Hydrogenaudio Knowledgebase - User contributions [en]

Free Lossless Audio Codec

2007-09-19T14:04:30Z

Kwanbis: /* Frontends (Windows) */

{{Codec Infobox
| name = FLAC
| logo = [[Image:FLAC logo.gif]]
| type = lossless
| purpose = Popular open source patent free lossless compression scheme.
| maintainer = Josh Coalson, Xiph Community
| recommended_encoder = FLAC encoder
| recommended_text = FLAC v1.1.4
| website = http://flac.sourceforge.net/
}}
'''Free Lossless Audio Codec''' ('''FLAC''') is a codec for lossless audiocompression.
Grossly oversimplified, FLAC is similar to [[MP3]], but [[lossless]], meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio, and you can play back compressed FLAC files in your favorite player (or your car or home stereo, if supported) just like you would an MP3 file.

== General aspects of the format ==
FLAC is freely available and supported on most operating systems, including Windows, UNIX (Linux, *BSD, Solaris, OS X, IRIX), BeOS, OS/2, and Amiga. There are build systems for autotools, MSVC, Watcom C, and Project Builder.

The FLAC project consists of:
* the stream format
* reference encoders and decoders in library form
* flac, a command-line program to encode and decode FLAC files
* metaflac, a command-line metadata editor for FLAC files
* input plugins for various music players

When we say that FLAC is ''free'' it means more than just that it is available at no cost. It means that the specification of the format is fully open to the public to be used for any purpose (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 known patent. It also means that all the source code is available under open-source licenses. It is the first truly open and free lossless audio format.

Some claim FLAC is the most widely used lossless compression format on UNIX systems (though it seems more likely that shn retains that honor on all OS platforms).
FLAC files also can be placed inside an Ogg container using libOggFLAC and libOggFLAC++.

== Features ==
* '''Lossless:''' The encoding of audio (PCM) data incurs no loss of information, and the decoded audio is bit-for-bit identical to what went into the encoder. Each frame contains a 16-bit CRC of the frame data for detecting transmission errors. The integrity of the audio data is further insured by storing an MD5 signature of the original unencoded audio data in the file header, which can be compared against later during decoding or testing.
* '''Fast:''' FLAC is asymmetric in favor of decode speed. Decoding requires only integer arithmetic, and is much less compute-intensive than for most perceptual codecs. Real-time decode performance is easily achievable on even modest hardware.
* '''Hardware support:''' Because of FLAC's free reference implementation and low decoding complexity, FLAC is currently the only lossless codec that has any kind of hardware support.
* '''Streamable:''' Each FLAC frame contains enough data to decode that frame. FLAC does not even rely on previous or following frames. FLAC uses sync codes and CRCs (similar to MPEG and other formats), which, along with framing, allow decoders to pick up in the middle of a stream with a minimum of delay.
* '''Seekable:''' FLAC supports fast sample-accurate seeking. Not only is this useful for playback, it makes FLAC files suitable for use in editing applications.
* '''Flexible metadata:''' New metadata blocks can be defined and implemented in future versions of FLAC without breaking older streams or decoders. Currently there are metadata types for tags, cue sheets, and seek tables. Applications can write their own APPLICATION metadata once they register an ID.
* '''Suitable for archiving:''' FLAC is an open format, and there is no generation loss if you need to convert your data to another format in the future. In addition to the frame CRCs and MD5 signature, flac has a verify option that decodes the encoded stream in parallel with the encoding process and compares the result to the original, aborting with an error if there is a mismatch.
* '''Convenient CD archiving:''' FLAC has a ''cue sheet'' metadata block for storing a CD table of contents and all track and index points. For instance, you can rip a CD to a single file, then import the CD's extracted cue sheet while encoding to yield a single file representation of the entire CD. If your original CD is damaged, the cue sheet can be exported later in order to burn an exact copy.
* '''Error resistant:''' Because of FLAC's framing, stream errors limit the damage to the frame in which the error occurred, typically a small fraction of a second worth of data. Contrast this with some other lossless codecs, in which a single error destroys the remainder of the stream.

== Pros ==
* Portable to many systems
* Source open and freely licenced
* Hardware support (PhatBox, Kenwood MusicKeg, Rio Karma, etc. See below)
* Streaming support
* Extremely fast decoding
* Supports multichannel and high resolution streams
* Supports [[Replay Gain]]
* Supports cue-sheet (with some limitations)
* Gaining wide use as successor to [[Shorten]]

== Cons ==
* Compresses less efficiently than other popular modern compressors ([[Monkey's Audio]], [[OptimFROG]])
* Higher compression modes slow, for little gain over the default setting.

== Hardware and software that support FLAC ==
For a more comprehensive list see the [http://flac.sourceforge.net/links.html FLAC links page].

=== Hardware ===
==== Home stereo ====
* [http://www.request.com/us/ AudioReQuest] music servers
* [http://www.avegasystems.com/ Avega Systems]' wireless [http://www.avegasystems.com/_documents/Oyster_Specifications.pdf Oyster] loudspeakers
* Digital Techniques' "iStereo" [http://www.digitaltechniques.com/M300A_Overview.html M300A Digital Music Player]
* Escient's [http://www.escient.com/ FireBall servers (E2-40/160/300, DVDM-300)]
* [http://www.hermstedt.com/english/hifidelio/hifidelio.html Hifidelio]
* [http://www.imuse.us/ iMuse] audio/video media servers
* Meda Systems' [http://www.medainc.com/ Bravo servers]
* The [http://www.cesweb.org/attendees/show_floor/product_locator/product_details.asp?prodid=5181 MS300 Music Server] by McIntosh Laboratory
* Olive's [http://www.olive.us/ Symphony] wireless digital music center
* [http://www.phatnoise.com/products/homeplayer/index.php PhatNoise Home Digital Media Player]
* [http://www.numark.com/ Numark]'s DJ equipment (HDX and CDX turntables, HDMIX mixer)
* [http://www.mock.com/receiver/ Rio Reciever] and Dell Digital Audio Receiver
* [http://www.rokulabs.com/products/photobridge/features.php Roku PhotoBridge HD] (with [http://homepage.ntlworld.ie/p.mc.quillan/FLAC_V0.7.zip plugin])
* [http://www.skipjam.com/ SkipJam]'s networked audio/video devices
* [http://www.sonos.com/ Sonos Digital Music System]
* Slim Devices' [http://www.slimdevices.com/pi_transporter.html Transporter] and [http://www.slimdevices.com/pi_squeezebox.html Squeezebox] networked audi players
* [http://www.z500series.com/ Zensonic Z500 Networked DVD Media Player]
* Ziova's [http://www.ziova.com/cs510.php CS510] and [http://www.ziova.com/cs505.php CS505] network media players

