reserved for padding shorter sequences. Case sensitivity is preserved. 

Four-byte identifiers are useful because they can be made up of four human-readable characters with mnemonic qualities. Thus, the codes can be used efficiently in program code as integers, as well as giving cues in binary data streams when inspected.

{{AvsPluscon}} Some FourCCs, such as those for certain [[High_bit_depth|high bit depth]] raw video formats, contain non-printable characters and are not human-readable without special formatting for display; for example, 10bit planar YUV422, known in [[AviSynth%2B]] as [[Avisynthplus_color_formats|YUV422P10]], can have a FourCC of <span style="white-space:nowrap">('Y', '3', 10, 10)<sup>[http://ffmpeg.org/doxygen/trunk/raw_8c_source.html#l00136 (1)]</sup></span> which ffmpeg displays as <span style="white-space:nowrap"><code>rawvideo (Y3[10][10] / 0xA0A3359), yuv422p10le</code>.</span>
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=====History===== __NOEDITSECTION__
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In 1985, [[wikipedia:Electronic Arts|Electronic Arts]] introduced the [[wikipedia:Interchange File Format|Interchange File Format]] (IFF) meta-format (family of file formats), originally devised for use on the [[wikipedia:Amiga|Amiga]]. These files consisted of a sequence of "chunks", which could contain arbitrary data, each chunk prefixed by a four-byte ID. The IFF specification explicitly mentions that the origins of the FourCC idea lie with Apple.<sup>[http://www.martinreddy.net/gfx/2d/IFF.txt (2)]</sup>

This IFF was adopted by a number of developers including [[wikipedia:Apple Computer|Apple]] for [[wikipedia:AIFF|AIFF]] files and [[wikipedia:Microsoft|Microsoft]] for [[wikipedia:RIFF (File format)|RIFF]] files (which were used as the basis for the [[wikipedia:Audio Video Interleave|AVI]] and [[wikipedia:WAV|WAV]] file format). Microsoft and [[wikipedia:Microsoft Windows|Windows]] developers refer to their four-byte identifiers as '''FourCC'''s.
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=====References===== __NOEDITSECTION__
# [http://ffmpeg.org/doxygen/trunk/raw_8c_source.html#l00136 ''RAW.C''] (ffmpeg.org)
# [http://www.martinreddy.net/gfx/2d/IFF.txt ''"EA IFF 85" Standard for Interchange Format Files''] (martinreddy.net)

=====External links===== __NOEDITSECTION__
* [http://www.fourcc.org Video codecs and Pixel Formats] (fourcc.org)


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''This page was adapted from Wikipedia: [https://en.wikipedia.org/w/index.php?title=FourCC&oldid=769753770 FourCC]; version 11 March 2017. ''

''Wikipedia text is available under the [https://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License Creative Commons Attribution-ShareAlike License]'' 

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