Commons:File types

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Wikimedia Commons only accepts "free content"; likewise, ONLY free file formats are allowed.

Currently permissible formats are: JPEG, GIF, PNG, SVG or XCF for images; Ogg Vorbis/FLAC/Speex or MIDI for sound; Ogg Theora for video; PDF or DjVu for text documents.

Patent-encumbered file formats like MP3, AAC, WMA, MPEG, AVI and the like are not accepted at Wikimedia Commons. Our mission requires content to be freely redistributable to all. Patent-encumbered formats fail to meet this standard.

Non-free formats must be converted to a free format before uploading. Fortunately, this is not difficult.

Contents

[edit] Tutorials for related topics

[edit] Summary of file types

Only certain file types are accepted on the Wikimedia Commons. These are (as of March 2008):

[edit] Images

On Wikimedia Commons, the file types we recommend are: SVG, PNG, JPEG, and XCF (GIMP).

Image formats that are not allowed at the Wikimedia Commons include TIFF and BMP. These can both be losslessly converted to PNG (in case of BMP file size will even be smaller).

Unfortunately the image scaling system is still fairly bad. Currently, thumbnails are generated in the same format as the original image and are always in 24-bit color unless the image is GIF, in which case the resulting image will have 256 colors. This means that scaling PNG images produces fairly large files even if the original image contained a palette. This also means that if you want to upload a lossless PNG of a photo for editing and archival, but want to use JPEG thumbnails in articles, you have to upload a (full scale) JPEG version manually.

Note that scaling of images may fail if the image is very large and rendering takes too much time or memory (in that case, either no scaled image is shown, or the full image is served to the browser, often causing it to lock up). For PNG images, a hard limit of 12 megapixels is in effect. Large JPEGs are only problematic if they are saved in progressive mode, use baseline mode instead. In case the full scale original is too large to process for the software, please overwrite it with a scaled down version (around 6 megapixels in size); the full scale version will still be available in the upload history, and you can add a reference to it in the image description.

[edit] JPEG

JPEG is appropriate for photographs; JPEG uses "lossy compression", sacrificing precision for smaller file size.

[edit] GIF

GIF should only be used for animated images on Wikimedia Commons (PNG is always superior for still images). GIF also uses lossless compression of images up to 256 colors per frame. (There exists an uncommon hack to render higher-color still images as GIF animations,[1] but PNG produces smaller results.)

[edit] PNG

PNG and SVG are better for drawings / diagrams (SVG is preferred when creating diagrams etc, PNG is good for scanned images, or for print-quality photographs).

PNG is a "lossless" format, meaning that the exact pixel color is preserved when saving and to be used for any kind of diagram that is not available in SVG format.

[edit] SVG

SVG is an XML-based vector graphics format, so it can be scaled at will without getting blurry or "pixelated", is easy to edit, and usually produces very small files. SVG is preferred when creating diagrams, flags, etc, while PNG is good for scanned images, or for print-quality photographs. You can find further information at SVG, Help:SVG and Commons:Transition to SVG.

[edit] Sound

On Wikimedia Commons, the file types we recommend are: Ogg (using FLAC, Speex, or Vorbis codecs) or MIDI (with extension .mid)

Non-free formats and lesser-known free formats must be converted before uploading - there is currently no legitimate way to store pristine original data for conversion to future formats or for use when patents expire, even if the license of a given work requires distributing such pristine original data (as is often the case for works distributed under the GNU Free Documentation License or other copyleft licenses).

Commons cannot accept MP3 sound files—there are numerous patent claims on MP3, making it illegal in some countries to use open source software with MP3, and even proprietary software companies are being threatened with various lawsuits.

The Commons also does not accept tracker formats, nor does it accept sound fonts for use with MIDI files. If it is important that a musical passage be heard with specific instrument definitions that General MIDI does not provide for, and the license allows it, use your tracker software to render the passage to RIFF WAVE, and then encode it to Ogg Vorbis.

[edit] Ogg

Speex is intended for recordings of speech, Vorbis is for general audio and is lossy (quality is reduced) — FLAC is for general audio and is lossless (quality is preserved), but current file size caps prevent its use for anything but short clips. In most cases, Vorbis should be used.

Do note that with FLAC, a native container format exists. If your output file has the extension .flac, it is likely using the native container format. You should not simply rename this to .ogg, instead you need to convert the container to .ogg.

[edit] Ogg Vorbis (audio)

en:Vorbis is a lossy audio codec. Also see the players for Ogg Theora videos below—they can also play Vorbis audio.

[edit] Video

Videos must be Ogg files using the Theora video codec. Again, non-free formats must be converted before uploading.

[edit] Ogg Theora (video)

Theora is a lossy video codec (see en:Theora). (Note: most software mentioned at Commons:Software should also be able to play Ogg Vorbis audio.)

[edit] Scanned text documents

Use DjVU. See Commons:DjVu.

See also Help:Scanning for advice on scanning non-text items.

[edit] External links

Retrieved from "http://commons.wikimedia.org/wiki/Commons:File_types"
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