==== Car stereo ====
* [http://www.phatnoise.com/products/digitalmediaplayers/kenwood_music_keg.php Kenwood Music Keg]
* [http://www.phatnoise.com/products/digitalmediaplayers/index.php PhatBox]

==== Portable ====
* [[Apple iPod]] with [[Rockbox]] firmware
* Bluedot's [http://www.digitalworldtokyo.com/2006/07/bluedot_pmp_runs_linux_loves.php BMP-1430]
* Green Apple's portable media player: [http://www.apod.com.cn/show_products.asp?photoID=437 AP3000]
* [[iAudio M3]] and X5
* [[iRiver]] iHP-120/iHP-140 with [[Rockbox]] firmware
* [[Iwod G10]]
* [[Rio Karma]]
* TrekStor's [http://www.trekstor.de/en/products/detail_mp3.php?pid=66 Vibez]

=== Software ===
==== Players ====
* [http://koti.welho.com/hylinen/apollo/ Apollo]
* [http://cogosx.sourceforge.net Cog] — for Mac OS X
* [[foobar2000]]
* [[JRiver Media Center]]
* [http://fondriest.frederic.free.fr/realisations/lamip/ LAMIP]
* [[MediaMonkey]]
* [http://www.mplayerhq.hu/ MPlayer]
* [http://www.mythtv.org/ MythTV]
* [http://www.quinnware.com/ QCD] ([http://www.quinnware.com/list_plugins.php?type=input plugin])
* [http://www.videolan.org/ VLC]
* [http://www.vuplayer.com/vuplayer.htm VUPlayer]
* [[Winamp]]
* [[Windows Media Player]] and other directshow-based players (MPC, TCMP, RadLight) (with [http://www.illiminable.com/ogg/ Illiminable's directshow filters] or [http://corecodec.org/projects/coreflac CoreFLAC])
* [http://xine.sourceforge.net/ Xine]
* [[XMMS]]
* [http://www.un4seen.com/ XMplay]

==== Frontends (Windows) ====
* [http://www.uninformative.com/flacattack/ Flacattack]
* Custom [http://members.home.nl/w.speek/flac.htm Windows Frontend] (by Speek)
* [http://www.unifront.boereck.de/ UniversalFront] by Böreck
* [http://home.vxu.se/mdati00/frontah/ Frontah] by Madah
* [http://www.webearce.com.ar/ MAREO] by Kwanbis

==== Frontends (Mac) ====
* [http://www.danrules.com/macflac/ MacFLAC]
* [http://www.sbooth.org/Max/ Max]
* [http://members.rogers.com/beamsplitter/ RipBeak]
* [http://www.versiontracker.com/dyn/moreinfo/macosx/21952 xACT]

==== Converters ====
* [http://www.dbpoweramp.com/ dBpowerAMP] Music Converter / Audio Player / CD Writer
* [http://www.mediamonkey.com/ MediaMonkey] Music Manager / Audio Player / CD Writer
* [http://www.germanixsoft.de/ GX:Transcoder] Music converter

==== Editors ====
* [[Adobe Audition]]

==== CD writers/rippers ====
* [http://www.ahead.de Ahead Nero Burning Rom]
* [http://arson.sourceforge.net/ Arson]
* [http://www.burnatonce.com/ burnatonce]
* [http://www.burrrn.net Burrrn] Audio CD burner
* [[Exact Audio Copy]] CD Ripper
* [http://cdexos.sourceforge.net CDex] CD ripper
* [http://www.cdwave.com/ CD Wave]

==== Taggers ====
* [http://www.saunalahti.fi/cse/files/Tag.zip Case's Tag] command line tagger
* [http://users.otenet.gr/~jtcliper/tgf/ The GodFather] Tagger / Music manager
* [http://www.mp3tag.de/en/index.html Mp3tag] Universal Tag Editor
* [http://sbooth.org/Tag/ Tag] — for Mac OS X 10.4 (Tiger)
* [http://flac.sourceforge.net/documentation.html#metaflac metaflac] - for general metadata (including Vorbis comments) maintenance

==== Other tools ====
* [http://www.burrrn.net/mrq/ Mr. QuestionMan]
* [http://www.bitattack.ro/ai/ Audio Identifier]
* [http://www.bunkus.org/videotools/mkvtoolnix/ mkvtoolnix] - tool to multiplex FLAC streams inside the Matroska container
* [http://flac.sourceforge.net/documentation.html#metaflac metaflac] - for general metadata (including Vorbis comments) maintenance, also to calculate [[Replay Gain]] values for FLAC files lacking such

...and many more; see the [http://flac.sourceforge.net/links.html#software FLAC software section] and [http://flac.sourceforge.net/download.html#extras download section] for a more comprehensive list.

== Frequently asked questions ==
''Question:'' Does the compression level affect decompression speed?

''Short Answer'': No.

''Long Answer'': In truth, the compression level does affect the decompression speed, but the difference between the various compress levels can barely be measured and is too small to be noticed, even on low-end machines.

''Question:'' What is the best compression level for encoding my music?

''Short Answer'': The default setting, 5.

''Long Answer'': Encoding at the default setting will give the best balance between compression and encoding speed. Encoding at 8 can more than quadruple the encoding time, while having an insignificant effect on compression.

