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This document provides a short explanation of what a Free format is, along with some specific information on the range of Free formats which are available for you to use. Warning - patent and copyright laws operate differently depending on which country you are in. Please obtain legal advice if you are unsure whether a particular patent or restriction applies to a format you wish to use in your country.
What is a Free format?
Some file formats are proprietary, which means that they are owned by a company or other organisation. Sometimes, the owners of such formats charge licensing fees or impose legal restrictions on the use of their formats. This means that people may be unable to use or distribute these formats without first paying a fee or applying for a license. A Free or open format is one which can be used by anyone, free of legal restrictions on how they use the format. Free formats are very popular - the World Wide Web is based on the open HTML standard. Ubuntu supports many free formats and the open-source community as a whole encourages their wider use. There are a number of Free formats which are preferred over patent and copyright encumbered formats. Keep in mind that some formats (like PDF or Flash) often have public or semi-public specifications but have some restrictions imposed by their patent-holders. Some replacement formats are listed here:
|Restricted Format||Preferred format|
|MP3, AAC, WMA||Ogg Vorbis|
|WMV, AVI, MPEG-4||Ogg Theora|
|doc, xls, ppt||OpenDocument format|
一些文件格式是私有的，这意味着他们由公司或其他组织拥有。有时，这样格式的所有者要收取专利费,或者通过法律限制使用这种格式，这就意味着，如果没有付费或者没有申请许可证，人们将可能无法使用或分发这些文件格式，自由或开放格式是可以由任何人使用，不用担心受到法律的限制。免费的格式都十分受欢迎-万维网是基于开放的H TML标准。Ubuntu的支持许多免费的格式，鼓励开放源代码社区更广泛地使用他们。有很多免费的格式，比受专利和版权限制的格式更受欢迎。请记住，一些格式（如PDF格式或Flash ） ，往往是自由或半自由的，但专利的持有人对其施加了限制。一些替换的格式都列在这里：
Purchasing equipment that supports free formats
Electronic equipment, such as portable audio players, often support only a handful of different formats. Often, these will be proprietary formats which the manufacturer of the device has obtained a license to use or similar. As such, it can sometimes be difficult to find a product which is able to use a chosen Free format. This section provides advice on purchasing equipment which can make use of Free formats.
If you are interested in purchasing new players (e.g. portable audio players), please refer to VorbisHardware to see what equipment is able to play these formats.
如果您有兴趣购买新的播放机（如便携式音频播放器） ，请参阅vorbishardware ，看看有什么设备是能够播放这些格式。
Specific format / application information
This section provides information on format-specific issues and lists alternatives to popular non-free formats.
Many popular audio formats are non-free and may be subject to legal restrictions in some countries. There are superior Free formats available, however.
The MP3 format is or may be subject to certain patents, for both encoding and decoding. These patents are being actively litigated, so usage and development of programs related to the MP3 format is at your own risk. Consider using Ogg Vorbis, which is a free and higher quality alternative to MP3 (you just need to buy audio equipment more carefully). Other free audio formats:
MP3格式音频的编码和解码，受到或可能受到专利的保护，这些专利正在积极诉讼，因此，使用和开发与MP3格式有关的程序，无疑你自己要承担风险。考虑使用ogg vorbis ，这是一个自由和更高质量的格式，它可以替代MP3文件（你只需要购买音响设备，更仔细） 。其他免费的音频格式：
FLAC (Free Lossless Audio Codec)——
speex (high quality speech compression)——高品质的语音压缩
Some video formats are also subject to legal restrictions in certain countries, or
attempt copy-protection methods which are non-free.
