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Ogg is a free, open container format maintained by the Xiph.Org Foundation. The creators of the Ogg format state that it is unrestricted by software patents〔http://www.vorbis.com/faq/#what〕 and is designed to provide for efficient streaming and manipulation of high quality digital multimedia. "Ogg" is derived from "ogging", jargon from the computer game ''Netrek'': The Ogg container format can multiplex a number of independent streams for audio, video, text (such as subtitles), and metadata. In the Ogg multimedia framework, Theora provides a lossy video layer. The audio layer is most commonly provided by the music-oriented Vorbis format but other codec options include the compression codec Opus, the lossless audio compression codec FLAC, and OggPCM. Before 2007, the .ogg filename extension was used for all files whose content used the Ogg container format. Since 2007, the Xiph.Org Foundation recommends that .ogg only be used for Ogg Vorbis audio files. The Xiph.Org Foundation decided to create a new set of file extensions and media types to describe different types of content such as .oga for audio only files, .ogv for video with or without sound (including Theora), and .ogx for multiplexed Ogg. As of August 4, 2011, the current version of the Xiph.Org Foundation's reference implementation, is libogg 1.3.0. Another version, libogg2, has been in development, but is awaiting a rewrite as of 2008. Both software libraries are free software, released under the New BSD License. Ogg reference implementation was separated from Vorbis on September 2, 2000.〔Xiph.Org (2002-07-19) (Ogg releases - libogg-1.0.tar.gz - CHANGES ). Retrieved 2009-09-01.〕 Because the format is free, and its reference implementation is not subject to restrictions associated with copyright, Ogg's various codecs have been incorporated into a number of different free and proprietary media players, both commercial and non-commercial, as well as portable media players and GPS receivers from different manufacturers. ==Naming== It is sometimes assumed that the name "Ogg" comes from the character of Nanny Ogg in Terry Pratchett's ''Discworld'' novels, but the Ogg developers say that is not true.〔 Ogg is derived from ogging, jargon from the computer game ''Netrek'', which came to mean doing something forcefully, possibly without consideration of the drain on future resources. At its inception, the Ogg project was thought to be somewhat ambitious given the power of the PC hardware of the time. Still, to quote the same reference: "Vorbis, on the other hand is named after the Terry Pratchett character from the book ''Small Gods''". The Ogg Vorbis project started in 1993. It was originally named "Squish" but that name was already trademarked, so the project underwent a name change. The new name, "OggSquish", was used until 2001 when it was changed again to "Ogg". Ogg has since come to refer to the container format, which is now part of the larger Xiph.org multimedia project. Today, "Squish" (now known as "Vorbis") refers to a particular codec typically stored in the Ogg container. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ogg」の詳細全文を読む スポンサード リンク
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