== See also ==
* [[Lossless]]
* [[Lossless comparison]]

== Externals links ==
* [http://flac.sourceforge.net FLAC website]
* [http://flac.sourceforge.net/download.html FLAC download]
* [http://flac.sourceforge.net/format.html Detailed description of the FLAC format]
* [http://flac.sourceforge.net/documentation.html FLAC documentation]
* [http://flac.sourceforge.net/faq.html FLAC FAQ]
* [http://people.ucsc.edu/~rswilson/flactest Omion's FLAC "File Size vs. Decoding Speed" test] - a very thorough test on [[Free Lossless Audio Codec#Frequently Asked Questions|the influence of the chosen encoding level on the decoding speed of FLAC]]; the only one so far to have covered FLAC's --super-secret-totally-impractical-compression-level to this extent as well.
* [http://www.losslessaudioblog.com/ The Lossless Audio Blog] Lossless Audio News & Information Site.

[[Category:Lossless]]
[[Category:Encoder/Decoder]]

WavPack

2007-09-19T14:04:14Z

Kwanbis: /* Frontends */

'''WavPack''' is a free, open source [[lossless]] audio compression format developed by David Bryant.

== Description ==
WavPack (pronounced "wave-pack") allows users to compress (and restore) all [[PCM]] audio formats including 8, 16, and 24-bit ints; 32-bit floats; [[mono]], [[stereo]], and [[multichannel]]; [[sampling rate]]s from 6 to 192 kHz. Like other lossless compression schemes the data reduction varies with the source, but it is generally between 25 % and 50 % for typical popular music and somewhat better than that for classical music and other sources with greater dynamic range.

WavPack also incorporates a unique "hybrid" mode that provides all the advantages of lossless compression with an additional bonus. Instead of creating a single file, this mode creates both a relatively small, high-quality lossy file that can be used all by itself, and a "correction" file that (when combined with the lossy file) provides full lossless restoration. For some users this means never having to choose between lossless and lossy compression!

== Feature Summary ==
* Fast and efficient encoding and decoding
* [[Open source]], released under a BSDish license
* Multiplatform
* Hardware support
* Error robustness
* Streaming support
* Supports multichannel audio and high resolutions
* Hybrid/lossy mode
* Tagging support ([[ID3v1]], [[APE]])
* Supports [[RIFF]] chunks
* Supports embedded CUE sheets
* Includes MD5 hashes for quick integrity checking
* Ability to create self extracting files for Win32 platform
* [[Replay Gain]] compatible

== History ==
David Bryant started development on WavPack in mid-1998, with the release of version 1.0. This first version compressed and decompressed audio losslessly, nothing else, but by then it already featured one of the best efficiency versus speed ratio among lossless encoders.

Very soon after the release of version 1.0, Bryant released v. 2.0, which featured lossy encoding (using only quantization for data reduction – no psychoacoustic process was applied to the stream).

In 1999, the developer released version 3.0, which featured novelties such as a fast mode (with reduced compression ratio), compression of RAW files and error detection using CRC checksums.

WavPack development is still going on, and a major feature added in late 3.x versions is the hybrid mode, where the encoder generates a lossy file + a correction file, so that both can be decompressed back to the original PCM stream.

WavPack 4 has been recently released. It included important changes, such as fast seeking, multichannel support, high resolution audio support, etc. turning it into one of the most full featured and modern lossless audio compressors.

== Software support ==
=== Players ===
* NullSoft [[Winamp]] (plugin with Replay Gain & Media Library support) and Winamp-compatible players
* [[foobar2000]] Advanced Audio Player (official encoding/decoding addon, with Replay Gain & Cuesheets support)
* [http://www.vuplayer.com/vuplayer.htm VUPlayer] (official plugin, supports encoding)
* [[Windows Media Player]] and other directshow-based players (MPC, TCMP, RadLight) (with [http://corewavpack.corecodec.org/ CoreWavPack] directshow filter)
* [http://koti.welho.com/hylinen/apollo/ Apollo] Audio Player (plugin with Replay Gain support)
* [http://www.un4seen.com/xmplay.html XMplay] (official plugin)
* [http://cogosx.sourceforge.net/ Cog] Audio player for MacOS X.
* [[XMMS]] (with Kuniklo's plugin)
* [http://fondriest.frederic.free.fr/realisations/lamip/ LAMIP] (official plugin)
* [http://mpxplay.net/ MPXplay] for DOS!
* [http://aqualung.sourceforge.net/ Aqualung] for GNU/Linux

=== Frontends ===
* Custom [http://members.home.nl/w.speek/wavpack.htm Windows Frontend] (by Speek)
* [http://www.unifront.boereck.de/ UniversalFront] by Böreck
* [http://home.vxu.se/mdati00/frontah/ Frontah] by Madah
* [http://www.webearce.com.ar/ MAREO] by Kwanbis

=== Converters ===
'''Note:''' ''Several players, like foobar2000 and VUplayer, can also convert from other formats to WavPack)''
* [http://www.dbpoweramp.com/ dBpowerAMP] Music Converter / Audio Player / CD Writer (official addon)
* [http://www.board-24.de/ GX:Transcoder] Music converter

=== Editors ===
* [[Adobe Audition]] and Cool Edit (filter with 32-bit floats & extra info save support)

=== CD writers/rippers ===
* [http://www.ahead.de Ahead Nero Burning Rom]
* [http://www.burrrn.net Burrrn] Audio CD burner
* [[Exact Audio Copy]] CD Ripper
* [http://cdexos.sourceforge.net CDex] CD ripper

=== Taggers ===
* [http://www.mp3tag.de/en/index.html Mp3tag] Universal Tag Editor
* [http://users.otenet.gr/~jtcliper/tgf/ The GodFather] Tagger / Music manager
* [[Tag.exe|Case's Tag]] command line tagger

