XiphWiki - User contributions [en]

TheoraDecoders

2005-09-05T20:13:53Z

Matc:

* [http://theora.org/ xiph]
* [http://ffmpeg.org ffmpeg] (only vp3 features, mmx, sse2 optimisations)

FLACDecoders

2005-09-05T20:13:25Z

Matc:

* [http://flac.sourceforge.net/ xiph]
* [http://ffmpeg.org ffmpeg]

Vorbis Decoders

2005-09-05T20:12:38Z

Matc:

* [http://vorbis.com/ xiph]
* [http://ffmpeg.org ffmpeg]

FLACDecoders

2005-09-05T20:11:35Z

Matc:

* [http://ffmpeg.org ffmpeg]

FLAC

2005-09-05T20:11:14Z

Matc:

'''FLAC''' stands for '''Free Lossless Audio Codec'''. FLAC is an [[audio compression]] [[codec]] that is [[lossless data compression|lossless]]. Unlike [[lossy data compression|lossy]] codecs such as [[MP3]] and [[Vorbis]], it does not remove any information from the audio stream.

On January 29th, 2003, Xiphophorus (now called the [[Xiph.org Foundation]]) announced the incorporation of FLAC under their xiph.org banner, to go along with [[Ogg]] Vorbis, Ogg [[Theora]], and [[Speex]].

== The Project ==

The FLAC project consists of:
* the stream format
* libFLAC, a library of reference encoders and decoders, and a metadata interface
* libFLAC++, an object wrapper around libFLAC
* flac, a command-line wrapper around libFLAC to encode and decode .flac files
* metaflac, a command-line metadata editor for .flac files
* input plugins for various music players ([[Winamp]], [[XMMS]], Foobar2000, and more in the works)

"Free" means that the specification of the stream format is in the [[public domain]] (the FLAC project reserves the right to set the FLAC specification and certify compliance), and that neither the FLAC format nor any of the implemented encoding/decoding methods are covered by any patent. It also means that the sources for libFLAC and libFLAC++ are available under Xiph.org's [[BSD license]] and the sources for flac, metaflac, and the plugins are available under the [[GPL]].

== Comparisons ==

FLAC is distinguished from general lossless algorithms such as [[ZIP file format|ZIP]] and [[gzip]] in that it is specifically designed for the efficient packing of audio data; while ZIP may compress a CD-quality audio file 20–40%, FLAC achieves compression rates of 30–70%.

While lossy codecs can achieve ratios of 80–90+%, they do this at the expense of discarding data from the original stream. Though FLAC uses a similar technique in its encoding process, it also adds "residual" data to allow the decoder to restore the original waveform flawlessly.

FLAC has become the preferred lossless format for trading live music online. It has a smaller file size than [[Shorten]], and unlike MP3, it's lossless, which ensures the highest fidelity to the source material, which is important to live music traders. It has recently become a favorite trading format of non-live lossless audio traders as well.

FLAC compiles on many platforms: most [[Unix|Unices]] (including [[Linux]], *[[BSD]], [[Solaris Operating Environment|Solaris]], and [[Mac OS X]]), [[Microsoft Windows|Windows]], [[BeOS]], and [[OS/2]]. There are build systems for [[autoconf]]/[[automake]], MSVC, Watcom C, and Project Builder.

== More information ==

* [[FLACDecoders]]: List of decoders
* [[FLACEncoders]]: List of encoders

== Non-PC playback support ==

FLAC is supported by a wide range of devices such as:

* Rio Karma http://www.digitalnetworksna.com/rioaudio/
* iAudio http://www.iaudio.com
* PhatNoise Phatbox
* PhatNoise Home Media Player
* Kenwood Music Keg

== External links ==

*[http://flac.sourceforge.net/ Project homepage]
*[http://mikewren.com/flac/ Unofficial FLAC installer for Windows]
*[http://www.danrules.com/macflac/ MacFLAC] [[GUI]] frontend to encode/decode FLAC on [[Mac OS X]]
*[[Wikipedia: FLAC]]

TheoraDecoders

2005-09-05T20:07:30Z

Matc:

* [http://ffmpeg.org ffmpeg] (only vp3 features, mmx, sse2 optimisations)

Theora

2005-09-05T20:05:09Z

Matc:

'''Theora''' is our video codec, based on the VP3 codec donated by [[On2 Technologies]]. We've refined and extended it, giving it the same future scope for encoder improvement [[Vorbis]] has. See http://theora.org/ for more information.

== Status ==

Alpha 5 is the latest release. The bitstream format is frozen. Every file created with the alpha 3 encoder (and, of course, later encoders) will be playable with future decoders. Beta 1 will be the next release.

It would be nice if somewhere it could be explained if Theora is a format appropriate for editing video - such formats would not do frame to frame compression and the file size and processor load would be smaller. On the other hand a distribution format would want to pack in a lot of compression which would mean using frame to for compression.

== Development ==

* [[Theora:Beta1ToDo|Todo for Beta1]]

== More information ==

* [[TheoraHardware]]: List of hardware-players supporting Ogg Theora
* [[TheoraSoftwarePlayers]]: List of media players that can play Ogg Theora
* [[TheoraDecoders]]: List of decoders
* [[TheoraEncoders]]: List of encoders

== External links ==

* [http://www.theora.org/ Theora homepage]
* [http://www.annodex.net/software/theora/ Theora documentation daily builds]
* [[Wikipedia: Theora]]
* [http://www.vp3.com VP3 homepage]: The homepage of the codec Theora is based on
* [http://www.on2.com On2 Technologies]: The creators of VP3

Vorbis Decoders

2005-09-05T20:02:31Z

Matc:

* [http://ffmpeg.org ffmpeg]