Non-encrypted DVDs should play, however be aware that mpeg2-video is arguably patent encumbered and the support for it is not installed by default in Ubuntu. Full DVD-Video support requires support for the Content Scrambling System (CSS). Because the encryption is weak, using libdvdcss from Medibuntu enables one to play DVDs in a Linux/Ubuntu system. In the United States, whether one can use libdvdcss to decrypt DVDs is governed by Title I of the Digital Millennium Copyright Act (DMCA). (17 U.S.C. Sec. 1201 et seq.) Although the law is technical, it need not frighten anyone. Decrypting DVDs is legal if the decryption is done to achieve interoperability of computer programs, such as the Linux/Ubuntu operating system. (See 17 U.S.C. Sec. 1201(f)) So, for instance, if you own a legally-purchased DVD and are trying to play it on your own computer with Ubuntu, using libdvdcss is legal because you are merely exercising the license that you acquired when you obtained the DVD. However, if you use libdvdcss for the purpose of circumventing copyright protection, such as for file sharing or redistributing the content, libdvdcss would be classed as an illegal 'circumvention device'. (For a more detailed description of the DMCA, see the Wikipedia article). Because Canonical cannot know in advance what you intend to do with libdvdcss, it has decided not to include it in the regular Ubuntu repositories. To be on the safe side if you live in the United States, only use libdvdcss to play your own movies, but don't use it to make copies so you can give the movie away to your friends and relatives. If they want to watch the movie, invite them over to your house or send them a gift card for the DVD rental place. However, as you can read at the DeCSS information page, in most European countries DVD backup is legal. In fact, in countries such as Norway and Sweden you can legally backup anything that you own. If you do not require compatibility with a DVD player, consider encoding your videos in the Ogg Theora format. Other free video formats:
- Dirac (another free video format in development)
Desktop publishing and graphics
- OpenDocument - This group of office document formats is seen as an excellent alternative to proprietary formats such as those used by Microsoft Office and is gaining widespread support in open-source office suites. OpenDocument recently became an International standard - ISO/IEC 26300. More information can be found on the ODF Alliance website.
- Scalable Vector Graphics (SVG)''''- SVG is a vector graphics format developed by the World Wide Web Consortium (W3C), which is responsible for major Web standards such as HTML, CSS and PNG. SVG is recommended as an alternative to proprietary vector graphics formats such as Adobe Illustrator (AI). A list of design tools which support this format is available. For more information, see the W3C's SVG pages.
Scribus is also a good alternative for desktop publishing.
在开放源代码办公室套装软件中，这组O ffice文档格式得到广泛支持，被认为能够替代其他专有的文件格式，例如代替M icrosoftO ffice。 OpenDocument的最近成为一项国际标准-（I SO/ I EC2 6300）。更多信息，请查阅 ODF Alliance website 。
可伸缩矢量图形（ SVG） -S VG是一个向量图形格式,它由万维网协会（ W 3C）开发，万维网协会主要负责制定W eb标准，如关于H TML， C SS和P NG。 建议用SVG替代专有的矢量图形格式，如Adobe Illustrator（AI） 。名单设计工具支持此格式。如需详细资讯，请参阅W3C的SVG的网页。
Other multimedia format types may be subject to legal restrictions.
There are several projects working to create a free implementation of
Macromedia Flash, so that people can view Flash animations without resorting to non-free software:
GPLFlash (and GPLFlash2)
Other popular formats may also be subject to restrictions in some jurisdictions.
Free implementation of Java is ongoing in many places, including
GCJ, GNU Classpath, gcjwebplugin and the new Apache Harmony. Together they aim to provide a full Java platform as Free software. Current implementations are already being used to run OpenOffice.org 2's Java components, the Eclipse IDE and many other applications. Sun has recently announced that future versions of Java will be licenced under the GPL.
GCJ, GNU Classpath, gcjwebplugin 和新推出的 Apache Harmony。他们共同的目标，提供完全的免费的Java平台，目前JAVA已应用到openoffice.org 2的Java组件，还有Eclipse的集成开发环境和许多其他应用。SUN公司最近宣布，未来的JAVA版本将遵守GPL协议。
- Wikipedia article on open formats - http://en.wikipedia.org/wiki/Open_format
- OpenFormats.org - http://www.openformats.org