=== Other tools ===
* [http://www.burrrn.net/mrq/ Mr. QuestionMan]
* [http://www.bitattack.ro/ai/ Audio Identifier]
* [http://www.bunkus.org/videotools/mkvtoolnix/ mkvtoolnix] – tool to multiplex WavPack streams inside the Matroska container
''It's worth mentioning the [[Matroska]] guys decided to concentrate on WavPack as the lossless compressor of choice for their container. Quite an honor... :-)''

== Hardware Support ==
* iRiver iHP-120/iHP-140 with the open source [http://www.rockbox.org Rockbox firmware]
* [http://www.rokulabs.com/products/photobridge/features.php Roku PhotoBridge HD] (with [http://www.wavpack.com/downloads.html plugin])

== Technology description ==
To ensure high-speed operation, WavPack uses a very simple predictor that is implemented entirely in integer math. In its "fast" mode the prediction is simply the arithmetic extrapolation of the previous two samples. For example, if the previous two samples were -10 and 20, then the prediction would be 50. For the default mode a simple adaptive factor is added to weigh the influence of the earlier sample on the prediction. In our example the resulting prediction could then vary between 20 for no influence to 50 for full influence. This weight factor is constantly updated based on the audio data's changing spectral characteristics, which is why it is called "adaptive".

The prediction generated is then subtracted from the actual sample to be encoded to generate the error value. In mono mode this value is sent directly to the coder. However, stereo signals tend to have some correlation between the two channels that can be further exploited. Therefore, two error values are calculated that represent the difference and average of the left and right error values. In the "fast" mode of operation these two new values are simply sent to the coder instead of the left and right values. In the default mode, the difference value is always sent to the coder along with one of the other three values (average, left, or right). An adaptive algorithm continuously determines the most efficient of the three to send based on the changing balance of the channels.

The developer has developed a unique data encoder for WavPack that he believes is better than Rice coding in two different areas. It is impossible to encode more efficiently than Rice coding because it represents the optimal bit coding (sometimes known as the Huffman code) for this type of data. WavPack's encoder is slightly less efficient than this, but only by about 0.15 bits/sample (or less than 1% for 16-bit data). The first advantage of WavPack's coder is that it does not require the data to be buffered ahead of encoding, instead it converts each sample directly to bitcodes. This is more computationally efficient and it is better in some applications where coding delay is critical. The second advantage is that it is easily adaptable to lossy encoding because all significant bits (except the implied "one" MSB) are transmitted directly. In this way it is possible to only transmit, for example, the 3 most significant bits (with sign) of each sample. In fact, it is possible to transmit only the sign and implied MSB for each sample with an average of only 3.65 bits/sample.

This coding scheme is used to implement the "lossy" mode of WavPack. In the "fast" mode the output of the non-adaptive decorrelator is simply rounded to the nearest codable value for the specified number of bits. In the default mode the adaptive decorrelator is used (which reduces the average noise about 1 dB) and also both the current and the next sample are considered in choosing the better of the two available codes (which reduces noise another 1 dB).

The developer has decided to not use any floating-point arithmetic in WavPack's data path because he believes that integer operations are less susceptible to subtle chip to chip variations that could corrupt the lossless nature of the compression, the Pentium floating point bug being a blatant example of this. It is possible that a lossless compressor that used floating-point math could generate different output when running on that faulty Pentium. Even disregarding actual bugs, floating-point math is complicated enough that there could be subtle differences between "correct" implementations that could cause trouble for this type of application. To further ensure confidence in the integrity of WavPack's compression, the encoder includes a 32-bit error detection code to the generated streams.

WavPack source code is very portable. It has been compiled on several Unices (Linux, Mac OS X, Solaris, FreeBSD, OpenBSD, NetBSD, Compaq Tru64, HP-UX...) as well as Windows, DOS and OpenVMS. It works on architectures such as x86, ARM, PowerPC, SPARC, DEC Alpha, PA-RISC, MIPS, Motorola 68k...

== External links ==
* [http://www.wavpack.com/ Official website]
* [http://www.rarewares.org/lossless.html Unofficial multiplatform versions] at RareWares
* [http://www.rjamorim.com/rrw/wavpack.html Historical versions] at ReallyRareWares
* [[Lossless_comparison|Lossless Codec Comparison]] by Rjamorim
* [[EAC_and_WavPack | Configuring EAC and Wavpack]]

[[Category:Codecs]]
[[Category:Lossless]]

WavPack

2006-03-24T14:02:31Z

Kwanbis: /* Frontends */

'''WavPack''' is a free, open source [[lossless]] audio compression format developed by David Bryant.

==Description==

WavPack allows users to compress (and restore) all [[PCM]] audio formats including 8, 16, and 24-bit ints; 32-bit floats; [[mono]], [[stereo]], and [[multichannel]]; [[sampling rate]]s from 6 to 192 kHz. Like other lossless compression schemes the data reduction varies with the source, but it is generally between 25% and 50% for typical popular music and somewhat better than that for classical music and other sources with greater dynamic range.

WavPack also incorporates a unique "hybrid" mode that provides all the advantages of lossless compression with an additional bonus. Instead of creating a single file, this mode creates both a relatively small, high-quality lossy file that can be used all by itself, and a "correction" file that (when combined with the lossy file) provides full lossless restoration. For some users this means never having to choose between lossless and lossy compression!

==Feature Summary==

* Fast and efficient encoding and decoding
* [[Open source]], released under a BSDish license
* Multiplatform
* Hardware support
* Error robustness
* Streaming support
* Supports multichannel audio and high resolutions
* Hybrid/lossy mode
* Tagging support ([[ID3v1]], [[APE]])
* Supports [[RIFF]] chunks
* Supports embedded CUE sheets
* Includes MD5 hashes for quick integrity checking
* Ability to create self extracting files for Win32 platform
* [[ReplayGain]] compatible

==History==

David Bryant started development on WavPack in mid-1998, with the release of version 1.0. This first version compressed and decompressed audio losslessly, nothing else, but by then it already featured one of the best efficiency vs. speed ratio among lossless encoders.

Very soon after the release of version 1.0, Bryant released v. 2.0, which featured lossy encoding (using only quantization for data reduction - no psychoacoustic process was applied to the stream).

In 1999, the developer released version 3.0, which featured novelties such as a fast mode (with reduced compression ratio), compression of RAW files and error detection using CRC checksums.

WavPack development is still going on, and a major feature added in late 3.x versions is the hybrid mode, where the encoder generates a lossy file + a correction file, so that both can be decompressed back to the original PCM stream.

WavPack 4 has been recently released. It included important changes, such as fast seeking, multichannel support, high resolution audio support, etc. turning it into one of the most full featured and modern lossless audio compressors.

==Software support==

===Players===
* NullSoft [[Winamp]] (plugin w/ ReplayGain & Media Library support) and Winamp-compatible players
* [[foobar2000]] Advanced Audio Player (official encoding/decoding addon, w/ ReplayGain & Cuesheets support)
* [http://www.vuplayer.com/vuplayer.htm VUPlayer] (official plugin, supports encoding)
* [[Windows Media Player]] and other directshow-based players (MPC, TCMP, RadLight) (with [http://corewavpack.corecodec.org/ CoreWavPack] directshow filter)
* [http://koti.welho.com/hylinen/apollo/ Apollo] Audio Player (plugin w/ ReplayGain support)
* [http://www.un4seen.com/xmplay.html XMplay] (official plugin)
* [http://cogosx.sourceforge.net/ Cog] Audio player for MacOS X.
* [[XMMS]] (with Kuniklo's plugin)
* [http://fondriest.frederic.free.fr/realisations/lamip/ LAMIP] (official plugin)
* [http://mpxplay.net/ MPXplay] for DOS!

===Frontends===
* Custom [http://members.home.nl/w.speek/wavpack.htm Windows Frontend] (by Speek)
* [http://www.unifront.boereck.de/ UniversalFront] by Böreck
* [http://home.vxu.se/mdati00/frontah/ Frontah] by Madah
* [http://www.webearce.com.ar/ MAREO] by Kwambis

===Converters===
'''Note:''' ''Several players, like foobar2000 and VUplayer, can also convert from other formats to WavPack)''
* [http://www.dbpoweramp.com/ dBpowerAMP] Music Converter / Audio Player / CD Writer (official addon)
* [http://www.board-24.de/ GX:Transcoder] Music converter

===Editors===
* [[Adobe Audition]] and Cool Edit (filter w/ 32-bit floats & extra info save support)

===CD writers/rippers===
* [http://www.ahead.de Ahead Nero Burning Rom]
* [http://www.burrrn.net Burrrn] Audio CD burner
* [[Exact Audio Copy]] CD Ripper
* [http://cdexos.sourceforge.net CDex] CD ripper

===Taggers===
* [http://www.mp3tag.de/en/index.html Mp3tag] Universal Tag Editor
* [http://users.otenet.gr/~jtcliper/tgf/ The GodFather] Tagger / Music manager
* [[Tag.exe|Case's Tag]] command line tagger

===Other tools===
* [http://www.burrrn.net/mrq/ Mr. QuestionMan]
* [http://www.bitattack.ro/ai/ Audio Identifier]
* [http://www.bunkus.org/videotools/mkvtoolnix/ mkvtoolnix] - tool to multiplex WavPack streams inside the Matroska container
It's worth mentioning the [[Matroska]] guys decided to concentrate on WavPack as the
lossless compressor of choice for their container. Quite an honor... :-)

==Hardware Support==

* iRiver iHP-120/iHP-140 with the open source [http://www.rockbox.org Rockbox firmware]
* [http://www.rokulabs.com/products/photobridge/features.php Roku PhotoBridge HD] (w/ [http://www.wavpack.com/downloads.html plugin])

==Technology description==

To ensure high-speed operation, WavPack uses a very simple predictor that is implemented entirely in integer math. In its "fast" mode the prediction is simply the arithmetic extrapolation of the previous two samples. For example, if the previous two samples were -10 and 20, then the prediction would be 50. For the default mode a simple adaptive factor is added to weigh the influence of the earlier sample on the prediction. In our example the resulting prediction could then vary between 20 for no influence to 50 for full influence. This weight factor is constantly updated based on the audio data's changing spectral characteristics, which is why it is called "adaptive".

The prediction generated is then subtracted from the actual sample to be encoded to generate the error value. In mono mode this value is sent directly to the coder. However, stereo signals tend to have some correlation between the two channels that can be further exploited. Therefore, two error values are calculated that represent the difference and average of the left and right error values. In the "fast" mode of operation these two new values are simply sent to the coder instead of the left and right values. In the default mode, the difference value is always sent to the coder along with one of the other three values (average, left, or right). An adaptive algorithm continuously determines the most efficient of the three to send based on the changing balance of the channels.

The developer has developed a unique data encoder for WavPack that he believes is better than Rice coding in two different areas. It is impossible to encode more efficiently than Rice coding because it represents the optimal bit coding (sometimes known as the Huffman code) for this type of data. WavPack's encoder is slightly less efficient than this, but only by about 0.15 bits/sample (or less than 1% for 16-bit data). The first advantage of WavPack's coder is that it does not require the data to be buffered ahead of encoding, instead it converts each sample directly to bitcodes. This is more computationally efficient and it is better in some applications where coding delay is critical. The second advantage is that it is easily adaptable to lossy encoding because all significant bits (except the implied "one" MSB) are transmitted directly. In this way it is possible to only transmit, for example, the 3 most significant bits (with sign) of each sample. In fact, it is possible to transmit only the sign and implied MSB for each sample with an average of only 3.65 bits/sample.

This coding scheme is used to implement the "lossy" mode of WavPack. In the "fast" mode the output of the non-adaptive decorrelator is simply rounded to the nearest codable value for the specified number of bits. In the default mode the adaptive decorrelator is used (which reduces the average noise about 1 dB) and also both the current and the next sample are considered in choosing the better of the two available codes (which reduces noise another 1 dB).

The developer has decided to not use any floating-point arithmetic in WavPack's data path because he believes that integer operations are less susceptible to subtle chip to chip variations that could corrupt the lossless nature of the compression, the Pentium floating point bug being a blatant example of this. It is possible that a lossless compressor that used floating-point math could generate different output when running on that faulty Pentium. Even disregarding actual bugs, floating-point math is complicated enough that there could be subtle differences between "correct" implementations that could cause trouble for this type of application. To further ensure confidence in the integrity of WavPack's compression, the encoder includes a 32-bit error detection code to the generated streams.

WavPack source code is very portable. It has been compiled on several Unices (Linux, Mac OS X, Solaris, FreeBSD, OpenBSD, NetBSD, Compaq Tru64, HP-UX...) as well as Windows, DOS and OpenVMS. It works on architectures such as x86, ARM, PowerPC, SPARC, DEC Alpha, PA-RISC, MIPS, Motorola 68k...

==Further reading==

* [http://www.wavpack.com/ Official website]
* [http://www.rarewares.org/lossless.html Unofficial multiplatform versions] at RareWares
* [http://www.rjamorim.com/rrw/wavpack.html Historical versions] at ReallyRareWares
* [[Lossless_comparison|Lossless Codec Comparison]] by Rjamorim
* [[EAC_and_WavPack | Configuring EAC and Wavpack]]

Free Lossless Audio Codec

2006-03-24T14:02:11Z

Kwanbis: /* Frontends (Windows) */

=What is FLAC?=

Grossly oversimplified, FLAC is similar to [[MP3]], but [[lossless]], meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio, and you can play back compressed FLAC files in your favorite player (or your car or home stereo, see supported devices) just like you would an MP3 file.

FLAC stands for Free Lossless Audio Codec. "Free" means "Free" - that the specification of the stream format is in the public domain. It also means that the sources for libFLAC and libFLAC++ are available under the BSD (Berkeley Software Distribution) licence.

FLAC compiles on many platforms.

Some claim FLAC is the most widely used lossless compression format on UNIX systems (though it seems more likely that shn retains that honor on all OS platforms).

FLAC files can be placed inside an Ogg container using libOggFLAC and libOggFLAC++.

==Pros==
* Portable to many systems
* Source open and freely licenced
* Hardware support (PhatBox, Kenwood MusicKeg, Rio Karma, etc. See below)
* Streaming support
* Extremely fast decoding
* Supports multichannel and high resolution streams
* Supports [[ReplayGain]]
* Supports cue-sheet (with some limitations)
* Gaining wide use as successor to [[Shorten]]

==Cons==
* Compresses less efficiently than other popular modern compressors ([[Monkey's Audio]], [[OptimFROG]])
* Higher compression modes slow, for little gain over the default setting.

=Players that support FLAC=
For a more complete list see the [http://flac.sourceforge.net/links.html FLAC links page].
==Hardware==
===Home stereo===
* [http://www.request.com/us/ AudioReQuest] music servers
* Digital Techniques' "iStereo" [http://www.digitaltechniques.com/M300A_Overview.html M300A Digital Music Player]
* Escient's [http://www.escient.com/ FireBall servers (E2-40/160/300, DVDM-300)]
* [http://www.hermstedt.com/english/hifidelio/hifidelio.html Hifidelio]
* Meda Systems' [http://www.medainc.com/ Bravo servers]
* The [http://www.cesweb.org/attendees/show_floor/product_locator/product_details.asp?prodid=5181 MS300 Music Server] by McIntosh Laboratory
* Olive's [http://www.olive.us/ Symphony] wireless digital music center
* [http://www.phatnoise.com/products/homeplayer/index.php PhatNoise Home Digital Media Player]
* [http://www.mock.com/receiver/ Rio Reciever] and Dell Digital Audio Receiver
* [http://www.rokulabs.com/products/photobridge/features.php Roku PhotoBridge HD] (with [http://homepage.ntlworld.ie/p.mc.quillan/FLAC_V0.7.zip plugin])
* [http://www.skipjam.com/ SkipJam]'s networked audio/video devices
* [http://www.sonos.com/ Sonos Digital Music System]
* [http://www.slimdevices.com/ Squeezebox2 and Squeezebox 3 (earlier models support via Slimserver)]
* [http://www.z500series.com/ Zensonic Z500 Networked DVD Media Player]

===Car stereo===
* [http://www.phatnoise.com/products/digitalmediaplayers/kenwood_music_keg.php Kenwood Music Keg]
* [http://www.phatnoise.com/products/digitalmediaplayers/index.php PhatBox]

===Portable===
* [[Apple iPod]] with [[Rockbox]] firmware
* [[iAudio M3]] and X5
* [[iRiver]] iHP-120/iHP-140 with [[Rockbox]] firmware
* [[Iwod G10]]
* [[Rio Karma]]

==Software==

===Players===
* [http://koti.welho.com/hylinen/apollo/ Apollo]
* [http://cogosx.sourceforge.net Cog] — for Mac OS X
* [[foobar2000]]
* [[JRiver Media Center]]
* [http://fondriest.frederic.free.fr/realisations/lamip/ LAMIP]
* [[MediaMonkey]]
* [http://www.mplayerhq.hu/ MPlayer]
* [http://www.mythtv.org/ MythTV]
* [http://www.quinnware.com/ QCD] ([http://www.quinnware.com/list_plugins.php?type=input plugin])
* [http://www.videolan.org/ VLC]
* [http://www.vuplayer.com/vuplayer.htm VUPlayer]
* [[Winamp]]
* [[Windows Media Player]] and other directshow-based players (MPC, TCMP, RadLight) (with [http://www.illiminable.com/ogg/ Illiminable's directshow filters] or [http://corecodec.org/projects/coreflac CoreFLAC])
* [http://xine.sourceforge.net/ Xine]
* [[XMMS]]
* [http://www.un4seen.com/ XMplay]

===Frontends (Windows) ===
* [http://www.uninformative.com/flacattack/ Flacattack]
* Custom [http://members.home.nl/w.speek/flac.htm Windows Frontend] (by Speek)
* [http://www.unifront.boereck.de/ UniversalFront] by Böreck
* [http://home.vxu.se/mdati00/frontah/ Frontah] by Madah
* [http://www.webearce.com.ar/ MAREO] by Kwambis

===Frontends (Mac) ===
* [http://www.danrules.com/macflac/ MacFLAC]
* [http://www.sbooth.org/Max/ Max]
* [http://members.rogers.com/beamsplitter/ RipBeak]
* [http://www.versiontracker.com/dyn/moreinfo/macosx/21952 xACT]

===Converters===
* [http://www.dbpoweramp.com/ dBpowerAMP] Music Converter / Audio Player / CD Writer
* [http://www.mediamonkey.com/ MediaMonkey] Music Manager / Audio Player / CD Writer
* [http://www.germanixsoft.de/ GX:Transcoder] Music converter

===Editors===
* [[Adobe Audition]]

===CD writers/rippers===
* [http://www.ahead.de Ahead Nero Burning Rom]
* [http://arson.sourceforge.net/ Arson]
* [http://www.burnatonce.com/ burnatonce]
* [http://www.burrrn.net Burrrn] Audio CD burner
* [[Exact Audio Copy]] CD Ripper
* [http://cdexos.sourceforge.net CDex] CD ripper
* [http://www.cdwave.com/ CD Wave]

===Taggers===
* [http://www.saunalahti.fi/cse/files/Tag.zip Case's Tag] command line tagger
* [http://users.otenet.gr/~jtcliper/tgf/ The GodFather] Tagger / Music manager
* [http://www.mp3tag.de/en/index.html Mp3tag] Universal Tag Editor
* [http://sbooth.org/Tag/ Tag] — for Mac OS X 10.4 (Tiger)

===Other tools===
* [http://www.burrrn.net/mrq/ Mr. QuestionMan]
* [http://www.bitattack.ro/ai/ Audio Identifier]
* [http://www.bunkus.org/videotools/mkvtoolnix/ mkvtoolnix] - tool to multiplex FLAC streams inside the Matroska container

...and many more; see the [http://flac.sourceforge.net/links.html#software FLAC software section] and [http://flac.sourceforge.net/download.html#extras download section] for a more comprehensive list.

=Frequently Asked Questions=

''Question:'' Does the compression level affect decompression speed?

''Short Answer'': No.

''Long Answer'': In truth, the compression level does affect the decompression speed, but the difference between the various compress levels can barely be measured and is too small to be noticed, even on low-end machines.

''Question:'' What is the best compression level for encoding my music?

''Short Answer'': The default setting, 5.

''Long Answer'': Encoding at the default setting will give the best balance between compression and encoding speed. Encoding at 8 can more than quadruple the encoding time, while having an insignificant effect on compression.

See also: [http://flac.sourceforge.net/faq.html FLAC FAQ]

=Addtional Reading=
* [http://flac.sourceforge.net FLAC Project Webpage]
* [http://flac.sourceforge.net/download.html Download]
* [http://www.digitalnetworksna.com/shop/_templates/item_main_Rio.asp?model=261 Rio Karma]
* [http://members.home.nl/w.speek/comparison.htm Speek's Comparison of lossless audio compressors]
* [[Lossless comparison|Lossless Codec Comparison]] by Rjamorim
* [http://people.ucsc.edu/~rswilson/flactest Omion's FLAC "File Size vs. Decoding Speed" test] - a very thorough test on [[FLAC#Frequently_Asked_Questions|the influence of the chosen encoding level on the decoding speed of FLAC]]; the only one so far to have covered FLAC's --super-secret-totally-impractical-compression-level to this extent as well.

Free Lossless Audio Codec

2006-03-24T14:01:51Z

Kwanbis: /* Frontends (Windows) */

=What is FLAC?=

Grossly oversimplified, FLAC is similar to [[MP3]], but [[lossless]], meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio, and you can play back compressed FLAC files in your favorite player (or your car or home stereo, see supported devices) just like you would an MP3 file.

FLAC stands for Free Lossless Audio Codec. "Free" means "Free" - that the specification of the stream format is in the public domain. It also means that the sources for libFLAC and libFLAC++ are available under the BSD (Berkeley Software Distribution) licence.

FLAC compiles on many platforms.

Some claim FLAC is the most widely used lossless compression format on UNIX systems (though it seems more likely that shn retains that honor on all OS platforms).

FLAC files can be placed inside an Ogg container using libOggFLAC and libOggFLAC++.

==Pros==
* Portable to many systems
* Source open and freely licenced
* Hardware support (PhatBox, Kenwood MusicKeg, Rio Karma, etc. See below)
* Streaming support
* Extremely fast decoding
* Supports multichannel and high resolution streams
* Supports [[ReplayGain]]
* Supports cue-sheet (with some limitations)
* Gaining wide use as successor to [[Shorten]]

==Cons==
* Compresses less efficiently than other popular modern compressors ([[Monkey's Audio]], [[OptimFROG]])
* Higher compression modes slow, for little gain over the default setting.

=Players that support FLAC=
For a more complete list see the [http://flac.sourceforge.net/links.html FLAC links page].
==Hardware==
===Home stereo===
* [http://www.request.com/us/ AudioReQuest] music servers
* Digital Techniques' "iStereo" [http://www.digitaltechniques.com/M300A_Overview.html M300A Digital Music Player]
* Escient's [http://www.escient.com/ FireBall servers (E2-40/160/300, DVDM-300)]
* [http://www.hermstedt.com/english/hifidelio/hifidelio.html Hifidelio]
* Meda Systems' [http://www.medainc.com/ Bravo servers]
* The [http://www.cesweb.org/attendees/show_floor/product_locator/product_details.asp?prodid=5181 MS300 Music Server] by McIntosh Laboratory
* Olive's [http://www.olive.us/ Symphony] wireless digital music center
* [http://www.phatnoise.com/products/homeplayer/index.php PhatNoise Home Digital Media Player]
* [http://www.mock.com/receiver/ Rio Reciever] and Dell Digital Audio Receiver
* [http://www.rokulabs.com/products/photobridge/features.php Roku PhotoBridge HD] (with [http://homepage.ntlworld.ie/p.mc.quillan/FLAC_V0.7.zip plugin])
* [http://www.skipjam.com/ SkipJam]'s networked audio/video devices
* [http://www.sonos.com/ Sonos Digital Music System]
* [http://www.slimdevices.com/ Squeezebox2 and Squeezebox 3 (earlier models support via Slimserver)]
* [http://www.z500series.com/ Zensonic Z500 Networked DVD Media Player]

===Car stereo===
* [http://www.phatnoise.com/products/digitalmediaplayers/kenwood_music_keg.php Kenwood Music Keg]
* [http://www.phatnoise.com/products/digitalmediaplayers/index.php PhatBox]

===Portable===
* [[Apple iPod]] with [[Rockbox]] firmware
* [[iAudio M3]] and X5
* [[iRiver]] iHP-120/iHP-140 with [[Rockbox]] firmware
* [[Iwod G10]]
* [[Rio Karma]]

==Software==

===Players===
* [http://koti.welho.com/hylinen/apollo/ Apollo]
* [http://cogosx.sourceforge.net Cog] — for Mac OS X
* [[foobar2000]]
* [[JRiver Media Center]]
* [http://fondriest.frederic.free.fr/realisations/lamip/ LAMIP]
* [[MediaMonkey]]
* [http://www.mplayerhq.hu/ MPlayer]
* [http://www.mythtv.org/ MythTV]
* [http://www.quinnware.com/ QCD] ([http://www.quinnware.com/list_plugins.php?type=input plugin])
* [http://www.videolan.org/ VLC]
* [http://www.vuplayer.com/vuplayer.htm VUPlayer]
* [[Winamp]]
* [[Windows Media Player]] and other directshow-based players (MPC, TCMP, RadLight) (with [http://www.illiminable.com/ogg/ Illiminable's directshow filters] or [http://corecodec.org/projects/coreflac CoreFLAC])
* [http://xine.sourceforge.net/ Xine]
* [[XMMS]]
* [http://www.un4seen.com/ XMplay]

===Frontends (Windows) ===
* [http://www.uninformative.com/flacattack/ Flacattack]
* Custom [http://members.home.nl/w.speek/flac.htm Windows Frontend] (by Speek)
* [http://www.unifront.boereck.de/ UniversalFront] by Böreck
* [http://home.vxu.se/mdati00/frontah/ Frontah] by Madah
* [http://www.webearce.com.ar/ Mareo] by Kwambis

===Frontends (Mac) ===
* [http://www.danrules.com/macflac/ MacFLAC]
* [http://www.sbooth.org/Max/ Max]
* [http://members.rogers.com/beamsplitter/ RipBeak]
* [http://www.versiontracker.com/dyn/moreinfo/macosx/21952 xACT]

===Converters===
* [http://www.dbpoweramp.com/ dBpowerAMP] Music Converter / Audio Player / CD Writer
* [http://www.mediamonkey.com/ MediaMonkey] Music Manager / Audio Player / CD Writer
* [http://www.germanixsoft.de/ GX:Transcoder] Music converter

===Editors===
* [[Adobe Audition]]

===CD writers/rippers===
* [http://www.ahead.de Ahead Nero Burning Rom]
* [http://arson.sourceforge.net/ Arson]
* [http://www.burnatonce.com/ burnatonce]
* [http://www.burrrn.net Burrrn] Audio CD burner
* [[Exact Audio Copy]] CD Ripper
* [http://cdexos.sourceforge.net CDex] CD ripper
* [http://www.cdwave.com/ CD Wave]

===Taggers===
* [http://www.saunalahti.fi/cse/files/Tag.zip Case's Tag] command line tagger
* [http://users.otenet.gr/~jtcliper/tgf/ The GodFather] Tagger / Music manager
* [http://www.mp3tag.de/en/index.html Mp3tag] Universal Tag Editor
* [http://sbooth.org/Tag/ Tag] — for Mac OS X 10.4 (Tiger)

===Other tools===
* [http://www.burrrn.net/mrq/ Mr. QuestionMan]
* [http://www.bitattack.ro/ai/ Audio Identifier]
* [http://www.bunkus.org/videotools/mkvtoolnix/ mkvtoolnix] - tool to multiplex FLAC streams inside the Matroska container

...and many more; see the [http://flac.sourceforge.net/links.html#software FLAC software section] and [http://flac.sourceforge.net/download.html#extras download section] for a more comprehensive list.

=Frequently Asked Questions=

''Question:'' Does the compression level affect decompression speed?

''Short Answer'': No.

''Long Answer'': In truth, the compression level does affect the decompression speed, but the difference between the various compress levels can barely be measured and is too small to be noticed, even on low-end machines.

''Question:'' What is the best compression level for encoding my music?

''Short Answer'': The default setting, 5.

''Long Answer'': Encoding at the default setting will give the best balance between compression and encoding speed. Encoding at 8 can more than quadruple the encoding time, while having an insignificant effect on compression.

See also: [http://flac.sourceforge.net/faq.html FLAC FAQ]

=Addtional Reading=
* [http://flac.sourceforge.net FLAC Project Webpage]
* [http://flac.sourceforge.net/download.html Download]
* [http://www.digitalnetworksna.com/shop/_templates/item_main_Rio.asp?model=261 Rio Karma]
* [http://members.home.nl/w.speek/comparison.htm Speek's Comparison of lossless audio compressors]
* [[Lossless comparison|Lossless Codec Comparison]] by Rjamorim
* [http://people.ucsc.edu/~rswilson/flactest Omion's FLAC "File Size vs. Decoding Speed" test] - a very thorough test on [[FLAC#Frequently_Asked_Questions|the influence of the chosen encoding level on the decoding speed of FLAC]]; the only one so far to have covered FLAC's --super-secret-totally-impractical-compression-level to this extent as well.